Protective effect of gallic acid isolated from Peltiphyllum peltatum against sodium fluoride-induced oxidative stress in rat’s kidney

Exploring potential targets for natural product therapy of DN: the role of SUMOylation

Diabetic nephropathy (DN) is a common and serious micro-vascular complication of diabetes and a leading cause of end-stage renal disease globally. This disease primarily affects middle-aged and elderly individuals, especially those with a diabetes history of over 10 years and poor long-term blood glucose control. Small ubiquitin-related modifiers (SUMOs) are a group of reversible post-translational modifications of proteins that are widely expressed in eukaryotes. SUMO proteins intervene in the progression of DN by modulating various signaling cascades, such as Nrf2-mediated oxidative stress, NF-κB, TGF-β, and MAPK pathways. Recent advancements indicate that natural products regulating SUMOylation hold promise as targets for intervening in DN. In a previous article published in 2022, we reviewed the mechanisms by which SUMOylation intervenes in renal fibrosis and presented a summary of some natural products with therapeutic potential. Therefore, this paper will focus on DN. The aim of this review is to elucidate the mechanism of action of SUMOylation in DN and related natural products with therapeutic potential, thereby summarising the targets and candidate natural products for the treatment of DN through the modulation of SUMOylation, such as ginkgolic acid, ginkgolide B, resveratrol, astragaloside IV, etc., and highlighting that natural product-mediated modulation of SUMOylation is a potential therapeutic strategy for the treatment of DN as a potential therapeutic strategy.

An interventional clinical trial investigating the effects of Spirulina platensis on dental fluorosis and antioxidant system in lambs reared in endemic areas

This study aimed to evaluate the protective effect of Spirulina platensis primary against dental fluorosis and secondary against oxidative stress in lambs reared in endemic fluorosis areas. Forty-eight lambs aged 5 months were divided into four equal groups (each one including 6 males and 6 females). Groups I and II served as controls belonging respectively to fluorosis-free (Settat) and endemic fluorosis (El Fokra) areas, while the other two Groups III and IV (belonging to El Fokra) received respectively a fixed daily intake of 250 and 500 mg/kg bodyweight (BW) of Spirulina platensis. The experiment was carried out for 13 months until the adult incisors appeared for all animals. According to the Dean's Fluorosis Index (DFI), 500 mg/kg BW/day of Spirulina platensis (Group IV) protected against dental fluorosis. Moreover, in both male and female lambs, this dose significantly (p < 0.0001) reduced the plasmatic levels of fluoride, proteins, GSH, and MDA compared to the Group II. Furthermore, enzymatic activities of catalase and SOD increased significantly (p < 0.0001) in male and female lambs of the Group IV as compared to Group II. In conclusion, our findings support the potential use of Spirulina platensis as a valuable solution for addressing fluorosis in sheep, warranting further clinical trials.

Action of crude ethanol extract of Hymenaea martiana leaf, gallic acid, and polypyrrole (PPy) against Aeromonas hydrophila

Pisciculture represents one of the industries with the fastest growth rates worldwide. However, it presents obstacles to its development, such as bacteriosis, which is conventionally treated with antibiotics. The indiscriminate and inappropriate use of antibiotics can lead to bacterial resistance, thus alternatives to the use of antibiotics have been researched. The study aimed to analyze the potential of crude ethanol extract (CEE) from Hymenaea martiana leaf, gallic acid (GA), and polypyrrole (PPy) against Aeromonas hydrophila. Tests were performed to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the compounds individually and in synergy (checkerboard) against A. hydrophila and in silico tests between the compounds evaluated. The CEE of H. martiana leaf and PPy were effective against A. hydrophila with MBC results of 3125 μg/mL for the CEE of H. martiana and 125 μg/mL for PPy. Evaluating the GA, a MIC and MBC of 125 μg/mL was obtained. In the interaction tests (checkerboard, using PPy/CEE and PPy/GA), there was a significant reduction in individual introductions. Thus, for the PPy/CEE tests, we had a reduction of MIC/MBC to 1.95 and 781.25 μg/mL, and for the synergy tests between PPy/GA to 7.8125 and 31.125 μg/mL, respectively. The synergy tests are encouraging, and it is possible to verify a decrease of up to 98% in the introduction of PPy, 75% in CEE for H. martiana and 75.1% for GA, when compared to their individual tests. The tests with GA are encouraging due to GA's effectiveness as an antimicrobial agent and high synergy with polypyrrole, both in vitro results and molecular docking experiments showed the actions at the same activation site in A. hydrophila. In vivo tests evaluating isolated components of CEE from H. martiana in synergy with PPy should be performed, to verify the quality of the interactions and the improvement of the immune responses of the animals. It was evidenced that gallic acid, a substance isolated from the extract, tends to have more promising results. This is relevant since the industry has been developing these compounds for different uses, thus providing easier access to the product. Thus, the present study indicates an efficient alternative in the use of bioactive compounds as substitutes for conventional antimicrobials.

The diminution and modulation role of water-soluble gallic acid-carboxymethyl chitosan conjugates against the induced nephrotoxicity with cisplatin

The toxicity of cisplatin (CDDP) toward the renal tubules and its severe effects on the proximal tubules limits its further use in cancer therapy. The current study was undertaken to evaluate the protective effects of gallic acid-grafted O-carboxymethyl chitosan (GA@CMCS) against nephrotoxicity induced by CDDP in rats. Renal injury was assessed in the GA@CMCS/CDDP-treated rats using kidney injury molecule-1 (KIM-1). Moreover, the levels of reduced glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO) were measured. The comet assay was performed to measure the DNA damage. The renoprotective activity of GA@CMCS was supported by histo- and immuno-pathological studies of the kidney. GA@CMCS significantly normalized the increases in kidney homogenate of KIM-1, MDA, and NO-induced by CDDP and significantly increased GSH as compared with the CDDP group. GA@CMCS also significantly protects rat kidneys from CDDP-induced histo- and immuno-pathological changes. Both biochemical findings and histo- and immuno-pathological evidence showed the renoprotective potential of GA@CMCS against CDDP-induced oxidative stress, inflammation, and renal dysfunction in rats. In conclusion, GA@CMCS has been shown to mitigate the nephrotoxicity impact of CDDP in cancer therapy.

Role of oxidative stress-mediated cell death and signaling pathways in experimental fluorosis

Free radicals and other oxidants have enticed the interest of researchers in the fields of biology and medicine, owing to their role in several pathophysiological conditions, including fluorosis (Fluoride toxicity). Radical species affect cellular biomolecules such as nucleic acids, proteins, and lipids, resulting in oxidative stress. Reactive oxygen species-mediated oxidative stress is a common denominator in fluoride toxicity. Fluorosis is a global health concern caused by excessive fluoride consumption over time. Fluoride alters the cellular redox homeostasis, and its toxicity leads to the activation of cell death mechanisms like apoptosis, autophagy, and necroptosis. Even though a surfeit of signaling pathways is involved in fluorosis, their toxicity mechanisms are not fully understood. Thus, this review aims to understand the role of reactive species in fluoride toxicity with an outlook on the effects of fluoride in vitro and in vivo models. Also, we emphasized the signal transduction pathways and the mechanism of cell death implicated in fluoride-induced oxidative stress.

