Search Results (160)

Drought stress severely limits crop productivity by impairing water balance, photosynthesis, and oxidative homeostasis. In this study, plant-derived extracts from Psidium guajava, Aloe vera, Allium sativum, and Medicago sativa were evaluated as biostimulants for improving drought tolerance in barley, rice, maize, and cucumber seedlings. Crop-level screening showed pronounced interspecific differences, with cucumber exhibiting the highest recovery of shoot fresh weight (79% of the non-stressed control at 0.1% extract concentration, compared to 39% under drought stress alone). Consequently, cucumber seedlings were selected for detailed physiological and biochemical analyses. Under drought stress, extract-treated plants maintained higher relative water content, preserved PSII efficiency (Fv/Fm), and retained chlorophyll and carotenoid contents compared with drought-stressed controls. Drought-induced oxidative damage, reflected by increased hydrogen peroxide and malondialdehyde, was significantly reduced by extract application. These protective effects were associated with higher activities of key antioxidant enzymes and increased accumulation of ascorbate and glutathione. Integrated analyses using oxidative stress indices and z-score heatmaps revealed coordinated improvements across multiple physiological and biochemical parameters, particularly under prolonged stress. Collectively, the results suggest that selected plant extracts enhance drought tolerance by supporting water status, antioxidant capacity, and photosynthetic stability, supporting their potential use as sustainable biostimulants in drought-resilient crop production systems. Full article

Background: Chronic and ischemic wounds are dysregulated, causing inflammation, oxidative stress, and bacterial colonization. This work developed a bionanocomposite hydrogel using biogenic selenium nanoparticles (SeNPs) to encapsulate and topically distribute two weakly water-soluble medicines, curcumin (Curc) and simvastatin (SMV), to improve wound healing. Methods: Green production of biogenic SeNPs utilizing Psidium guajava (guava) leaf extract. Based on entrapment efficiency (%EE; E1) and cumulative drug release after 2 and 8 h (E2) and (E3), a two-factor, three-level Box–Behnken design selected the SeNP-to-drug weight ratio (C₁) and ethanol concentration (C₂). The selected nanoconstruct was integrated into a 2% w/v Carbopol 934 hydrogel and characterized by UV-vis, FTIR, SEM, and DLS. In a 14-day full-thickness excisional wound model in Wistar rats, wound contraction, tissue remodeling, inflammatory responses, and healing kinetics were examined to determine its therapeutic efficiency. Results: Formulation F9 had the highest overall attractiveness (0.998) and %EE values of 94.71% for SMV and 93.92% for Curc. DLS showed a hydrodynamic particle size of 177.7 nm and PDI of 0.41. Both medications were successfully incorporated without chemical incompatibility based on FTIR analysis. The selected nanogel maintained a skin-friendly pH of 6.2 ± 0.1 and sustained biphasic drug release. In vivo, the half-dose nanogel showed an enhanced wound-healing response, accelerating wound contraction and achieving complete epithelialization in 14 ± 1.06 days (p < 0.05) compared to 22 ± 2.5 days for the sham control, corresponding to a 36% reduction in healing time. Histopathology showed epidermal thickness restoration and well-organized collagen deposition. In addition, therapy dramatically decreased the proinflammatory biomarkers IL-1β, MMP-9, and COX-2 and increased IL-10 levels without causing tissue discomfort. Conclusions: The biogenic SeNP-based nanogel delivers Curc and SMV locally with prolonged drug release and anti-inflammatory and tissue-remodeling effects. The half-dose combination accelerated wound healing while retaining tissue compatibility, suggesting this green nanocomposite hydrogel could be a promising topical method for advanced cutaneous wound therapy. Full article

