Search Results (709)

Background: Paclitaxel is a widely used chemotherapeutic agent whose clinical efficacy is limited by gonadotoxic side effects. Oxidative stress, apoptosis, and inflammation are key mechanisms underlying paclitaxel-induced testicular injury. This study aimed to comparatively evaluate the protective effects of melatonin and apigenin in a rat model. Methods: Adult male Sprague-Dawley rats were randomly assigned to seven groups: control, solvent control, melatonin, apigenin, paclitaxel, paclitaxel + melatonin, and paclitaxel + apigenin. Testicular malondialdehyde (MDA) and reduced glutathione (GSH) levels were measured, together with apoptotic activity (caspase-3), oxidative DNA damage (8-OHdG), inflammatory signaling (NF-κB/p65, immunoreactivity), and histopathological alterations (Johnsen score). Results: Paclitaxel significantly increased MDA levels and decreased GSH content, accompanied by elevated caspase-3, 8-OHdG, and NF-κB/p65 immunoreactivity, as well as marked degeneration of seminiferous tubules. Melatonin improved redox balance, suppressed apoptotic and inflammatory responses, and preserved testicular architecture. Apigenin reduced lipid peroxidation and improved antioxidant status in paclitaxel-treated rats while decreasing GSH levels under basal conditions without inducing histological damage, suggesting a context-dependent redox-modulating effect. Both agents significantly improved Johnsen scores compared with paclitaxel alone. Conclusions: Paclitaxel-induced testicular injury is mediated by a coordinated interplay of oxidative stress, apoptosis, inflammation, and structural degeneration. Melatonin and apigenin effectively mitigate these processes, with apigenin exhibiting context-dependent antioxidant activity. These findings suggest that melatonin and apigenin may serve as adjunctive strategies for preserving male reproductive function during chemotherapy. Full article

Pharmacomicrobiomics is the study of drug–microbiome interactions. It examines the dynamic relationship between the drug, the host, and the microbiome, and has become a rapidly evolving area in the realm of pharmacology and personalized medicine. Emerging evidence demonstrates that the gut microbiome can influence the pharmacodynamics and pharmacokinetics of drugs through various mechanisms, while drugs can simultaneously alter microbial composition. Treatment approaches include regular targeted pharmaceutical therapies (e.g., antibiotics, antidepressants) and alternative treatment approaches (e.g., CAM treatments such as supplements and herbs). Microbiome-based medication treatment is an alternative treatment approach that has been studied extensively in the last decade. This article reviews the current knowledge on drug–microbiome interactions across multiple therapeutic systems, including cardiovascular, central nervous system, gastrointestinal, respiratory, endocrine, oncologic, musculoskeletal, anti-infective therapies, and supplements (such as melatonin). We also highlight the various pathways by which microbes can alter the mechanisms (such as drug absorption), bioavailability, efficacy, and incidence of adverse effects, along with highlighting the clinical implications of drug-induced dysbiosis. Full article

The discovery of melatonin as a multifunctional free radical scavenger and its possible synthesis in the mitochondrial matrix of peripheral eukaryotic somatic cells highlights a critical new perspective on the importance of this indole. Experimental evidence supporting these findings is substantial, but there are still lingering questions whether melatonin is a direct radical scavenger in vivo and whether it is synthesized in the mitochondrial matrix. We systematically analyze the innovative experimental approaches that support melatonin’s radical scavenging actions and assess the compelling data supporting its production in mitochondria. Melatonin concentrations are reportedly higher in this organelle than in other cellular compartments. Proteins for the enzymes required to convert serotonin to melatonin are present in the mitochondrial matrix and purified mitochondria synthesize melatonin. In the mitochondrial matrix, melatonin is likely located within the “damage radius” of highly reactive oxygen species. We also summarize novel actions of melatonin associated with its regulation of membrane fluidity, determine the molecular composition of membrane lipid rafts, and modulate liquid–liquid phase separation and biomolecular condensates intracellularly. If the findings discussed herein continue to be validated, melatonin would be in an optimal position to function as an antioxidant and may be a key driver in the context of preserving mitochondrial redox homeostasis and disease mitigation. Full article

