Effect of fruit vinegars on liver damage and oxidative stress in high-fat-fed rats

Context: Vinegar has long been used as a condiment and a traditional medicine worldwide.

Objective: The current study investigates the antioxidant effect of three types of fruit vinegars (FV) namely pomegranate [Punica granatum L. (Punicaceae)], prickly pear [Opuntia ficus-indica (L.) Mill. (Cactaceae)], and apple [Malus domestica Borkh. (Rosaceae)] vinegars in high-fat diet (HFD)-induced hyperlipidemic Wistar rats.

Materials and methods: Fifty male Wistar rats were divided into five groups; HFD (80?cal/d) fed rats were orally dosed with fruit vinegars (7?ml/kg) once daily for 28?weeks. At the end of the experiment, lipid profile, lipid peroxidation products, antioxidant enzymes, and trace elements were assessed in serum. In addition, a liver histopathological study was performed.

Results: HFD showed a significant increase (p?≤?0.05) in lipid profile and TBARS levels when compared with normal control. Daily oral administration of FV normalized various biochemical, metabolic, and histopathological changes. However, pomegranate vinegar exhibited a very significant (p?≤?0.001) reduction in lipid profile levels (total cholesterol: 165%, triglycerides: 68%, LDL-c: 76%, and atherogenic index: 80%), whereas an increase in antioxidant status (SOD: 7-fold, GPx: 4.81-fold, GRx: 1.66-fold, and TAS: 3.45-fold) when compared with hyperlipidemic control. Histopathological examinations also confirmed the protective effects of pomegranate vinegar against lipid accumulation and the improvement of hepatic lesions.

Discussion and conclusion: The fruit vinegars regulate lipid metabolism and decrease liver damage in high-fat fed rats as shown in this study.     

Renoprotective effect of Caralluma fimbriata against high-fat diet-induced oxidative stress in Wistar rats

The current study was designed to evaluate the renoprotective effect of hydro-alcoholic extract of Caralluma fimbriata (CFE) against high-fat diet-induced oxidative stress in Wistar rats. Male Wistar rats were randomly divided into five groups: control (C), control treated with CFE (C + CFE), high-fat diet fed (HFD), high-fat diet fed treated with CFE (HFD + CFE), and high-fat diet fed treated with metformin (HFD + metformin). CFE was orally administered (200 mg/kg body weight) to Groups C + CFE and HFD + CFE rats for 90 days. Renal functional markers such as, urea, uric acid, and creatinine levels in plasma were quantified during the experimental period. At the end of the experimental period, activities of transaminases and oxidative stress markers, i.e., reduced glutathione (GSH), lipid peroxidation, protein oxidation, and activities of antioxidant enzymes were assayed in renal tissue. Coadministration of CFE along with HF-diet in Group HFD + CFE prevented the rise in the levels of plasma urea, uric acid, and creatinine, and elevated activities of renal transaminases with decreased protein content of Group HFD (p < 0.05). Establishment of oxidative stress in Group HFD, as evident from elevated lipid peroxidation, protein oxidation levels with depleted levels of GSH, and decreased activities of GSH dependent and independent antioxidant enzymes, was prevented in Groups HFD + CFE and HFD + metformin rats. Further, there were no deviations in the studied parameters but there was improved antioxidant status of Group C + CFE from Group C which revealed the nontoxic nature of CFE even under chronic treatment. Thus, CFE treatment effectively alleviated the HF-diet induced renal damage. Hence, this plant could be used as an adjuvant therapy for the prevention and/or management of HF-diet induced renal damage.     

Antihyperlipidemic activity of Ichnocarpus frutescens in triton WR-1339-induced and high-fat diet animals

Context: Ichnocarpus frutescens (L.) R.Br. (Apocynaceae) is used to treat diabetes and hyperlipidemia in folk medicine.

Objective: The crude methanol extract and fractions of I. frutescens were investigated for antihyperlipidemic effect.

