Hypolipidemic and antioxidant effects of Morus alba L. (Egyptian mulberry) root bark fractions supplementation in cholesterol-fed rats

The 70% alcohol extract of the Egyptian Morus alba L. root bark was fractionated over cellulose CC eluted with water, 50% methanol and finally with 100% methanol to yield 3 fractions (MRBF-1, MRBF-2 and MRBF-3), respectively. In continuation of chromatographic purification of 70% alcohol extract fractions of the Egyptian M. alba L. root bark, 4 compounds namely: mulberroside A, 5,7,2'-trihydroxyflavanone-4'-O-beta-D-glucoside and albanols A and B were isolated from MRBF-2 for the first time from the Egyptian plant. Experimentally induced atherosclerosis was produced by feeding rats a diet enriched in coconut oil (25% by weight) and cholesterol (2% by weight) for 21 days. Then, hypercholesterolemic rats were orally administered (MRBF-1, MRBF-2 and MRBF-3 fractions) in a dose of 500 mg kg(-1) day(-1) for 15 successive days, in order to evaluate their expected hypocholesterolemic activity. Lipid profile parameters such as plasma total cholesterol, LDL-C, VLDL-C, LDL:HDL ratio and triglycerides, as well as plasma and liver lipid peroxides and glutathione-S-transferase enzyme levels, serum paraoxonase enzyme level, LDL oxidation, LDL aggregation and LDL retention, were measured. Plasma and liver glutathione-S-transferase enzyme levels were unaffected in all studied groups. The results revealed that the administration of (MRBF-2 and/or MRBF-3) fractions resulted in alleviation of atherosclerotic state. Administration of MRBF-3 significantly retained plasma and liver peroxides towards their normal levels, and also, produced significant increase in resistance towards major atherogenic modifications; namely LDL oxidation, LDL aggregation and LDL retention by 44%, 30%, and 33%, respectively. Thus, it can be concluded that the consumption of MRBF-2 and (MRBF-3, in some extent) fractions of M. alba L. root bark 70% alcohol extract may act as a potent hypocholesterolemic nutrient and powerful antioxidant via the inhibition of LDL atherogenic modifications and lipid peroxides formation in hypercholesterolemic rats.     

In vitro antioxidant activity of Juglans regia L. bark extract and its protective effect on cyclophosphamide-induced urotoxicity in mice

Walnut (Juglans regia L.) bark has been claimed to possess anti-inflammatory, blood purifying, anticancer, depurative, diuretic and laxative activities. It contains several therapeutically active constituents, especially polyphenols. We studied the antioxidant potential of aqueous extract of walnut bark and its modulatory effect on cyclophosphamide (CP)-induced urotoxicity in Swiss albino male mice. Free radical-scavenging activity of extract was assessed in four in vitro assays. The phenolic and flavonolic contents of the extract were also measured. Walnut bark extract treatment (150 mg/kg p.o. x 10 days) resulted in protective restoration of decreased antioxidants in CP-treated (18 mg/kg i.p. x 10 days) animals. CP treatment caused decreases in the activities of catalase (CAT), glutathione peroxidase (GP), glutathione reductase (GR) and glutathione S-transferase (GST) and in the glutathione (GSH) content in urinary bladder and a significant concomitant increase in lipid peroxidation (LPO). Administration of extract restored all the antioxidants significantly and lowered the elevated LPO in the bladder. A correlation between radical scavenging capacities of the extract with phenolic content was observed thus justifying its antioxidant potential against oxidative stress-mediated urotoxicity in mice. Walnut is reported to possess antiproliferative activity. Its protective effect on CP-induced toxicity in bladder is a promising activity, which warrants possible clinical investigations on this medicinal plant.     

Free radical scavenging activity of the marine mangrove Rhizophora apiculata bark extract with reference to naphthalene induced mitochondrial dysfunction

Rhizophora apiculata bark extract was tested for its free radical scavenging activity and protective role against mitochondrial dysfunction in naphthalene stressed rats. Lipid peroxidation activity was increased and activity of mitochondrial enzymes (cytochrome-c-oxidase, NADH-dehydrogenase, alpha-ketoglutarate dehydrogenase and succinate dehydrogenase) and glutathione was decreased in the liver and kidney of rats intoxicated with naphthalene when compared to control rats. Intraperitoneal administration of plant extract significantly reduced the lipid peroxidation, increased the activity of mitochondrial enzymes and increased glutathione to near control levels. These results suggest that the sulfated polysaccharides in R. apiculata play a protective role through their free radical scavenging properties.     

