Modulatory potential of ellagic acid, a natural plant polyphenol on altered lipid profile and lipid peroxidation status during alcohol-induced toxicity: A pathohistological study

An overview on the protective effects of ellagic acid against heavy metals, drugs, and chemicals

Ellagic acid (EA) is a polyphenol extracted from many plants. EA modulates inflammatory mediators via antioxidant mechanisms, such as catalase (CAT) activities, superoxide dismutase (SOD), enhancement, increase in glutathione (GSH), and lipid peroxidation (LPO) suppression. EA has anti-apoptotic properties that are thought to be mediated by regulating the expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and caspase-3. In this article, we surveyed the literature dealing with the protective effects of EA against different heavy metals, drugs, and natural toxins. The findings indicated that EA has remarkable protective properties against various toxicants. Its protective effects were mostly mediated via normalizing lipid metabolism, oxidative stress, and inflammatory mediators, for example, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β. The results of this study showed that EA has significant protective effects against a varied range of compounds, either chemical or natural. These effects are mainly mediated via intensifying the antioxidant defense system. However, other mechanisms such as inhibition of inflammatory responses and suppression of apoptosis are important.

The effect of ellagic acid on the metabolic syndrome: A review article

Objective

(s): Metabolic syndrome is a collection of metabolic abnormalities that includes hyperglycemia, dyslipidemia, hypertension, and obesity. Ellagic acid is found in various fruits and vegetables. It has been reported to have several pharmacological properties, such as antibacterial, antifungal, antiviral, anti-inflammatory, hepatoprotective, cardioprotective, chemopreventive, neuroprotective, gastroprotective, and antidiabetic. Our current study aims to shed light on the probable efficiency of ellagic acid in managing metabolic syndrome and its complications.

Materials and methods

To prepare the present review, the databases or search engines utilized included Scopus, PubMed, Science Direct, and Google Scholar, and relevant articles have been gathered with no time limit until March 2023.

Results

Several investigations indicated that ellagic acid could be a potent compound for the treatment of many disorders such as diabetes, hypertension, and hyperlipidemia by various mechanisms, including increasing insulin secretion, insulin receptor substrate protein 1 expression, regulating glucose transporter 4, triglyceride, total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), attenuating tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), reactive oxygen species (ROS), malondialdehyde (MDA), and oxidative stress in related tissues. Furthermore, ellagic acid ameliorates mitochondrial function, upregulates uncoupling protein 1 (found in brown and white adipose tissues), and regulates blood levels of nitrate/nitrite and vascular relaxations in response to acetylcholine and sodium nitroprusside.

Conclusion

Ellagic acid can treat or manage metabolic syndrome and associated complications, according to earlier studies. To validate the beneficial effects of ellagic acid on metabolic syndrome, additional preclinical and clinical research is necessary.

Ellagic Acid Prevents Binge Alcohol-Induced Leaky Gut and Liver Injury through Inhibiting Gut Dysbiosis and Oxidative Stress

Alcoholic liver disease (ALD) is a major liver disease worldwide and can range from simple steatosis or inflammation to fibrosis/cirrhosis, possibly through leaky gut and systemic endotoxemia. Many patients with alcoholic steatohepatitis (ASH) die within 60 days after clinical diagnosis due to the lack of an approved drug, and thus, synthetic and/or dietary agents to prevent ASH and premature deaths are urgently needed. We recently reported that a pharmacologically high dose of pomegranate extract prevented binge alcohol-induced gut leakiness and hepatic inflammation by suppressing oxidative and nitrative stress. Herein, we investigate whether a dietary antioxidant ellagic acid (EA) contained in many fruits, including pomegranate and vegetables, can protect against binge alcohol-induced leaky gut, endotoxemia, and liver inflammation. Pretreatment with a physiologically-relevant dose of EA for 14 days significantly reduced the binge alcohol-induced gut barrier dysfunction, endotoxemia, and inflammatory liver injury in mice by inhibiting gut dysbiosis and the elevated oxidative stress and apoptosis marker proteins. Pretreatment with EA significantly prevented the decreased amounts of gut tight junction/adherent junction proteins and the elevated gut leakiness in alcohol-exposed mice. Taken together, our results suggest that EA could be used as a dietary supplement for alcoholic hepatitis patients.

