Search Results (13)

Ilex guayusa Loes., an Amazonian holly cultivated by indigenous Kichwa communities, is valued for its caffeine-rich leaves (2.0–3.5% dry weight). However, industrial processing generates substantial by-products that remain undercharacterized and underutilized. This study provides baseline quantitative assessment and physicochemical characterization of guayusa processing residues from the Kallari cooperative (Napo, Ecuador) to explore their potential within a circular bioeconomy framework. Granulometric analysis showed that processing produces predominantly coarse material (>425 μm, 67.5%), while intermediate and fine fractions (<425 μm) account for 32.5% of total biomass. Comparative analysis of pooled fractions (n = 10 subsamples per fraction) did not show clear compositional differences across twelve physicochemical parameters (p > 0.05), suggesting relatively comparable compositional profiles within the analyzed material. Residues contained relevant bioactive compounds, including total phenolics (15.7–16.0 mg GAE g⁻¹ DW) and condensed tannins (9.4–10.0 mg GAE g⁻¹ DW). Preliminary caffeine analysis (n = 2 composite samples) indicated values of 1.89–2.09% DW. Correlation analysis showed a negative association between protein and tannins (r = −0.785, p = 0.007) and a positive relationship between fiber and tannins (r = 0.660, p = 0.038). Exploratory principal component analysis suggested structural–phenolic patterns, although results should be interpreted cautiously due to the limited sample size. At the cooperative scale (18–25 t yr⁻¹), these residues represent 5.8–8.1 t yr⁻¹ of underutilized biomass. While the findings suggest potential suitability for applications such as functional ingredients, bioactive extraction, and cosmetic formulations, further validation including independent biological replication, compound-specific profiling, and techno-economic assessment is required. This study establishes a baseline dataset to support future valorization strategies within Amazonian indigenous bioeconomy contexts. Full article

This work studies the underexplored potential of Ilex guayusa and demonstrates the influence of geographical (locations: A, B, C) and ontogenetic (young: 0; old: 2) factors on its biochemical profile. The total phenolic content (TPC) was consistently higher than the total flavonoid content (TFC) in all samples, with the highest values for site B: B2 for TPC (77.91 μg GAE/mg extract) and B0 for TFC (6.77 μg QE/mg extract). GC–MS identified 29 metabolites, and clustering analysis grouped samples B and C as rich in phenols and flavonoids, while site A was richer in alcohols, aldehydes, and hydrocarbons. Antioxidant potential was demonstrated, with B2 being the most active in ABTS (TEAC value of 0.3885 (mg/g dw)), whereas A2 and C2 showed the strongest activity in DPPH (0.0968 and 0.1850 (mg/g dw), respectively). No sample exhibited hemolysis and α-amylase inhibition; however, α-glucosidase inhibition was observed with the best activity for B0 (IC₅₀ = 68.05 µg/mL). Molecular docking, ADME, and correlation analyses indicated that B0 had the highest TFC, DPPH, and α-glucosidase inhibition values, while B2 showed the highest TPC and ABTS activity. Overall, the promising antioxidant and hypoglycemic activity combined with low toxicity highlights and expands the therapeutic and applicative potential of the species. Full article

One of the medicinal plants used in Ecuador that has the best prospects for industrialization is guayusa (Ilex guayusa Loes.). This review shows the potential of the species, analyzing the ethnobotanical aspects, ancestral uses, secondary metabolites, and research. The plant has been consumed for thousands of years by the high Amazonian peoples of Ecuador and currently forms part of the gardens of ancestral peoples and mestizo settlers. The most relevant secondary metabolites that have been investigated are xanthine alkaloids, terpenes, and phenolic compounds, while from the pharmacological point of view, the following uses stand out: physical and mental stimulants, analgesic, antioxidant, antimicrobial, anti-inflammatory, anti-diabetic, and phytohormonal. The goal of this review is to make known the benefits of guayusa, with the purpose of representing a resource that will provide benefits to the Amazonian inhabitants in the future. Full article

Background: Cardiovascular diseases are the leading cause of morbidity and mortality among diabetic patients, with their incidence rising globally. Streptozotocin (STZ)-induced diabetic rats, untreated with insulin, exhibit human-like symptoms such as hyperglycemia, polydipsia, polyuria, weight loss, cardiomyopathy, neuropathy, and oxidative stress. Thus, this study evaluated the effects of Ilex guayusa tea on cardiovascular, autonomic, metabolic, and oxidative stress parameters in diabetic rats, as well as its antioxidant and phytochemical properties. Methods: Thirteen female Wistar rats were divided into two groups: diabetic (D; n = 7) and diabetic + Ilex guayusa (DG; n = 6). Diabetes was induced by a single STZ injection (50 mg/kg, i.v.), and guayusa tea was provided ad libitum for 21 days (3.0 g/L). Results: Glycemia and body mass were initially similar between the groups; however, throughout the protocol, the D group showed an increase in glycaemia and a decrease in body mass when compared to initial values. While no differences in arterial pressure, heart rate, linear heart rate variability, and oxidative stress were observed, the D group showed reduced vascular sympathetic modulation (LF-SAP and VAR-SAP) compared to the DG group. This reduced vascular sympathetic modulation, which was a poor prognostic marker in this model, was inversely correlated with glycemia (VAR-SAP and final glycemia, r: −0.81, p = 0.002). Conclusions: These findings suggest that Ilex guayusa tea consumption may mitigate metabolic and autonomic dysfunction in diabetes, highlighting its potential therapeutic role in managing diabetic complications. Full article