Gallic acid attenuates cerebral ischemia/re-perfusion-induced blood-brain barrier injury by modifying polarization of microglia

Microglia, the main immune effector cells in the central nervous system, play a dual role in the function/structure of the blood-brain barrier (BBB) and brain health. During and soon after a cerebral ischemic injury, microglia produce neurotrophic factors and neurotoxins that can impact on the injury itself and pathology progression. At the same time, microglia undergo polarization to M1 or M2 pro- vs. anti-inflammatory subtypes that also help drive the outcome of the injury process. Thus, agents that can mitigate cerebral ischemic injury progression, promote protective functions of microglia, and help maintain BBB and overall brain health/host neurologic function after a cerebral ischemic event would be of great use in clinical settings. Protective effects from gallic acid (GA) in cerebral ischemia/re-perfusion-induced injury to the BBB and other sites in the brain have not yet been assessed. To address this, a middle cerebral artery occlusion (MCAO) method was used to establish an experimental ischemic stroke model in mice. Mice were placed in sham operation (Sham), model (MCAO), MCAO + GA (50 mg/kg), MCAO + GA (100 mg/kg), or MCAO + GA (150 mg/kg) groups. At various times post-stroke, cerebral infarct volume and host neurological function were evaluated. In addition, qRT-PCR, Western blotting, and ELISA were used to evaluate the expression and tissue content of microglia-related factors. The results showed GA treatment protected the integrity of the BBB, significantly reduced brain edema, and helped lead to improved neurological function scores in the MCAO mice. Whether these changes were due to that GA attenuated cerebral ischemia/re-perfusion-induced activation of microglial cells overall, in part, by inhibiting their polarization to the M1 subtype, is uncertain. Taking these outcomes together, for now it is reasonable to suggest that use of GA either as a prophylactic or immediately in the event of a cerebral ischemic event/stroke could help to promote neuronal survival and allow for a more likely of host neurological function over time.

Antioxidant Phytochemicals for the Prevention of Fluoride-Induced Oxidative Stress and Apoptosis: a Review

Fluorosis is a major public health problem globally. The non-availability of specific treatment and the irreversible nature of dental and skeletal lesions poses a challenge in the management of fluorosis. Oxidative stress is known to be one of the most important mechanisms of fluoride toxicity. Fluoride promotes the accumulation of reactive oxygen species by inhibiting the activity of antioxidant enzymes, resulting in the excessive production of reactive oxygen species at the cellular level which further leads to activation of cell death processes such as apoptosis. Phytochemicals that act as antioxidants have the potential to protect cells from oxidative stress. Evidence confirms that clinical symptoms of fluorosis can be mitigated to some extent or prevented by long-term intake of antioxidants and plant products. The primary purpose of this review is to examine recent findings that focus on the amelioration of fluoride-induced oxidative stress and apoptosis by natural and synthetic phytochemicals and their molecular mechanisms of action.

A comprehensive review on endemic and experimental fluorosis in sheep: Its diverse effects and prevention

Fluoride is a natural element widely distributed in the environment and plays an important role in the growth of humans and animals. However, in many species, high concentrations of fluoride induce several problems, such as dental, skeletal, and non-skeletal fluorosis. Sheep living in endemic areas are sensitive to the chronic toxicity of fluoride, and they have been found to suffer not only from teeth and bone problems but also from other organs. Studies indicating the chronic harmful effects of fluoride on teeth, bones, blood biochemical parameters, kidney, liver, heart, reproductive system and growth in sheep have been clearly summarized in this review. Besides, this work also includes updated progress in terms of prevention or reduction of fluoride toxicity in this species.

Acute hepatotoxicity and nephrotoxicity risk assessment of the Tibetan medicine 25 flavors of the turquoise pill based on 1H-NMR metabonomics

ETHNOPHARMACOLOGICAL RELEVANCE

25 flavors of the turquoise pill, a traditional Tibetan medicine for the treatment of various types of hepatitis, has not been investigated on its safety, especially the component mineral turquoise, which is believed to be essential but worried for its potential toxicity.

AIM OF THE STUDY

To explore the potential acute toxicity and function of 25 flavors of the turquoise pill and turquoise, the possible mechanism of the effects of turquoise and 25 flavors of the turquoise pill were systematically studied based on 1H NMR metabolomics.

MATERIALS AND METHODS

The rats were administered with turquoise and 25 flavors of the turquoise pill by gavage for 7 days, and samples of serum, liver, and kidney were collected. The potential toxicity and function of turquoise and 25 flavors of the turquoise pill on the liver and kidney of SD rats were evaluated by 1H NMR metabonomics, histopathology, and biochemical indexes.

RESULTS

The results demonstrated that 25 flavors of the turquoise pill could scavenge free oxygen radicals, strengthen aerobic respiration and inhibit glycolysis in the liver. It did not cause oxidative stress in the kidney with no obvious damage. By modulation of branched-chain amino acids (BCAAs), 25 flavors of the turquoise pill can improve the utilization of glucose and promote aerobic respiration of the kidney.

CONCLUSION

Considering the high dosage and short duration used in this study relative to their typical clinical usage, administration of 25 flavors of the turquoise pill and its component mineral turquoise are safe to livers and kidneys.

Hesperidin protects liver and kidney against sodium fluoride-induced toxicity through anti-apoptotic and anti-autophagic mechanisms

AIM

High dose of fluoride intake is associated with toxic effects on liver and kidney tissues. One approach to tackle these toxicities is using natural antioxidants as supplements. This study evaluated the ameliorative effects of hesperidin (HSP) against sodium fluoride (NaF)-induced hepatotoxicity and nephrotoxicity in wistar albino rats.

MATERIALS AND METHODS

In the present study, the rats were randomly allocated into five groups of seven male rats each group: control, NaF (600 ppm), HSP-200, NaF + HSP-100 and NaF + HSP 200.

KEY FINDINGS

Hepatic and renal injuries induced by NaF were confirmed by the alteration in kidney function parameters in the serum (urea and creatinine), levels of liver enzymes (ALT, ALP and AST), activities of the antioxidant enzymes (SOD, CAT and GPx) and levels of inflammatory markers (NF-κB, IL-1β and TNF-α). NaF also inhibited PI3K/Akt/mTOR pathway, increased levels of autophagic markers (Beclin-1, LC3A and LC3B) and expression levels of apoptotic and anti-apoptotic proteins (Bax, Bcl-2, cytochrome c, p53 and procaspase-3) in the liver and kidney tissues. Administration of HSP concurrently with NaF significantly ameliorated the deviation in the above-studied parameters.