Background: Postmenopausal women are at high risk of Alzheimer’s disease (AD) incidence and progression. Irisin, an exercise-induced myokine, has neuroprotective and antiaging effects against AD, especially in menopausal women suffering from insulin resistance (IR). For the first time, the novel role of irisin induced by melatonin (MTN) or/and physical exercise (PHE) was investigated in the current ovariectomized (OVX)/AD rat model by modulating brain neuroinflammation and IR-related markers. Methods: Fifty female Wistar rats were divided into five groups, with one representing a sham group. AD was induced in the other four bilateral OVX rat groups by daily intraperitoneal injection of D-galactose/AlCl₃ (60 and 10 mg/kg, respectively) for 42 days. Group III–V: Animals were exposed to MTN (10 mg/kg/day; i.p.), PHE, and a combination of these, respectively, in the final 14 days of the experiment. Results: The OVX/AD rats showed significant deterioration in learning, memory, neurochemical, and histopathological examinations, while the MTN or/and PHE treatments significantly increased serum and brain irisin, improving memory in a Y-maze assessment. Thus, hippocampal histopathological alterations and IR-related markers decreased. In addition, suppressed hippocampal amyloid-beta protein expression and neuroinflammatory content of tumor necrosis factor-alpha (TNF-α), p38 mitogen-activated protein kinase (p38 MAPK), and NOD-like receptor protein-3 (NLRP3) were associated with an increase in peroxisome proliferator-activated receptor-gamma (PPAR-γ) protein expression and insulin-like growth factor-1 content in hippocampal tissues, collectively suppressing glial fibrillary acidic protein (GFAP) content, leading to an increase in brain-derived neurotrophic factor expression. Conclusions: Irisin induction may serve as a novel avenue in AD/menopause treatment and prevention via modulating the TNF-α/p38 MAPK/PPAR-γ/NLRP3/GFAP pathway. Full article

Omega-6 polyunsaturated fats (ω-6 PUFAs) are vital for many physiological functions, but their impact on cardiovascular disease (CVD) risk is controversial. Eryptosis alters blood viscosity by providing a procoagulant surface and leads to anemia, which is a recognized risk factor for CVD. This study examines the toxic mechanisms of adrenic acid (ADR), an ω-6 PUFA enriched in inflammatory and oxidative conditions, in red blood cells (RBCs). Purified RBCs were prepared from healthy volunteers and treated with 10–100 μM of ADR for 24 h at 37 °C under various physiological conditions. Eryptotic markers were studied through flow cytometry including Ca²⁺ (Fluo4/AM), loss of volume (forward scatter), phosphatidylserine (PS) exposure (annexin-V-FITC), and oxidative stress (H₂DCFDA). Moreover, hemolytic markers were measured by colorimetric methods, whereas cellular morphology was visualized using a scanning electron microscope. ADR led to significant Ca²⁺ elevation, cell shrinkage and schistocyte formation, PS externalization, hemolysis, and oxidative stress. While guanosine, heparin, and NSC 23766 prevented eryptosis and hemolysis, melatonin, ATP, adenine, and L-NAME only prevented eryptosis. Conversely, mannitol and urea exacerbated eryptosis, whereas caffeine, mannitol, and urea under Ca²⁺ deprivation and membrane potential dissipation aggravated hemolysis. ADR induces erythrocyte membrane injury and eryptosis through Ca²⁺ elevation, oxidative stress, and metabolic exhaustion subject to inhibition by the Rac1 GTPase/NOS/COX pathway. Altogether, these findings present a novel mechanistic link between lipid dysregulation and RBC dysfunction which may improve dietary strategies to prevent and manage CVD. Full article