Effects of pycnogenol treatment on oxidative stress in streptozotocin-induced diabetic rats

Free radicals and oxidative stress have been implicated in the etiology of diabetes and its complications. This in vivo study has examined whether subacute administration of pycnogenol, a French pine bark extract containing procyanidins that have strong antioxidant potential, alters biomarkers of oxidative stress in normal and diabetic rats. Diabetes was induced in female Sprague-Dawley rats by a single injection of streptozotocin (90 mg/kg body weight, ip), resulting (after 30 days) in subnormal body weight, increased serum glucose concentrations, and an increase in liver weight, liver/body weight ratios, total and glycated hemoglobin, and serum aspartate aminotransferase activity. Normal and diabetic rats were treated with pycnogenol (10 mg/kg body weight/day, ip) for 14 days. Pycnogenol treatment significantly reduced blood glucose concentrations in diabetic rats. Biochemical markers for oxidative stress were assessed in the liver, kidney, and heart. Elevated hepatic catalase activity in diabetic rats was restored to normal levels after pycnogenol treatment. Additionally, diabetic rats treated with pycnogenol had significantly elevated levels of reduced glutathione and glutathione redox enzyme activities. The results demonstrate that pycnogenol alters intracellular antioxidant defense mechanisms in streptozotocin-induced diabetic rats.     

Antitumour activity of some plants from Meghalaya and Mizoram against murine ascites Dalton's lymphoma

Total five plants, three from Mizoram (Dillenia pentagyna, Ageratum conyzoides, Blumea lanceolaria) and two from Meghalaya (Potentilla fulgens, Taxus baccata) were studied for their antitumour activity against murine ascites Dalton's lymphoma (DL) in vivo. Only three plants showed the different magnitude of antitumour activity. Out of these three plants, the antitumour activity was maximally observed with the methanol extract of the stem bark of D. pentagyna as compared to the aqueous extract of the roots of A. conyzoides and aqueous extract of the root of P. fulgens. An increase in glutathione levels in Dalton's lymphoma cells was observed during tumour growth. Changes in glutathione and protein levels were also investigated in the liver and Dalton's lymphoma cells of tumour-bearing mice following the treatment with the extract of D. pentagyna which showed the highest antitumour activity as compared to the other two plant extracts. Glutathione in the liver and DL cells of treated tumour-bearing mice was found to be decreased. The protein concentration in liver and DL cells decreased mainly at 96 hr of treatment. It may be concluded that the natural product of D. pentagyna promises to be more active against Dalton's lymphoma than others and the decrease in glutathione level may be one of the important steps in resulting this antitumour effect.     

Etude de l’effet androgénique de l’extrait au méthanol deBasella alba L. (Basellaceae) sur la fonction de reproduction du rat mâle

Basella alba is a plant used by some herbalists of the West province of Cameroon to enhance male virility and fertility. Previousin vitro studies have shown the androgenic activity of its methanol extract. This study therefore focused on confirmation of the androgenic activity of the methanol extract ofB. alba in vivo in male rats. A suspension of this extract in corn starch was administered daily to 5 groups of rats at doses of 0,0.1, 1, 10 and 100 mg/kg respectively for 30 days. The animals were weighed every second day during this period. On the 31^st day of the experiment, the animals were sacrificed and blood was collected for serum assays. The liver and reproductive organs (testes, epididymides, seminal vesicles and prostates) were also collected and weighed. Serum testosterone level was determined by radio-immunoassay (¹²⁵I-RIA) techniques, and various markers of liver and kidney toxicity (alanine aminotransferase and creatinine) were also assayed. Liver post-mitochondrial supernatant was used to estimate other markers of cell integrity, such as malondialdehyde, glutathione, and aniline hydroxylase activity. The results showed that the methanol extract ofB. alba has no effect on the weight of the animal and reproductive organs compared to the control. After 30 days of treatment, serum testosterone levels were significantly increased (p<0.0005) up to the dose of 1 mg/kg, but decreased at higher dosages of the extract, although remained higher than that of controls. Aniline hydroxylase and aminotransferase activities, malondialdehyde, protein, glutathione and creatinine levels were not significantly altered by administration of the methanol extract ofB. alba. These results suggest that the methanol extract ofB. alba has anin vivo androgenic activity with a maximum effect at the dose of 1 mg/kg body weight.     

