Valorization of Date Seed Waste for Sustainable Dermocosmetic Sunscreens: Phytochemical Insights and Formulation Advances

Abstract

Valorization of Phoenix dactylifera L. (date) seeds, an abundant agro-industrial byproduct, offer a sustainable approach to developing multifunctional ingredients for dermocosmetic photoprotection. Rich in polyphenols, flavonoids, and lipophilic antioxidants, date seed extracts and oils demonstrate promising UV-absorbing, anti-inflammatory, and free-radical-scavenging properties. Recent in vitro, ex vivo, and preclinical studies underscore their potential as bioactive agents in sunscreen formulations, supporting both skin barrier integrity and oxidative stress mitigation, although clinical validation is still required. This review consolidates current knowledge on the phytochemical profile and biological efficacy of date seed derivatives, with emphasis on their integration into advanced delivery systems such as nanocarriers, Pickering emulsions, and cyclodextrin complexes to enhance photostability, skin permeability, and esthetic acceptability. Safety aspects, including allergenicity, phototoxicity, and regulatory gaps, are critically examined alongside environmental and ethical advantages, including biodegradability and vegan suitability. The findings advocate for the inclusion of Phoenix dactylifera L. seed actives in next-generation dermocosmetic sunscreens that align with circular bioeconomy principles, consumer demand for “reef-safe” products, and evolving international regulations. Further clinical validation is encouraged to fully translate these botanically derived agents into effective and ethically sound sun care innovations.

1. Introduction

Skin disorders, including photoaging, sunburn, hyperpigmentation, and carcinogenesis, continue to pose significant global health and cosmetic challenges, particularly as exposure to ultraviolet (UV) radiation intensifies due to environmental and behavioral factors [1,2,3]. UVB radiation (290–320 nm) is primarily responsible for acute dermal responses, such as erythema and DNA damage, which may culminate in actinic keratosis or malignant transformation. In contrast, UVA radiation (320–400 nm) penetrates deeper into the dermis, where it accelerates collagen degradation, induces elastosis, and stimulates melanogenesis, leading to premature aging and uneven pigmentation [4,5]. UV exposure also modulates immune and inflammatory responses via cytokine and growth factor receptor activation contributing to both immediate inflammation and long-term dermal remodeling or carcinogenesis [2,3].

In this context, sunscreen formulations have evolved from basic UV shields into multifunctional cosmetic and dermocosmetic tools designed not only to prevent photodamage but also to deliver esthetic and therapeutic benefits. Since the 1930s, synthetic UV filters have dominated commercial sunscreens, initially focusing on UVB filtration and later expanding toward broad-spectrum protection against UVA radiation as well [6]. However, concerns over systemic absorption, allergenicity, and the environmental persistence of synthetic filters have driven innovation toward nature-derived alternatives that are safer for both human and marine ecosystems [7,8,9].

Plant-derived bioactives with photoprotective properties offer compelling advantages due to their intrinsic antioxidant, anti-inflammatory, and UV-absorbing properties [10,11,12]. Polyphenols, flavonoids, carotenoids, and tocopherols found in botanical sources act as reactive oxygen species (ROS) scavengers and biological UV filters, mitigating oxidative stress and preserving dermal integrity [13,14]. Recent technological advances, such as nanoencapsulation, bioemulsification, and biodegradable carriers, have further enhanced the stability, bioavailability, and photoprotective efficacy of these natural compounds [15,16].

Responding to both regulatory pressure and shifting consumer values, certifications like COSMOS, NATRUE, ICEA, VEGANOK and EU ECOLABEL for green cosmetics, which are made up of natural/organic, vegetarian/vegan and ecological products, and contextualizes them within the current legislation framework, now stipulate that sun care products meet rigorous standards of natural origin, sustainability, and efficacy [17]. This has catalyzed the replacement of petroleum-derived emulsifiers and preservatives with biocompatible, biodegradable agents such as xanthan gum, lecithin, and chitosan, which provide not only structural stability to formulations but also additional bioactivity and skin compatibility [18,19].

A particularly promising but underutilized resource in this green transformation is the seed of Phoenix dactylifera L. (date palm), a common by-product of date fruit processing. Typically discarded or relegated to low-value uses, date seeds are now recognized for their rich phytochemical profile, including polyphenols, flavonoids, tocopherols, unsaturated fatty acids, and polysaccharides, that confer antioxidant, anti-inflammatory, and UV-protective properties [20,21,22]. Notably, the seed’s high content of phenolic compounds such as gallic acid, caffeic acid, rutin, and quercetin aligns well with the mechanisms of cutaneous photoprotection, including ROS scavenging and tyrosinase inhibition [22,23].

In addition to offering bioactivity, date seed-derived ingredients fulfill the principles of circular bioeconomy and sustainable product development. The global date processing industry generates thousands of tons of seed waste annually. Harnessing this biomass for dermocosmetic applications not only reduces environmental burden but also adds significant economic value to agricultural chains [24,25,26].

However, despite this dual advantage of phytochemical richness and sustainability, several gaps still hinder the widespread adoption of date seed extracts in commercial sunscreen formulations. These include the lack of standardized extraction protocols, limited clinical and regulatory validation of their photoprotective efficacy, and challenges in aligning them with existing cosmetic legislation [27,28]. Addressing these limitations is essential to fully unlock their potential as functional, eco-friendly sun care ingredients and to translate laboratory evidence into market-ready applications.

To compile the current knowledge on the phytochemical profile, biological effects, and dermocosmetic applications of Phoenix dactylifera L. seed waste, a systematic literature search was conducted using PubMed, Scopus, Web of Science, and Google Scholar databases, covering studies published from January 2020 to June 2025. Keywords included “Phoenix dactylifera”, “date seeds”, “phytochemicals”, “antioxidant”, “cosmetic”, “dermocosmetic”, “skin protection” and “sunscreen”. Only original research articles, reviews, and preclinical or clinical studies focused on date seed extracts, and reporting phytochemical characterization or biological activity relevant to skin applications, were included. Studies unrelated to date seeds, focusing solely on nutritional or food applications without cosmetic relevance, or non-peer-reviewed reports were excluded. Extracted data were organized according to phytochemical composition, antioxidant and photoprotective activity, formulation strategies, and safety considerations, emphasizing the integration of date seed derivatives into advanced delivery systems such as nanocarriers, cyclodextrin complexes, and Pickering emulsions.

Given the rising incidence of UV-induced skin disorders, the demand for biocompatible, ethically formulated, and environmentally sustainable sunscreens is stronger than ever. The valorization of Phoenix dactylifera L. seed extract via advanced delivery systems and synergistic formulation with physical filters presents a viable strategy for the creation of next-generation sun care products. These formulations can simultaneously address dermatological safety, ecological responsibility, and consumer appeal.

This review aims to consolidate current knowledge on the integration of Phoenix dactylifera L. seed-derived actives into green sunscreen development, emphasizing their functional properties, formulation potential, and broader relevance in the sustainable cosmetics and dermocosmetics sectors.

