Protective activities of ellagic acid and urolithins against kidney toxicity of environmental pollutants: A review

Ellagic acid mitigates heat-induced testicular detriment in a mouse model

Heat stress has been shown to have a detrimental impact on testicular activity and spermatogenesis. Ellagic acid is a plant-derived organic compound that has a variety of biological functions. Thus, it is believed that ellagic acid may improve heat-stressed testicular dysfunction. There has been no research on the impact of ellagic acid on heat-stressed testicular dysfunction. The mice were divided into 4 groups. The first group was the normal control group (CN), and the second received heat stress (HS) by submerging the lower body for 15 min in a water bath with a thermostatically controlled temperature kept at 43°C (HS), and the third and fourth groups were subjected to heat-stress similar to group two and given two different dosages of ellagic acid (5 mg/kg (EH5) and 50 mg/kg (EH50) for 14 days. Ellagic acid at a dose of 50 mg/kg improved the level of circulating testosterone (increased 3βHSD) and decreases the oxidative stress. The testicular and epididymal architecture along with sperm parameters also showed improvement. Ellagic acid treatment significantly increases the germ cell proliferation (GCNA, BrdU staining) and Bcl2 expression and decreases active caspase 3 expression. Heat stress downregulated the expression of AR, ER-α and ER-β, and treatment with ellagic acid increased the expression of ER-α and ER-β markers in the 50 mg/kg treatment group. Thus, our finding suggests that ellagic acid ameliorates heat-induced testicular impairment through modulating testosterone synthesis, germ cell proliferation, and oxidative stress. These effects could be manifested by regulating androgen and estrogen receptors. However, the two doses showed differential effects of some parameters, which require further investigation.

Phytochemicals Involved in Mitigating Silent Toxicity Induced by Heavy Metals

Heavy metals (HMs) are natural elements present in the Earth's crust, characterised by a high atomic mass and a density more than five times higher than water. Despite their origin from natural sources, extensive usage and processing of raw materials and their presence as silent poisons in our daily products and diets have drastically altered their biochemical balance, making them a threat to the environment and human health. Particularly, the food chain polluted with toxic metals represents a crucial route of human exposure. Therefore, the impact of HMs on human health has become a matter of concern because of the severe chronic effects induced by their excessive levels in the human body. Chelation therapy is an approved valid treatment for HM poisoning; however, despite the efficacy demonstrated by chelating agents, various dramatic side effects may occur. Numerous data demonstrate that dietary components and phytoantioxidants play a significant role in preventing or reducing the damage induced by HMs. This review summarises the role of various phytochemicals, plant and herbal extracts or probiotics in promoting human health by mitigating the toxic effects of different HMs.

Mitochondrial reactive oxygen species initiate gasdermin D-mediated pyroptosis and contribute to paraquat-induced nephrotoxicity

Paraquat (PQ)-induced acute kidney injury (AKI) progresses rapidly and is associated with high mortality rates; however, no specific antidote for PQ has been identified. Poor understanding of toxicological mechanisms underlying PQ has hindered the development of suitable treatments to combat PQ exposure. Gasdermin D (GSDMD), a key executor of pyroptosis, has recently been shown to enhance nephrotoxicity in drug-induced AKI. To explore the role of pyroptosis in PQ-induced AKI, the plasma membrane damage of the cells was detected by LDH release assay. Western blot was performed to detect the cleavage of GSDMD. RNA sequencing analysis was performed to explore the mechanism of PQ induced nephrotoxicity. Herein, we demonstrated that PQ could induce pyroptosis in HK-2 cells and nephridial tissues. Mechanistically, PQ initiated GSDMD cleavage, and GSDMD knockout attenuated PQ-induced nephrotoxicity in vivo. Further analysis revealed that the accumulation of mitochondrial reactive oxygen species (ROS) induced p38 activation, contributing to PQ-induced pyroptosis. Furthermore, mitoquinone, a mitochondria-targeted antioxidant, reduced mitochondrial ROS levels and inhibited pyroptosis. Collectively, these findings provide insights into the role of GSDMD-dependent pyroptosis as a novel mechanism of PQ-induced AKI.

The Green Synthesis of Reduced Graphene Oxide Using Ellagic Acid: Improving the Contrast-Enhancing Effect of Microbubbles in Ultrasound

There is an urgent need to realize precise clinical ultrasound with ultrasound contrast agents that provide high echo intensity and mechanical index tolerance. Graphene derivatives possess exceptional characteristics, exhibiting great potential in fabricating ideal ultrasound contrast agents. Herein, we reported a facile and green approach to synthesizing reduced graphene oxide with ellagic acid (rGO-EA). To investigate the application of a graphene derivative in ultrasound contrast agents, rGO-EA was dispersed in saline solution and mixed with SonoVue (SV) to fabricate SV@rGO-EA microbubbles. To determine the properties of the product, analyses were performed, including ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectrum (XPS), X-ray diffraction analysis (XRD) and zeta potential analysis. Additionally, cell viability measurements and a hemolysis assay were conducted for a biosafety evaluation. SV@rGO-EA microbubbles were scanned at various mechanical index values to obtain the B-mode and contrast-enhanced ultrasound (CEUS) mode images in vitro. SV@rGO-EA microbubbles were administered to SD rats, and their livers and kidneys were imaged in CEUS and B-mode. The absorption of rGO-EA resulted in an enhanced echo intensity and mechanical index tolerance of SV@rGO-EA, surpassing the performance of SV microbubbles both in vitro and in vivo. This work exhibited the application potential of graphene derivatives in the field of ultrasound precision medicine.