Materials and methods: Fresh leaves of I. frutescens were extracted with methanol and fractionated with hexane, benzene, ethyl acetate, acetone, and methanol. The active acetone fraction was subfractionated, which resulted in active fraction 3. The antihyperlipidemic effects of the methanol extract and fractions of I. frutescens were studied in triton WR-1339-induced and high-fat diet (HFD) obese animals. Further, lipid absorption and excretion were studied.

Results and discussion: The methanol extract significantly reduced total cholesterol (TC) by 29.63% and triglyceride (Tg) by 51.10% at 400?mg/kg in triton WR-1339-induced animals and significantly reduced TC (27.81%) and Tg (37.03%) at 400?mg/kg in HFD animals. Fraction 3 showed significant reduction in TC (25.03%) and Tg (58.05%) at 200?mg/kg. Feeding of HFD consisting 3% of fraction 3 increased feces weight and Tg level in mice. Fraction 3, showed significant decrease in plasma Tg level at the second hour, after oral administration of the lipid emulsion to rats.

Conclusion: The observed properties apparently validate the folk medicinal use of this plant in amelioration of hyperlipidemia.     

Effects of the hydroalcoholic extract of Rosa damascena on learning and memory in male rats consuming a high-fat diet

Context: High-fat diet (HFD) can cause deficits in learning and memory through oxidative stress and increase Alzheimer disease risk. Rosa damascena Mill. (Rosaceae) extract possesses potent antioxidant properties.

Objective: This study investigated the effects of the hydroalcoholic extracts of petals of R. damascena on learning and memory in male rats consuming an HFD.

Materials and methods: Forty male Wistar rats (200–250?g) were randomly assigned to four groups: control, R. damascena extract, HFD and HFD?+?extract. The extract (1?g/kg bw daily) was administered by oral gavage for 1?month. Animals were allowed free access to high-fat chow for 3?months. The Morris water maze and the passive avoidance learning tests were used to assess learning and memory.

Results: In the passive avoidance learning test, the step-through latencies in the retention test (STLr) of the extract (147.4?±?23.3) and HFD (150.3?±?25.2) groups were significantly lower than those of the control group (270.4?±?10.5) (respectively, p?p?p?p?Discussion and conclusion: Our results indicate that, while HFD or R. damascena extract alone leads to memory deficits, R. damascena extract exerted a positive effect on HFD-induced memory deficits. We hypothesize that the observed effects of R. damascena extract are likely due to its strong antioxidant properties.     

Flavonoid-enriched extract from Hippophae rhamnoides seed reduces high fat diet induced obesity,hypertriglyceridemia, and hepatic triglyceride accumulation in C57BL/6 mice

Context: Flavonoid-enriched extract from Hippophae rhamnoides L. (Elaeagnaceae) seed (FSH) has shown beneficial effects in anti-hypertension and lowering cholesterol level. However, evidence for its efficacy in treating obesity is limited.

Objective: We sought to determine if FSH can reduce body weight and regulate lipid metabolism disorder in high fat diet (HFD)-induced obese mouse model, and to investigate potential molecular targets involved.

Materials and methods: C57BL/6 mice were fed with HFD for 8 weeks to induce obesity. The modeled mice were divided into four groups and treated with vehicle, rosiglitazone (2?mg/kg), low (100?mg/kg) and high (300?mg/kg) dose of FSH, respectively. Normal control was also used. The treatments were administered orally for 9 weeks. We measured the effect of FSH on regulating body weight, various liver and serum parameters, and molecular targets that are key to lipid metabolism.

Results: FSH administration at 100 and 300?mg/kg significantly reduced body weight gain by 33.06 and 43.51%, respectively. Additionally, triglyceride concentration in serum and liver were decreased by 15.67 and 49.56%, individually, after FSH (300?mg/kg) treatment. Upon FSH (100 and 300?mg/kg) treatment, PPARα mRNA expression was upregulated in liver (1.24- and 1.42-fold) and in adipose tissue (1.66- and 1.72-fold). Furthermore, FSH downregulated PPARγ protein level both in liver and adipose tissue. Moreover, FSH inhibited macrophage infiltration into adipose tissues, and downregulated TNFα mRNA expression in adipose tissue (38.01–47.70%).