SIGNIFICANCE

The results of the current study revealed that HSP could be used as a beneficial adjuvant that confers protection against NaF-induced liver and kidney damage through antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagic mechanisms.

Selenium Exerts Protective Effects Against Fluoride-Induced Apoptosis and Oxidative Stress and Altered the Expression of Bcl-2/Caspase Family

Fluoride is widely distributed in nature, and at high concentrations, it targets the kidney and especially proximal tubule epithelial cells. Selenium is a typical trace element beneficial to humans, and the role of selenium in the prevention and treatment of fluoride-induced organ damage is an important research topic. The purpose of this study was to investigate the possible protective effects of selenium against fluoride-induced oxidative stress and apoptosis in rat renal tubular epithelial cells. We showed that the activity of antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and total antioxidant capacity were significantly reduced in NaF-treated normal rat kidney cells (NRK-52E), whereas the levels of nitrogen monoxide (NO) and malondialdehyde (MDA) were significantly increased. Moreover, the number of apoptotic cells, mRNA expression of Bax, Bad, caspase-3, caspase-8, and caspase-9, and protein expression of Bax were elevated, while mitochondrial membrane potential and the protein expression of Bcl-2 were reduced. Compared with the NaF group, pretreatment with selenium enhanced the activity of antioxidant enzymes, mitochondrial membrane potential, and protein expression of Bcl-2, while the levels of NO and MDA, number of apoptotic cells, mRNA expression of Bax, Bad, caspase-3, caspase-8, and caspase-9, and protein expression of Bax were decreased. In conclusion, selenium exerted remarkable protective effect against NaF-induced oxidative stress and apoptosis and altered the expression of Bcl-2/caspase family.

Plasma and water fluoride levels and hyperuricemia among adolescents: A cross-sectional study of a nationally representative sample of the United States for 2013-2016

Exposure to excessive fluoride has been associated with a number of adverse health outcomes; however, there is a lack of evidence on the relation between fluoride exposure and serum uric acid levels, especially in human populations. The present study examined a potential relationship between fluoride exposure, measured as both plasma and water fluoride concentrations, and uric acid levels in an adolescent population. A nationally representative subsample of 1933 adolescents, aged 12-19 years, in the 2013-2016 National Health and Nutrition Examination Survey was analyzed for the association of fluoride concentrations with serum uric acid levels using multivariate general linear and logistic regression models, adjusting for potential confounders. Since uric acid levels change during development, hyperuricemia was defined in this study as over the mean plus one standard deviation for each sex and age group of adolescents. Of the study participants, 276 adolescents (weighted prevalence, 16.56%) had hyperuricemia. A significant and dose-dependent increase in prevalence of hyperuricemia was seen among the participants cross increasing quartiles of plasma fluoride (p-trend = 0.0017). After adjusting for potential confounders, we found that adolescents in the higher quartiles of plasma fluoride (≥0.32 µmol/L) and in the highest quartile of water fluoride (≥0.73 mg/L) had significantly increased odds of hyperuricemia compared with those in the lowest quartile. A 1.95-fold increased odds (95% CI: 1.37, 2.77) of hyperuricemia was also observed when analyzing plasma fluoride concentrations as continuous variable. A general linear model revealed that a 1 µmol/L increase in ln-plasma fluoride was associated with a 0.212 mg/dL (p < 0.0001) increased serum uric acid level. Furthermore, a positive relationship was observed between water and plasma fluoride concentrations (β = 0.1907; p < 0.0001). Our study demonstrates a potential relation between fluoride exposure and hyperuricemia in adolescents. Further studies are warranted to overcome the limitations of this study to examine the impact of long-term exposure to low levels of fluoride during development on hyperuricemia and its related health outcomes.

Gallic acid exerts anti-inflammatory, anti-oxidative stress, and nephroprotective effects against paraquat-induced renal injury in male rats

Paraquat (PRQ) is a toxic chemical compound that is very noxious to animals and humans. Gallic acid is a phenolic compound that has antioxidant properties. In this study, we evaluated the ameliorative effect of gallic acid against PRQ-induced renal injury and oxidative stress. In this research, the rats were segregated into six groups. Group 1 is the control group; group 2 received paraquat only; group 3 received gallic acid only; and groups 4, 5, and 6 received paraquat plus gallic acid at doses of 25, 50, and 100 mg/kg bw respectively. Findings of this work displayed that the renal contents of the vitamin C, superoxide dismutase (SOD), and catalase (CAT) significantly reduced and the levels of the serum protein carbonyl, creatinine, serum glutamate pyruvate transaminase (sGPT), urea, serum glutamate oxaloacetate transaminase (sGOT), uric acid, MDA, serum IL-1β, and the kidney IL-1β gene expression were remarkably increased in the group receiving PRQ only compared with that in the control group. On the other hand, treatment with gallic acid after exposure to PRQ led to a significant elevation in renal vitamin C, SOD, and CAT levels plus a remarkable decrease in the serum protein carbonyl, creatinine, sGPT, urea, sGOT, uric acid, MDA, IL-1β, and renal gene expression of IL-1β in comparison with the PRQ-only-treated rats. Histological changes were also ameliorated by gallic acid administration. The data approve that gallic acid diminished the deleterious effects of PRQ exposure. In this regard, our results indicated that the administration of gallic acid could alleviate the noxious effects of PRQ on the antioxidant defense system and renal tissue.

Gallic acid mitigates diclofenac-induced liver toxicity by modulating oxidative stress and suppressing IL-1β gene expression in male rats

CONTEXT

Diclofenac (DIC) is an NSAID and consumption of this drug creates side effects such as liver injury. Gallic acid (GA), a natural component of many plants, is used as an antioxidant agent.

OBJECTIVE

This study assesses the hepatoprotective effects of GA in the rat model of DIC-induced liver toxicity.

MATERIALS AND METHODS

In this research, the male Wistar rats were separated into five groups (n = 6). Group 1, control, received normal saline (1 mL/kg bw, i.p.); Group 2 received DIC-only (50 mg/kg bw, i.p.); Groups 3, received DIC (50 mg/kg bw, i.p.) plus silymarin (100 mg/kg bw, po), groups 4 and 5 received DIC (50 mg/kg bw, i.p.) plus GA (50 and 100 mg/kg, po, respectively).

RESULTS

The data demonstrated that the liver levels of the GSH, GPx, SOD, and CAT significantly reduced and the levels of the serum protein carbonyl, AST, ALP, ALT, total bilirubin, MDA, serum IL-1β, and the liver IL-1β gene expression were remarkably increased in the second group compared to control group. On the other hand, treatment with GA led to a significant elevation in GSH, GPx, SOD, CAT, and a significant decrease in protein carbonyl, AST, ALP, ALT, total bilirubin, MDA, serum IL-1β, and gene expression of IL-1β in comparison with the second group. Histological changes were also ameliorated by GA oral administration. Discussion and Conclusions: The data show that the oral administration of GA could alleviate the noxious effects of DIC on the antioxidant defense system and liver tissue.