Role of ellagic acid for the prevention and treatment of liver diseases

Globally, one of the alarming problems is the prevalence and burden of liver diseases, which accounts for 2 million cases per year. Chronic liver aetiologies such as hepatitis infections, alcoholic or non-alcoholic liver disease, environmental agents, and drug-induced toxicity are invariably responsible for liver fibrosis progression to finally hepatocellular carcinoma. Current treatment options are unable to overwhelm and cure liver diseases. Emerging findings suggest researchers' interest in using evidence-based complementary medicine such as ellagic acid with extensive pharmacological properties. They include antioxidant, anti-inflammatory, anti-hyperlipidaemic, anti-viral, anti-angiogenic, and anticancer activity. The molecular functions elicited by ellagic acid include scavenging of free radicals, regulation of lipid metabolism, the prohibition of fibrogenesis response-mediating proteins, inhibits hepatic stellate cells and myofibroblasts, restrains hepatic viral replication, facilitates suppression of growth factors, regulates transcription factors, proinflammatory cytokines, augments the liver immune response, fosters apoptosis and inhibits cell proliferation in tumorigenic cells. This review will most notably focus on preclinical and clinical information based on currently available evidence to warrant ellagic acid's prospective role in preventing liver diseases.

Hepatoprotective potential of 7,8-Dihydroxyflavone against alcohol and high-fat diet induced liver toxicity via attenuation of oxido-nitrosative stress and NF-κB activation

BACKGROUND

Fatty liver diseases are the most common and major health concern arises from the modern lifestyle and alcohol (ethanol) abuse. The prevalence of non-alcoholic fatty liver diseases (NAFLD) has been observed prominently in obese and diabetic individuals, while alcoholic liver disease is common in alcoholic persons. Fatty liver disease, such as steatohepatitis, leads to fibrosis, cirrhosis and eventually hepatocellular carcinoma. The present study was designed to investigate the effect of 7,8-Dihydroxyflavone (7,8-DHF) against high-fat diet (HFD) and ethanol (EtOH)-induced hepatotoxicity in rats.

METHODS

Male Wistar rats (150-200 g) were fed HFD (58% calories from fat) and EtOH (3-15% in drinking water) for 12 weeks. 7,8-DHF was administered intraperitoneally at the dose of 5 mg/kg/day for the last four weeks. After 12 weeks, biochemical, ELISA, RT-PCR, and histological studies have been carried out.

RESULTS

Biochemical analyses revealed the involvement of oxidative stress and inflammation in the liver of HFD and EtOH-fed rats. 7,8-DHF treatment significantly reduced HFD and EtOH-induced oxidative stress as evidenced by the reduction of lipid peroxidation and augmentation of reduced glutathione level. Moreover, IL-1β level was found significantly reduced in 7,8-DHF treated EtOH, HFD and EtOH+HFD groups. The semi-quantitative RT-PCR results indicated down-regulation of Nrf-2 and HO-1 and up-regulation of NF-κB and iNOS mRNA expression level in the liver of HFD and EtOH-fed rats, which was ameliorated by 7,8-DHF treatment.

CONCLUSION

The present study suggested that 7,8-DHF could be an effective pharmacological intervention in combating HFD and EtOH-induced hepatotoxicity.

Aldose Reductase Inhibitors of Plant Origin in the Prevention and Treatment of Alcoholic Liver Disease: A Minireview

Alcoholic liver disease (ALD) is caused by heavy alcohol consumption over a long period. Acetaldehyde-mediated toxicity, oxidative stress, and imbalance of lipid metabolism are generally considered involved in the initiation of ALD. There is an increasing requirement for alternative and natural medicine to treat ALD. Recently, aldose reductase (AR) has been reported to be involved in the development of ALD by affecting inflammatory cytokines, oxidative stress, and lipid metabolism. Here, we review the effect of plant-derived AR inhibitors on ALD in rodents. And we conclude that AR inhibitors of plant origin may enhance antioxidant capacity, inhibit lipid peroxidation and inflammatory cytokines expression, and activate AMP-activated protein kinase thereby subsequently suppressing alcohol-induced lipid synthesis in liver to achieve ALD protection. This review reveals that natural AR inhibitor may be potential therapeutic agent for ALD.