Conclusion: This effect was mediated via regulation of PPARγ and PPARα gene expression, and suppression of adipose tissue inflammation.     

In vitro antioxidant properties and in vivo lowering blood lipid of Forsythia suspense leaves

The active compounds from Forsythia suspense were screened for antioxidant activities in vitro and lowering blood lipid and lipid peroxidation in vivo. Five compounds, ursolic acid, phillygenin, (+)-pinoresinol, and quercetin, from EtOAC extract and rutin from n-BuOH extract were isolated and identified by spectroscopic methods. Phillygenin and (+)-pinoresinol had notable scavenging activity against DPPH, ABTS radicals, as well as potent reducing power in FRAP assay in vitro. Intragastric administration of EtOAC extract (500 mg/kg body weight per day), ursolic acid (150 mg/kg), phillygenin (150 mg/kg), and rutin (70 mg/kg) to groups of hyperlipidemia mice for 10 days significantly decreased the level of blood triglyceride and the level of low-density lipoprotein cholesterol (P < 0.001) in serum. However, the level of blood high-density lipoprotein cholesterol in the same treated mice decreased slightly (P > 0.05). The level of hepatic malondialdehyde (MDA, an index of lipid peroxidation) was assayed to evaluate the mechanism(s) of EtOAC extract, ursolic acid, phillygenin, and rutin. Under hyperlipidemia condition, the level of hepatic MDA increased. After intragastric administration of EtOAC extract, ursolic acid, phillygenin, and rutin, the level of hepatic MDA significantly decreased. The result showed that EtOAC extract, ursolic acid, phillygenin, and rutin had a high hypolipidemic activity and this activity may be attributed to their antioxidant potential.     

Comparative Antidiabetic,Hypolipidemic, and Antioxidant Properties of Phyllanthus niruri. in Normal and Diabetic Rats

Abstract

The antidiabetic, hypolipidemic, and antioxidant properties of Phyllanthus niruri. (L) (Euphorbiaceae) were compared in normal, insulin-dependent diabetes mellitus (IDDM), and non–insulin-dependent diabetes mellitus (NIDDM) animals through evaluating the effects on carbohydrate and lipid metabolism and antioxidant activities. The alcohol extract of Phyllanthus niruri. produced significant antidiabetic effect in IDDM alone but lowered lipid profiles and improved body antioxidant activities in both IDDM and NIDDM animals. This investigation revealed that the lipid-lowering effect of Phyllanthus niruri. is independent from its antidiabetic action.     

Silymarin improved diet-induced liver damage and insulin resistance by decreasing inflammation in mice

Context: Silymarin is the main flavonoid extracted from milk thistle, which has been used to treat liver diseases.

Objective: The in vivo effect of silymarin on HFD-induced insulin resistance and fatty liver in mice was studied.

Materials and methods: Male C57BL/6 mice were fed with high-fat diet (HFD) to induce obesity and insulin resistance and treated with 30, 60?mg/kg silymarin for 18 days. Food intake, body weight and the content/histology of epididymal fat and liver tissue were examined; the content of lipids, AST, ALT and inflammatory cytokines in serum were estimated.

Results: Administration of silymarin caused bodyweight loss in diet induced obesity (DIO) mice (HFD group: 47.7?g, 60?mg/kg group: 43.0?g) while the food intake remain unchanged. Silymarin (60?mg/kg) significantly reduced the epididymal fat mass (from 1.75?g to 1.12?g). Elevated plasma lipids (TC 6.1?mM, TG 1.3?mM, LDL 1.2?mM) in DIO mice were all suppressed by silymarin (TC 4.5?mM, TG 0.89?mM, LDL 0.9?mM), as well as insulin (5.1?ng/ml in HFD group to 2.0?ng/ml (60?mg/kg silymarin). Examination of cytokine levels (TNF-α, IL-1β and IL-6) in each group proved that silymarin treatment significantly decreased inflammation in DIO mice. Finally, silymarin effectively protected liver from HFD-induced injury as evidenced by decreasing histological damage and reducing ALT and AST levels, as follows: ALT; 47.4?U/L in HFD group to 28.4?U/L (60?mg/kg silymarin); AST; 150.1?U/L in HFD group to 88.1?U/L (60?mg/kg silymarin) in serum.