Background: Type 2 diabetes mellitus (T2DM) remains a major global health challenge, prompting interest in plant-based interventions with multi-target metabolic effects. This study evaluated the individual and combined effects of Psidium guajava (PG) and Seriphium plumosum (SP) on hepatic and skeletal muscle glucose metabolism. Methods: HepG2 hepatocytes and differentiated C2C12 myotubes were treated with PG, SP, and a 1:1 PG+SP combination. Cell viability, glucose uptake, GLUT2 expression, glycogen content, and AMP levels were assessed. Interactions were evaluated using Bliss Independence, Combination Index (CI), Loewe Additivity, and Zero Interaction Potency (ZIP) models. Results: SP exhibited minimal cytotoxicity, whereas PG induced concentration-dependent reductions in HepG2 viability. The PG+SP combination maintained higher viability than PG alone and demonstrated additive-to-synergistic interactions (CI = 0.51–0.89). In HepG2 cells, all treatments significantly enhanced glucose uptake relative to controls (p < 0.05), with the combination achieving approximately 94% of the metformin response. The combination also significantly reduced GLUT2 expression, with the greatest effect observed at 125 + 125 µg/mL (0.77 ± 0.14-fold, p < 0.0001). In C2C12 myotubes, PG, SP, and PG+SP significantly increased glucose uptake and glycogen accumulation (p < 0.05). SP increased AMP levels at lower concentrations, whereas the PG+SP combination reduced AMP levels below control values. Synergy analyses consistently indicated concentration- and endpoint-dependent interactions ranging from additivity to synergy. Conclusions: The PG+SP combination co-ordinately modulated glucose uptake, glycogen storage, GLUT2 expression, and AMP-related energy status across hepatic and skeletal muscle models. These findings provide mechanistic support for further investigation of this botanical combination as a potential multi-target strategy for T2DM and metabolic dysfunction. Full article

Psidium guajava L. leaves are a valuable source of phenolic compounds, particularly glycosylated flavonoids, with possible applications as standardised nutraceutical ingredients. However, the intrinsic variability of botanical matrices requires reproducible production processes integrating extraction optimisation, phytochemical characterisation, and biological validation. This study aimed to develop an integrated workflow for obtaining a standardised Psidium guajava leaf extract from a pilot cultivation in south-eastern Sicily. A Design of Experiments (DoE) approach was used to optimise the aqueous extraction process. The optimal extraction conditions were a drug-to-solvent ratio of 1:30 (w/v) and an extraction temperature and time of 95 °C and 24 min, respectively. The optimised crude extract yielded a dry residue of 0.81% w/v, with a total polyphenol content of 0.253% w/v and a total flavonoid content of 0.052% w/v. Comparative HPLC-DAD screening of two macroporous resins identified Resin B as the most effective material for flavonoid enrichment, mainly targeting avicularin, guaijaverin, and hyperoside, three biomarker compounds highly characteristic of this plant species. The resulting enriched extract showed a dry residue of 3.22% w/w and a total flavonoid content of 11.071% w/v, including 3.019% w/v avicularin, 2.845% w/v guaijaverin, and 1.196% w/v hyperoside. The enriched extract was subsequently formulated on a maltodextrin carrier to obtain a standardised ingredient with a total flavonoid content of 7.75% w/v. The final formulation exhibited strong antioxidant activity in cell-free assays and significantly reduced nitric oxide production in LPS-stimulated RAW264.7 macrophages, supporting its possible use as a reproducible botanical ingredient for nutraceutical applications. Full article

The melon fly, Zeugodacus cucurbitae, and the oriental fruit fly, Bactrocera dorsalis, are economically important tephritid pests whose sympatric distribution and overlapping host ranges precipitate intense interspecific competitive interactions. To explore the interspecific competition during larval development between these two species, we conducted a comparative study under controlled laboratory conditions. Larvae were evaluated on five host fruits—pumpkin (Cucurbita moschata), cucumber (Cucumis sativus), winter melon (Benincasa hispida), bitter gourd (Momordica charantia), and guava (Psidium guajava)—across six larval density gradients (4.0, 1.33, 0.8, 0.57, 0.44, and 0.36 larvae g⁻¹ of host tissue). In mixed-species treatments, Z. cucurbitae exhibited significantly higher survival rates and greater adult dry weights than B. dorsalis on all cucurbit hosts except guava, indicating a consistent competitive advantage. Under high-density conditions, mixed-species treatments displayed stronger competitive effects than single-species treatments. Survival rate and adult dry weight of both species were significantly affected by the interactive effects of host plant species and larval density, with these factors jointly determining competitive outcomes. These findings improve our understanding of interspecific competition in tephritid fruit flies and provide a scientific basis for developing more effective management strategies for these economically important pests. Full article