2. Valorization of Date Seed Waste: A Sustainable Resource for Dermocosmetic Innovation

2.1. Phytochemical Composition: Unlocking Bioactivity from Agro-Residues

Phoenix dactylifera L. seeds, traditionally regarded as agro-industrial waste, have emerged as a reservoir of biologically active compounds with significant therapeutic and cosmetic potential. Their phytochemical profile encompasses a complex matrix of phenolic acids (gallic, protocatechuic, caffeic acids often enriched through ultrasound-assisted extraction (UAE) with ethanol or deep eutectic solvents……), flavonoids (quercetin, rutin, epicatechin efficiently recovered via UAE and hydrothermal pretreatments…), tocopherols (particularly α-tocopherol, best preserved and isolated using supercritical CO₂ extraction), essential fatty acids (oleic, linoleic, palmitic acids, typically obtained from lipid fractions by supercritical CO₂ or Soxhlet extraction), and mannose-rich polysaccharides (mannans and galactomannans, which are more accessible after hydrothermal or pressure-drop pretreatments) (Table 1) [29]. These compounds act synergistically to confer antioxidant, anti-inflammatory, antimicrobial, and photoprotective properties that are highly valued in dermocosmetic formulations [20,21,30].

The phenolic content of date seed extracts has been positively correlated with free radical scavenging capacity, lipid peroxidation inhibition, and DNA protection, which are vital mechanisms in defending skin against ultraviolet-induced oxidative stress [21]. These antioxidant mechanisms contribute to cellular protection by preserving endogenous enzymatic antioxidants such as glutathione peroxidase, catalase, and superoxide dismutase, thereby preventing UV-induced ROS accumulation and subsequent biomolecular damage [22,31].

Meanwhile, tocopherols, particularly α-tocopherol, are potent lipid-soluble antioxidants that stabilize skin cell membranes and quench singlet oxygen and other reactive oxygen species generated by photooxidative processes, particularly under UVA exposure [32]. Supporting this photoprotective potential, clinical and mechanistic evidence highlights the effectiveness of several plant-derived bioactives in dermocosmetic applications. Ferulic acid typically isolated via solvent-based Soxhlet or UAE approaches [33], improves skin erythema, pigmentation, hydration, elasticity, and texture in humans, both alone and in combination with other actives [34]. Rutin enriched through UAE and NADES-assisted extraction, protects human skin fibroblasts from UVA-induced oxidative stress by reducing ROS, enhancing glutathione, and modulating the Nrf2 pathway [35]. Also, rutin incorporated into optimized microemulsion and gel formulations showed effective photoprotective properties, achieving a sun protection factor (SPF) of 13 [36]. Caffeine conventionally extracted by hot-water or Soxhlet methods, demonstrates mechanistic and clinical photoprotective potential in topical formulations, including sunscreens [37]. Rosmarinic acid has demonstrated strong photoprotective and antioxidant properties, showing an in vitro SPF of 12.63 together with notable radical scavenging activity [38]. Furthermore, when conjugated with chitosan to improve solubility and bioavailability, rosmarinic acid exhibited enhanced antioxidant, anti-inflammatory, and photoprotective effects in fibroblasts and keratinocytes, effectively reducing UVB-induced oxidative damage and ROS production [39]. Furthermore, hybrid diffuse reflectance spectroscopy (HDRS) has been demonstrated as a robust method for assessing sunscreen performance, providing high-resolution absorbance spectra across UVA and HEV ranges and emphasizing the importance of methodological precision in evaluating photoprotective efficacy [40]. Collectively, these findings reinforce the rationale for incorporating date seed extracts alongside other plant-derived bioactives in dermocosmetic sunscreens.

The seed lipids, particularly rich in oleic acid, linoleic acid, and palmitic acid (optimally extracted via SFE-CO₂ for solvent-free, thermolabile lipid recovery), also serve as emollients and contribute to skin barrier function [41,42]. Oleic acid, for instance, is a well-known penetration enhancer that disrupts and fluidizes the stratum corneum lipid bilayers, thereby facilitating the transdermal delivery of active compounds [43]. In contrast, linoleic and palmitic acids support barrier integrity and help maintain lipid bilayers in the stratum corneum, wich can contribute to skin hydration and resilience [44,45,46]. Meanwhile, the presence of mannans and galactomannans (released more effectively after hydrothermal or instant controlled pressure-drop pretreatment before aqueous extraction) adds another dimension to the functionality of date seed extracts. These macromolecules modulate extracellular matrix (ECM) activity and fibroblast proliferation, accelerating re-epithelialization and improving skin texture and elasticity, properties especially relevant to anti-aging and post-sun exposure treatments [23].

In sum, the intrinsic biochemical diversity of Phoenix dactylifera L. seeds, ranging from polyphenols and lipophilic antioxidants to bioactive carbohydrates, positions them as highly versatile candidates in dermocosmetic science. Their ability to support skin barrier function, combat oxidative stress, and modulate inflammation provides a coherent foundation for multifunctional formulation strategies. Unlike many single-action compounds, date seed derivatives offer a synergistic profile that aligns with current demands for minimalistic yet efficacious skincare. This integrative potential not only meets scientific and consumer expectations but also fosters innovation in the development of next-generation botanical-based sunscreens and skin-repair systems.

Table 1. Representative phytochemical constituents of Phoenix dactylifera L. seed extracts from various studies, highlighting their antioxidant-rich profile.

Phytochemical Group	Identified Compounds	Extraction Protocol	Biological Function	References
Phenolic acids	3,4-dihydroxybenzoic acid, ferulic acid, p-coumaric acid, caffeic acid, gallic acid	-MAE with acid hydrolysis pretreatment -UAE with NADES	Antioxidant, anti-inflammatory, inhibition of α-amylase, α-glucosidase	[33,47,48]
Flavonoids	Epicatechin, rutin, quercetin	-UAE, ultrasound –NADES	Anti-inflammatory, antioxidative defense antimicrobial activity	[47,49]
Tocopherols	α-, γ-, δ-Tocopherols	-Soxhlet (hexane, petroleum ether) -Supercritical CO2 Extraction	Antioxidant activity, improve oxidative stability	[50,51]
Fatty acids	Oleic, linoleic, palmitic acids, sterols	-Soxhlet (hexane, petroleum ether) -UAE with hexane, combined with hydrothermal pre-treatment, -UAAEE with thermal pretreatment	Cardio-protective role, hypocholesterolemic effect; oxidative and thermal stability	[50,51,52,53]
Polysaccharides	Heteropolysaccharides: galacturonic acid, glucose, mannose, fructose, galactose	-MA using DES systems -HWE -UAE -Ultrasonication-assisted green extraction	Antioxidant, antimicrobial, enzyme inhibition, anticancer, and prebiotic potential.	[23,54,55]

(MAE: Microwave-Assisted Extraction; UAE: Ultrasound-Assisted Extraction; NADES: natural deep eutectic solvents; UAAEE—Ultrasound-Assisted Aqueous Enzymatic Extraction; MA-DES: Microwave-Assisted Deep Eutectic Solvent Extraction; HWE—Hot Water Extraction).

Table 1. Representative phytochemical constituents of Phoenix dactylifera L. seed extracts from various studies, highlighting their antioxidant-rich profile.

