Antioxidant and anti-inflammatory mechanisms of polyphenols isolated from virgin coconut oil attenuate cadmium-induced oxidative stress-mediated nephrotoxicity and inflammation in rats

Naringenin blocks hepatic cadmium accumulation and suppresses cadmium-induced hepatotoxicity via amelioration of oxidative inflammatory signaling and apoptosis in rats

Liver is one of the targets of cadmium (Cd) bioaccumulation for hepatic damage and pathologies via oxidative inflammation and apoptosis. The current study explored whether the citrus flavonoid naringenin (NAR) could prevent hepatic accumulation of Cd and Cd hepatotoxicity in a rat model. Rats in group 1 received normal saline; group 2 received NAR (50 mg/kg body weight); group 3 received CdCl2 (5 mg/kg body weight); group 4 received NAR + CdCl2, for four consecutive weeks. Assays related to markers of oxidative stress, inflammation, and apoptosis were carried out using liver homogenate. Blood and liver sample analyses revealed significant elevation of blood and hepatic Cd levels coupled with prominent increases in alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities, whereas the albumin and total protein levels were decreased considerably. Hepatic superoxide dismutase (SOD), catalase (CAT), glutathione peroxide (GPx) activities diminished significantly compared to control followed by marked increases in malondialdehyde (MDA) levels, and dysregulation in caspase and cytokine (TNF-α, IL-6, IL-4, IL-10) levels. However, it was found that in the rats administered NAR + Cd, the levels of Cd, hepatic enzymes, MDA, TNF-α, IL-6, and caspases-3/-9 were prominently reduced compared to the Cd group. The hepatic SOD, CAT, GPx, IL-4, IL-10, albumin, and total protein were markedly elevated along with alleviated hepatic histopathological abrasions. Taken together therefore, NAR is a potential flavonoid for blocking hepatic Cd bioaccumulation and consequent inhibition of Cd-induced oxidative inflammation and apoptotic effects on the liver of rats.

Delineating the protective action of cordycepin against cadmium induced oxidative stress and gut inflammation through downregulation of NF-κB pathway

Cadmium (Cd) exposure is known to cause gut inflammation. In this study, we investigated the protective effects of cordycepin, a natural compound with pharmacological properties, against gut inflammation induced by Cd exposure. Using zebrafish larvae and colon cell line models, we examined the impact of cordycepin on Cd-induced toxicity and inflammation. Zebrafish larvae were exposed to Cd (2 µg/mL) and treated with different concentrations of cordycepin (12.5, 25 and 50 µg/mL). Cordycepin treatment significantly reduced Cd-induced embryotoxicity in zebrafish larvae. It also alleviated Cd-induced oxidative stress by reducing reactive oxygen species (ROS), lipid peroxidation and apoptosis. Furthermore, cordycepin treatment normalized the levels of liver-related biomarkers affected due to Cd exposure. Additionally, cordycepin (50 µg/mL) demonstrated a significant reduction in Cd bioaccumulation and downregulated the expression of inflammatory genes in both zebrafish larval gut and colon cell lines. These findings suggest that cordycepin could be an effective agent against Cd-induced gut inflammation.

Extra virgin coconut oil (Cocos nucifera L.) intake shows neurobehavioural and intestinal health effects in obesity-induced rats