Ellagic acid as a potential antioxidant, alleviates methotrexate-induced hepatotoxicity in male rats

BACKGROUND

Hepatotoxicity is one of the most life-threatening side-effects of Methotrexate therapy. Former studies highlighted the significance of oxidative stress in promoting Methotrexate-induced hepatotoxicity (MIH). Hence, the current study investigated the protective effect of Ellagic acid (EA), a poly-phenolic antioxidant, against MIH.

METHODS

Twenty-eight male Wistar rats were grouped into four sets: group 1 (control), group 2 (injected intraperitoneally with 20 mg/kg of Methotrexate on the 9th day), group 3 (treated orally with 10 mg/kg/day of EA for 10 days and injected with Methotrexate on the 9th day) and group 4 (treated with EA for 10 days). Subsequently, biochemical and histopathological parameters were evaluated in serum samples and liver tissues.

RESULTS

Methotrexate significantly increased activities of aminotransferases and ALP enzymes as well as levels of oxidative stress parameters in liver tissue. Likewise, Methotrexate decreased hepatic reduced glutathione level and activities of antioxidant enzymes. EA pre-treatment markedly attenuated the activities of aminotransferases and ALP, levels of oxidative stress parameters and augmented activities of antioxidant enzymes. Similarly, the remarkable protective effect of EA on liver has been confirmed by histological examination.

CONCLUSION

In sum, the current study supports the hypothesis that EA may be used as a promising pre-therapy to prevent the MIH.

Ellagic acid: A promising protective remedy against testicular toxicity induced by arsenic

Chronic exposure to arsenic, an inducer of oxidative stress, is one of the major causes of male infertility. Therefore, the present study investigated the protective role of Ellagic acid (EA), as a natural antioxidant, against testicular toxicity evoked by arsenic. Thirty-five male Wistar rats were divided into 5 treatment groups. Group 1 served as control, group 2 were orally exposed to sodium arsenite (SA, 10 mg/kg; 21 days), groups 3 and 4 were initially exposed to SA for 7 days and then were treated with both EA (10 and 30 mg/kg) and SA up to 21 days, and group 5 was treated with EA for 14 days. After this period, biochemical and histopathological parameters were evaluated in serum samples and testicular tissue. SA markedly reduced levels of serum testosterone, total antioxidant capacity, reduced glutathione as well as the activity of antioxidant enzymes. Furthermore, SA enhanced levels of malondialdehyde, tumor necrosis factor-α, interleukin-1β and nitric oxide in testes. Treatment with EA was found to reduce testicular arsenic accumulation and oxidative stress parameters. In addition, EA improved the serum testosterone level, testicular antioxidant markers and histological parameters after exposure to SA. EA may emerge as a promising therapeutic option to protect testes from arsenic-induced toxicity through reducing oxidative stress and inflammatory responses.

Feeding on ripening and over-ripening fruit: interactions between sugar, ethanol and polyphenol contents in a tropical butterfly

In ripe fruit, energy mostly derives from sugar, while in over-ripe fruit, it also comes from ethanol. Such ripeness differences may alter the fitness benefits associated with frugivory if animals are unable to degrade ethanol when consuming over-ripe fruit. In the tropical butterfly Bicyclus anynana, we found that females consuming isocaloric solutions mimicking ripe (20% sucrose) and over-ripe fruit (10% sucrose, 7% ethanol) of the palm Astrocaryum standleyanum exhibited higher fecundity than females consuming a solution mimicking unripe fruit (10% sucrose). Moreover, relative to butterflies consuming a solution mimicking unripe fruit, survival was enhanced when butterflies consumed a solution mimicking either ripe fruit supplemented with polyphenols (fruit antioxidant compounds) or over-ripe fruit devoid of polyphenols. This suggests that (1) butterflies have evolved tolerance mechanisms to derive the same reproductive benefits from ethanol and sugar, and (2) polyphenols may regulate the allocation of sugar and ethanol to maintenance mechanisms. However, variation in fitness owing to the composition of feeding solutions was not paralleled by corresponding physiological changes (alcohol dehydrogenase activity, oxidative status) in butterflies. The fitness proxies and physiological parameters that we measured therefore appear to reflect distinct biological pathways. Overall, our results highlight that the energy content of fruit primarily affects the fecundity of B. anynana butterflies, while the effects of fruit consumption on survival are more complex and vary depending on ripening stage and polyphenol presence. The actual underlying physiological mechanisms linking fruit ripeness and fitness components remain to be clarified.