Objectives: This study aimed to investigate the therapeutic efficacy of a hydrogel loaded with Wharton’s Jelly mesenchymal stem cells (WJ-MSCs) and melatonin, administered to the liver either via mesh–hydrogel implantation or intraperitoneal hydrogel injection, in a thioacetamide (TAA)-induced liver fibrosis animal model. Methods: A collagen-based hydrogel containing WJ-MSCs and melatonin was prepared for injection as well as combined with electrospun mesh for implantation. Hydrogel and mesh were characterized with respect to morphology, degradation, and mechanical properties. In in vivo studies, liver fibrosis was induced in rats by intraperitoneal injection of TAA for 6 weeks. After fibrosis induction, animals received either hydrogel injection or implantation of the combined construct. After 21 days, serum and liver tissues were collected, and biochemical, histopathological, and ultrastructural analyses were performed through comparative evaluation of experimental groups. Results: SEM results demonstrated that hydrogel, with appropriate porosity, was well integrated with the mesh without any detachment. The mesh, composed of submicron-scale fibers, exhibited a Young’s modulus of 10.37 ± 2.33 MPa. The hydrogel presented a degradation profile with a 40% mass loss in 24 h, reaching approximately 50% by day 30. Biochemical results indicated significant improvement in liver regeneration with both treatment strategies, particularly with the implanted construct. Histopathological analysis revealed decreased inflammation and hepatocyte vacuolization following both treatments; however, collagen accumulation was significantly reduced in the implant group. Ultrastructural analysis showed preserved nuclear integrity and reduced endoplasmic reticulum dilation and degenerative changes in implant group. Conclusions: The combination of WJ-MSCs and melatonin-loaded hydrogel with supportive mesh particularly enhanced tissue regeneration in liver fibrosis. Full article

Soil acidity is a major constraint in many agricultural regions, where increased aluminum (Al³⁺) solubility at low pH severely affects plant health by inhibiting root elongation, disrupting nutrient uptake, and inducing oxidative stress. Recent studies have highlighted melatonin, a widely occurring indoleamine with strong antioxidant and stress-modulating properties, which alleviates Al-induced damage in crops. This review synthesizes current physiological, biochemical, and agronomic evidence demonstrating that exogenous melatonin enhances plant tolerance to aluminum toxicity. Across multiple model and crop species, melatonin application has been shown to improve root elongation by 20–45%, reduce lipid peroxidation by 30–60%, and enhance key antioxidant enzymes such as SOD, POD, and CAT by 25–70% under Al stress. Case studies in soybean, wheat, maize, and rice further indicate that melatonin protects root meristems from oxidative damage, stabilizes photosynthetic machinery, and improves nutrient acquisition. In acidic soils (pH 4.5), melatonin-treated soybean exhibited 28% greater biomass and 15–22% higher N and P uptake, while wheat plants demonstrated 10–18% higher grain filling under field-simulated Al stress. Emerging long-term studies show that melatonin also benefits soil health. Multi season experiments reveal that melatonin enhances root exudates that support beneficial rhizosphere microbes, increases soil enzymatic activities (urease, phosphatase) by 20–35%, and lowers exchangeable Al by 12–18%. These improvements contribute to cumulative yield gains of 10–18% over successive cropping cycles. Additionally, genetic approaches aimed at increasing endogenous melatonin levels in plants have demonstrated 12–30% yield improvement in acid soil conditions. This review highlights the need for multi-year, multi-location studies to further clarify how melatonin can support sustainable agricultural practices, enhance soil fertility, and mitigate aluminum toxicity in acid-affected regions. Full article

Petunia × hybrida is a highly valued ornamental species worldwide, prized for its bright flower colors and long flowering period. Soil salinization is a major abiotic stress that negatively impacts both agriculture and ornamental plant cultivation. Its detrimental effects stem from osmotic stress, ionic toxicity, and oxidative stress induced by the accumulation of reactive oxygen species (ROS). Melatonin, a multifunctional signaling molecule, can enhance plant resistance under adverse conditions. In this study, Petunia × hybrida cv. ‘Mirage Rose’ was used to investigate these effects. The five treatment groups consisted of control (CK), salt stress alone (NaCl, 200 mmol·L⁻¹), and salt stress combined with 50, 100, or 200 µmol·L⁻¹ melatonin (NaCl + MT50, NaCl + MT100, and NaCl + MT200). Evaluations covered developmental morphology, physiological and biochemical parameters, stomatal density, and transcript levels of antioxidant enzymes. Results indicated that high salinity significantly inhibited vegetative growth and reduced stomatal density while increasing the accumulation of malondialdehyde (MDA), superoxide anions (O₂⁻), and hydrogen peroxide (H₂O₂). Exogenous melatonin application significantly alleviated these adverse effects, with 100 µmol·L⁻¹ being the most effective concentration among the tested doses. This treatment enhanced the activity and gene expression of antioxidant enzymes, reduced membrane lipid peroxidation, promoted the accumulation of compatible solutes for osmotic balance, and improved stomatal development. Overall, 100 µmol·L⁻¹ melatonin effectively enhanced salt tolerance in Petunia by regulating redox homeostasis and modulating stomatal characteristics. Full article