Discussion and conclusion: Our results suggested that silymarin-induced alleviation of inflammatory response could be a mechanism responsible for its benefits against liver damage and insulin resistance.     

Anti-obesity effects of galangin,a pancreatic lipase inhibitor in cafeteria diet fed female rats

Abstract

Context: Alpinia galanga Willd (Zingiberaceae) (AG) is a rhizomatous herb widely cultivated in shady regions of Malaysia, India, Indochina and Indonesia. It is used in southern India as a domestic remedy for the treatment of rheumatoid arthritis, cough, asthma, obesity, diabetes, etc. It was reported to have anti-obesity, hypoglycemic, hypolipidemic and antioxidant properties.

Objective: A flavonol glycoside, galangin, was isolated from AG rhizomes. Based on its in vitro pancreatic lipase inhibitory effect, the study was further aimed to clarify whether galangin prevented obesity induced in female rats by feeding cafeteria diet (CD) for 6 weeks.

Materials and methods: The in vitro pancreatic lipase inhibitory effect of galangin was determined by measuring the release of oleic acid from triolein. For in vivo experiments, female albino rats were fed CD with or without 50?mg/kg galangin for 6 weeks. Body weight and food intake was measured at weekly intervals. On day 42, serum lipids levels were estimated and then the weight of liver and parametrial adipose tissue (PAT) was determined. The liver lipid peroxidation and triglyceride (TG) content was also estimated.

Results: The IC₅₀ value of galangin for pancreatic lipase was 48.20?mg/mL. Galangin produced inhibition of increased body weight, energy intake and PAT weight induced by CD. In addition, galangin produced a significant decrease in serum lipids, liver weight, lipid peroxidation and accumulation of hepatic TGs.

Conclusion: Galangin present in AG rhizomes produces anti-obesity effects in CD-fed rats; this may be mediated through its pancreatic lipase inhibitory, hypolipidemic and antioxidant activities.     

Desalted Salicornia europaea powder and its active constituent,trans-ferulic acid,exert anti-obesity effects by suppressing adipogenic-related factors

Context: Salicornia europaea (Amaranthaceae) (SE) has been shown to reduce obesity, but it remains a problem as a food supplement because of its high salt content (25–35% NaCl).

Objectives: This study investigated the anti-obesity effects and mechanism of action of desalted SE powder (DSP).

Materials and methods: Sprague–Dawley rats (n?=?50) were divided into a normal control group (NC), a high-fat diet (HFD)-induced obesity control group (HFD), and HFD groups co-administered DSP (250 and 500?mg/kg) or Garcinia cambogia (Clusiaceae) extract (GE, 200?mg/kg, standard control) orally each day for 12?weeks.

Results: The body weight was significantly reduced by co-administration of DSP (596.51?±?19.84?kg, 4.60% and 562.08?±?9.74?kg, 10.10%, respectively) and GE (576.00?±?11.29?kg, 7.88%) relative to the HFD group (625.25?±?14.02?kg) and was accompanied by reduced abdominal fat mass, and serum lipid levels, with no effects on feed intake. To find the underlying mechanism of the anti-obesity effects, trans-ferulic acid (TFA) was identified as the main ingredient and investigated with regard to whether it attenuated adipogenesity in 3T3L-1 cells. DSP-derived TFA suppressed adipocyte differentiation and accumulation of intracellular lipids. TFA also down-regulated the adipogenesis-related gene expression of sterol regulatory element-binding protein 1, peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein-α and fatty acid synthase.

Conclusions: These findings suggest that DSP may be considered for use as a food supplement intent of controlling obesity through its antiobesity and antiadipogenic properties.     