Phytochemical Group	Identified Compounds	Extraction Protocol	Biological Function	References
Phenolic acids	3,4-dihydroxybenzoic acid, ferulic acid, p-coumaric acid, caffeic acid, gallic acid	-MAE with acid hydrolysis pretreatment -UAE with NADES	Antioxidant, anti-inflammatory, inhibition of α-amylase, α-glucosidase	[33,47,48]
Flavonoids	Epicatechin, rutin, quercetin	-UAE, ultrasound –NADES	Anti-inflammatory, antioxidative defense antimicrobial activity	[47,49]
Tocopherols	α-, γ-, δ-Tocopherols	-Soxhlet (hexane, petroleum ether) -Supercritical CO2 Extraction	Antioxidant activity, improve oxidative stability	[50,51]
Fatty acids	Oleic, linoleic, palmitic acids, sterols	-Soxhlet (hexane, petroleum ether) -UAE with hexane, combined with hydrothermal pre-treatment, -UAAEE with thermal pretreatment	Cardio-protective role, hypocholesterolemic effect; oxidative and thermal stability	[50,51,52,53]
Polysaccharides	Heteropolysaccharides: galacturonic acid, glucose, mannose, fructose, galactose	-MA using DES systems -HWE -UAE -Ultrasonication-assisted green extraction	Antioxidant, antimicrobial, enzyme inhibition, anticancer, and prebiotic potential.	[23,54,55]

(MAE: Microwave-Assisted Extraction; UAE: Ultrasound-Assisted Extraction; NADES: natural deep eutectic solvents; UAAEE—Ultrasound-Assisted Aqueous Enzymatic Extraction; MA-DES: Microwave-Assisted Deep Eutectic Solvent Extraction; HWE—Hot Water Extraction).

2.2. Circular Bioeconomy and Green Valorization Pathways: From Waste to Wealth

The valorization of Phoenix dactylifera L. seed by-products represents a compelling model of circular bioeconomy, where agro-residues are rechanneled into high-value cosmetic and therapeutic applications, reducing environmental burdens while creating economic incentives. Globally, the date processing industry discards millions of tons of seeds annually, posing significant waste management challenges, particularly in arid regions where dates are a dietary staple [29].

Efforts to reintroduce these seeds into the production cycle have led to their successful inclusion in food, energy, and cosmetic applications. For example, defatted date seed flour has been utilized in baked goods to increase fiber, phenolic content, and antioxidant activity, demonstrating feasibility for upcycled food innovations [24,25,56]. Similarly, roasted date seed coffee has gained consumer approval in Europe, supported by toxicological safety and historical consumption data, eliminating the need for additional regulatory hurdles [57].

In non-edible domains, date seed oil has shown promise as a biodiesel feedstock. A study employing hydroxyapatite catalysts derived from camel bones achieved conversion yields of 89%, meeting ASTM D6751 standards [26]. Date seeds also provide a sustainable material source for environmental remediation; biochar derived from date seeds can efficiently adsorb emerging pesticides from contaminated wastewater [58]. Additionally, the seeds, along with fibrous materials and dried fruits, represent a rich source of degradable biomass suitable for natural fiber composites, activated carbon, and nano-featured sheets, although much of this waste is currently burned due to limited processing strategies [59].

Processing conditions play a critical role in preserving bioactive compounds. Drying date seeds at 60 °C has been shown to retain the highest levels of phenols, flavonoids, tannins, and carotenoids, while also maintaining α-amylase inhibition and antibacterial activity, highlighting the importance of optimized protocols to conserve functional properties [60].

These valorization streams align with the United Nations Sustainable Development Goals (SDGs), particularly SDG 12 (Responsible Consumption and Production) and SDG 13 (Climate Action) [30]. Moreover, integrating date seed by-products into dermocosmetic supply chains can reduce dependence on synthetic raw materials, improve traceability, and enhance supply chain transparency, attributes increasingly demanded by eco-conscious consumers.

2.3. Pharmacological and Dermatological Potential: Bridging Systemic and Topical Benefits

The pharmacological value of date seed extracts transcends cosmetic utility and includes substantial systemic effects relevant to dermatological well-being (Table 2). Multiple preclinical and clinical studies have documented their antidiabetic, antihyperlipidemic, and hepatoprotective activities, with mechanisms largely attributed to their polyphenol and tocopherol content [22]. Importantly, a recent quasi-experimental clinical study demonstrated that oral consumption of steeped date seeds (2.5 g/day for 14 days) in healthy middle-aged women significantly reduced the expression of key inflammatory mediators, including IL-1β, IL-6, TNF-α, COX-1, and COX-2 [61]. Likewise, an ethnopharmacological investigation using a CFA-induced arthritis rat model showed that both polar and non-polar extracts of date seeds markedly suppressed paw edema, neutrophil infiltration, and inflammatory cytokines such as NF-κB, TNF-α, IL-1β, IL-6, IL-17, IL-22, IL-23, and STAT3, while also exhibiting potent antioxidant activity and identifying over 80 bioactive phytochemicals, including chlorogenic acid and naringenin [62].These systemic anti-inflammatory effects are intrinsically linked to skin health, as metabolic dysfunctions, such as insulin resistance and oxidative stress, are known exacerbators of chronic inflammatory skin conditions, including psoriasis and acne [30].

In dermatology-specific applications, aqueous and ethanolic extracts of date seeds have exhibited significant anti-inflammatory activity by inhibiting protein denaturation and cyclooxygenase activity, outcomes comparable to standard NSAIDs [63]. Moreover, clinical evidence, though still limited, supports the topical benefits of date seed extracts: a 2024 trial evaluating an 8% Ajwa date (Phoenix dactylifera L.) seed extract lotion in elderly patients with xerosis cutis demonstrated significant improvement in skin hydration, highlighting their potential in managing dry skin conditions [32]. In addition, in vitro studies show that date seed extracts possess antioxidant properties and can attenuate melanogenesis by downregulating PKA signaling pathways in B16F10 murine melanoma cells, indicating potential applications in photoprotection and skin lightening [64]. However, beyond this early clinical trial, the majority of dermatology-related findings remain at the in vitro or preclinical stage, underscoring the need for well-designed human studies before broad integration into dermocosmetic practice.

Furthermore, date seed extracts exhibit UV-absorbing properties, suggesting potential as natural alternatives or enhancers to conventional UV filters. Their combination of hydrophilic and lipophilic bioactives allows for multi-compartmental skin protection; from the aqueous layers of the dermis to lipid-rich epidermal barriers. Their tyrosinase-inhibiting effects support applications in skin-brightening products, while their regenerative properties make them ideal for post-sun exposure repair and barrier restoration [21,23].

Table 2. Documented biological activities of date seeds extracts relevant to dermocosmetics.