Argan oil ameliorates sodium fluoride-induced renal damage via inhibiting oxidative damage, inflammation, and intermediate filament protein expression in male rats

Fluoride is widely distributed in the environment and has been associated with the development of different health hazards in animals and humans. Argan oil (AO) is a natural vegetable oil with various beneficial pharmacological effects. This study was designed to investigate the potential protective effect of AO supplementation as pre-treatment or co-treatment on sodium fluoride (NaF)-induced nephrotoxicity in rats. Male Sprague Dawley rats (n = 50) were randomly assigned to one of five equal groups: control group, AO-treated group (6 ml/kg b.wt.), NaF-treated group (20 mg/kg b.wt.), pre-treated group, and co-treated group. All rats were daily administered by oral gavage for duration of 30 days. The results showed that AO administration significantly improved renal function and antioxidant status and decreased the lipid peroxidation in NaF-treated rats. Additionally, AO normalized the renal levels of inflammatory markers and mRNA expression level of the intermediate filament protein genes, indicating NaF-induced podocyte damage was ameliorated. Histopathological evaluation of the kidney confirmed the before mentioned biochemical results. AO counteracted the nephrotoxic effects of NaF in rats particularly at co-exposure. These results concluded that AO administration exhibited a significant nephroprotective effect against renal injury induced by NaF in rats.

Bioactive Variability and In Vitro and In Vivo Antioxidant Activity of Unprocessed and Processed Flour of Nine Cultivars of Australian lupin Species: A Comprehensive Substantiation

The aim of this present investigation was to analyze bioactive compounds, as well as demonstrate the antioxidant activities of nine cultivars of Australian lupin species accompanied by observing the effect of domestic heat processing on their antioxidant activities adopting in vivo and in vitro approaches. Gas chromatography mass spectroscopy (GC-MS) analysis was performed for profiling bioactive compounds present in lupin cultivars. Multiple assay techniques involving quantification of polyphenolics, flavonoids and flavonol, electron transfer (ET) based assay, hydrogen atom transfer (HAT)-based assay and in vivo assays were performed. The major compounds found were hexadecanoic acid methyl ester, 9,12-octadecadienoic acid methyl ester, methyl stearate, lupanine,13-docosenamide and 11-octadecenoic acid (Z)- methyl ester. Mandelup was found to show excellent antioxidant activity. Moreover, Jurien, Gunyidi and Barlock had strong antioxidant activity. Both positive and negative impacts of heat processing were observed on antioxidant activity. Heating and usage of excess water during processing were the key determinants of loss of antioxidants. Negligible loss of antioxidant activity was observed in most of the assays whereas inhibition of both lipid peroxidation (33.53%) and hemolysis of erythrocytes (37.75%) were increased after processing. In addition, in vitro and in vivo antioxidant assays are found to show statistically significant (* p < 0.05 and ** p < 0.01) results, which are supported by the presence of a number of antioxidant compounds in GC-MS analysis.

Fluoride contamination, health problems and remediation methods in Asian groundwater: A comprehensive review

In low concentration, fluoride is considered a necessary compound for human health. Exposure to high concentrations of fluoride is the reason for a serious disease called fluorosis. Fluorosis is categorized as Skeletal and Dental fluorosis. Several Asian countries, such as India, face contamination of water resources with fluoride. In this study, a comprehensive overview on fluoride contamination in Asian water resources has been presented. Since water contamination with fluoride in India is higher than other Asian countries, a separate section was dedicated to review published articles on fluoride contamination in this country. The status of health effects in Asian countries was another topic that was reviewed in this study. The effects of fluoride on human organs/systems such as urinary, renal, endocrine, gastrointestinal, cardiovascular, brain, and reproductive systems were another topic that was reviewed in this study. Different methods to remove fluoride from water such as reverse osmosis, electrocoagulation, nanofiltration, adsorption, ion-exchange and precipitation/coagulation were introduced in this study. Although several studies have been carried out on contamination of water resources with fluoride, the situation of water contamination with fluoride and newly developed technology to remove fluoride from water in Asian countries has not been reviewed. Therefore, this review is focused on these issues: 1) The status of fluoride contamination in Asian countries, 2) health effects of fluoride contamination in drinking water in Asia, and 3) the existing current technologies for defluoridation in Asia.

Fluoride Exposure Induces Inhibition of Sodium-and Potassium-Activated Adenosine Triphosphatase (Na+, K+-ATPase) Enzyme Activity: Molecular Mechanisms and Implications for Public Health

In this study, several lines of evidence are provided to show that Na + , K + -ATPase activity exerts vital roles in normal brain development and function and that loss of enzyme activity is implicated in neurodevelopmental, neuropsychiatric and neurodegenerative disorders, as well as increased risk of cancer, metabolic, pulmonary and cardiovascular disease. Evidence is presented to show that fluoride (F) inhibits Na + , K + -ATPase activity by altering biological pathways through modifying the expression of genes and the activity of glycolytic enzymes, metalloenzymes, hormones, proteins, neuropeptides and cytokines, as well as biological interface interactions that rely on the bioavailability of chemical elements magnesium and manganese to modulate ATP and Na + , K + -ATPase enzyme activity. Taken together, the findings of this study provide unprecedented insights into the molecular mechanisms and biological pathways by which F inhibits Na + , K + -ATPase activity and contributes to the etiology and pathophysiology of diseases associated with impairment of this essential enzyme. Moreover, the findings of this study further suggest that there are windows of susceptibility over the life course where chronic F exposure in pregnancy and early infancy may impair Na + , K + -ATPase activity with both short- and long-term implications for disease and inequalities in health. These findings would warrant considerable attention and potential intervention, not to mention additional research on the potential effects of F intake in contributing to chronic disease.

HPLC Analysis and In Vivo Renoprotective Evaluation of Hydroalcoholic Extract of Cucumis melo Seeds in Gentamicin-Induced Renal Damage

Background and objectives: Cucumis melo, of family Cucurbitaceae, has traditionally been used to treat variety of kidney disorders. However to best of our knowledge there is no scientific study available that validates its renaoprotective uses. Therefore, this study aimed to evaluate nephroprotective effects of hydroalcoholic extract of Cucumis melo seeds (CMHE) and to identify its phytoconstituents. Materials and Methods: HPLC was performed to identify key phytochemicals of CMHE. Gentamicin (100 mg/kg/day, i.p) was administered to induce nephrotoxicity in Swiss albino mice for 8 days. Gentamicin (100 mg/kg/day, i.p) and oral CMHE were co-administered to mice at doses of 250 and 500 mg/kg to evaluate protective effects of CMHE. Normal control group mice were administered normal saline. Changes in body weights, biochemical and histopathological studies were conducted to establish nephroprotective effects of CMHE. Results: HPLC analysis indicated presence of quercetin, m-coumaric acid, gallic acid, chlorogenic acid, and trans-4-hydroxy-3-methoxy cinnamic acid in CMHE. Mice treated with CMHE showed significant increase in body weight and decrease in kidney weight as compared with toxic control group. Dose-dependent significant decrease in total blood urea nitrogen, serum creatinine, serum urea, and uric acid levels were observed in CMHE-treated groups as compared with toxic control group. Histopathological analysis of CMHE-treated groups showed improvement in kidney structures as compared with toxic control group. Conclusions: Biochemical, histopathological, and phytochemical screening of hydroalcoholic extract of Cucumis melo seeds suggest that it has nephroprotective potential. Furthermore, standardization of extract against identified phytochemicals, as well as long-term toxicological studies are suggested before commencement of clinical trials.