The present study aimed to evaluate the effect of E-VCO on the neurobehaviour and intestinal health parameters of obesity-induced rats, focusing on food consumption, body composition, bacterial and faecal organic acids and histological analyses in the hippocampus and colon. A total of 32 male Wistar rats were randomized into healthy (HG, n = 16) and obese groups (OG, n = 16), which consumed a control or cafeteria diet for eight weeks, respectively. After this period, they were subdivided into four groups: healthy (HG, n = 8); healthy treated with E-VCO (HGCO, n = 8); obese (OG, n = 8); obese treated with E-VCO (OGCO, n = 8), continuing for another eight weeks with their respective diets. The treated groups received 3000 mg kg^-1 of E-VCO and control groups received water via gavage. Food preference, body weight gain, body composition, anxiety- and depression-like behaviour were evaluated. Bacteria and organic acids were evaluated in faeces, and histological analyses of the hippocampus and M1 and M2 macrophages in the colon were performed. E-VCO reduced energy intake (16.68%) and body weight gain (16%), although it did not reduce the fat mass of obese rats. E-VCO showed an antidepressant effect, increased lactic acid bacteria counts and modulated organic acids in obese rats. Furthermore, E-VCO protected the hippocampus from neuronal degeneration caused by the obesogenic diet, decreased the M1 macrophage and increased the M2 macrophage population in the gut. The results suggest neurobehavioural modulation and improved gut health by E-VCO, with promising effects against obesity-related comorbidities.

Beneficial effects of phenolic compounds: native phenolic compounds vs metabolites and catabolites

In the human body, the positive effects of phenolic compounds are increasingly observed through their presence in tissues and organs in their native form or in the form of metabolites or catabolites formed during digestion, microbial metabolism, and host biotransformation. The full extent of these effects is still unclear. The aim of this paper is to review the current knowledge of beneficial effects of native phenolic compounds or their metabolites and catabolites focusing on their role in the health of the digestive system, including disorders of the gastrointestinal and urinary tracts and liver. Studies are mostly connecting beneficial effects in the gastrointestinal and urinary tract to the whole food rich in phenolics, or to the amount of phenolic compounds/antioxidants in food. Indeed, the bioactivity of parent phenolic compounds should not be ignored due to their presence in the digestive tract, and the impact on the gut microbiota. However, the influence of their metabolites and catabolites might be more important for the liver and urinary tract. Distinguishing between the effects of parent phenolics vs metabolites and catabolites at the site of action are important for novel areas of food industry, nutrition and medicine.

Asperuloside attenuates cadmium-induced toxicity by inhibiting oxidative stress, inflammation, fibrosis and apoptosis in rats

This present study investigated the protective effects of asperuloside (ASP) against cadmium-induced nephrocardiac toxicity. Rats were treated with 50 mg/kg of ASP for five weeks and CdCl2 (5 mg/kg, p.o., once daily) during the last 4 weeks of ASP treatment. The serum levels of blood urea nitrogen (BUN), creatinine (Scr), aspartate transaminase (AST), creatine kinase-MB (CK-MB), troponin T (TnT) and lactate dehydrogenase (LDH) were evealuted. Oxido-inflammatory parameters were detected via malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), interleukin-1beta (IL-1β) and nuclear factor kappa B (NF-κB). Additionally, the cardiorenal levels of caspase 3, transforming growth factor-β (TGF-β), α-smooth muscle actin (α-SMA), collagen IV and Bcl2 were measured by ELISA or immunohistochemical assays. The results indicated that ASP significantly decreased Cd-instigated oxidative stress, serum BUN, Scr, AST, CK-MB, TnT and LDH as well as histopathological alterations. Furthermore, ASP notably attenuated Cd-induced cardiorenal and apoptosis and fibrosis by reducing caspase 3 and TGF-β levels, as well as reducing the stain intensity of a-SMA and collagen IV, while increasing Bcl2 intensity. These results revealed that ASP attenuated Cd induced cardiac and renal toxicity which may be attributed to reducing oxidative stress, inflammation, fibrosis and apoptosis.

Virgin coconut oil: A comprehensive review of antioxidant activity and mechanisms contributed by phenolic compounds

Virgin coconut oil (VCO) is obtained by processing mature coconut cores with mechanical or natural methods. In recent years, VCO has been widely used in the food, pharmaceutical, and cosmetic industries because of its excellent functional activities. VCO has biological functions such as antioxidant, anti-inflammatory, antibacterial, and antiviral, and also has potential therapeutic effects on many chronic degenerative diseases. Among these functions, the antioxidant is the most basic and important function, which is mainly determined by phenolic compounds and medium-chain fatty acids (MCFAs). This review aims to elucidate the antioxidant functions of each phenolic compound in VCO, and discuss the antioxidant mechanisms of VCO in terms of the role of phenolic compounds with fat, intestinal microorganisms, and various organs. Besides, the composition of VCO and its application in various industries are summarized, and the biological functions of VCO are generalized, which should lay a foundation for further research on the antioxidant activity of VCO and provide a theoretical basis for the development of food additives with antioxidant activity.