Chromium (Cr) contamination leads to the accumulation of Cr in crops, thereby posing a significant threat to food security and human health. It is essential to comprehend the mechanisms underlying Cr toxicity and to develop effective mitigation strategies to ensure healthy crop growth. Melatonin (MT), a multifunctional regulatory molecule, plays a pivotal role in the response of plants to heavy metal stress. This study is designed to investigate the underlying mechanisms through which exogenous application of MT mitigates the toxicity of Cr stress in maize seedlings. The findings of the study indicate that under Cr stress conditions, treatment with MT significantly decreased the Cr concentrations in the roots and leaves of maize, with reductions of 22% and 28.5%, respectively. Concurrently, MT demonstrated effectiveness in alleviating the toxic effects induced by Cr exposure, as evidenced by substantial improvements in the leaf area, chlorophyll content, and photosynthetic rate, which increased by 40.3%, 47.7%, and 64.8%, respectively. This led to a 42.2% increase in the total dry weight of maize. Further analysis indicates that MT modulates the antioxidant system, thereby reducing the production of reactive oxygen species and reducing membrane lipid damage associated with Cr toxicity. Moreover, MT upregulates the expression and activity of enzymes involved in polyamine synthesis while simultaneously inhibiting the activity of polyamine-degrading enzymes, leading to a 38% increase in total polyamine content. This study has enhanced our understanding of the mechanisms through which melatonin alleviates chromium toxicity in crops and has provided a theoretical foundation for its sustainable application in agricultural production. Full article

Cisplatin is a potent chemotherapeutic agent whose clinical application is frequently limited by severe nephrotoxicity. N-acetylserotonin (NAS), a precursor of melatonin and a selective agonist of the TrkB receptor, has demonstrated significant antioxidant and neuroprotective properties. This study aimed to evaluate the potential renoprotective effects of NAS against cisplatin-induced acute kidney injury (AKI) in a rat model. Thirty-five Wistar Albino rats were divided into five groups: Control, Sham, NAS (5 mg/kg), Cisplatin (CP; 7.5 mg/kg), and CP + NAS. NAS was administered daily for seven days, while cisplatin was given as a single dose on the fourth day. Renal function was assessed via serum urea and creatinine. Oxidative stress markers, including Malondialdehyde (MDA), Superoxide Dismutase (SOD), Total Antioxidant Status (TAS), and Total Oxidant Status (TOS), were measured in kidney tissue. Comprehensive histopathological evaluations were performed to assess tubular and glomerular damage. Cisplatin administration significantly increased serum creatinine levels and induced severe histopathological damage (p < 0.05). While cisplatin reduced SOD and TAS levels, NAS treatment showed a trend toward biochemical recovery without reaching statistical significance in oxidative markers. Notably, NAS administration significantly ameliorated cisplatin-induced histopathological lesions, specifically reducing tubular epithelial loss, glomerular degeneration, interstitial inflammation, and vacuolization (p < 0.05). Our findings indicate that NAS exerts a profound structural protective effect against cisplatin-induced renal injury. The preservation of renal parenchyma, despite modest systemic biochemical shifts, suggests that NAS-mediated protection may involve localized TrkB-dependent pro-survival signaling and stabilization of mitochondrial integrity. NAS represents a promising therapeutic candidate for mitigating chemotherapy-induced nephrotoxicity. Full article

Erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is widely used in cancer therapy; however, hepatotoxicity limits its clinical use. This study investigated the protective effects of Liv-52, a polyherbal hepatoprotective formulation, against erlotinib-induced hepatotoxicity in rats and compared its efficacy with melatonin. The animals (n = 24, Wistar albino rats) were randomly categorized into four groups: healthy (HG), erlotinib (ERG), Liv-52 + erlotinib (LEG), and melatonin + erlotinib (MEG). Liv-52 (50 mg/kg/day, orally) and melatonin (10 mg/kg/day, orally) were administered once daily for two weeks. Erlotinib (10 mg/kg, orally) was given every other day to ERG, LEG, and MEG groups for two weeks. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were measured. Hepatic malondialdehyde (MDA), total glutathione (tGSH), superoxide dismutase (SOD), and catalase (CAT) levels were analyzed. Additionally, double immunofluorescence staining was performed to evaluate apoptotic (poly[ADP-ribose] polymerase-1 [PARP-1], apoptosis-inducing factor [AIF]), inflammatory (cyclooxygenase-2 [COX-2]), and anti-inflammatory (interleukin-10 [IL-10]) biomarkers in liver tissues. Histopathological examination was also conducted to assess structural alterations. Erlotinib significantly increased MDA, ALT, AST, and LDH while decreasing tGSH, SOD, and CAT (p < 0.001). Strong immunoreactivity for PARP-1, AIF, IL-10, and COX-2, as well as severe hydropic degeneration and necrosis, was observed in ERG (p < 0.05). Both Liv-52 and melatonin significantly ameliorated biochemical, histopathological, apoptotic, and inflammatory alterations (p < 0.05). Notably, Liv-52 demonstrated superior hepatoprotective efficacy compared to melatonin. These findings indicate that Liv-52 effectively attenuates erlotinib-induced hepatotoxicity by modulating oxidative stress, inflammatory responses, and apoptotic pathways, thereby preserving liver function and structural integrity. Full article

Background/Objectives: Dietary antioxidants are frequently utilized by breast cancer (BC) patients to mitigate treatment-related toxicities and enhance quality of life. However, their clinical efficacy remains highly controversial due to conflicting epidemiological and clinical data. This review aims to critically evaluate the molecular mechanisms, clinical outcomes, and translational challenges of antioxidant supplementation in BC management. Methods: A comprehensive evaluation of current literature—encompassing observational cohorts, randomized controlled trials, and mechanistic in vitro/in vivo models—was conducted. The analysis focused on the pharmacological interactions of diverse bioactive compounds (polyphenols, vitamins, carotenoids) with BC progression and standard antineoplastic regimens. Results: Current evidence demonstrates a paradoxical, double-edged role of antioxidants in oncology. While specific interventions (e.g., Coenzyme Q10, melatonin) effectively ameliorate treatment-induced toxicities without compromising therapeutic efficacy, the concurrent administration of antioxidants during cytotoxic chemotherapy can inadvertently neutralize essential reactive oxygen species (ROS), correlating with increased disease recurrence and mortality. Furthermore, clinical translation is severely hindered by the intrinsic hydrophobicity of natural compounds, the lack of whole-food matrix standardization, and dose-dependent hepatotoxicity. Emerging targeted delivery systems, such as lipid nanoformulations, show significant potential in overcoming these pharmacokinetic barriers. Conclusions: The therapeutic viability of antioxidant supplementation in BC is not universal; it is heavily dictated by intrinsic tumor biology, specific treatment modalities, and chronopharmacology. These findings underscore a critical biological imperative to transition from generalized dietary guidelines toward a rigorous paradigm of precision nutritional oncology, strictly avoiding concurrent antioxidant supplementation during active oxidative therapies. Full article

Pinealectomy leads to melatonin deficiency, which is known to disrupt circadian clock regulation and may increase vulnerability of the hippocampus to oxidative stress and neuroinflammatory processes. The objective of this study was to examine the gene expression levels of circadian locomotor output cycles kaput (CLOCK), brain and muscle ARNT-like 1 (BMAL1), period circadian regulator 1 (PER1), cryptochrome circadian regulator 1 (CRY1), brain-derived neurotrophic factor (BDNF), and interleukin-6 (IL-6) in the hippocampus to elucidate the impact of pinealectomy-induced circadian dysregulation on these gene expressions and to assess its association with hippocampal alterations. A total of 30 Wistar rats were randomly divided into three groups: Control, Sham, and Pinealectomy (PNX) (n = 10 per group). Gene expression levels were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical analysis was performed to assess caspase-3 and glial fibrillary acidic protein (GFAP) immunoreactivity. In addition, oxidative stress parameters, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH), as well as the inflammatory marker tumor necrosis factor-alpha (TNF-α), were measured. The pinealectomy group showed a significant downregulation of BMAL1, BDNF, CLOCK, CRY1, and PER1 gene expression levels, with decreases ranging from approximately 60% to 83% compared with the sham and control groups, whereas IL-6 expression was significantly increased by approximately 185% (p < 0.05). Immunohistochemical analysis demonstrated significantly increased caspase-3 and GFAP immunoreactivity in the PNX group. Furthermore, pinealectomy resulted in a significant increase in MDA and TNF-α levels, accompanied by marked decreases in SOD, CAT, and GSH levels (p < 0.05). In conclusion, pinealectomy is associated with significant disruption of hippocampal circadian clock gene expression, accompanied by oxidative stress, neuroinflammation, and histopathological alterations. These findings highlight the critical role of circadian regulation in maintaining hippocampal cellular integrity. Full article