Activity	Mechanism	Test Model	Key Findings	References
Antioxidant	Free radical scavenging (DPPH, ABTS)	In vitro assays	Superior to Trolox in some aqueous extracts; solvent-dependent performance	[30,65]
Anti-inflammatory	Inhibition of protein denaturation, cytokine modulation	In vitro (protein denaturation)	Comparable to ibuprofen; relevant for reducing UV-induced inflammation	[61,62,65]
Photoprotective	UV absorption, SPF enhancement, ROS reduction	in vitro models	Enhanced SPF when combined with ZnO/TiO2; potential as natural UV booster	[66]
Antimicrobial	Bactericidal activity against skin pathogens	In vitro (E. coli, S. aureus)	Encapsulated extracts exhibited significant antimicrobial efficacy	[65,67,68]
Skin Moisturizing	Barrier enhancement, lipid replacement, water retention	Topical formulations with oils and emulsions	Improves hydration and reduces trans-epidermal water loss (TEWL)	[32,69,70]
Anti-aging	Collagen preservation, antioxidant protection, wrinkle reduction	In vivo and in vitro models	Comparable to active botanicals like green tea and resveratrol	[15,21]
Photostability Support	Protects UV filters and antioxidants from degradation	Nanocarrier formulations (SLNs, cyclodextrins)	Improves SPF longevity and antioxidant retention	[71]

Table 2. Documented biological activities of date seeds extracts relevant to dermocosmetics.

Activity	Mechanism	Test Model	Key Findings	References
Antioxidant	Free radical scavenging (DPPH, ABTS)	In vitro assays	Superior to Trolox in some aqueous extracts; solvent-dependent performance	[30,65]
Anti-inflammatory	Inhibition of protein denaturation, cytokine modulation	In vitro (protein denaturation)	Comparable to ibuprofen; relevant for reducing UV-induced inflammation	[61,62,65]
Photoprotective	UV absorption, SPF enhancement, ROS reduction	in vitro models	Enhanced SPF when combined with ZnO/TiO2; potential as natural UV booster	[66]
Antimicrobial	Bactericidal activity against skin pathogens	In vitro (E. coli, S. aureus)	Encapsulated extracts exhibited significant antimicrobial efficacy	[65,67,68]
Skin Moisturizing	Barrier enhancement, lipid replacement, water retention	Topical formulations with oils and emulsions	Improves hydration and reduces trans-epidermal water loss (TEWL)	[32,69,70]
Anti-aging	Collagen preservation, antioxidant protection, wrinkle reduction	In vivo and in vitro models	Comparable to active botanicals like green tea and resveratrol	[15,21]
Photostability Support	Protects UV filters and antioxidants from degradation	Nanocarrier formulations (SLNs, cyclodextrins)	Improves SPF longevity and antioxidant retention	[71]

Hence, date seed extracts offer a pharmaco-cosmetic bridge, supporting both internal and external health benefits, and fit within the evolving paradigm of holistic skincare, where beauty and wellness are interdependent (Figure 1).

2.4. Regulatory Considerations, Traditional Usage, and Consumer Acceptance

From a regulatory and safety perspective, Phoenix dactylifera L. seed products benefit from a unique position: they are both culturally ingrained and scientifically vetted [24]. Their use in food and beverage products across the Middle East and North Africa is centuries-old. Recent innovations such as the commercialization of date seed coffee in Europe have been supported by toxicological assessments and historical consumption data, which confirmed safety and exemption from novel food regulations under EU standards [57]. These findings highlight the low-risk profile of date seed derivatives and support their transition into cosmetic and topical applications.

Moreover, unlike many synthetic or animal-derived cosmetic ingredients, such as polydeoxyribonucleotide (PDRN) derived from Salmonidae species, which raises ethical and sustainability concerns) date seed derivatives align well with consumer preferences for halal, vegan, and cruelty-free product development [28]. This makes them attractive candidates for modern clean beauty formulations. Their non-sensitizing, non-irritant profile has been demonstrated in in vivo and in vitro dermatological studies, reinforcing their safety for use in sensitive-skin products, pediatric care, and therapeutic cosmeceuticals [17,28].

Their broad regulatory acceptance, safety documentation, and compatibility with cultural and ethical values position Phoenix dactylifera L. seed extracts as market-ready and sustainable raw materials. This makes them ideal for incorporation into eco-labeled and dermatologically approved product lines, without invoking the regulatory complications often faced by novel synthetic or marine-derived actives [17,28,57].

3. Sunscreen Formulation and Photoprotection Mechanisms

3.1. Reassessing Conventional Sunscreens: Efficacy, Limitations, and Health Concerns

Sunscreens play a vital role in mitigating the harmful effects of ultraviolet radiation (UVR), including acute responses like erythema and longer-term consequences such as immunosuppression, photoaging, and skin cancer [5,72,73]. While early sunscreen formulations primarily targeted UVB wavelengths, current understanding highlights the importance of broad-spectrum protection that includes UVA, visible light, and infrared radiation (IRA; 700–2500 nm) [4,74,75]

However, the widespread reliance on synthetic organic UV filters, such as oxybenzone, octocrylene, and avobenzone, has raised significant concerns. These compounds are known to undergo photodegradation, generate reactive oxygen species (ROS), and permeate into systemic circulation, with potential endocrine-disrupting effects [7,76]. Environmental toxicity is also well-documented, with residues contributing to coral bleaching and aquatic bioaccumulation [6,77]. Even rinse-off rates, once presumed high, have been shown to be significantly formulation-dependent, with studies in porcine models suggesting values below 1.4% for some synthetic filters [78]. These findings underscore the need for photoprotective solutions that not only protect human skin but also minimize ecological footprint.

In addition to health and environmental concerns, sunscreen usage patterns further compromise efficacy. A comprehensive survey of over 11,000 participants revealed that consumer behavior; particularly related to application thickness, body surface area coverage, and seasonality; affects both protection levels and environmental emissions modeling [79]. This highlights the importance of developing photoprotective systems that remain effective even under suboptimal application conditions.

3.2. Botanical Actives and Bio-Based Delivery Platforms

To overcome the limitations of conventional sunscreen formulations, there has been increasing interest in plant-derived photoprotective agents, particularly those enriched in polyphenols, tocopherols, carotenoids, and unsaturated fatty acids [28,75]. Seed and fruit extracts, such as grape, pomegranate, papaya, carrot, nutmeg, sunflower, and bitter melon, represent promising natural alternatives to synthetic UV filters (Table 3).

Grape seed extract (GSE) and grape seed oil (GSO), rich in catechins, epicatechins, gallic acid, and polyphenols, enhance SPF, photostability, water resistance, and key skin parameters including melanin content, erythema, hydration, and elasticity, with nanocarrier systems further improving stability, bioavailability, and sustained release [80,81,82,83,84,85].

Pomegranate peel extracts, containing ellagic acid, punicalagin, quercetin, and rutin, provide multifunctional UV protection, demonstrating antioxidant and antimicrobial properties [86]. Papaya seed extracts, rich in flavonoids, phenols, alkaloids, saponins, and tannins, have shown SPF values up to 12 in vitro [87].

Carrot seed oil formulated in nanoemulgels exhibits SPF of 20.28 with additional anti-aging benefits, including pore reduction and wrinkle improvement [11]. Nutmeg seed oil stabilized in carbopol emulgels maintains SPF above 8 with stable physicochemical properties [88]. Sunflower seed oil in gel formulations achieves moderate SPF (15.60) with favorable spreadability and viscosity [89].

Bitter melon seed oil incorporated in ZnO-based creams enhances SPF up to 24.27, improves spreadability, and reduces pigmentation and erythema transmission [90]. Additionally, seed oils from Brazilian native and naturalized species, such as pomegranate, grape, and prickly pear, demonstrate synergistic enhancement of SPF when combined with organic or inorganic UV filters, achieving values up to 107.67 [91].