Ellagic and ferulic acids alleviate gamma radiation and aluminium chloride-induced oxidative damage

AIM

Ionizing radiation interacts with biological systems through the generation of free radicals, which induce oxidative stress. Aluminium (Al) can negatively impact human health by direct interaction with antioxidant enzymes. Ellagic acid (EA) and Ferulic acid (FA) are plant polyphenolic compounds, have gained attention due to their multiple biological activities. To date, no studies investigating the antioxidant effect of EA/FA in a model involving both γ radiation and aluminium chloride (AlCl3) have been reported. Herein, we investigated the protective effect of EA and FA against oxidative stress induced by γ radiation and AlCl3 in rats.

METHODS

Rats were divided into thirteen groups: a negative control group, 3 positive control groups (γ-irradiated, AlCl3-treated and γ-irradiated+AlCl3-treated) and 9 groups (3 γ-irradiated, 3 AlCl3-treated and 3 γ-irradiated+AlCl3-treated) treated with EA and/or FA. Liver function and lipid profile were assessed. Levels of lipid peroxidation, protein oxidation and endogenous antioxidants as well as the concentrations of copper, iron and zinc were estimated in liver tissue homogenate. Furthermore, liver tissue sections were histologically examined.

RESULTS

Oral administration of EA and/or FA resulted in 1) amelioration of AlCl3 and/or γ-radiation-induced hepatic function impairment, dyslipidemia and hepatic histological alterations; 2) reduction in liver MDA and PCC levels; 3) elevation of liver CAT, GPx and SOD activity as well as GSH level; 4) elevation in liver Cu concentrations which was accompanied by a reduction in Fe and Zn concentrations.

CONCLUSIONS

Oral administration of EA and/or FA may be useful for ameliorating γ radiation and/or AlCl3-induced oxidative damage.

Nuclear receptor-mediated alleviation of alcoholic fatty liver by polyphenols contained in alcoholic beverages

To elucidate the effect of the polyphenols contained in alcoholic beverages on the metabolic stress induced by ethanol consumption, four groups of mice were fed for five weeks on Lieber's diet with or without ethanol, with ethanol plus ellagic acid, and with ethanol plus trans-resveratrol. Alcoholic fatty liver was observed in the group fed the ethanol diet but not in those fed the ethanol plus polyphenol diets. Liver transcriptome analysis revealed that the addition of the polyphenols suppressed the expression of the genes related to cell stress that were up-regulated by ethanol alone. Conversely, the polyphenols up-regulated the genes involved in bile acid synthesis, unsaturated fatty acid elongation, and tetrahydrofolate synthesis that were down-regulated by ethanol alone. Because parts of these genes were known to be regulated by the constitutive androstane receptor (CAR), we performed the same experiment in the CAR-deficient mice. As a result, fatty liver was observed not only in the ethanol group but also with the ethanol plus polyphenol groups. In addition, there was no segregation of the gene expression profiles among these groups. These results provide a molecular basis for the prevention of alcohol-induced stress by the polyphenols in alcoholic beverages.

Antiproliferative and apoptotic-inducing potential of ellagic acid against 1,2-dimethyl hydrazine-induced colon tumorigenesis in Wistar rats