Oxidative stress critically affects cellular viability and function under in vitro culture conditions, often compromising physiological integrity of somatic cells used in livestock biotechnology. This study aimed to investigate hydrogen peroxide (H₂O₂)-induced oxidative stress in buffalo fibroblasts and evaluated the cytoprotective effects of melatonin, focusing on redox homeostasis, mitochondrial function, apoptosis, and antioxidant defence. Fibroblasts were exposed to graded concentrations of H₂O₂ (100–1000 µM) for 2 h, followed by treatment for 72 h in culture media with and without melatonin (10⁻⁹ M). Oxidative stress markers, including GSSG/GSH ratio, ROS generation, mitochondrial membrane potential (MMP), and apoptosis, were assessed using flow cytometry and biochemical assays, while antioxidant (GPx, SOD, CAT) and apoptotic (BAX, Caspase 9) gene expression was analyzed by qPCR. H₂O₂ exposure induced a dose-dependent increase in oxidative stress, evidenced by elevated ROS, redox imbalance, mitochondrial depolarization, and enhanced apoptosis. Severe oxidative damage was observed at higher H₂O₂ (500–1000 µM) concentrations. Melatonin (MT) significantly (p ≤ 0.05) alleviated oxidative stress under mild to moderate conditions (100–200 µM H₂O₂) by restoring redox homeostasis, preserving mitochondrial integrity, suppressing ROS accumulation, enhancing antioxidant defence, and reducing apoptosis. However, its protective efficacy was lost under severe oxidative stress, indicating a defined redox threshold beyond which cellular damage becomes irreversible. These findings suggest that melatonin exerts cytoprotective effect against oxidative stress within a limited oxidative window and provide mechanistic insights for improving fibroblasts culture systems in livestock biotechnology and regenerative applications. Full article

Apis cerana is widely managed in apiculture in Southern China but experiences substantial colony losses during prolonged summer heat. Developing effective strategies to support colony over-summering is therefore critical. This study demonstrates that dietary supplementation with melatonin significantly enhances thermal tolerance and extends worker lifespan in A. cerana under heat stress. Laboratory bioassays revealed that melatonin supplementation (20 µg/mL) markedly improved worker survival at both 35 °C and 37 °C, with the most pronounced effect at 37 °C, where mortality was significantly reduced. Consistently, field trials demonstrated that melatonin supplemented colonies gained significantly more weight during summer heatwaves than colonies without melatonin supplementation. Mechanistically, melatonin orchestrates a biphasic adaptive response. In an early phase (day 4), melatonin rapidly upregulates heat shock proteins (HSC70-4, CRYAA, l(2)efl) and detoxification enzymes (GST-like), accompanied by reduced reactive oxygen species (ROS) accumulation and enhanced proboscis extension response (PER), indicative of preserved sensory function. This is followed by a later maintenance phase (day 11), characterized by sustained upregulation of fatty acyl-CoA reductases (FAR1, FAR11-like, FARwat) and peroxisomal components (PMP34), which promote lipid remodeling and membrane stabilization. RNA-seq analysis identified differentially expressed genes (DEGs) significantly enriched in pathways related to redox homeostasis, lipid metabolism, detoxification (GSTs, CarEs, CYP450s), and longevity. These molecular responses were associated with enhanced antioxidant capacity, reduced oxidative damage, and sustained foraging activity under thermal stress. Collectively, these results indicate that melatonin serves as a potent nutritional intervention that reprograms redox metabolic networks to mitigate heat-induced damage, extend worker longevity, and enhance colony productivity under climate warming. These findings highlight melatonin’s potential as a practical tool to reduce summer colony losses in apiculture. Full article