Gallic acid ameliorates sodium arsenite-induced renal and hepatic toxicity in rats

Chronic exposure to toxic inorganic arsenic results in the adverse health effects including skin lesions, cardiovascular diseases, diabetes, neurological disorders, and liver and kidney diseases. Gallic acid (GA) is an important phenolic compound, which could protect different tissues from oxidative stress induced damage. The present study investigated effects of GA against sodium arsenite (SA)-induced renal and hepatic toxicity. Thirty-five rats were randomly divided in to five groups; group 1 was treated with normal saline (2 ml/kg/day, p.o.; for 21 days); group 2 was exposed to SA (10 mg/kg/day, p.o.; for 14 days); groups 3 and 4 were treated with GA (10 and 30 mg/kg/day, respectively; for 7 days) prior to exposure to SA, and treatment was continued up to 21 days in parallel with SA administration; group 5 was treated with GA (30 mg/kg/day, p.o.; for 21 days). The level of MDA, IL-1β, NO and glutathione (GSH) and the activity of glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) were evaluated in kidney and liver tissues. Histopathological parameters and serum levels of ALT, AST, ALP, Cr and BUN were also assessed. Treatment with GA remarkably improved SA-induced alteration of hematological and histopathological parameters; these protective effects were associated with the reduction of SA-induced elevation of MDA, IL-1β and NO levels as well as reduction of GSH level and GPx, SOD and CAT activity. Our results suggest that GA may inhibit SA-induced kidney and liver toxicity through scavenging reactive free radicals and increasing intracellular antioxidant capacity.

Molecular targets of curcumin in breast cancer (Review)

Curcumin (diferuloylmethane), an orange‑yellow component of turmeric or curry powder, is a polyphenol natural product isolated from the rhizome of Curcuma longa. For centuries, curcumin has been used in medicinal preparations and as a food colorant. In recent years, extensive in vitro and in vivo studies have suggested that curcumin possesses activity against cancer, viral infection, arthritis, amyloid aggregation, oxidation and inflammation. Curcumin exerts anticancer effects primarily by activating apoptotic pathways in cancer cells and inhibiting pro‑cancer processes, including inflammation, angiogenesis and metastasis. Curcumin targets numerous signaling pathways associated with cancer therapy, including pathways mediated by p53, Ras, phosphatidylinositol‑3‑kinase, protein kinase B, Wnt‑β catenin and mammalian target of rapamycin. Clinical studies have demonstrated that curcumin alone or combined with other drugs exhibits promising anticancer activity in patients with breast cancer without adverse effects. In the present review, the chemistry and bioavailability of curcumin and its molecular targets in breast cancer are discussed. Future research directions are discussed to further understand this promising natural product.

Role of Some Natural Antioxidants in the Modulation of Some Proteins Expressions against Sodium Fluoride-Induced Renal Injury

Background

The aim of the present work is to find the effects of N-acetylcysteine (NAC) and/or thymoquinone (THQ) in the protection against acute renal injury induced by sodium fluoride (NaF).

Method

Rats were distributed into five groups: G1 was normal (control), G2 was intoxicated with 10mg/kg NaF i.p., G3 was treated with 10mg THQ /kg, G4 was treated with 20mg NAC /kg, and G5 was treated with a combination of THQ and NAC. The previous treatments were given daily along with NaF for four weeks orally.

Result

Rats intoxicated with NaF showed a significant increase in serum urea, creatinine, uric acid, renal lipid peroxidation, nitric oxide, and TNF-α levels, whereas the activity of superoxide dismutase (SOD) and glutathione (GSH) level was reduced. The expressions of Toll-like receptor-4 (TLR4), Lipocalin, vascular adhesion molecule-1(VCAM-1), and BAX proteins were upregulated, whereas Bcl-2 and NF-E2-related factor 2 (Nrf2) proteins expressions were downregulated. DNA fragmentation was also amplified. Histological analysis revealed that NaF caused a destructive renal cortex in the form of the glomerular corpuscle, the obliterated proximal and distal convoluted tubules, vacuolization in tubular cells focal necrosis, and cell infiltration. THQ and NAC supplementation counteracted NaF-induced nephrotoxicity as reflected by the increase in renal GSH and SOD. THQ and NAC ameliorated all the altered proteins expressions, improved renal architecture, and declined DNA fragmentation.

Conclusion

The role of oxidative stress in the enhancement of NaF toxicity suggested the renoprotective effects of NAC and THQ against the toxicity of fluoride via multiple mechanisms.

The impact of gallic acid on the methotrexate-induced kidney damage in rats

Prolonged use of an antineoplastic agent methotrexate (MTX), can cause numerous side effects such as nephrotoxicity. The aim of this study was to examine the effects of MTX on kidneys and demonstrate the protective effects of gallic acid (GA). Twenty-four, male, rats distributed into three groups. Each groups consisted eight rats and only saline was administered to the control group. The MTX group received a single dose (20 mg/kg) MTX intraperitoneally. The MTX + GA group received same dose MTX and 100 mg/kg GA orally during the 7 days. Renal functions, oxidative stress markers, histopathological and immunohistochemical changes were evaluated at the end of the experiment. Blood urea nitrogen, creatinine, uric acid levels and tissue oxidative stress markers, total oxidant status and oxidative stress index levels significantly increased and total antioxidant status levels significantly decreased in MTX group compared with the control group. At the histopathological examination hemorrhages, tubular cell necrosis, glomerulosclerosis, inflammatory cell infiltrations and proteinous materials in tubules were noticed in MTX group. Immunohistochemical examination revealed that increased expressions of serum amyloid A (SAA), tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE-2) and C-reactive protein (CRP) in tubular epithelial cells of kidneys in this group. There were no immunoreaction with SAA and CRP, only small number of PGE-2 and TNF-α positive tubular epithelial cells were observed in MTX + GA group. In conclusion, all evidence suggested that oxidative stress caused MTX-induced nephrotoxicity and GA prevent the kidney from the nephrotoxicity due to its antioxidant and anti-inflammatory activities.