Protective effect of green tea against lipid peroxidation in the rat liver, blood serum and the brain

This paper reports data on the effect of green tea on the lipid peroxidation products formation and parameters of antioxidative system of the liver, blood serum and central nervous tissue of healthy young rats drinking green tea for five weeks. The rats were permitted free access to solubilized extract of green tea. Bioactive ingredients of green tea extract caused in the liver an increase in the activity of glutathione peroxidase and glutathione reductase and in the content of reduced glutathione as well as marked decrease in lipid hydroperoxides (LOOH), 4-hydroksynonenal (4-HNE) and malondialdehyde (MDA). The concentration of vitamin A increased by about 40%. Minor changes in the measured parameters were observed in the blood serum. GSH content increased slightly, whereas the index of the total antioxidant status increased significantly. In contrast, the lipid peroxidation products, particularly MDA was significantly diminished. In the central nervous tissue the activity of superoxide dismutase and glutathione peroxidase decreased while the activity od glutathione reductase and catalase increased after drinking green tea. Moreover the level of LOOH, 4-HNE and MDA significantly decreased. The use of green tea extract appeared to be beneficial to rats in reducing lipid peroxidation products. These results support and substantiate traditional consumption of green tea as protection against lipid peroxidation in the liver, blood serum, and central nervous tissue.     

Enhancement of the Tyrosinase Inhibitory Activity of Mori Cortex Radicis Extract by Biotransformation Using Leuconostoc paramesenteroides PR

Mori Cortex Radicis (MCR), the root bark of Morus alba L., consists of various phytochemicals and exhibits a strong inhibitory effect on tyrosinase. To enhance the tyrosinase inhibitory activity of MCR extract without further purification of bioactive compounds, whole MCR extract was biotransformed with crude enzyme extract from a selected lactic acid bacterium, Leuconostoc paramesenteroides PR (LP). Mulberroside A (MA), a major stilbene glucoside of MCR, contains two β-glucosyl residues at the C3 and C4' positions of oxyresveratrol (OXY). The crude enzyme of LP hydrolyzed the two glycosidic bonds of MA effectively, and 97.1% of MA was biotransformed into OXY within 2 h. Commercial almond β-glucosidase hydrolyzed only one site of the two glycosidic bonds of MA, and 68.7% of MA was biotransformed to OXY-glucoside. The tyrosinase inhibitory activity of the crude extract of MCR was increased approximately 6.5-fold by biotransformation using LP, and the IC(50) value of the transformed MCR was 3.7 μg/mL.     

Ocimum sanctum aqueous leaf extract provides protection against mercury induced toxicity in Swiss albino mice

HgCl2 (5.0 mg/kg body weight) induced toxicity led to significant elevation of lipid peroxidation (LPO) level but decline in the glutathione content in liver of Swiss albino mice. In serum of HgCl2 treated mice there was significant elevation in serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) activities but significant decline in the alkaline phosphatase activity. Animals treated with O. sanctum extract (10 mg/kg body weight, po) before and after mercury intoxication showed a significant decrease in LPO level, SGOT and SGPT activities and increase in serum alkaline phosphatase activity and glutathione (GSH) content. Ocimum treatment alone did not alter SGOT, SGPT and alkaline phosphatase activities but significantly enhanced reduced glutathione. The results suggest that oral administration of Ocimum extract provides protection against HgCl2 induced toxicity in Swiss albino mice.     

Inhibition of potassium bromate-induced renal oxidative stress and hyperproliferative response by Nymphaea alba in Wistar rats

KBrO3-mediated renal injury and hyperproliferative response in Wistar rats. In this communication, we report the efficacy of Nymphaea alba on KBrO3 (125 mg/kg body weight, intraperitoneally) caused reduction in renal glutathione content, renal antioxidant enzymes and phase-II metabolising enzymes with enhancement in xanthine oxidase, lipid peroxidation, gamma-glutamyl transpeptidase and hydrogen peroxide (H202). It also induced blood urea nitrogen, serum creatinine and tumor promotion markers, viz., ornithine decarboxylase (ODC) activity and DNA synthesis. Treatment of rats with Nymphaea alba (100 and 200 mg/kg body weight) one hour before KBrO3 (125 mg/kg body weight, i.p.) resulted in significant decreases in xanthine oxidase (P < 0.05), lipid peroxidation, gamma-glutamyl transpeptidase, H202 generation, blood urea nitrogen, serum creatinine, renal ODC activity and DNA synthesis (P < 0.001). Renal glutathione content, glutathione metabolizing enzymes and antioxidant enzymes were also recovered to significant levels (P < 0.001). These results show that Nymphaea alba acts as chemopreventive agent against KBrO3-mediated renal injury and hyperproliferative response.     