Notably, Ajwa date fruit extract, obtained via Soxhlet extraction, exhibits strong anti-tyrosinase and anti-collagenase activity (67.77% and 49.12%, respectively) and an SPF value of 17.09, indicating its potential as a multifunctional ingredient for pigmentation control, elasticity improvement, and UV protection in cosmeceutical formulations [92]. Similarly, Phoenix dactylifera L. seed extracts and their ethanol, ethyl acetate, and residue fractions, containing phenolic and terpenoid compounds, demonstrate significant photoprotective activity, achieving SPF values of 3.38, 6.13, and 3.14, respectively, whereas the n-hexane fraction, rich in steroids, exhibits minimal UV protection [66]. The integration of bio-based delivery platforms, including hydrophobic silica aerogels and PEG-PLGA nanocarriers, further improves photostability, water resistance, and controlled release of botanical actives [83,85]. Collectively, these findings highlight the multifunctional potential of seed- and fruit-derived bioactives as photoprotective, antioxidant, anti-inflammatory, and anti-aging agents, establishing a foundation for the development of novel sunscreen formulations, including underexplored candidates such as date seeds.

Table 3. Comparative SPF and bioactivity of plant-based and other sunscreen formulations.

Delivery/ Formulation	Seed/Fruit Source	Key Bioactives	SPF Value	Bioactivity	References
Nanoemulgel (benchmark)	Carrot seed	Carotenoids, polyphenols	20.28	Anti-aging, wrinkle reduction, pore size control	[11]
Green lotion	Green tea & lemon	Polyphenols, flavonoids	15.0	Antioxidant, broad-spectrum UVR absorption	[18]
Ethyl acetate fraction sunscreen	Padina boergesenii (brown seaweed)	Polyphenols	20.55	Stable DPPH activity (54%), UVB-induced cytoprotection	[93]
Vegetable oils (commercial)	Carrot, raspberry, rosehip	Unsaturated fatty acids, carotenoids	<2.8 (in vitro)	Low UV absorption; SPF claims not substantiated	[94]
SLM sunscreen formulation	Rutin + UVA filter	Flavonoids	Not specified	Enhanced photostability and antioxidant synergy	[95]
Chitosan hydrogel sunscreen	Vanillin + DHBA	Polyphenols	Robust UV absorbance	Self-healing, antioxidant, skin-compatible delivery	[96]
Extracts, oil, nanocarriers	Grape seed	Catechins, epicatechins, gallic acid, polyphenols	28.17	SPF enhancement, photostability, water resistance, antioxidant, anti-aging, improved melanin, erythema, hydration, elasticity	[80,81,82,83,84,85]
Emulsions	Pomegranate peel	Ellagic acid, punicalagin, quercetin, rutin	13.59–50.65	SPF enhancement, antioxidant, antimicrobial	[86]
Extract	Papaya seed	Flavonoids, phenols, alkaloids, saponins, tannins	12	SPF, photoprotective	[87]
Carbopol emulgel	Nutmeg seed	Polyphenols, essential oil	>8	SPF, stable physicochemical properties	[88]
Gel	Sunflower seed	Unsaturated fatty acids, polyphenols	15.60	SPF, good spreadability, viscosity	[89]
ZnO-based cream	Bitter melon seed	Alpha-oleo stearic acid, flavonoids, tannins, polyphenols, phytosterols	24.27	SPF, improved spreadability, reduced pigmentation/erythema transmission	[90,97]
Various formulations	Brazilian native seed oils (pomegranate, grape, prickly pear)	Unsaturated fatty acids, tocopherols, polyphenols	Up to 107.67 (with UV filters)	Synergistic SPF enhancement, UV absorption, antioxidant	[91]
Soxhlet extract	Ajwa date fruit	Phenolics, flavonoids	17.09	SPF, anti-tyrosinase, anti-collagenase, pigmentation control, elasticity improvement	[92]

Table 3. Comparative SPF and bioactivity of plant-based and other sunscreen formulations.

Delivery/ Formulation	Seed/Fruit Source	Key Bioactives	SPF Value	Bioactivity	References
Nanoemulgel (benchmark)	Carrot seed	Carotenoids, polyphenols	20.28	Anti-aging, wrinkle reduction, pore size control	[11]
Green lotion	Green tea & lemon	Polyphenols, flavonoids	15.0	Antioxidant, broad-spectrum UVR absorption	[18]
Ethyl acetate fraction sunscreen	Padina boergesenii (brown seaweed)	Polyphenols	20.55	Stable DPPH activity (54%), UVB-induced cytoprotection	[93]
Vegetable oils (commercial)	Carrot, raspberry, rosehip	Unsaturated fatty acids, carotenoids	<2.8 (in vitro)	Low UV absorption; SPF claims not substantiated	[94]
SLM sunscreen formulation	Rutin + UVA filter	Flavonoids	Not specified	Enhanced photostability and antioxidant synergy	[95]
Chitosan hydrogel sunscreen	Vanillin + DHBA	Polyphenols	Robust UV absorbance	Self-healing, antioxidant, skin-compatible delivery	[96]
Extracts, oil, nanocarriers	Grape seed	Catechins, epicatechins, gallic acid, polyphenols	28.17	SPF enhancement, photostability, water resistance, antioxidant, anti-aging, improved melanin, erythema, hydration, elasticity	[80,81,82,83,84,85]
Emulsions	Pomegranate peel	Ellagic acid, punicalagin, quercetin, rutin	13.59–50.65	SPF enhancement, antioxidant, antimicrobial	[86]
Extract	Papaya seed	Flavonoids, phenols, alkaloids, saponins, tannins	12	SPF, photoprotective	[87]
Carbopol emulgel	Nutmeg seed	Polyphenols, essential oil	>8	SPF, stable physicochemical properties	[88]
Gel	Sunflower seed	Unsaturated fatty acids, polyphenols	15.60	SPF, good spreadability, viscosity	[89]
ZnO-based cream	Bitter melon seed	Alpha-oleo stearic acid, flavonoids, tannins, polyphenols, phytosterols	24.27	SPF, improved spreadability, reduced pigmentation/erythema transmission	[90,97]
Various formulations	Brazilian native seed oils (pomegranate, grape, prickly pear)	Unsaturated fatty acids, tocopherols, polyphenols	Up to 107.67 (with UV filters)	Synergistic SPF enhancement, UV absorption, antioxidant	[91]
Soxhlet extract	Ajwa date fruit	Phenolics, flavonoids	17.09	SPF, anti-tyrosinase, anti-collagenase, pigmentation control, elasticity improvement	[92]

3.3. Advances in Delivery Technologies for Natural Sunscreen Agents

Recent developments in nanotechnology and green formulation have allowed for enhanced delivery and photostability of plant-derived actives. Several delivery platforms have been explored to improve the bioavailability and photostability of Phoenix dactylifera L. seed actives (

Table 4. Delivery systems and formulation strategies for plant-based sunscreen applications.