Protective effects of tree peony seed protein hydrolysate on Cd-induced oxidative damage, inflammation and apoptosis in zebrafish embryos

The objective of this study was to investigate protective effects of tree peony seed protein hydrolysate by Alcalase (AL-TPSPH) on oxidative damage, inflammation and apoptosis using Cd-induced zebrafish embryos. Zebrafish embryos were treated with either Cd (2 μg/L) or AL-TPSPH (25, 50 and 75 μg/mL) alone or in combination of both from 4 to 144 h post fertilization (hpf). The effects of these treatments on developments, antioxidant parameters and mRNA expression of genes related to oxidative damage, inflammation and apoptosis were examined. The results showed that co-treatment with Cd and AL-TPSPH significantly increased hatching and survival rates and decreased malformation rates of zebrafish embryos compared with Cd treatment alone group (P < 0.05). Cd-induced increase of MDA content, decreases of T-AOC content, GSH/GSSG ratio and activities of SOD, CAT and GPx in zebrafish embryos were modified upon treatment with AL-TPSPH. AL-TPSPH treatment significantly suppressed Cd-induced down-regulations of the antioxidant gene expressions (Mn-sod, Cat and GPx1a) in zebrafish embryos (P < 0.05). AL-TPSPH also prevented Cd-induced up-regulations of pro-inflammatory cytokine (TNF-α, IL-1β and IFN-γ) expressions. Moreover, AL-TPSPH inhibited Cd-induced up-regulations of pro-apoptotic genes (C-jun, Caspase-3 and Caspase-9) in zebrafish embryos. Collectively, these results indicated that AL-TPSPH could reduce Cd-induced oxidative damage, inflammation and apoptosis in zebrafish embryos, suggesting its future applications as functional food or pharmaceutical ingredient.

The possible alleviating effect of garlic supplement on the neural retina in a rat model of hypercholesterolemia: a histological and immunohistochemical study

The purpose of this work was to prove that oxidative stress is the main mechanism responsible for retinal neurodegenerative changes, subsequent apoptosis, and inflammatory cytokine release in rats fed with a high cholesterol diet (HCD) and determine the role of garlic in alleviating these changes. Forty rats were equally divided into four groups: control, garlic-treated (positive control), HCD, and HCD + garlic-treated (HCD + G). By the end of the experiment (24 weeks) blood samples were collected for assessment of serum lipid profile, oxidative stress parameters, and plasma levels of IL-6 and TNF-α. Both eyes of the rats were enucleated; one was used for light microscopic examination and the other for electron microscopic examination. There was a significant increase in the levels of serum lipids, oxidative stress parameters, IL-6 and TNF-α, and area of expression of caspase-3 in the HCD group compared to both the control and HCD + G groups. Histological examination revealed degenerative changes in all layers of the neural retina in the HCD group. Garlic administration resulted in a significant improvement in the biochemical, immunohistochemical, and histological characteristics of hypercholesterolemic rats. These findings support the hypotheses that garlic has strong antioxidant, anti-apoptotic, and anti-inflammatory properties. Garlic ameliorates the neurodegenerative changes in the neural retina of hypercholesteremic rats.