Antihyperglycemic and antioxidant effect of hydroethanolic extract of Butea monosperma bark in diabetic mice

The antihyperglycemic, antihyperlipidemic and antioxidative properties of hydroethanolic extract of Butea monosperma bark were investigated in alloxan-induced diabetic mice. Alloxan administration resulted in higher blood glucose level and reduced hepatic glycogen content as compared to normal animals. Besides, serum lipid profile parameters such as total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and very low density lipoprotein (VLDL) cholesterol were also found to be significantly elevated, whereas the level of high density lipoprotein (HDL) cholesterol was markedly reduced in diabetic animals. Oxidative damage in the tissues of diabetic mice was evidenced by a marked increase in the level of thiobarbituric acid reactive substances (TBARS), distinct decrease in reduced glutathione (GSH) content and declined activity of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). The daily treatment of diabetic animals with crude extract of B. monosperma bark (300 mg kg(-1)) for 45 days significantly lowered blood glucose level and elevated hepatic glycogen content, bringing the values close to those observed in normal control and glibenclamide-treated diabetic mice. Furthermore, the level of various lipid profile parameters was also reversed towards normal. TBARS and GSH also restored towards normal and the declined activity of antioxidant enzymes in diabetic animals was also normalized in crude extract administered mice, thus indicating the antioxidant efficacy of the drug in diabetes-induced oxidative damage. Significant antihyperglycemic and antioxidant potential of the crude extract of B. monosperma bark indicated that it may find use in the management of diabetes and resultant oxidative stress.     

Pharmacological credence of the folklore use of Bauhinia malabarica in the management of jaundice

The information on the hepatoprotective effect of Bauhinia malabarica Roxb. (Family Leguminosae) used in the folkloric medical practice in Malabar coast and Walayar valley of southern India for the treatment of liver related disorders is completely unknown. Hence, the efficacy of the aqueous methanolic extract of stem bark of B. malabarica (AqMeOH-Ba) was evaluated for liver function serum biochemical markers along with the antioxidant markers in liver tissues of Wistar albino rats. The biochemical observations as well as the histopathological examination of liver sections manifested considerable hepatoprotective activity of B. malabarica stem bark, and thus validated the folkloric claim.     

Pulmonary and hepatic glutathione levels, glutathione shuttle enzymes and lipid peroxidation in rats exposed intratracheally to coal fly ash

Fly ash and fly ash residue increased the formation of conjugated dienes and the levels of oxidized glutathione (GSSG) and reduced the levels of reduced glutathione (GSH) in lung and liver whereas fly ash extract administration had no effect on the formation of conjugated dienes and glutathione levels in lung and liver. Fly ash and fly ash residue reduced the activity of glutathione reductase both in lung and liver but did not alter the activity of glutathione peroxidase. Fly ash and fly ash extract significantly increased glucose-6-phosphate dehydrogenase activity in lung whereas in liver, fly ash and fly ash residue reduced the activity of glucose-6-phosphate dehydrogenase. Fly ash residue did not alter the activity of glucose-6-phosphate dehydrogenase in lung whereas fly ash extract was not effective in liver.     

Effect of procyanidins from Pinus maritima on glutathione levels in endothelial cells challenged by 3-morpholinosydnonimine or activated macrophages

The effects of reactive nitrogen species on glutathione homeostasis in human endothelial ECV 304 cells challenged by 3-morpholinosydnonimine-N-ethylcarbamide (SIN-1) on RAW 264.7 activated macrophages using a co-culture model were investigated. SIN-1 or macrophages activated by lipopolysaccharide plus interferon-gamma induced a significant glutathione decrease in ECV 304 cells. Pre-incubation of ECV 304 cells with French maritime pine bark extract containing mainly oligomeric procyanidins protected endothelial cells from activated macrophage-induced glutathione depletion. Data demonstrate that reactive nitrogen species generated with different kinetics and mechanisms impair glutathione levels in endothelial cells, and that pine bark extract significantly enhances antioxidant defenses.     

Moringa peregrina leaf extracts produce anti-obesity,hypoglycemic, anti-hyperlipidemic,and hepatoprotective effects on high-fat diet fed rats