Formulation Type	Carrier or Approach	Functional Benefit	Application Model	Ref.
Nanoencapsulation	MCM-41 mesoporous silica	Enhances antioxidant release; bactericidal effects; pH-responsive delivery	Biomedical and cosmetic	[67]
Solid Lipid Microparticles (SLMs)	Rutin co-loaded with UVA filter	Improves photostability and photoprotection of actives	Sunscreen formulations	[95]
Cyclodextrin Complexation	Inclusion with polyphenols or UV filters	Stabilizes actives, improves solubility, and enhances dermal delivery	Antioxidant sunscreens	[71]
Pickering Emulsions	ZnO and silica-coated TiO2 nanoparticles	surfactant-free stability; UV filtering and structuring agent	Oil-in-water natural sunscreen prototype	[98]
Nanoemulgel Systems	Natural oils (e.g., carrot, hibiscus, date seed)	Enhances SPF, reduces wrinkles, boosts absorption and spreadability	Topical cosmetic sunscreens	[11]
Hydrogel Networks	Chitosan + Vanillin + DHBA	UVA/UVB absorption; antioxidant synergy; self-healing and biocompatible delivery	Advanced photoprotective formulations	[96]
Textile Carriers	Emulsion-soaked fabrics (e.g., Daucus carota oil)	Occlusive barrier effect; prolonged skin hydration and antioxidant delivery	Transdermal textile delivery in skincare	[19]

), including nanoemulgels, Pickering emulsions, cyclodextrin complexes, solid lipid microparticles, and mesoporous silica carriers [11,67,71,95].

Mesoporous silica (MCM-41) nanocarriers encapsulating date seed phenolics have demonstrated over 90% loading efficiency and effective bacterial inhibition, particularly under acidic conditions, suggesting potential dermal release specificity [67]. Likewise, solid lipid microparticles co-loaded with rutin, a known photoprotective flavonoid, have exhibited synergistic antioxidant and SPF-boosting effects, which could be extended to date seed formulations [95].

The incorporation of xanthan gum as a natural emulsifier in O/W systems has also garnered attention. Studies have shown that emulsions stabilized with xanthan gum and enriched with botanical oils enhance hydration, skin compatibility, and biophysical properties, particularly when applied via occlusive carriers [19]. This supports the integration of xanthan gum into emulsions containing date seed oil for optimized dermal hydration and sustained bioactivity. Layered double hydroxide (LDH) nanocomposites have also shown promise in stabilizing bioactives like lycopene, enhancing both antioxidant activity and SPF [16]. Applying similar strategies to date seed phenolics may yield enhanced formulation stability and bioefficacy (Figure 2).

3.4. Beyond UV: Addressing Visible and Infrared Radiation

Modern photoprotection extends beyond UV into the visible light (VL) and infrared A (IRA) spectrum. VL, especially when combined with UVA1, has been shown to induce persistent hyperpigmentation in phototypes IV–VI and erythema in lighter skin tones [99]. IRA exposure contributes to the degradation of skin carotenoids, oxidative stress, and activation of MMPs, accelerating skin aging and potential carcinogenesis [1,75]. Recent studies have demonstrated that certain cold-pressed plant oils, including perilla, pomegranate, and fig seed oils, improve skin reflectance in the IRA spectrum (1000–2500 nm), suggesting their role as IR-blocking agents in sunscreen formulations [11,75,94].

Additionally, the use of visible-light boosters such as Xanthochrome^®; a cephalopod-derived chromophore; has emerged as a potent method for increasing VL and UVA absorbance. In formulations containing zinc oxide, Xanthochrome enhanced UV absorbance by 28% and visible light blocking by 45%, without coral toxicity or skin irritation [100]. These strategies align with our aim to develop a holistic and environmentally conscious sunscreen incorporating multifunctional botanical actives such as those from Phoenix dactylifera L.

4. Toxicology, Safety, and Regulatory Aspects of Botanical Sunscreen Actives

4.1. Dermal Toxicity and Cellular Compatibility

The dermal safety of sunscreen components remains a critical concern in cosmetic science, particularly as consumer interest shifts toward natural alternatives. Recent toxicological investigations have revealed that the cytotoxic potential of conventional sunscreen formulations is primarily attributed to soluble, metabolically transformed fractions of synthetic UV filters, rather than to inert particulates such as titanium dioxide (TiO₂) or zinc oxide (ZnO) [7]. These compounds may compromise lysosomal integrity, alter cytoskeletal organization, or induce apoptosis in keratinocytes and fibroblasts. In vitro studies using HaCaT cells and 3D reconstructed epidermal models have documented dose-dependent mitochondrial disruption and oxidative stress as principal mechanisms of cytotoxicity [3,7].

In contrast, botanical actives such as polyphenols, tocopherols, and unsaturated fatty acids (abundant in Phoenix dactylifera L. seed oil and extract) exhibit a markedly favorable safety profile. Their intrinsic antioxidant activity mitigates UV-induced ROS formation, while their lipid compatibility enhances skin barrier integrity without inciting inflammation or irritation [20,30]. Comparative studies have demonstrated that vegan or plant-based sunscreen formulations offer equivalent or superior hydration, biocompatibility, and consumer acceptability compared to synthetic formulations [101].

4.2. Phototoxicity and Allergenicity of Botanical Ingredients

Despite their natural origin, plant-derived ingredients are not inherently devoid of adverse effects. Botanical extracts contain complex phytochemical mixtures, some of which may exhibit photoreactive or allergenic behavior when exposed to ultraviolet radiation. Compounds such as phenolic acids, flavonoids, and volatile essential oils may undergo photochemical transformations, generating ROS and paradoxically contributing to oxidative damage or triggering photoallergic reactions [102]. For example, although raspberry seed oil and carrot seed oil are often promoted as natural sunscreens, rigorous in vitro studies demonstrate that their intrinsic SPF values are negligible, raising concerns over misleading marketing and unverified exposure protection [94].

Phoenix dactylifera L. seed extracts, while rich in potent antioxidants like caffeic acid and epicatechin, may contain residual tannins, proteins, or enzymatic compounds capable of inducing hypersensitivity reactions in predisposed individuals. Therefore, it is essential to conduct standardized photopatch testing, acute dermal toxicity assays, and allergenicity screenings as part of the preclinical validation of botanical sunscreen actives.

4.3. Standardization Challenges and Batch Variability

Botanical extracts, despite their therapeutic promise, present significant challenges in achieving formulation consistency, safety, and regulatory compliance, especially in advanced dermatocosmetic applications such as sunscreens. Unlike synthetic UV filters with defined molecular structures and standardized assays, natural extracts are inherently heterogeneous. Their composition can vary widely depending on plant genotype, geographic origin, climatic conditions, plant part used (seed, pulp, peel…), harvest time, and post-harvest handling [20,24].

This variability is especially pronounced in Phoenix dactylifera L. seed derivatives. Several studies have reported marked differences in total polyphenol content, antioxidant activity, and SPF potential between aqueous, ethanolic, and oil-based extracts (

Table 5. Phytochemical composition, antioxidant activity, and SPF potential of Phoenix dactylifera L. seed extracts according to extraction method.