Polyphenols Extracted from Shanxi-Aged Vinegar Inhibit Inflammation in LPS-Induced RAW264.7 Macrophages and ICR Mice via the Suppression of MAPK/NF-κB Pathway Activation

Shanxi-aged vinegar, a traditional Chinese grain-fermented food that is rich in polyphenols, has been shown to have therapeutic effects on a variety of diseases. However, there has been no comprehensive evaluation of the anti-inflammatory activity of polyphenols extracted from Shanxi-aged vinegar (SAVEP) to date. The anti-inflammatory activities of SAVEP, both in RAW 264.7 macrophages and mice, were extensively investigated for the potential application of SAVEP as a novel anti-inflammatory agent. In order to confirm the notion that polyphenols could improve inflammatory symptoms, SAVEP was firstly detected by gas chromatography mass spectrometry (GC-MS). In total, 19 polyphenols were detected, including 12 phenolic acids. The study further investigated the protective effect of SAVEP on lipopolysaccharide-induced inflammation in RAW264.7 macrophages and ICR mice. The results showed that compared with those of the model group, SAVEP could remarkably recover the inflammation of macrophage RAW264.7 and ICR mice. SAVEP can normalise the expression of related proteins via the suppression of MAPK/NF-κB pathway activation, inhibiting the expression of iNOS and COX-2 proteins, and consequently the production of inflammatory factors, thus alleviating inflammatory stress. These results suggest that SAVEP may have a potential function against inflammation.

Hesperidin protects against cadmium-induced pancreatitis by modulating insulin secretion, redox imbalance and iNOS/NF-ĸB signaling in rats

AIM

Cadmium is a persistent ubiquitous environmental toxicant that elicits several biological defects on delicate body organs. Growing evidence suggests that cadmium (Cd) may perturb signaling pathways to induce oxidative pancreatitis. Thus, we explored whether hesperidin, a flavonone, could mitigate Cd-induced oxidative stress-mediated inflammation and pancreatitis in Wistar rats.

MAIN METHODS

Forty (40) rats randomly assigned to 5 groups (n = 8) were administered normal saline or hesperidin (Hsp) followed by Cd intoxication for 28 days.

KEY FINDINGS

Cadmium accumulated in the pancreas of rats, and markedly decreased insulin, pancreatic superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities and glutathione (GSH) level. Cadmium considerably increased malondialdehyde (MDA), serum lipase and amylase activities. Cadmium induced pancreatic pro-inflammation via over-expression of inducible nitric oxide synthase (iNOS), nuclear factor-ĸB (NF-κB), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), along with histopathological alterations. Hesperidin prominently decreased serum amylase and lipase activities, and markedly increased insulin level, pancreatic antioxidant defense mechanism, whereas iNOS, NF-κB, IL-6 and TNF-α levels significantly decreased. Changes in histology confirmed our biochemical findings.

SIGNIFICANCE

Our findings suggest that Cd induced pancreatitis via pro-inflammation and oxidative stress; Hsp, thus, protects against Cd-induced pancreatitis via attenuation of oxidative stress and proinflammatory responses in pancreas.

Molecular mechanisms linking environmental toxicants to cancer development: Significance for protective interventions with polyphenols

Human exposure to environmental toxicants with diverse mechanisms of action is a growing concern. In addition to well-recognized carcinogens, various chemicals in environmental and occupational settings have been suggested to impact health, increasing susceptibility to cancer by inducing genetic and epigenetic changes. Accordingly, in this review, we have discussed recent insights into the pathological mechanisms of these chemicals, namely their effects on cell redox and calcium homeostasis, mitochondria and inflammatory signaling, with a focus on the possible implications for multi-stage carcinogenesis and its reversal by polyphenols. Plant-derived polyphenols, such as epigallocatechin-gallate, resveratrol, curcumin and anthocyanins reduce the incidence of cancer and can be useful nutraceuticals for alleviating the detrimental outcomes of harmful pollutants. However, development of therapies based on polyphenol administration requires further studies to validate the biological efficacy, identifying effective doses, mode of action and new delivery forms. Innovative microphysiological testing models are presented and specific proposals for future trials are given. Merging the current knowledge of multifactorial actions of specific polyphenols and chief environmental toxicants, this work aims to potentiate the delivery of phytochemical-based protective treatments to individuals at high-risk due to environmental exposure.