Enantioselective Modulatory Effects of Naringenin Enantiomers on the Expression Levels of miR-17-3p Involved in Endogenous Antioxidant Defenses

Naringenin is a flavanone present in citrus fruit as a mixture of chiral isomers. The numerous biological properties attributed to this compound include antioxidant and anti-inflammatory activities, even though the molecular mechanisms of these remain unknown. This study aims to evaluate the effects of racemic and enantiomeric naringenin on the expression levels of miR-17-3p, miR-25-5p and relative mRNA targets, to elucidate the mechanisms underlying these antioxidant and anti-inflammatory properties. Caco-2 cells, a well characterized in vitro model which mimics the intestinal barrier, were treated with subtoxic concentrations of racemate and enantiomers. The expression levels of miR-17-3p and miR-25-5p were determined by Real-Time PCR and were found to be decreased for both miRNAs. miR-17-3p behavior was in agreement with the increased levels of target mRNAs coding for two antioxidant enzymes, manganese-dependent superoxide dismutase (MnSOD) and glutathione peroxidase 2 (GPx2), while expression levels of miR-25-5p were not in agreement with its target mRNAs, coding for two pro-inflammatory cytokines, Tumor necrosis factor-alpha (TNF-α) and Interleukin-6 (IL-6). These results lead to the conclusion that naringenin could exert its antioxidant activity through epigenetic regulation operated by miRNAs, while anti-inflammatory activity is regulated by other miRNAs and/or mechanisms.

Antioxidant and Nephroprotective Activities of the Extract and Fractions of Homonoia riparia Lour

BACKGROUND

Homonoia riparia is a plant, which is widely used in the indigenous system of medicine for the treatment of urolithiasis, renal disorders and inflammatory conditions. This is the first report on the antioxidant and nephroprotective activities of whole plant of H. riparia.

OBJECTIVE

The present study aims at investigating the in vitro antioxidant and nephroprotective activity of the methanol extract and its different fractions of H. riparia.

METHODS

Petroleum ether (HRPE), Ethyl acetate (HREA), Butanol (HRBU), aqueous fractions (HRAQ) were prepared from the crude methanol extract of H. riparia (HRM) using liquid partitioning. Total phenolic content, flavonoid content and antioxidant activity assay were performed according to suitable methods. Nephroprotective activities were evaluated by MTT assay using Human Embryonic Kidney cells against cisplatin induced toxicity. Quantification of gallic acid was performed using validated HPTLC method.

RESULTS

The studies showed that extract and fractions possess significant nephroprotective activity against cisplatin induced renal toxicity. All the extracts/fractions of whole plant of Homonoia riparia was found to be significantly reducing cisplatin induced toxicity (< 0.05). The highest activity was observed with HRBU and HRAQ with a percentage viability of 293.09 ± 4.3 and 345.07 ± 3.2 at a concentration of 200 µg/ml. Gallic acid was detected in the HRM/fractions using HPTLC.

SUMMARY

Cisplatin (8 μg/ml) exhibited 50 % inhibition in cell viability in HEK 293 cellsButanol and aqueous fractions of Homonoia riparia showed significant nephroprotective activity against cisplatin induced cell damage in HEK cells.Gallic acid was detected and quantified in the extract and fractions of whole plant of Homonoia ripariaAbbreviations used: HPTLC: High Performance Thin Layer Chromatography, DPPH: 1,1-diphenyl-2-picrylhydrazyl, ABTS: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, MTT: 3-(4,5-dimethylthiazolyl-2-yl)-2,5- diphenyl tetrazolium bromide, GAE: Gallic acid equivalents, QE: Quercetin equivalents, HEK: Human Embryonic Kidney, HRM: Methanol extract of H. riparia, HRPE: Petroleum ether fraction of H. riparia, HREA: ethyl acetate fraction of H. riparia, HRBU: Butanol fraction of H. riparia, HRAQ: Aqueous fraction of H. riparia, DMEM: Dulbecco's minimum essential medium, FBS: Foetal bovine serum, DMSO: Dimethyl sulfoxide, ANOVA: One way analysis of variance.

Taurine Ameliorates Renal Oxidative Damage and Thyroid Dysfunction in Rats Chronically Exposed to Fluoride

Excessive exposure to fluoride poses several detrimental effects to human health particularly the kidney which is a major organ involved in its elimination from the body. The influence of taurine on fluoride-induced renal toxicity was investigated in a co-exposure paradigm for 45 days using five groups of eight rats each. Group I rats received normal drinking water alone, group II rats were exposed to sodium fluoride (NaF) in drinking water at 15 mg/L alone, group III received taurine alone at a dose of 200 mg/kg group IV rats were co-administered with NaF and taurine (100 mg/kg), while group V rats were co-administered with NaF and taurine (200 mg/kg). Administration of taurine significantly reversed the fluoride-mediated decrease in absolute weight and organo-somatic index of the kidney in the exposed rats. Taurine significantly prevented fluoride-induced elevation in plasma urea and creatinine levels in the exposed rats. Moreover, taurine restored fluoride-mediated decrease in the circulatory concentrations of triiodothyronine, thyroxine, and the ratio of triiodothyronine to thyroxine. Taurine ameliorated fluoride-mediated decrease in renal antioxidant status by significantly enhancing the antioxidant enzyme activities as well as glutathione level in the exposed rats. Additionally, taurine inhibited fluoride-induced renal oxidative damage by markedly decreasing the hydrogen peroxide and malondialdehyde levels as well as improved the kidney architecture in the treated rats. Collectively, taurine protected against fluoride-induced renal toxicity via enhancement of thyroid gland function, renal antioxidant status, and histology in rats.

Post-Stroke Depression Modulation and in Vivo Antioxidant Activity of Gallic Acid and Its Synthetic Derivatives in a Murine Model System

Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is a plant secondary metabolite, which shows antioxidant activity and is commonly found in many plant-based foods and beverages. Recent evidence suggests that oxidative stress contributes to the development of many human chronic diseases, including cardiovascular and neurodegenerative pathologies, metabolic syndrome, type 2 diabetes and cancer. GA and its derivative, methyl-3-O-methyl gallate (M3OMG), possess physiological and pharmacological activities closely related to their antioxidant properties. This paper describes the antidepressive-like effects of intraperitoneal administration of GA and two synthetic analogues, M3OMG and P3OMG (propyl-3-O-methylgallate), in balb/c mice with post-stroke depression, a secondary form of depression that could be due to oxidative stress occurring during cerebral ischemia and the following reperfusion. Moreover, this study determined the in vivo antioxidant activity of these compounds through the evaluation of superoxide dismutase (SOD) and catalase (Cat) activity, thiobarbituric acid-reactive substances (TBARS) and reduced glutathione (GSH) levels in mouse brain. GA and its synthetic analogues were found to be active (at doses of 25 and 50 mg/kg) in the modulation of depressive symptoms and the reduction of oxidative stress, restoring normal behavior and, at least in part, antioxidant endogenous defenses, with M3OMG being the most active of these compounds. SOD, TBARS, and GSH all showed strong correlation with behavioral parameters, suggesting that oxidative stress is tightly linked to the pathological processes involved in stroke and PSD. As a whole, the obtained results show that the administration of GA, M3OMG and P3OMG induce a reduction in depressive symptoms and oxidative stress.