Extraction Method	Key Solvent	Major Phytochemicals Identified	Antioxidant Activity	Estimated SPF Potential	Ref.
Aqueous Extract	Water	Caffeic acid, ferulic acid, gallic acid, epicatechin	High DPPH inhibition (70–85%), moderate FRAP	Low (SPF < 5)	[20,22]
Ethanolic Extract	70% Ethanol	Epicatechin, rutin, quercetin, vanillic acid	Very high DPPH (90%+), strong FRAP and ABTS	Moderate (SPF 6–10)	[30,67,92]
Oil Extract	Cold-pressed	Tocopherols, unsaturated fatty acids, phytosterols	Moderate antioxidant (low polyphenol)	Low (SPF < 3) but enhances lipid barrier	[20,67]
Methanolic Extract	Methanol	Syringic acid, catechin, chlorogenic acid	High DPPH and FRAP, better phenolic yield	Moderate (SPF ~6)	[22]

) [22,30]. These differences not only affect biological efficacy but also impact stability, photoreactivity, and compatibility with other formulation components. For instance, Farousha et al. observed that the polyphenolic fingerprint of date seed extract (notably caffeic acid, epicatechin, and rutin) shifted significantly with solvent polarity and extraction temperature [67]. This underscores the importance of using standardized extraction protocols to ensure reproducible performance.

To address these issues, rigorous phytochemical characterization is essential. This includes

• Establishing phytochemical markers for quality control (caffeic acid, gallic acid, rutin…) [22,67];
• Analytical validation using high-performance liquid chromatography (HPLC), mass spectrometry (MS), and UV-visible spectroscopy [20];
• Good Manufacturing Practices (GMP) for botanical processing to reduce batch-to-batch variability [103,104].

By incorporating these techniques, it becomes possible to define acceptable ranges of active compound concentrations, ensuring that each batch of extract used in sunscreen formulations delivers consistent photoprotective and antioxidant effects.

Furthermore, regulatory agencies such as the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) increasingly expect evidence of batch consistency and chemical fingerprinting for plant-derived actives used in dermocosmetics. For date seed, studies already provide baseline data on its polyphenolic content, antioxidant indices, and SPF-enhancing properties [20,30]. These should be explicitly cited and included in the product dossier to meet regulatory expectations for both safety and efficacy.

In the context of green formulation and ingredient valorization, this standardization process is not merely a regulatory formality, it is fundamental to transforming agricultural by-products like date seeds into high-value, scientifically validated photoprotective agents. Proper profiling also facilitates international commercialization, improves consumer trust, and paves the way for inclusion in pharmacopeial monographs or cosmetic ingredient compendia.

In practical manufacturing contexts, overcoming batch variability requires a multi-tier strategy. First, establishing reference phytochemical fingerprints (via LC-MS/MS or NMR metabolomics) enables producers to benchmark quality across suppliers and harvests. Second, the application of Good Agricultural and Collection Practices (GACP) ensures control at the cultivation and harvesting stage, reducing variability introduced by soil and climate [105]. Third, standardized extraction protocols such as supercritical CO₂ extraction or hydroethanolic extraction under fixed temperature/solvent ratios, are crucial to maintaining reproducibility at industrial scale. In parallel, implementation of real-time quality monitoring tools, including near-infrared (NIR) spectroscopy coupled with chemometric modeling, allows the rapid detection of deviations during processing. Finally, aligning production with ISO 16128 guidelines for natural cosmetic ingredients and pharmacopoeial standards guarantees not only consistency and safety, but also smoother regulatory approval and global market integration [106].

4.4. Global Regulatory Landscape and SPF Claims

Regulatory oversight of sunscreen products varies markedly between jurisdictions, particularly in terms of ingredient classification, permissible claims, and validation re-quirements. Within the European Union, sunscreens are governed by Regulation (EC) No. 1223/2009, which classifies them as cosmetic products. Under this framework, all formu-lations must undergo a thorough safety assessment that includes toxicological risk evalu-ation, product stability testing, and verification of claimed efficacy. Specific performance claims such as Sun Protection Factor (SPF) and UVA Protection Factor (UVA-PF) must be substantiated through internationally recognized methodologies, namely ISO 24444:2019 for SPF determination and ISO 24443:2021 for UVA protection [74,107,108]. More recently, additional standards such as ISO 23675:2024 (in vitro spectral absorbance SPF determination) and ISO 23698:2024 (hybrid diffuse reflectance spectroscopy for in situ SPF/UVA-PF evaluation) have been introduced, expanding the validated toolbox for industry testing [109,110]. These protocols involve either in vivo testing on human volunteers or in vitro alternatives, depending on the claim being made, and serve to ensure reproducibility and consumer safety [111].

Despite increasing consumer demand for natural or plant-based alternatives, botan-ical extracts such as Phoenix dactylifera L. are not classified as approved UV filters within this regulatory system. They may be incorporated into formulations as functional or adjunct ingredients, owing to their antioxidant, emollient, or anti-inflammatory properties, but cannot independently justify SPF labeling unless photoprotective activity is demonstrated through validated testing. Importantly, outdated approaches such as the Mansur equation are no longer accepted, and SPF claims must be based exclusively on ISO-recognized methodologies.

The situation is further complicated by widespread marketing of artisanal, organic, or “clean beauty” sunscreen products that often include untested oils or botanical blends and promote them as natural SPF agents. As highlighted by Ince et al., such practices pose a significant regulatory and public health challenge, given the absence of substantiated SPF values and the potential for inadequate UV protection [112]. This disconnect between consumer perception and scientific validation underscores the need for clearer guidelines and stricter enforcement regarding natural sunscreen claims, particularly as botanical actives gain commercial traction in sun care formulations. Harmonization with FDA sunscreen monograph requirements and international ISO standards will be essential for ensuring global regulatory acceptance and consumer safety.

4.5. Environmental Safety and Marine Impact of Sunscreen Ingredients

The environmental implications of sunscreen formulations have attracted substantial regulatory and scientific concern, particularly regarding their ecotoxicological effects on marine ecosystems. Several synthetic ultraviolet (UV) filters (most notably oxybenzone, octinoxate, and homosalate) have been identified as contributors to coral reef bleaching, endocrine disruption in marine life, and the bioaccumulation of persistent organic pollutants (POPs) in aquatic food chains [76,77]. These compounds can enter marine environments through recreational water use, wastewater effluent, and runoff, raising questions about their long-term ecological safety.

In response, legislative bans and restrictions on specific chemical filters have been implemented in several jurisdictions, including Hawaii, Palau, and parts of the European Union [76,77]. These regulatory actions underscore the urgent need for biodegradable, non-toxic, and environmentally compatible alternatives. Botanical ingredients such as Phoenix dactylifera L. (date seed) extract and oil offer a promising solution in this context. Their inherent biodegradability, absence of synthetic aromatic structures, and lack of documented marine toxicity position them as attractive candidates for eco-friendly sunscreen formulations [28,77].

Additionally, plant-derived bioactives typically exhibit low water solubility and low potential for aquatic bioaccumulation, further supporting their environmental compatibility (

Table 6. Comparative summary of synthetic UV filters vs. botanical sunscreen actives.