Rhododendron groenlandicum (Labrador tea), an antidiabetic plant from the traditional pharmacopoeia of the Canadian Eastern James Bay Cree,improves renal integrity in the diet-induced obese mouse model

Content Our team has identified Labrador tea [Rhododendron groenlandicum L. (Ericaceae)] as a potential antidiabetic plant from the traditional pharmacopoeia of the Eastern James Bay Cree. In a previous in vivo study, the plant extract was tested in a high-fat diet (HFD)-induced obese model using C57BL/6 mice and it improved glycaemia, insulinaemia and glucose tolerance.

Objective In the present study, we assessed the plant’s potential renoprotective effects.

Materials and methods Rhododendron groenlandicum was administered at 250?mg/kg/d to mice fed HFD for 8 weeks to induce obesity and mild diabetes. Histological (periodic acid–Schiff (PAS), Masson and Oil Red O staining), immunohistochemical (IHC) and biochemical parameters were assessed to evaluate the renoprotective potential of R. groenlandicum treatment for an additional 8 weeks.

Results Microalbuminuria and renal fibrosis were developed in HFD-fed mice. Meanwhile, there was a tendency for R. groenlandicum to improve microalbuminuria, with the values of albumin-creatinine ratio (ACR) reducing from 0.69 to 0.53. Renal fibrosis value was originally 4.85 arbitrary units (AU) in HFD-fed mice, dropped to 3.27 AU after receiving R. groenlandicum treatment. Rhododendron groenlandicum reduced renal steatosis by nearly one-half, whereas the expression of Bcl-2-modifying factor (BMF) diminished from 13.96 AU to 9.43 AU.

Discussion and conclusions Taken altogether, the results suggest that R. groenlandicum treatment can improve renal function impaired by HFD.     

Effects of Piper nigrum extracts: Restorative perspectives of high-fat diet-induced changes on lipid profile,body composition,and hormones in Sprague–Dawley rats

Abstract

Context: Piper nigrum Linn (Piperaceae) (PnL) is used in traditional medicine to treat gastric ailments, dyslipidemia, diabetes, and hypertension.

Objective: The present study explores the possible protective effects of P. nigrum extracts on high-fat diet-induced obesity in rats.

Materials and methods: High-fat diet-induced obese rats were treated orally with 200?mg/kg bw of different extracts (hexane, ethylacetate, ethanol, and aqueous extracts) of PnL for 42?d. The effects of PnL extracts on body composition, insulin resistance, biochemical parameters, leptin, adiponectin, lipid profile, liver marker enzymes, and antioxidants were studied.

Results and discussion: The HFD control group rats showed a substantial raise in body weight (472.8?±?9.3?g), fat% (20.8?±?0.6%), and fat-free mass (165.9?±?2.4?g) when compared with normal control rats whose body weight, fat%, and fat-free mass were 314.3?±?4.4?g, 6.4?±?1.4%, and 133.8?±?2.2?g, respectively. Oral administration of ethyl acetate or aqueous extracts of PnL markedly reduced the body weight, fat%, and fat-free mass of HFD-fed rats. In contrast to the normal control group, a profound increase in plasma glucose, insulin resistance, lipid profile, leptin, thiobarbituric acid reactive substance (TBARS), and the activities of lipase and liver marker enzymes, and a decrease in adiponectin and antioxidant enzymes were noted in HFD control rats. Administration of PnL extracts to HFD-induced obese rats significantly (p?<?0.05) restored the above profiles.

Conclusion: PnL extracts significantly reduced the body weight, fat%, and ameliorated HFD-induced hyperlipidemia and its constituents.     

Antiatherosclerotic Effect of Caparis decidua. Fruit Extract in Cholesterol-fed Rabbits

Abstract

The fruit alcohol extract of the plant Capparis decidua (Frosk.).. Edgew was investigated for its antiatherosclerotic activity. Hyperlipidemia was induced by atherodiet and cholesterol feeding to animals. Rabbits were fed Capparis decidua. (500 mg/kg body weight) or pitavastatin (0.2 mg/kg body weight) in distilled water along with standard laboratory diet and atherodiet for 60 days. C. decidua. fruit extract and pitavastatin were found to lower serum cholesterol, LDL-cholesterol, triglyceride, phospholipid, and atherogenic index, but found to increase the HDL to total cholesterol ratio as compared with hyperlipidemic control group. Pitavastatin or C. decidua. fruit extract treated hyperlipidemic rabbits showed a decrease in the lipid profile of liver, heart, and aorta. The plant extract feeding brings about a definite regression of atheroma and hindered plaque formation in aorta as compared with the hyperlipidemic control group. Thus, this study demonstrates that C. decidua. fruit extract possesses hypolipidemic and antiatherosclerotic effects.     