Colon cancer remains one of the major worldwide causes of cancer-related morbidity and mortality in Western countries and is increasingly common in Asia. Ellagic acid (EA), a major component of polyphenol possesses attractive remedial features. The aim of this study is to divulge the potential effect of EA during 1,2-dimethyl hydrazine (DMH)-induced colon cancer in male Wistar albino rats. The rats were segregated into four groups: group I, control rats; group II, rats received EA (60 mg/kg b.wt./day, orally); rats in group III, induced with DMH (20 mg/kg b.wt.) subcutaneously for 15 weeks; DMH-induced group IV rats were initiated with EA treatment. Colon of the rats treated with DMH exhibited higher glycoconjugates and proliferation index such as elevated expressions of argyrophilic nucleolar organizing regions (AgNORs), proliferating cell nuclear antigen (PCNA), cyclin D1, matrix metalloproteins (MMP-2 and -9), and mast cells. DMH induction also increased phase I-metabolizing enzymes with simultaneous decrease in the phase II detoxifying enzymes. In contrast, dietary administration of EA significantly (p < 0.05) down regulated the proliferation index and restored back the levels of biotransformation enzymes. The carcinogenic insult also altered the expression of pro-apoptotic protein p53, whereas dietary EA administration significantly (p < 0.01) up regulates p53 expression to further induce apoptotic pathway. Ultrastructural changes in colon were also in accord with the above aberrations. Overall findings suggested that the suppression of colon cancer by EA in vivo involves inhibition of cell proliferation, activation of apoptosis, and efficient detoxification.

Litsea deccanensis ameliorates myocardial infarction in wistar rats: evidence from biochemical and histological studies

The present study was designed to evaluate the cardioprotective effects of methanolic extract of Litsea deccanensis (MELD) against isoproterenol-induced myocardial infarction in rats by studying cardiac markers, lipid peroxidation, lipid profile, and histological changes. Male Wistar rats were treated orally with MELD (100 and 200 mg/kg) daily for a period of 21 days. After 21 days of pretreatment, isoproterenol (100 mg/kg) was injected subcutaneously to rats at an interval of 24 h for 2 days to induce myocardial infarction. Isoproterenol-induced rats showed significant (P < 0.05) increase in the levels of serum creatine kinase, lactate dehydrogenase, thiobarbituric acid reactive substances, and lipid hydro peroxides. The serum lipid levels were altered in the isoproterenol-induced myocardial infarcted rats. The histopathological findings of the myocardial tissue evidenced myocardial damage in isoproterenol-induced rats. The oral pretreatment with MELD restored the pathological alterations in the isoproterenol-induced myocardial infarcted rats. The MELD pretreatment significantly reduced the levels of biochemical markers, lipid peroxidation and regulated the lipid profile of the antioxidant system in the isoproterenol-induced rats. An inhibited myocardial necrosis was evidenced by the histopathological findings in MELD pretreated isoproterenol-induced rats. Our study shows that oral pretreatment with MELD prevents isoproterenol-induced oxidative stress in myocardial infarction. The presence of phenolic acid and flavonoid contents were confirmed by preliminary phytochemical tests. The reducing power and free radical scavenging activities of the MELD may be the possible reason for it pharmacological actions.

A specific, accurate, and sensitive measure of total plasma malondialdehyde by HPLC

Malondialdehyde (MDA) is one of the most commonly reported biomarkers of lipid peroxidation in clinical studies. The reaction of thiobarbituric acid (TBA) with MDA to yield a pink chromogen attributable to an MDA-TBA₂ adduct is a common assay approach with products being quantified by ultraviolet-Vis assay as nonspecific TBA-reactive substances (TBARS) or chromatographically as MDA. The specificity of the TBARS assay was compared with both chromatographic assays for total plasma MDA. The levels of total plasma MDA were significantly lower than the plasma TBARS in each of the samples examined, and interestingly, the interindividual variation apparent in the level of plasma MDA was not evident in the plasma TBARS assay. Each of the four online chromatographic detectors yielded a precise, sensitive, and accurate determination of total plasma MDA, and selected-ion monitoring was the most-accurate assay (101.3%, n = 4). The online diode array detectors provided good assay specificity (peak purity index of 999), sensitivity, precision, and accuracy. This research demonstrates the inaccuracy that is inherent in plasma TBARS assays, which claim to quantify MDA, and it is proposed that the TBARS approach may limit the likelihood of detecting true differences in the level of lipid peroxidation in clinical studies.