Biomass-derived carbon dots (CDs) have attracted increasing attention in agriculture due to their simple synthesis and low environmental impact. In this study, CDs were synthesized from guava (Psidium guajava) leaves using a hydrothermal method (200 °C, 15 h). The particles had an average size of 6.17 nm and a quantum yield of 2.46%, confirming the successful synthesis of fluorescent carbon nanomaterials from the natural precursor. The effects of CDs on rice (Oryza sativa L., variety HT1) were evaluated through both seed treatment and field application. Soaking seeds in a 200 ppm CD solution for 24 h significantly enhanced shoot and root lengths (28.87 mm and 34.00 mm, respectively) among the tested treatments. In field trials, applying CDs at the same concentration also promoted plant growth, as evidenced by improvements in plant height, leaf development, tillering, and flag leaf characteristics. These changes were reflected in yield, with the highest grain yield of 6.13 t ha⁻¹ at 200 ppm, exceeding that of the control treatment. The observed positive effects may be due to enhanced photosynthetic activity and better control of oxidative processes in plants. Nevertheless, the effect was less pronounced at higher concentrations. This trend suggests a dose-dependent response. Full article

Increasing volumes of dye-containing wastewater generated by the textile industry have become a serious environmental issue, particularly in Indonesia, where textile production contributes substantially to industrial activity. Among synthetic dyes, methylene blue (MB) is widely used because of its low cost and high solubility in water; however, its persistence, toxicity, and potential carcinogenicity make its removal from wastewater highly important. Conventional treatment methods are often limited by incomplete degradation and secondary waste generation. In this study, iron oxide nanoparticles (IONPs) were synthesized through a green route using Psidium guajava leaf extract as both a reducing and stabilizing agent. Characterization by PSA, UV-Vis, SEM-EDX, and XRD confirmed the formation of magnetite-like iron oxide particles with sizes ranging from 209.2 to 291.4 nm. Photocatalytic experiments showed high MB degradation efficiency (94.7–99.0%) under UV irradiation, highlighting the potential of guava leaf-mediated IONPs as low-cost, sustainable photocatalysts for wastewater treatment. Full article

Guava (Psidium guajava L.) processing produces peels, seeds, and residual pulp. Previous studies have shown that this fraction contains a significant amount of bioactive molecules (more than in the pulp), such as phenolic compounds, which have demonstrated health-beneficial bioactivities, including antioxidant, anti-obesogenic, and antihyperlipidemic activities, among others. In this study, we aimed to characterize total phenolic compounds, total flavonoids, the phenolic profile, and the in vitro antioxidant and antihyperlipidemic properties of guava byproduct extracts, which were evaluated for their potential use as functional ingredients. Phenolic analysis indicated the total phenolic content (46.45 mg GAE/g), the total flavonoid content (3.86 mg CE/g), and contents of individual phenolic compounds, namely ellagic, syringic, rutin, luteolin, and kaempferol. The extracts showed good antioxidant activity (236.22, 344.89, and 387.1 µmol TE/100 g for TEAC, DPPH, and FRAP, respectively). Moreover, the extracts could bind bile acids (18.50–40.34%) and reduce cholesterol solubility in artificial micelles (53.0–67.6%). Modest pancreatic lipase inhibition (33.33%), stronger cholesterol esterase inhibitory activities (60.22%), and mild HMG-CoA inhibitory potential (16.90%) were recorded. Guava processing byproducts demonstrate the potential to be considered as value-added ingredients in functional foods. Full article