Assessment of bioactive metabolites and hypolipidemic effect of polyphenolic-rich red cabbage extract

Context: Cardiovascular disease is the leading cause of death worldwide and the consumption of red cabbage (Brassica oleracea var. capitata f. rubra DC. – Brassicaceae) has been linked with the reduction risk of chronic diseases.

Objective: The present study assesses the bioactive metabolites and hypolipidemic effect of red cabbage on rats.

Materials and methods: The content of total phenols, flavonoids, anthocyanins, carotenoids, ascorbic acid and antioxidant capacity were assessed, while individual phenolic acids and flavonoids were detected using reverse phase-high performance liquid chromatography (HPLC) analysis. Acute hypolipidemic activity of aqueous extract of red cabbage (RC – 125, 250 and 500?mg/kg) was investigated using a Triton WR-1339 (400?mg/kg) induced hyperlipidemic Wistar rats compared to fenofibrate (65?mg/kg).

Results: The HPLC analysis of extracts revealed eight phenolic acids, gallic, protocatechuic, p-hydroxybenzoic, m-coumaric, syringic, caffeic, cinnamic, dicaffeoylquinic and three flavonoids, epicatechin, epigallocatechin, gallocatechin. Furthermore, the aqueous extract showed higher amounts of total phenolics (116.00?mg/g), flavonoids (161.32?μg/g) and, antioxidant activity (87.19%) than the hydromethanolic (89.33?mg/g, 123.34?μg/g and 75.07%), respectively. The RC significantly (p < 0.001) ameliorated the levels of cholesterol, triglycerides and lipoproteins alterations in hyperlipidemic rats without toxicity.

Discussion and conclusion: Herein, the RC presented the higher amounts of phenolics and flavonoids comparing with the hydromethanolic extract. Additionally, the RC showed as the majority compounds, dicaffeoylquinic and cinnamic acids, and the flavonoids epicatechin and gallocatechin. Furthermore, the RC demonstrated a beneficial effect against hypercholesterolemia and hypertriglyceridemia, demonstrating its potential therapeutic effect on these risk factors of cardiovascular diseases.     

Houttuynia cordata alleviates high-fat diet-induced non-alcoholic fatty liver in experimental rats

Abstract

Context: Houttuynia cordata Thunb. (Saururaceae) is used traditionally in Asian countries to treat various disease symptoms.

Objective: To study the effect of H. cordata ethyl acetate (HC-EA) extract on high-fat diet (HFD)-induced hepatic steatosis.

Materials and methods: HFD fed rats were orally dosed with HC-EA (100, 200, or 300?mg/kg) once daily for 8?weeks and the lipid profiles and protein expressions in hepatocytes were evaluated.

Results: HFD rats showed an increase (p?<?0.05) in the plasma lipid levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), free fatty acids (FFAs), and reduced the high-density lipoprotein (HDL) levels. Treatment with HC-EA extract (300?mg/kg) restored the changes in plasma lipid levels of TC, TG, LDL, FFA, and HDL in HFD-fed rats by 34.8, 31.1, 51.4, 32.4, and 56.3%, respectively, compared with control rats (p?<?0.01). HC-EA treatment also decreased the hepatic lipid accumulation (p?<?0.001 at 300?mg/kg) and improved hepatic histological lesions. HC-EA extract enhanced AMPK phosphorylation and its primary downstream targeting enzyme, acetyl-CoA carboxylase (ACC), up-regulated the gene expression of carnitine palmitoyl transferase-1 (CPT-1), and down-regulated sterol regulatory element binding protein 1, fatty acid synthase, and glutamate pyruvate transaminase protein levels in the livers of HFD-fed rats. Further, the increased expression of hepatic cytochrome P450 (CYP) composition such as CYP2E1 and CYP4A was also suppressed.