Parameter	Synthetic UV Filters (e.g., Oxybenzone, Octinoxate)	Botanical Actives (e.g., Phoenix dactylifera L. Seed Oil/Extract)
Phototoxicity/Allergenicity	High potential for photoreactivity and allergic reactions	Low; generally well-tolerated with antioxidant and anti-inflammatory properties
Systemic Absorption	Documented systemic absorption and endocrine disruption risk	Minimal transdermal absorption; negligible systemic toxicity
Marine Impact	Contributes to coral bleaching, bioaccumulation	Biodegradable; low to no known aquatic toxicity
Regulatory Status	FDA-approved (monograph) ingredients; increasingly restricted	Not monograph-listed; requires safety and efficacy substantiation
Biocompatibility	May impair mitochondrial and lysosomal function in skin cells	Supports skin barrier function; reduces oxidative stress
Ethical Concerns	Some derived from petrochemicals, animal testing common	Vegan, halal, and cruelty-free compliant
Cultural/Religious Acceptability	May conflict with halal or vegan standards	Acceptable across major cultural and religious contexts
Sustainability	Non-renewable, synthetic origin	Derived from agri-food byproducts; promotes circular bioeconomy

). The use of such compounds aligns with growing consumer preferences for “reef-safe” and environmentally responsible skincare products, while also addressing sustainability criteria that are becoming increasingly integrated into international regulatory evaluation [77,108].

4.6. Ethical and Cultural Considerations in Botanical Sunscreen Development

Beyond clinical efficacy and environmental compatibility, ethical and cultural factors are increasingly central to the formulation and commercialization of cosmetic sunscreens. Issues such as animal testing, the use of animal-derived ingredients, and the religious acceptability of product components have become critical in global product development, particularly in markets with stringent ethical standards or religious guidelines.

One notable example is the use of polydeoxyribonucleotide (PDRN), a DNA-based active compound commonly extracted from salmonid sperm, which has demonstrated regenerative properties in dermatological applications. Despite its biological efficacy, PDRN raises significant ethical and cultural objections related to animal welfare, sustainability, and religious permissibility [28]. This has prompted calls for alternatives that fulfill similar biological roles without invoking ethical dilemmas.

In contrast, date seed derivatives, being plant-based, biodegradable, and culturally neutral, offer a viable and ethically sound substitute. These ingredients are compatible with vegan, halal, and cruelty-free standards, making them suitable for diverse global markets. Their antioxidant, anti-inflammatory, and photoprotective properties further support their integration into dermatological formulations without compromising ethical or religious values [67,95].

Moreover, increasing consumer awareness and demand for transparent ingredient sourcing have compelled formulators to prioritize traceable, non-animal-derived bioactives. This trend not only reflects shifting societal values but also aligns with emerging international cosmetic regulations that favor ethical sourcing and testing protocols [74]. Consequently, the valorization of agricultural byproducts such as date seeds aligns with both ethical innovation and the principles of circular bioeconomy.

5. Future Trends and Commercial Potential of Botanical-Based Sunscreens

The growing convergence of environmental awareness, consumer health consciousness, and regulatory scrutiny is accelerating the shift toward plant-derived bioactives in sunscreen development. Botanical ingredients such as Phoenix dactylifera L. (date seed) extract and oil have gained attention for their potent antioxidant, anti-inflammatory, and photoprotective effects, which align with the emerging demand for multifunctional skincare [67,95].

Recent advancements in extraction technologies and delivery systems (solid lipid microparticles, Pickering emulsions, and cyclodextrin complexes) have improved the stability and skin penetration of these phytochemicals, enabling their incorporation into sophisticated sunscreen formulations [71,93,95]. Furthermore, the valorization of agricultural waste products like date seeds offers an economically and ecologically sustainable innovation strategy, supporting circular bioeconomy principles [77].

From a commercial standpoint, the compatibility of date seed derivatives with vegan, halal, and cruelty-free standards makes them highly attractive in diverse global markets (Figure 3). The ability to cater to culturally sensitive populations, while also addressing sustainability and safety, positions such botanicals as leading candidates in the next generation of dermatological formulations [28].

Market dynamics further support this transition. According to Ince et al., the surge in consumer preference for “reef-safe,” natural, and ethically formulated sunscreens has outpaced the regulatory adaptation of existing SPF validation frameworks [112]. This opens opportunities for innovators to bridge scientific substantiation with ethical branding, providing evidence-backed botanical alternatives that meet both efficacy and consumer trust benchmarks. Nonetheless, challenges remain regarding the standardization of botanical actives, regulatory classification, and harmonization across jurisdictions. The future will likely see an expansion of regulatory pathways that accommodate novel botanical UV filters, incentivizing further research and clinical validation of plant-based sun protectants.

6. Future Directions

The application of Phoenix dactylifera L. seed extracts in sunscreen formulation presents a promising frontier in cosmetic science, particularly within the broader context of sustainable innovation, dermatological safety, and regulatory evolution. However, several critical research and development gaps remain to be addressed to enable clinical translation and commercial viability.

First, standardized profiling of date seed phytochemicals (particularly polyphenols such as caffeic acid and epicatechin) must be harmonized across extraction methods to ensure reproducibility in antioxidant and photoprotective performance [20,113]. Comparative studies exploring solvent polarity, extractive yield, and skin permeability are needed to establish formulation-grade bioactive benchmarks.

Second, while in vitro evidence of SPF enhancement and ROS inhibition is encouraging [30,71], future work should prioritize controlled in vivo photoprotection trials, dermal absorption studies, and long-term safety evaluation. Such data are essential to support regulatory claims and facilitate the listing of Phoenix dactylifera L. derivatives within international sunscreen monographs.

Additionally, interdisciplinary strategies involving nanocarriers, cyclodextrin inclusion complexes, and Pickering emulsions offer significant potential to improve photostability, reduce dose thresholds, and minimize allergenic risks [67,95]. Integrating such delivery technologies with bio-based actives can redefine the functional and ethical boundaries of next-generation sunscreens.

Finally, in the context of the circular bioeconomy, further investigation into the valorization of date seed byproducts can strengthen economic feasibility and sustainability metrics. The use of agricultural waste as a high-value cosmeceutical input aligns with rising consumer demands for traceability, “reef-safe” claims, and halal/vegan certifications. The opportunity to couple dermatological efficacy with ethical transparency places Phoenix dactylifera L. at the convergence of scientific innovation and socio-environmental responsibility.

7. Conclusions

This review underscores the growing potential of Phoenix dactylifera L. seeds extracts as multifunctional agents in eco-friendly sunscreen formulations. Rich in antioxidant, anti-inflammatory, and photoprotective compounds, date seed derivatives offer a natural, biodegradable alternative to conventional synthetic filters, with a reduced risk of marine toxicity and improved consumer acceptability.

While significant advancements have been made in identifying the phytochemical constituents and initial SPF-promoting properties of date seed extracts, comprehensive toxicological validation, regulatory recognition, and formulation optimization remain pressing imperatives. The integration of nanocarrier-based delivery systems, adherence to international safety protocols, and alignment with clean beauty principles can elevate date seed actives from experimental use to mainstream application.

Crucially, the valorization of Phoenix dactylifera L. seed byproducts represents not only a technological innovation but a paradigm shift in sustainable cosmetic science, transforming agricultural waste into dermatologically effective, culturally inclusive, and environmentally compatible ingredients. By bridging phytochemistry, formulation science, and regulatory awareness, botanical sunscreens derived from date seeds may lead the next wave of responsible photoprotection.

While date seed extracts show promising antioxidant and photoprotective effects, any SPF claims must be validated through recognized in vivo or in vitro standards; thus, they should be considered supportive rather than standalone UV filters.