This present research investigated the anti-obesity and hepatoprotective effects of ethanolic Moringa peregrina leaf (MPLE) and bark extracts (MPBE), in the rats fed with a high-fat diet (HFD). Healthy male rats (n = 48) were randomly distributed to six groups (n = 8): control AIN-93 diet; HFD; HFD + MPBE bark extracts ((300 mg/kg); HFD + MPBE (600 mg/kg); HFD + MPLE (300 mg/kg); HFD + MPLE (600 mg/kg). HFD-fed rats in the Moringa peregrina (MP) treatment groups received orally administered MP leaf or bark extract daily for eight weeks. The results revealed that both doses of MP leaf extract significantly reduced HFD-induced increases in their food intake and the gained body weight, fat pad weights (visceral, subcutaneous, and epididymal), glucose and insulin plasma levels, and leptin and resistin serum levels in HFD-fed rats. Concomitantly, MP leaf extract improved glucose levels after oral or intraperitoneal glucose tolerance tests, reduced serum cholesterol, triglycerides, and the low-density lipoprotein LDL concentration, reduced hepatic triglycerides and cholesterol levels, and increased serum high-density lipoproteins HDL levels and triglycerides and cholesterol levels in fecal. Moreover, the administration of MPLE to HFD-fed rats improved liver architecture, reduced fat accumulation, reduced hepatic malondialdehyde, tumor necrosis factor-α, and interleukin-6 levels. Hepatic glutathione peroxidase, superoxide dismutase, and catalase activities were significantly increased. All observed effects were more pronounced in HFD-fed rats treated with a 600 mg/kg MP dose. However, neither dose of MPBE altered the measured markers in the HFD-fed rats. In conclusion, MPLE showed potential anti-obesity and hepatoprotective activity in HFD-induced obese rats, mediated by reduced lipid absorption, anti-hyperlipidemic effects, and hepatic antioxidant effects.     

Effect of procyanidins from Pinus maritima on glutathione levels in endothelial cells challenged by 3-morpholinosydnonimine or activated macrophages

Abstract

The effects of reactive nitrogen species on glutathione homeostasis in human endothelial ECV 304 cells challenged by 3-morpholinosydnonimine-N-ethylcarbamide (SIN-1) or RAW 264.7 activated macrophages using a co-culture model were investigated. SIN-1 or macrophages activated by lipopolysaccharide plus interferon-gamma induced a significant glutathione decrease in ECV 304 cells. Pre-incubation of ECV 304 cells with French maritime pine bark extract containing mainly oligomeric procyanidins protected endothelial cells from activated macrophage-induced glutathione depletion. Data demonstrate that reactive nitrogen species generated with different kinetics and mechanisms impair glutathione levels in endothelial cells, and that pine bark extract significantly enhances antioxidant defenses.     

Antioxidant activity and hepatoprotective potential of Hammada scoparia against ethanol-induced liver injury in rats

The present work was aimed at studying the antioxidative activity and hepatoprotective effects of methanolic extract (ME) of Hammada scoparia leaves against ethanol-induced liver injury in male rats. The animals were treated daily with 35 % ethanol solution (4 g?kg^?1?day^?1) during 4 weeks. This treatment led to an increase in the lipid peroxidation, a decrease in antioxidative enzymes (catalase, superoxide dismutase, and glutathione peroxidase) in liver, and a considerable increase in the serum levels of aspartate and alanine aminotransferase and alkaline phospahatase. However, treatment with ME protects efficiently the hepatic function of alcoholic rats by the considerable decrease in aminotransferase contents in serum of ethanol-treated rats. The glycogen synthase kinase-3 β was inhibited after ME administration, which leads to an enhancement of glutathione peroxidase activity in the liver and a decrease in lipid peroxidation rate by 76 %. These biochemical changes were consistent with histopathological observations, suggesting marked hepatoprotective effect of ME. These results strongly suggest that treatment with methanolic extract normalizes various biochemical parameters and protects the liver against ethanol induced oxidative damage in rats.     

Antiviral flavonoids from the root bark of Morus alba L

A prenylated flavonoid, moralbanone, along with seven known compounds kuwanon S, mulberroside C, cyclomorusin, eudraflavone B hydroperoxide, oxydihydromorusin, leachianone G and alpha-acetyl-amyrin were isolated from the root bark of Morus alba L. Leachianone G showed potent antiviral activity (IC(50) = 1.6 microg/ml), whereas mulberroside C showed weak activity (IC(50) = 75.4 microg/ml) against herpes simplex type 1 virus (HSV-1). Their structures were elucidated by spectroscopic methods.     

两种天然植物提取物的抑菌效果的快速评价与比较

本文研究了绿茶和桑叶提取物在不同浓度时对细菌的抑制作用,采用D值计算法快速评价了它们的抑菌效果。结果表明,绿茶提取物对金黄色葡萄球菌和大肠杆菌的最低抑制浓度分别为0.034%,0.42%;而桑叶提取物分别为0.86%,1.54%。绿茶的抑菌效果更好。     

Steroidal constituents and anti-inflammatory activity of the horse chestnut (Aesculus hippocastanum L.) bark

The content and the composition of sterols in the bark of the horse chestnut, Aesculus hippocastanum L., have been examined. Stigmasterol and alpha-spinasterol were, with the beta-sitosterol, the most abundant sterols. The petrol extract from bark shows anti-inflammatory activity.