Discussion and conclusion: Data suggest that HC-EA extract might act by regulating the AMPK-dependent pathway and related mediators and might be used in treating obesity-related liver diseases.     

Monoterpene phenolic compound thymol prevents high fat diet induced obesity in murine model

Context: Obesity has become a worldwide health problem. Most of the synthetic anti-obesity drugs have failed to manage the obesity due to either ineffectiveness or adverse effect. The research of prominent chemical constituents from herbal for the management of obesity has greatly increased.

Objective: The main objective of the present study was intended to examine the effects of thymol in high-fat diet (HFD)-induced obesity in murine model.

Methods: Male Wistar rats were fed HFD for 6 weeks to induce obesity. Thymol (14?mg/kg) administered orally twice a day to HFD-fed rats for 4 weeks. Alteration in body weight gain, visceral fat-pads weight and serum biochemical markers were assessed.

Results: At the end of study, rats fed with HFD exhibited significantly (p?p?Discussion and conclusions: Thymol prevents HFD-induced obesity in murine model through several mechanisms including attenuation of visceral fat accumulation, lipid lowering action, improvement of insulin and leptin sensitivity and enhanced antioxidant potential.     

Effect of curcumin in mice model of vincristine-induced neuropathy

Abstract

Context: Curcumin exhibits a wide spectrum of biological activities which include neuroprotective, antinociceptive, anti-inflammatory, and antioxidant activity.

Objective: The present study evaluates the effect of curcumin in vincristine-induced neuropathy in a mice model.

Materials and methods: Vincristine sulfate (0.1?mg/kg, i.p. for 10 consecutive days) was administered to mice to induce neuropathy. Pain behavior was assessed at different days, i.e., 0, 7, 10, and 14?d. Sciatic nerve total calcium, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), nitric oxide (NO), and lipid peroxidation (LPO) were also estimated after the 14th day of study. Pregabalin (10?mg/kg, p.o.) and curcumin (15, 30, and 60?mg/kg, p.o.) were administered for 14 consecutive days.

Results: Curcumin at 60?mg/kg significantly attenuated the vincristine-induced neuropathic pain manifestations in terms of thermal hyperalgesia (p?<?0.001) and allodynia (p?<?0.001); mechanical hyperalgesia (p?<?0.001); functional loss (p?<?0.001); and in the delayed phase of formalin test (p?<?0.001). Curcumin at 30 and 60?mg/kg exhibited significant changes (p?<?0.001) in antioxidant levels and in total calcium levels in vincristine-injected mice.

Conclusion: Curcumin at 30 and 60?mg/kg dose levels significantly attenuated vincristine-induced neuropathy which may be due to its multiple actions including antinociceptive, calcium inhibitory, and antioxidant effect.     

Effects of Grifola frondosa non-polar bioactive components on high-fat diet fed and streptozotocin-induced hyperglycemic mice

Abstract

Context: Consumption of medicinal mushrooms for disease prevention and maintaining health has a very long history in Asia. Grifola frondosa (Fr) S.F. Gray (GF) (Meripilaceae) is a medicinal fungus popularly used for enhancing immune systems, lowering blood glucose, and improving spleen, stomach, and nerve functions.

Objective: This study examines the hypoglycemic effects of GF in vitro and in vivo, and analyzes the chemical profiles of its bioactive components.

Materials and methods: In vitro hypoglycemic effects of GF was evaluated enzymatically using α-amylase and α-glucosidase inhibition assays, whereas in vivo study was conducted on high-fat diet fed and streptozotocin (HFD?+?STZ)-induced hyperglycemic mice. GC-MS was used to determine the chemical profiles of bioactive components.