Ellagic Acid and Cancer Hallmarks: Insights from Experimental Evidence

Cancer is a complex and multifaceted disease with a high global incidence and mortality rate. Although cancer therapy has evolved significantly over the years, numerous challenges persist on the path to effectively combating this multifaceted disease. Natural compounds derived from plants, fungi, or marine organisms have garnered considerable attention as potential therapeutic agents in the field of cancer research. Ellagic acid (EA), a natural polyphenolic compound found in various fruits and nuts, has emerged as a potential cancer prevention and treatment agent. This review summarizes the experimental evidence supporting the role of EA in targeting key hallmarks of cancer, including proliferation, angiogenesis, apoptosis evasion, immune evasion, inflammation, genomic instability, and more. We discuss the molecular mechanisms by which EA modulates signaling pathways and molecular targets involved in these cancer hallmarks, based on in vitro and in vivo studies. The multifaceted actions of EA make it a promising candidate for cancer prevention and therapy. Understanding its impact on cancer biology can pave the way for developing novel strategies to combat this complex disease.

In Vitro Gastrointestinal Digestion Affects the Bioaccessibility of Bioactive Compounds in Hibiscus sabdariffa Beverages

Hibiscus sabdariffa possess great versatility to be used as an ingredient for a whole range of products with natural-based ingredients, which are growing in popularity due to the health benefits of bioactive compounds (BC). Therefore, the objective of this study was to characterize the BC content in Hibiscus beverages and to evaluate their in vitro bioaccessibility. Results showed significant differences (p < 0.05) in the total contents of BC prior to the in vitro intestinal digestion. Hibiscus acid was the most abundant compound identified. Thirty-five compounds were identified in the Hibiscus beverage at the initial stage, while a maximum of 15 compounds were quantified in the different fractions of gastrointestinal digestion. After digestion, significant differences were found compared with the initial content of BC. That phenolic acids were the less bioaccessible group, while flavonoids were the most diverse. Principal components analysis showed different clusters and changes in the profiles of BC present at the initial stage and those bioaccessible, showing that intestinal digestion significantly affects the BC profile of the beverage.

Pretreatment of ellagic acid protects ifosfamide-induced acute nephrotoxicity in rat kidneys: A mitochondrial, histopathological and oxidative stress approaches

Ifosfamide (IFO) kidney damage is an important organ toxicity in children and adults undergoing chemotherapy. Previous evidence has shown that IFO toxic metabolites such as acrolein and are associated with mitochondrial dysfunction, depletion of antioxidants, oxidative stress and may predispose the kidney to IFO toxicity. Bioactive food compounds such as ellagic acid (EA) found in fruits has been described as antioxidant and mitochondrial protective agents against toxicity-related mitochondrial damage and oxidative stress. In current study, the protective effects of EA on IFO-induced nephrotoxicity in male Wistar rats were investigated with histopathological, biochemical, and mitochondrial methods. The rats were randomly divided into four groups, control, IFO, IFO + EA, and EA groups. EA (25 mg/kg, i.p. daily) were administered to animals for 2 consecutive days and IFO (500 mg/kg, i.p.) was administered on third day. The results showed that pretreatment EA significantly increased mitochondrial succinate dehydrogenases (SDH) activity, and protected mitochondrial swelling, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) formation, lipid peroxidation (LPO) and depletion glutathione (GSH). Histopathological findings demonstrated that EA had protective effects and reduced histopathological abnormalities caused by IFO. These results showed that EA administration protects the kidneys against mitochondrial dysfunction, oxidative stress and histopathological abnormality induced by IFO. Taken together, our results demonstrated that EA played a protective role against IFO-induced nephrotoxicity through mitochondrial protection and antioxidant properties.

Targeted UHPLC-MS Analysis Reveals Disparate Polyphenol Composition and Concentration in Muscadine Grape Supplements with Proportional Antioxidant Activity

Muscadine grape supplements (MGS) with high polyphenol content are a potential therapeutic option to combat oxidative stress; however, the precise identity and concentration of individual phenolics in commercially processed MGSs is not well defined. We probed for 17 phenolic compounds by ultra-high pressure liquid chromatography and mass spectroscopy from distinct lots of four commercially processed MGSs composed of MG seed and/or skin waste products. The total phenolic content (TPC) and antioxidant capacity were highest in a dried water-extract MGS as compared to three ground seed and/or skin products. The TPC was not different between MGS lots from individual companies and remained stable for 3 years without microbial contamination. The extract MGS had the highest concentration of epicatechin, ellagic acid, gallic acid, procyanidin B2, catechin and catechin gallate compared to the other supplements. Only ellagic acid and gallic acid were detected in all four MGSs, while catechin and catechin gallate were below detection in two supplements. Based on gram weight, only the extract MGS prevented the angiotensin II-induced increase in malondialdehyde and 4-hydroxynonenol in rat H9c2 cardiomyocytes as well as upregulated superoxide dismutase and catalase. This study demonstrates that commercial MGSs differ in phenolic composition and concentration, resulting in disparate antioxidant activity.