The guava tree (Psidium guajava L.) is a tropical fruit tree of worldwide importance; however, the salinity of irrigation water severely limits its development in semi-arid regions. However, magnesium (Mg) can mitigate this stress by promoting plant photosynthetic activity. The objective was to evaluate the effect of foliar Mg in mitigating saline stress on photosynthesis and the growth of guava cultivar seedlings. The experiment was conducted in a randomized complete block design, in a 2 × 2 × 3 factorial scheme, with two guava cultivars (Kumagai and Paluma), two irrigation water salinity levels (a low-salinity control—0.5 dS m⁻¹, and salt stress—2.5 dS m⁻¹), and three doses of foliar Mg (0, 1, and 2 mL L⁻¹), and six replications. A salinity of 2.5 dS m⁻¹ reduced growth and gas exchange in both cultivars, with a reduction of approximately 30% in total dry mass, and 16% in CO₂ assimilation rate. Supplementation with 1 mL L⁻¹ of Mg attenuated the effects of stress, stimulating chlorophyll synthesis and gas exchange, reducing approximately leaf temperature in 3.5%, and vapor pressure deficit (VPD) in 12%. The Paluma cultivar was more responsive to Mg under salinity, with improved CO₂ assimilation rate, stomatal control, and water use efficiency. Kumagai showed greater growth in height and diameter with 1 mL L⁻¹ under stress. Foliar application of magnesium (1 mL L⁻¹) is a promising strategy to produce guava seedlings under saline stress. Full article

Social wasps are frequently associated with fruit injuries in agroecosystems, but the diversity of species involved and the ecological context of these interactions remain poorly synthesized in Brazil. This study aimed to compile and analyze records of social wasp interactions with fruits in Brazil, combining opportunistic field observations, iNaturalist records, and published studies. In total, 19 field observations, 87 iNaturalist records, and 11 published studies were incorporated into the dataset, resulting in 2443 records involving 51 social wasp species in 10 genera and 36 plant species. Most records involved fruits still attached to the plant (1853; 75.8%), whereas 590 records (24.2%) were associated with fallen fruits. Large-bodied wasps were disproportionately associated with fruits on the plant, while small- and medium-sized species were more frequent on fallen fruits, and this association was significant (χ² = 554.71; p < 0.001). Records also varied significantly throughout the year (χ² = 5693.28; p < 0.001), with peaks in February, March, and July. The interactions were strongly concentrated in a few genera, especially Polybia, Polistes, and Agelaia, and in a few fruit species, particularly Psidium guajava, Anacardium occidentale, and Mangifera indica. Overall, the compiled evidence indicates that fruit exploitation by social wasps in Brazil is structured by body size, resource accessibility, and seasonality. However, because the study compiles heterogeneous records rather than directly measuring economic losses, the agricultural significance of these interactions remains context-dependent and requires further evaluation. Full article

Background: Psidium guajava L. (Psidium guajava) is an edible plant; its parts are widely used to cure and prevent many health disorders. Psidium guajava leaves contain a wide array of polyphenols that inhibit peroxidation and may play a role in the prevention and treatment of common, degenerative chronic disorders such as diabetes, cardiovascular disease, and cancer. Colon cancer is the third most common type of cancer diagnosed and the second most common cause of cancer-related deaths globally. In contrast, prostate cancer is the second most diagnosed cancer and the fifth leading cause of cancer-related death worldwide. This study aims to evaluate the pharmacological potential of the Psidium guajava plants cultivated in Romania on colon and prostate cancer cell lines. Methods: Phenolic compounds extraction was made using an average sample of all nine Psidium guajava varieties. Analyses were carried out using a HP-1200 liquid chromatograph. The effect of the alcoholic extract of Psidium guajava leaves was tested on two colon cancer and one prostate cancer cell line as in vitro models. Results: The Psidium guajava leaf extract exhibited anticancer activity against the tested cell lines, with decreased proliferation, increased apoptosis, and cell cycle arrest. The extract reduced the cancer cell line’s migration and invasion capacity, demonstrating greater selectivity for the colon cancer cell line than for the prostate cancer cell lines. Conclusions: This study provides further proof of the Psidium guajava plant’s anticancer properties against colon cancer cell lines. Further studies are needed to confirm its use either alone or in conjunction with conventional cancer treatments as an alternate treatment for certain kinds of malignancies. Full article