Dietary agents in the prevention of alcohol-induced hepatotoxicty: preclinical observations

Long term alcohol consumption is one of the important causes for liver failure and death. To complicate the existing problem there are no dependable hepatoprotective drugs and a large number of patients prefer using complementary and alternative medicines for treating and managing hepatic complications. Almost 25 centuries ago, Hippocrates, the father of medicine, proclaimed "Let food be thy medicine and medicine be thy food." Exploring the association between diet and health continues even today. Preclinical studies carried out in the recent past have shown that the commonly used dietary agents like Allium sativum (garlic), Camellia sinensis (tea), Curcuma longa (turmeric), Emblica officinalis (Indian gooseberry), Ferula asafoetida (asafoetida), Garcinia cambogia (Malabar tamarind), Glycine max (soyabean), Murraya koenigii (curry leaves), Piper betle (beetle leaf), Prunus armeniaca (apricot), Ocimum gratissimum (wild basil), Theobroma cacao (cocoa), Trigonella foenum-graecum (fenugreek) and Vitis vinifera (grapes) protect against ethanol-induced hepatotoxicity. Mechanistic studies have shown that the beneficial effects of these phytochemicals in preventing the ethanol-induced hepatotoxicity are mediated by the antioxidant, free radical scavenging, anti-inflammatory and anti-fibrotic effects. The present review for the first time collates the hepatoprotective effects of these agents and also emphasizes on aspects that need future research to establish their utility in humans.

Effects of ellagic acid on copper, zinc, and biochemical values in serum and liver of experimental cholestatic rats

Ellagic acid (EA) is a natural polyphenolic compound. Although, modulator effects of EA on copper (Cu) and zinc (Zn) levels in some liver diseases have been reported in experimental animals, its effects in obstructive jaundice (OJ) has not been clarified. We aimed to evaluate potential effects of EA on Cu and Zn levels in liver and serum of cholestatic rats. Forty Wistar albino rats were equally divided into four groups. First group was used as controls. Second group received EA (60 mg(-1) kg(-1) day(-1)) for 8 days. Third was OJ group, and fourth group was OJ plus EA group. After 8 days, blood and liver samples were obtained. Higher serum and liver Cu and lower serum and liver Zn levels were found in OJ group (p < 0.05) compared with other groups. However, these differences reached to significant levels for Cu in serum and for Zn in lever. Higher serum copper levels were decreased, and lower liver Zn levels were increased by EA treatment in cholestatic rats (p < 0.05). Also, higher Cu/Zn ratio in OJ group was decreased by EA treatment both in liver (p < 0.05) and in serum (p < 0.05). Significantly higher serum bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase values were found in OJ and OJ + EA groups compared with the control and EA groups (p < 0.05). In conclusion, result of the current study indicated that ellagic acid has modulator effects on Cu and Zn levels in liver and serum of cholestatic rats.

Estimation of lipid peroxidation induced by hydrogen peroxide in cultured human lymphocytes

Malondialdehyde (MDA) is used for the estimation of damage by reactive oxygen species. MDA is a major reactive aldehyde resulting from the peroxidation of biological membranes. The most common method used to assess MDA production is the thiobarbituric acid (TBARS) assay. However, the value of this method is curbed by low specificity and has been criticized for its use in human studies. In the present study we have used an alternative method for the estimation of MDA production i.e. reaction of MDA with a chromogenic agent 1-methyl-2-phenylindole at 45°C. The paper describes the method of preparing standards for the estimation of MDA (lipid peroxidation) after the treatment with an oxidative stress inducing agent hydrogen peroxide (H(2)O(2)). In the present study, the treatments of 1, 5, 10, 20, 50, 100, 150 and 200 μM of H(2)O(2) induced significant increase in lipid peroxidation as compared to the untreated ones. The results suggest that the present method can be used to measure the lipid peroxidation in cultured human peripheral blood lymphocytes and is specific for MDA estimation.