Nephroprotective Effect of Moringa Oleifera Seed Oil on Gentamicin-Induced Nephrotoxicity in Rats: Biochemical Evaluation of Antioxidant, Anti-inflammatory, and Antiapoptotic Pathways

Objective: Gentamicin is an efficacious aminoglycoside antibiotic widely used to treat life-threatening Gram-negative bacteria infections. However, its specific non-targeted induction of nephrotoxicity is a worrying clinical challenge. The study explored the nephroprotective effect of Moringa oleifera seed oil (MOO) against gentamicin-induced oxidative nephrotoxicity, pro-inflammation, and apoptosis in male Wistar rats.Method: Twenty-four rats divided into 4 groups (n = 6) were administered MOO (5 ml/kg) for 16 days and/or gentamicin (100 mg/kg bw/d, ip) injected from day 11 to day 16. The renal antioxidant enzyme activities reduced glutathione, lipid peroxidation, and serum renal markers. Urea and creatinine levels were estimated. The renal expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nitric oxide (NO) were determined. Renal levels of inducible nitric oxide synthase (iNOS), nuclear factor-ĸB (NF-ĸB), and caspase-3 were determined to detect possible mechanism of inflammation and apoptosis with histology.Results: MOO prominently reduced serum creatinine and urea levels with amelioration of histopathological abrasions induced by gentamicin (GM). It significantly depressed oxidative stress through lowering of renal malondialdehyde (MDA) and elevation of renal superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, and reduced glutathione (GSH) level. MOO restored renal content of IL-1β, IL-6, TNF-α, and NO, coupled with the mechanistic downregulation of NF-ĸB, iNOS, and caspase-3 activities. The histopathological alterations were ameliorated by MOO.Conclusions: MOO possesses marked nephroprotective effect against GM-induced renal damage via modulating oxidative stress, inflammation, and apoptosis in Wistar rats.

Selenium alleviates cadmium-induced inflammation and meat quality degradation via antioxidant and anti-inflammation in chicken breast muscles

Cadmium (Cd) as a widespread toxic heavy metal accumulates in animal food including chicken meat through food chain enrichment and finally threatens human health. Selenium (Se) is an essential mineral and possesses antagonistic effects on Cd-induced multiple organs' toxicity in chickens. The objective of the present study was to reveal the antagonistic mechanisms of Se to Cd from the aspects of oxidative stress, inflammation, and meat quality in chicken breast muscles. Firstly, the results showed that Cd significantly elevated the levels of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and protein carbonyl, and declined the levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) to trigger oxidative stress in chicken breast muscles. However, Se treatment significantly alleviated Cd-induced oxidative stress by increasing the levels of GSH-Px, SOD, and CAT, and decreasing the levels of MDA, H₂O₂, and protein carbonyl. Secondly, Se obviously inhibited the expressions of Cd-activated inflammation-related genes including tumor necrosis factor (TNF-α), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), inducible nitric oxide synthase (iNOS), prostaglandin-endoperoxide synthase 2 (COX-2), and prostaglandin E synthase (PTGEs) in chicken breast muscles. Thirdly, meat quality-related parameters including pH_45min, ultimate pH (pHu), and drip loss were also detected, and the results showed that Se markedly recovered Cd-induced dropt of pH_45min and increase of drip loss in chicken breast muscles. In brief, these findings demonstrated that Se significantly alleviated Cd-induced oxidative stress and inflammation, and declined meat quality of chicken breast muscles.