Background/Objectives: This study aimed to develop botanical nanofibers loaded with Psidium guajava leaf extract to heal wounds effectively. Methods: A 2³ factorial design was conducted to study the impact of freeze-drying parameters—freezing time, vacuum, and lyophilization time—on the total phenolic and flavonoid content in the lyophilized extract. Then, a polyurethane-based nanofiber dressing loaded with Psidium guajava leaf extract was fabricated using a one-step electrospinning technique. The nanofiber was evaluated considering total polyphenol and flavonoid content, surface roughness, and morphological assessment by scanning electron microscopy. Finally, the nanofiber was evaluated using in vivo wound-healing studies, histopathological analyses, and assessments of tissue levels of tumor necrosis factor-alpha, interleukin-6, matrix metalloproteinase, and growth factors. Results: The optimal conditions for freeze-drying the aqueous extract of Psidium guajava leaves were a freezing time of 24 h, a vacuum adjusted to 0.02 bar, and a lyophilization time of 48 h. The total polyphenol and flavonoid content within the nanofiber was 96 ± 1.2% and 91.83 ± 2.4%, respectively. Incorporating lyophilized extract in the nanofiber led to a decreased roughness average and root mean square roughness of the nanofiber. The nanofiber was continuous and had a smooth, uniform surface. The in vivo wound-healing assay showed superior wound-healing compared to the commercial Panthenol cream. These results were confirmed with histopathological studies. Conclusions: The extraction technique and lyophilization parameters significantly affect the bioactive content of Psidium guajava leaf extract. The botanical-loaded nanofiber showed greater wound-healing potential than a commercial cream, confirming its potential in regenerative medicine and wound repair applications. Full article

Background: Natural alternatives are becoming more popular as a result of health risks associated with synthetic preservatives in pharmaceuticals. Because of its antibacterial properties, Psidium guajava (L.) leaf extract is a practical choice for sustainable preservation. Objectives: The aim of this research is to evaluate the efficacy of Psidium guajava (L.) leaf extract as a 10% (w/w) natural preservative in five different base formulations: creams (clotrimazole cream, permethrin cream, and gentamicin cream) and gels (indomethacin emulgel and ibuprofen gel). Methods: Over the course of 28 days, antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Aspergillus brasiliensis, and Candida albicans was evaluated. In accordance with USP/BP guidelines, three months of accelerated conditions (40 ± 2 °C/75% ± 5% RH) were used to assess chemical, physical, and microbiological stability. The stability of the active component was examined using HPLC. Results: Our findings showed that the extract completely inhibited the growth of tested bacterial species in clotrimazole cream, permethrin cream, gentamicin cream, and indomethacin emulgel, demonstrating significant antibacterial activity across all formulations. However, the antifungal activity was restricted. The preservation effectiveness criterion (bacterial/yeast counts < 10 CFU, mold < 20 CFU) was only fulfilled by ibuprofen gel and clotrimazole cream. Although there were color changes, stability tests verified that the active components such as ibuprofen (reduced from 97.5% to 92%) and clotrimazole (reduced from 99.9% to 95%) decomposed minimally and had acceptable physical characteristics. Particularly against fungus, the extract was surpassed by chemical preservatives (methyl/propyl paraben). Conclusions: Certain semi-solid pharmaceuticals can benefit from the stability and antimicrobial protection provided by guava leaf extract, a natural preservative. The weak antifungal activity of the guava leaf extract emphasizes the necessity for specific improvements in the formulation. Full article

Anthracnose, caused by the Colletotrichum sp. gloeosporioides complex, severely affects guava quality, highlighting the need for sustainable alternatives to synthetic postharvest fungicides. This study is the first to evaluate modulated UV-C radiation as an innovative approach to controlling postharvest diseases and extending guava shelf-life. The modulation frequency significantly influenced mycelial growth and conidial germination, following a quadratic model (R² = 0.98), with maximum efficacy at ~30 Hz, reducing germination to 5.3 × 10⁴ CFU per plate. In vivo, the combinations of 0.99 kJ m⁻²/30 Hz and 0.66 kJ m⁻²/45 Hz inhibited anthracnose incidence and severity. Most physicochemical parameters remained unaffected after seven days of storage. However, treated fruits showed a higher hue angle (h) and lower a*, indicating the maintenance of shades closer to green due to slower chlorophyll degradation, and firmness was preserved, suggesting delayed ripening. Modulated UV-C also significantly reduced the respiration rate, lowering the climacteric peak. These findings demonstrate that anthracnose control depends on the modulation frequency, with 0.99 kJ m⁻²/30 Hz being particularly effective. Modulated UV-C radiation represents a promising, sustainable, and effective strategy for improving guava postharvest quality and shelf-life. Full article