Results: The non-polar fraction of GF exhibited a stronger anti-α-glucosidase activity (IC₅₀: 0.0332?mg/ml) than acarbose, but its anti-α-amylase activity (IC₅₀: 0.671?mg/ml) was weaker. Oral administration of GF at 600?mg/kg (GF600) significantly lowered the blood glucose, HbA1c, average blood glucose, and serum total cholesterol levels in hyperglycemic mice. Although GF was found to contain mainly oleic acid and linoleic acid, their levels in the fungus were low, suggesting that the effects of GF on HFD?+?STZ-induced hyperglycemic mice could be due to factors other than these fatty acids.

Conclusion: These results conclude that GF possesses anti-α-glucosidase activity, and hypoglycemic effect in HFD?+?STZ-induced hyperglycemic mice.     

Inhibitory effect of aqueous extract of different parts of unripe pawpaw (Carica papaya) fruit on Fe2+-induced oxidative stress in rat pancreas in vitro

Abstract

Context: Carica papaya L. (Caricaceae) is widespread throughout tropical Africa; it is cultivated for its fruits and it is eaten in various ways.

Objective: This study sought to investigate the inhibitory effect of the aqueous extract of different parts of unripe pawpaw fruit on Fe²⁺-induced lipid peroxidation in rat’s pancreas in vitro.

Materials and methods: The aqueous extract of the unripe pawpaw fruit parts; peel (PG), seed (SG), flesh (FG), flesh with peel (FPG) and a combination of equal amount of all parts (CG) were prepared, the total phenolic content and the antioxidant activities of the extracts were then evaluated using various spectrophotometric methods.

Result: PG had the highest total phenol content (1.24?mg GAE/g), flavonoid content (0.63?mg QUE/g), reducing power (7.07?mg AAE/g) and Fe²⁺ chelating ability while the SG had the highest 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability. Furthermore, all the extracts caused a significant decrease (p?<?0.05) in the malondialdehyde contents in the pancreas with SG (IC₅₀?=?4.25?mg/mL) having the highest inhibitory effect on Fe²⁺-induced lipid peroxidation.

Discussion and conclusion: This protective effect of the extracts on Fe²⁺-induced lipid peroxidation in rat pancreas could be attributed to their phenolic compounds and, the possible mechanism may be through their antioxidant activities. However, the effect of combination of different parts of unripe pawpaw fruit in equal amount (w/w) on the inhibition of Fe²-induced lipid peroxidation in rat pancreas exhibited additive properties.     

Hypolipidemic effects of Solidago chilensis hydroalcoholic extract and its major isolated constituent quercetrin in cholesterol-fed rats

Abstract

Context: Despite several studies on the effects of Solidago chilensis Meyen (Asteraceae), the phytochemical and hypolipidemic properties remain underappreciated.

Objective: This study evaluates the hypolipidemic and antioxidant effects of hydroalcoholic extract (HE) and quercetrin from S. chilensis aerial parts in cholesterol-fed rats.

Materials and methods: The HE was analyzed by high-performance liquid chromatography, followed by quercetrin isolation. Hypercholesterolemic rats (1% cholesterol and 0.5% cholic acid for 15?d) were treated with HE (150, 300, and 600?mg/kg p.o.; n?=?6), simvastatin (4?mg/kg p.o.; n?=?6), or quercetrin (10?mg/kg p.o.; n?=?6) once a day for 30?d. During this period, a high-cholesterol diet was maintained until the 30th day of treatment.

Results: Rats treated with HE (150, 300, and 600?mg/kg) and quercetrin showed decreased serum levels of total cholesterol (?19.9, ?27.5, ?31.0, and ?39.4%), lipoprotein-cholesterol (?36.0, ?37.5, ?43.3, and ?59.4%), and triacylglycerides (?15.6, ?23.5, ?29.8, and ?27.2%) when compared with the control group similar to simvastatin. Moreover, treatment with HE and quercetrin decreased hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity (35.1% on average) and increased fecal cholesterol levels (38.2% on average).

Discussion and conclusions: Our results suggest that hypolipidemic effects of HE are associated with it modulating the activity of HMG-CoA reductase and its interference in the reabsorption and/or excretion of intestinal lipids. Solidago chilensis and its main constituent, quercetrin, may thus be effective as cholesterol-lowering agents and in preventing atherosclerosis.