Effect of Winemaking on the Composition of Red Wine as a Source of Polyphenols for Anti-Infective Biomaterials

Biomaterials releasing bactericides have currently become tools for thwarting medical device-associated infections. The ideal anti-infective biomaterial must counteract infection while safeguarding eukaryotic cell integrity. Red wine is a widely consumed beverage to which many biological properties are ascribed, including protective effects against oral infections and related bone (osteoarthritis, osteomyelitis, periprosthetic joint infections) and cardiovascular diseases. In this study, fifteen red wine samples derived from grapes native to the Oltrepò Pavese region (Italy), obtained from the winemaking processes of “Bonarda dell’Oltrepò Pavese” red wine, were analyzed alongside three samples obtained from marc pressing. Total polyphenol and monomeric anthocyanin contents were determined and metabolite profiling was conducted by means of a chromatographic analysis. Antibacterial activity of wine samples was evaluated against Streptococcus mutans, responsible for dental caries, Streptococcus salivarius, and Streptococcus pyogenes, two oral bacterial pathogens. Results highlighted the winemaking stages in which samples exhibit the highest content of polyphenols and the greatest antibacterial activity. Considering the global need for new weapons against bacterial infections and alternatives to conventional antibiotics, as well as the favorable bioactivities of polyphenols, results point to red wine as a source of antibacterial substances for developing new anti-infective biomaterials and coatings for biomedical devices.

Polyphenolic Composition of Crataegus monogyna Jacq.: From Chemistry to Medical Applications

The abundance of scientific evidence has shown that many synthetic drugs can cause serious adverse effects in patients. Recently, the search of natural therapeutic agents with low adverse effects has attracted much attention. In particular, considerable interest has focused on edible and medicinal plants, which play an important role in human diet, and have been used for disease treatment since ancient times. Crataegus monogyna Jacq. (hawthorn) is one of the most important edible plants of the Rosaceae family and is also used in traditional medicine. Growing evidence has shown that this plant has various interesting physiological and pharmacological activities due to the presence of different bioactive natural compounds. In addition, scientific evidence suggests that the toxicity of hawthorn is negligible. Therefore, the aim of this paper is to provide a critical review of the available scientific literature about pharmacological activities as well as botanical aspects, phytochemistry and clinical impacts of C. monogyna.

Therapeutic Potential of Dietary Phenolic Acids

Although modern lifestyle has eased the quality of human life, this lifestyle's related patterns have imparted negative effects on health to acquire multiple diseases. Many synthetic drugs are invented during the last millennium but most if not all of them possess several side effects and proved to be costly. Convincing evidences have established the premise that the phytotherapeutic potential of natural compounds and need of search for novel drugs from natural sources are of high priority. Phenolic acids (PAs) are a class of secondary metabolites spread throughout the plant kingdom and generally involved in plethora of cellular processes involved in plant growth and reproduction and also produced as defense mechanism to sustain various environmental stresses. Extensive research on PAs strongly suggests that consumption of these compounds hold promise to offer protection against various ailments in humans. This paper focuses on the naturally derived PAs and summarizes the action mechanisms of these compounds during disease conditions. Based on the available information in the literature, it is suggested that use of PAs as drugs is very promising; however more research and clinical trials are necessary before these bioactive molecules can be made for treatment. Finally this review provides greater awareness of the promise that natural PAs hold for use in the disease prevention and therapy.

Gallic acid ameliorates renal functions by inhibiting the activation of p38 MAPK in experimentally induced type 2 diabetic rats and cultured rat proximal tubular epithelial cells

Diabetic nephropathy (DN) is one of the leading causes of morbidity and mortality in diabetic patients that accounts for about 40% of deaths in type 2 diabetes. p38 mitogen activated protein kinase (p38 MAPK), a serine-threonine kinase, plays an important role in tissue inflammation and is known to be activated under conditions of oxidative stress and hyperglycemia. The role of p38 MAPK has been demonstrated in DN, and its inhibition has been suggested as an alternative approach in the treatment of DN. In the present study, we investigated the nephroprotective effects of an anti-inflammatory phenolic compound, gallic acid (GA, 3,4,5-trihydroxybenzoic acid), in high fat diet/streptozotocin (HFD/STZ) induce type 2 diabetic wistar albino rats. GA (25 mg/kgbw and 50 mg/kgbw, p.o.) treatment for 16 weeks post induction of diabetes led to a significant reduction in the levels of blood glucose, HbA1c, serum creatinine, blood urea nitrogen and proteinuria as well as a significant reduction in the levels of creatinine clearance. GA significantly inhibited the renal p38 MAPK and nuclear factor kappa B (N-κB) activation as well as significantly reduced the levels of renal transforming growth factor beta (TGF-β) and fibronectin. Treatment with GA resulted in a significant reduction in the serum levels of proinflammatory cytokines viz. interleukin 1 beta (IL-1β), IL-6 and tumor necrosis factor alpha (TNF-α). Moreover, GA significantly lowered renal pathology and attenuated renal oxidative stress. In cultured rat NRK 52E proximal tubular epithelial cells, GA treatment inhibited high glucose induced activation of p38 MAPK and NF-κB as well as suppressed proinflammatory cytokine synthesis. The results of the present study provide in vivo and in vitro evidences that the p38 MAPK pathway plays an important role in the pathogenesis of DN, and GA attenuates the p38 MAPK-mediated renal dysfunction in HFD/STZ induced type 2 diabetic rats.

Effects of Fluoride on DNA Damage and Caspase-Mediated Apoptosis in the Liver of Rats

Fluoride compounds are abundant and widely distributed in the environment at a variety of concentrations. Further, fluoride induces toxic effects in target organs such as the liver. In this study, we investigated liver histopathology, DNA damage, apoptosis, and the mRNA and protein expressions of caspase-3 and -9 in the rat livers by administering varying concentrations of fluoride (0, 50, 100, 200 mg/L ) for 120 days. The results showed fluoride-induced morphological changes and significantly increased apoptosis and DNA damage in rats exposed to fluoride, especially in response to higher doses. The immunohistochemical and qRT-PCR results indicated that caspase-3, caspase-9 protein positive expression and mRNA relative expression enhanced with increasing NaF concentration. In summary, our findings suggest that chronic exposure to fluoride causes damages to liver histopathology and leads to liver apoptosis through caspase-mediated pathways.