Corrosion is a critical industrial problem. To solve this problem, the present research analyzed the influence of corrosive media on the efficiency of a guayusa inhibitor. Therefore, guayusa extract was obtained, and five groups of ASTMS A36 steel test tubes were prepared, each with variable extract concentrations (200 ppm, 400 ppm, 600 ppm, 800 ppm, and 1000 ppm) that were exposed to different corrosive media (5% NaCl, 5% NaCl + acetic acid, 1% HNO₃, and 10% HNO₃). The results obtained were compared to determine the percentage efficiency of the inhibitor in each of the corrosive media. This study provides a detailed understanding of how the corrosive environment influences the effectiveness of a guayusa inhibitor, which is used as a green inhibitor for the first time, allowing its viability and performance to be assessed under various conditions. Full article

Yerba mate beverage is prepared from Ilex paraguariensis grown in South America, and its popularity still is increasing. The aim of this study was to show the differences in the content of antioxidant compounds between hot- and cold-prepared mate beverages. The antioxidant capacity of the infusions was tested using the Folin–Ciocalteu, ABTS, and DPPH assays. A comprehensive analysis of different phenolic and other constituents was performed with the use of high-performance liquid chromatography–tandem mass spectrometry (LC-MS/MS). The hot-prepared infusions on average contain considerably more active compounds than the cold-prepared infusions, which resulted in greater antioxidant activity of hot-prepared beverages. While the hot-prepared infusions of pure yerba mate contained a similar amount of bioactive compounds as those with different additives, for cold-prepared beverages, greater antioxidant activity was found for samples containing additives. In both conditions, the lowest antioxidant activity was noted for Ilex guayusa, which contained less rutin, caffeoylquinic acids, dicaffeoylquinic acids, and theobromine, but more caffeine. Full article

This study investigated the valorization of Ilex guayusa leaves by producing a low-caffeine, antioxidant-rich product through the supercritical antisolvent extraction (SAE) process. The objective was to concentrate the antioxidants while selectively reducing the caffeine. The SAE treatments were conducted using an ethanolic extract of guayusa leaves under varying pressure (80 bar–150 bar) and temperature (35–45 °C) conditions to improve the recovery of chlorogenic acid (CGA) and caffeine fractionation. The co-precipitation of antioxidants with polyvinylpyrrolidone (PVP) (ratio 1:1–1:2 mass/mass) as an encapsulant was also studied. The SAE precipitates were analyzed for their recovery yield, CGA and caffeine contents, antioxidant activity, and total phenols. Based on the statistical analysis, the optimal conditions for the SAE were 120 bar and 45 °C. Under these conditions, the CGA concentration increased from 43.02 mg/g extract to 237 mg/g precipitate, while the caffeine was reduced to less than 1% mass. Co-precipitation with PVP improved the recovery yield by more than two times than the SAE alone while maintaining the caffeine content below 1% mass. Additionally, the co-precipitation with PVP facilitated the formation of spherical microparticles, indicating successful encapsulation of the bioactive compounds, with an IC₅₀ of 0.51 ± 0.01 mg/mL for DPPH and 0.18 ± 0.01 mg/mL for ABTS. These results highlight the effectiveness of the SAE co-precipitation process in developing low-caffeine functional ingredients with potential food and pharmaceutical applications. Full article

Background: Amelogenesis imperfecta is a hereditary disorder affecting dental enamel. Among its phenotypes, hypocalcified AI is characterized by mineral deficiency, leading to tissue wear and, consequently, dental sensitivity. Excessive fluoride intake (through drinking water, fluoride supplements, toothpaste, or by ingesting products such as pesticides or insecticides) can lead to a condition known as dental fluorosis, which manifests as stains and teeth discoloration affecting their structure. Our recent studies have shown that extracts from Colombian native plants, Ilex guayusa and Piper marginatum, deposit mineral ions such as phosphate and orthophosphate into the dental enamel structure; however, it is unknown whether these extracts produce toxic effects on the dental pulp. Objective: To assess cytotoxicity effects on human dental pulp stem cells (hDPSCs) exposed to extracts isolated from I. guayusa and P. marginatum and, hence, their safety for clinical use. Methods: Raman spectroscopy, fluorescence microscopy, and flow cytometry techniques were employed. For Raman spectroscopy, hDPSCs were seeded onto nanobiochips designed to provide surface-enhanced Raman spectroscopy (SERS effect), which enhances their Raman signal by several orders of magnitude. After eight days in culture, I. guayusa and P. marginatum extracts at different concentrations (10, 50, and 100 ppm) were added. Raman measurements were performed at 0, 12, and 24 h following extract application. Fluorescence microscopy was conducted using an OLIMPUS fv1000 microscope, a live–dead assay was performed using a kit employing a BD FACS Canto TM II flow cytometer, and data analysis was determined using a FlowJo program. Results: The Raman spectroscopy results showed spectra consistent with viable cells. These findings were corroborated using fluorescence microscopy and flow cytometry techniques, confirming high cellular viability. Conclusions: The analyzed extracts exhibited low cytotoxicity, suggesting that they could be safely applied on enamel for remineralization purposes. The use of nanobiochips for SERS effect improved the cell viability assessment. Full article