Optimization, isolation, characterization and hepatoprotective effect of a novel pigment-protein complex (phycocyanin) producing microalga: Phormidium versicolorNCC-466 using response surface methodology

In our study, we focused on the optimization; antioxidant and hepatoprotective potentials of novel pigment-protein complex(C-PC) isolated from Phormidium versicolor against cadmium induced liver injury in rats. From analysis, the C-PC extraction parameters were optimized using the response surface methodology (RSM) for optimal recoveries of C-PC extraction. For analysis, the optimum operational conditions for maximizing phycocyanins concentration (67.45mg/g DM) were found to be water/solid 2, temperature 32.5°C and pH7.2.This pigment was identified using HPLC and FTIR analysis. In addition, the molecular masses of α and β subunits were 17 and 19kDa. Scavenging activity of superoxide anion, hydroxyl, nitric oxide radicals and metal chelating in vitro results indicated that C-PC has an excellent capacity as antioxidant. In vivo study, C-PC significantly prevented cadmium-induced elevation of ALAT, ASAT and bilirubin levels in rats. The histopathological observations supported the results serum enzymes assays. The results of this study revealed that C-PC has significant hepatoprotective potential. C-PC (50mgkg^-1 body weight) significantly enhanced the levels of antioxidant enzymes. It can be concluded that C-PC possesses prevention action against hepatotoxicity caused by cadmium.

Protective effects of Allium hirtifolium Boiss extract on cadmium-induced renal failure in rats

Cadmium (Cd), as a toxic metal, can accumulate in kidneys and induce renal failure. This study was undertaken to evaluate the protective effects of Allium hirtifolium Boiss bulbs against Cd-induced renal failure in rats. Thirty-six rats were divided into 6 groups: group 1, 2, and 3 received vehicle, Cd (100 mg/L/day by drinking water), and AhB extract (200 mg/kg/day; orally), respectively. Groups 4, 5, and 6 were Cd groups which treated AhB extract (50, 100, and 200 mg/kg/day, respectively). After 2 weeks, renal function and oxidative stress markers were determined by using colorimetric methods. Our findings showed that Cd caused a significant increase in creatinine (Cr; p<0.05), uric acid (p<0.01), BUN (p<0.05), serum levels, lipid peroxidation (LPO; p<0.01), and nitric oxide (NO; p<0.01); the depletion of the total antioxidant capacity (TAC; p<0.01) and total thiol molecules (TTM; p<0.001); and structural alterations in the renal tissue. Following AhB extract administration, a remarkable improvement was observed in the functional and oxidative stress markers of renal tissue.This study suggests that AhB may prevent progression of Cd-induced renal failure via improvement of oxidative/antioxidant balance in renal tissue.

Hepatoprotective effect of polyphenols isolated from virgin coconut oil against sub-chronic cadmium hepatotoxicity in rats is associated with improvement in antioxidant defense system

Cadmium (Cd) is a ubiquitous non-essential environmental and industrial toxicant that affects various organs in humans and experimental animals. Robust evidence confirms the contribution of oxidative stress to the pathogenesis of Cd-induced hepatic damage. Potent polyphenols found in virgin coconut oil (VCO) are free radical scavengers that may be beneficial against Cd hepatotoxicity. Thus, we aimed to evaluate the possible protective effect of polyphenols isolated from VCO on Cd-induced hepatotoxicity and oxidative stress in rats. Rats were pretreated with polyphenols isolated from VCO (10, 20, and 50 mg/kg, orally) 2 weeks prior to concurrent Cd administration (5 mg/kg, orally) for 5 weeks. Subsequently, liver damage, hepatic oxidative stress, and histopathological alterations were evaluated. In vitro antioxidant assays (DPPH and FRAP) were carried out on VCO polyphenols. Cadmium induced liver damage demonstrated by significant alterations in serum markers of liver damage, as well as pronounced decrease in albumin and total protein compared to control. Further, Cd remarkably depressed hepatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) content. Hepatic lipid peroxidation was markedly increased as highlighted by malondialdehyde (MDA) content. Sub-chronic administration of VCO polyphenols to Cd-treated rats produced a significant hepatoprotective effect and restored hepatic oxidative stress markers comparable to control. The prominent improvement in histopathology of rat liver confirmed the biochemical findings. The findings suggest potential beneficial effect of VCO polyphenols on Cd-induced hepatotoxicity and oxidative stress in rats; the mechanism underlying this action is associated with improvement in antioxidant defense system.