Gallic acid induces necroptosis via TNF-α signaling pathway in activated hepatic stellate cells

Gallic acid (3, 4, 5-trihydroxybenzoic acid, GA), a natural phenolic acid widely found in gallnuts, tea leaves and various fruits, possesses several bioactivities against inflammation, oxidation, and carcinogenicity. The beneficial effect of GA on the reduction of animal hepatofibrosis has been indicated due to its antioxidative property. However, the cytotoxicity of GA autoxidation causing cell death has also been reported. Herein, we postulated that GA might target activated hepatic stellate cells (aHSCs), the cell type responsible for hepatofibrosis, to mitigate the process of fibrosis. The molecular cytotoxic mechanisms that GA exerted on aHSCs were then analyzed. The results indicated that GA elicited aHSC programmed cell death through TNF–α–mediated necroptosis. GA induced significant oxidative stress through the suppression of catalase activity and the depletion of glutathione (GSH). Elevated oxidative stress triggered the production of TNF–α facilitating the undergoing of necroptosis through the up-regulation of key necroptotic regulatory proteins TRADD and receptor-interacting protein 3 (RIP3), and the inactivation of caspase–8. Calmodulin and calpain–1 activation were engaged, which promoted subsequent lysosomal membrane permeabilization (LMP). The TNF–α antagonist (SPD–304) and the RIP1 inhibitor (necrostatin–1, Nec–1) confirmed GA-induced TNFR1–mediated necroptosis. The inhibition of RIP1 by Nec–1 diverted the cell death from necroptosis to apoptosis, as the activation of caspase 3 and the increase of cytochrome c. Collectively, this is the first report indicating that GA induces TNF signaling–triggered necroptosis in aHSCs, which may offer an alternative strategy for the amelioration of liver fibrosis.

Gallic acid and methyl-3-O-methyl gallate: a comparative study on their effects on prostate cancer stem cells

The study shows the different ability of gallic acid and methyl-3-O-methyl gallate to inhibit NF-κB activity and the growth of PCa cells with stem-like properties.

Gallic acid: a versatile antioxidant with promising therapeutic and industrial applications

Oxidative stress, a result of an overproduction and accumulation of free radicals, is the leading cause of several degenerative diseases such as cancer, atherosclerosis, cardiovascular diseases, ageing and inflammatory diseases.

Interactions of the active components of Punica granatum (pomegranate) with the essential renal and hepatic human Solute Carrier transporters

Abstract Context: Solute carrier transporters (SLCs) are membrane proteins responsible for cellular influx of various substances including many pharmaceutical agents; therefore, they largely impact on drug disposition and elimination in body. Punica granatum Linnaeus (Lythraceae), pomegranate, is a fruit with antidiabetic potential. Oleanolic acid (OA), ursolic acid (UA), and gallic acid (GA) are the major bioactive components of pomegranate. Co-administration of these compounds with other drugs could result in altered drug pharmacokinetics, possibly due to competing for transporter proteins.

OBJECTIVE

We investigated the interactions of these three compounds with the essential hepatic and renal SLC transporters.

MATERIALS AND METHODS

Uptake of radiolabeled transporter model substrates was assessed in HEK293 cells over-expressing SLC transporters including the organic anion transporters (OATs), organic anion transporting polypeptides (OATPs) and organic cation transporters (OCTs), in the presence or absence of 10.0 µM UA, OA, or GA. Their IC50 values on specific SLC transporters were also evaluated using varying concentrations of the particular compound (ranging from 0.10 nM to 80.0 µM).

RESULTS

Our results demonstrated UA could significantly inhibit OAT3 and OATP2B1 uptake (IC50: 18.9 ± 8.20 µM and 11.0 ± 5.00 µM, respectively) and GA has a pronounced inhibitory effect on OATP1B3 uptake (IC50: 1.60 ± 0.60 μM).

DISCUSSION AND CONCLUSION

Our study reports the interactions of OA, UA, and GA with the essential SLC transporters. This information may contribute to elucidating the drug-drug/herb interactions involved with these three compounds and form the basis of therapeutic optimization when drugs are co-administered.

Modulation of human miR-17-3p expression by methyl 3-O-methyl gallate as explanation of its in vivo protective activities

SCOPE

Methyl-3-O-methyl gallate (M3OMG) possesses in vivo antioxidant activity due to the partial restoration of the antioxidant enzymes, whose expression is altered in oxidative stress. Literature data suggest that miR-17-3p is a microRNA involved in the regulation of cellular redox status, interfering with transcription of the mRNAs responsible for the synthesis of antioxidant enzymes. To obtain deeper insight into the potential mechanism of action of M3OMG, the aim of this study was to investigate its effect on the expression levels of miR-17-3p in human cells.

METHODS AND RESULTS

Peripheral blood mononuclear cells and EVC-304 cells were treated with increasing subtoxic concentrations of M3OMG. The expression levels of miR-17-3p, extracted from cells and exosomes, were determined by quantitative real-time PCR. M3OMG induced a decrease in the miR-17-3p levels, and an increase in the levels of mRNA coding for the antioxidant enzymes, when compared to the control samples. Differently, in exosomes the expression levels of miR-17-3p were depended on the compound, its concentration, and the type of cell.

CONCLUSION

These results suggest a potential mechanism of action of M3OMG that, inducing the reduction of the levels of miR-17-3p and the increase of mRNA coding for antioxidant enzymes, allows to these latter to perform their protective effects.

Epigallocatechin gallate supplementation protects against renal injury induced by fluoride intoxication in rats: Role of Nrf2/HO-1 signaling

Fluoride intoxication generates free radicals, causing oxidative stress that plays a critical role in the progression of nephropathy. In the present study, we hypothesized that epigallocatechin gallate (EGCG), found in green tea, protects the kidneys of rats treated with fluoride by preventing oxidative stress, inflammation, and apoptosis. Pretreatment of fluoride-treated rats with EGCG resulted in a significant normalization of creatinine clearance and levels of urea, uric acid, and creatinine. Fluoride intoxication significantly increased renal oxidative stress markers and decreased the levels of renal enzymatic and non-enzymatic antioxidants. In addition, renal NO, TNF-α, IL-6 and NF-κB were also increased in the renal tissue of fluoride-treated rats. Further, EGCG pretreatment produced a significant improvement in renal antioxidant status and reduced lipid peroxidation, protein carbonylation and the levels of inflammatory markers in fluoride-treated kidney. Similarly, mRNA and protein analyses showed that EGCG pretreatment normalized the renal expression of Nrf2/Keap1 and its downstream regulatory proteins in fluoride-treated rat kidney. EGCG also effectively attenuated fluoride-induced renal apoptosis by the up-regulation of anti-apoptotic proteins such as Bcl-2 and down-regulation of Bax, caspase-3, caspase-9 and cytochrome c. Histology and immunohistochemical observations of Kim-1 provided further evidence that EGCG effectively protects the kidney from fluoride-mediated oxidative damage. These results suggest that EGCG ameliorates fluoride-induced oxidative renal injury by activation of the Nrf2/HO-1 pathway.