Unrefined and refined black raspberry seed oils significantly lower triglycerides and moderately affect cholesterol metabolism in male Syrian hamsters

Unrefined and refined black raspberry seed oils (RSOs) were examined for their lipid-modulating effects in male Syrian hamsters fed high-cholesterol (0.12% g/g), high-fat (9% g/g) diets. Hamsters fed the refined and the unrefined RSO diets had equivalently lower plasma total cholesterol and high-density lipoprotein (HDL) cholesterol in comparison with the atherogenic coconut oil diet. The unrefined RSO treatment group did not differ in liver total and esterified cholesterol from the coconut oil-fed control animals, but the refined RSO resulted in significantly elevated liver total and esterified cholesterol concentrations. The unrefined RSO diets significantly lowered plasma triglycerides (46%; P=.0126) in comparison with the coconut oil diet, whereas the refined RSO only tended to lower plasma triglyceride (29%; P=.1630). Liver triglyceride concentrations were lower in the unrefined (46%; P=.0002) and refined (36%; P=.0005) RSO-fed animals than the coconut oil group, with the unrefined RSO diet eliciting a lower concentration than the soybean oil diet. Both RSOs demonstrated a null or moderate effect on cholesterol metabolism despite enrichment in linoleic acid, significantly lowering HDL cholesterol but not non-HDL cholesterol. Dramatically, both RSOs significantly reduced hypertriglyceridemia, most likely due to enrichment in α-linolenic acid. As a terrestrial source of α-linolenic acid, black RSOs, both refined and unrefined, provide a promising alternative to fish oil supplementation in management of hypertriglyceridemia, as demonstrated in hamsters fed high levels of dietary triglyceride and cholesterol.

Ellagic acid ameliorates isoproterenol induced oxidative stress: Evidence from electrocardiological, biochemical and histological study

The present study was designed to evaluate the cardioprotective effects of ellagic acid against isoproterenol induced myocardial infarction in rats by studying electrocardiography, blood pressure, cardiac markers, lipid peroxidation, antioxidant defense system and histological changes. Male Wistar rats were treated orally with ellagic acid (7.5 and 15mg/kg) daily for a period of 10 days. After 10 days of pretreatment, isoproterenol (100mg/kg) was injected subcutaneously to rats at an interval of 24h for 2 days to induce myocardial infarction. Isoproterenol administered rats showed significant changes in the electrocardiogram pattern, arterial pressure, and heart rate. Isoproterenol-induced rats also showed significant (P<0.05) increase in the levels of serum troponin-I, creatine kinase, lactate dehydrogenase, C-reactive protein, plasma homocysteine, heart tissue thiobarbituric acid reactive substances and lipid hydro peroxides. The activities/levels of antioxidant system were decreased in isoproterenol-induced rats. The histopathological findings of the myocardial tissue evidenced myocardial damage in isoproterenol induced rats. The oral pretreatment of ellagic acid restored the pathological electrocardiographic patterns, regulated the arterial blood pressures and heart rate in the isoproterenol induced myocardial infarcted rats. The ellagic acid pretreatment significantly reduced the levels of biochemical markers, lipid peroxidation and significantly increased the activities/levels of the antioxidant system in the isoproterenol induced rats. An inhibited myocardial necrosis was evidenced by the histopathological findings in ellagic acid pretreated isoproterenol induced rats. Our study shows that oral pretreatment of ellagic acid prevents isoproterenol induced oxidative stress in myocardial infarction.

Taiwanese native plants inhibit matrix metalloproteinase-9 activity after ultraviolet B irradiation

Medicinal plants have long been used as a source of therapeutic agents. They are thought to be important anti-aging ingredients in prophylactic medicines. The aim of this study was to screen extracts from Taiwanese plant materials for phenolic contents and measure the corresponding matrix metalloproteinase-9 (MMP-9) activity. We extracted biological ingredients from eight plants native to Taiwan (Alnus formosana, Diospyros discolor, Eriobotrya deflex, Machilus japonica, Pyrrosia polydactylis, Pyrus taiwanensis, Vitis adstricta, Vitis thunbergii). Total phenolic content was measured using the Folin-Ciocalteu method. MMP-9 activities were measured by gelatin zymography. The extracted yields of plants ranged from 3.7 % to 16.9 %. The total phenolic contents ranged from 25.4 to 36.8 mg GAE/g dry material. All of these extracts (except Vitis adstricta Hance) were shown to inhibit MMP-9 activity of WS-1 cell after ultraviolet B irradiation. These findings suggest that total phenolic content may influence MMP-9 activity and that some of the plants with higher phenolic content exhibited various biological activities that could serve as potent inhibitors of the ageing process in the skin. This property might be useful in the production of cosmetics.