Guayusa tea is derived from the leaves of the Ilex guayusa Loes. plant, which is native to the Amazon rainforest. Beyond its pleasant sensory properties, Guayusa tea is rich in antioxidants, phenolics, and minerals. In this study, the effects of infusion time, temperature, and solvent conditions on the color, antioxidant capacity, total phenolic content, phenolic profile, and antimicrobial activity of Guayusa (Ilex guayusa Loes.) tea were investigated. Guayusa tea samples were prepared using two different solvents, ethanol and water, with 4, 6, and 8-h infusions at 60 and 70 °C. Liquid chromatography, diode array detection, and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) were used to determine a comprehensive profile of phenolic compounds and to detect differences due to infusion conditions. Moreover, after the Guayusa tea infusion with the highest bioactive properties was determined, the effects of in vitro gastrointestinal digestion on the total phenolic content, antioxidant capacity, and phenolic compounds of the Guayusa tea infusion were measured. Phenolic profile analysis identified 29 compounds, among which chlorogenic acid and its derivatives were predominant. The increase in infusion time was correlated with an elevation in total phenolic content. Significant differences were observed between water and ethanol infusions of Guayusa in terms of phenolics and antioxidants. The total amount of phenolic compounds in the samples prepared with both solvents was found to increase after oral intake, depending on the digestion stage; meanwhile, the amounts of flavonoid compounds and di-O-caffeoylquinic acid derivatives decreased during digestion. Full article

Ilex guayusa Loes. is a shrub native to the Neotropics, traditionally consumed as an infusion. Despite its cultural value and extensive use, genetic research remains scarce. This study examined the genetic and clonal diversity of guayusa in three different Ecuadorian Amazon regions using 17 species-specific SSR markers. The results obtained suggest a moderately low degree of genetic diversity (He = 0.396). Among the 88 samples studied, 71 unique multilocus genotypes (MLGs) were identified, demonstrating a high genotypic diversity. A Discriminant Analysis of Principal Components (DAPC) revealed the existence of two genetic clusters. We propose that a model of isolation-by-environment (IBE) could explain the genetic differentiation between these clusters, with the main variables shaping the population’s genetic structure being temperature seasonality (SD × 100) (Bio 4) and isothermality ×100 (Bio 3). Nonetheless, we cannot dismiss the possibility that human activities could also impact the genetic diversity and distribution of this species. This study gives a first glance at the genetic diversity of I. guayusa in the Ecuadorian Amazon. It could assist in developing successful conservation and breeding programs, which could promote the economic growth of local communities and reinforce the value of ancestral knowledge. Full article

Tea and coffee are caffeinated beverages commonly consumed around the world in daily life. Tea from Camellia sinensis is widely available and is a good source of caffeine and other bioactive compounds (e.g., polyphenols and carotenoids). Other tea-like beverages, such as those from the genus Ilex, the large-leaved Kudingcha (Ilex latifolia Thunb and Ilex kudingcha C.J. Tseng), Yerba Mate (Ilex paraguariensis A. St.-Hil), Yaupon Holly (Ilex vomitoria), and Guayusa (Ilex guayusa Loes) are also traditional drinks, with lesser overall usage, but have attracted much recent attention and have been subjected to further study. This review summarizes the distribution, composition, and health benefits of caffeinated beverages from the genus Ilex. Plants of this genus mainly contain polyphenols and alkaloids, and show diverse health benefits, which, as well as supporting their further popularization as beverages, may also lead to potential applications in the pharmaceutical or nutraceutical industries. Full article

This paper seeks to contribute to the discussion on how to enhance food tourism in emerging, tropical countries characterized by a large number of indigenous groups and a high biodiversity. A sacred plant for the Kichwa indigenous communities labelled Ilex guayusa Loes. (Aquifoliceae) is used as a case study. Twelve recorded interviews with different stakeholders of the Amazon region of Napo in Ecuador were analysed. The results of this qualitative research show that the Western-based theory on niche tourism based on experiential and intimacy theory is compatible with four principles which are related to the cosmovision (worldview) of Kichwa indigenous groups, namely: mutual learning, empowerment, regulated access to intellectual property and community legislation. The framework proposed seems suitable to understand food tourism in an indigenous setting. Furthermore, the integration of Western-based food tourism with an indigenous cosmovision might contribute to a more sustainable land use and more equitable social development. Full article