Pinoresinol-4-O-ß-D-glucopyranoside: a lignan from prunes (Prunus domestica) attenuates oxidative stress, hyperglycaemia and hepatic toxicity in vitro and in vivo.

OBJECTIVES: This study aimed to explore the pharmacological properties of pinoresinol-4-O-ß-D-glucopyranoside (PG), isolated from prunes. METHODS: In-vitro antioxidant activity was assessed using ferric reducing antioxidant power (FRAP) and 2,2'-azino-bis [3-ethylbenzothiazoline-6-sulfonic acid]-diammonium salt (ABTS) assays. In-vivo hepatoprotective activity was evaluated using CCl4 -induced hepatotoxicity mouse model. The antihyperglycaemic activity was determined in vitro using α-glucosidase and α-amylase inhibiting activity and in vivo using streptozotocin-treated model. Molecular modelling was done on α-amylase, α-glucosidase, aldose reductase and peroxisome proliferator-activated receptor gamma. KEY FINDINGS: Pinoresinol-4-O-ß-D-glucopyranoside showed promising antioxidant activity in FRAP and ABTS assays with total antioxidant capacity equal 418.47 and 1091.3 µmol/g in terms of ascorbic acid, respectively. PG (50 mg/kg b.w.) exhibited a hepatoprotective activity in vivo as it lowered AST and ALT levels. PG showed a potent in-vitro antihyperglycaemic activity as it inhibited α-glucosidase with an IC50 value of 48.13 µg/ml. PG caused a prominent decline in serum glucose level by 37.83% in streptozotocin-treated mice with promising elevation in insulin level of 25.37%. Oxidative stress markers were reduced by PG, and it showed a high fitting on α-amylase and α-glucosidase active sites. CONCLUSIONS: Pinoresinol-4-O-ß-D-glucopyranoside is a natural entity combating oxidative stress, hepatic damage and diabetes.

Chemical profiling of secondary metabolites of Eugenia uniflora and their antioxidant, anti-inflammatory, pain killing and anti-diabetic activities: A comprehensive approach.

ETHNOPHARMACOLOGICAL RELEVANCE: The red Brazilian cherry, Eugenia uniflora, is widely used in traditional medicine. The aim of this study was to investigate the phytochemical composition of a methanol extract from leaves of E. uniflora and characterization of the isolated compounds. In addition, we aimed to determine the antioxidant activities in vitro and in a cell-based (HaCaT cell) model. We also studied the anti-inflammatory, analgesic, antipyretic and antidiabetic activities in relevant rat models. The molecular mode of action of the antidiabetic activities was also investigated. MATERIALS AND METHODS: UV, MS, and NMR (1H, 13C, DEPT, COSY, HMQC, and HMBC) were used to identify the secondary metabolites. Antioxidant effects were determined in vitro and in HaCaT cells. The ani-inflammatory and antidibetic activities were studied in experimental animals. RESULTS: In this work, a new compound, gallic acid 3-O-[6'-O-acetyl-ß-D-glucoside], along with 16 known plant secondary metabolites (PSM) were isolated, characterized using UV, MS, and NMR (1H, 13C, DEPT, COSY, HMQC, and HMBC). Noticeable antioxidant effects were determined in HaCaT cells: The extract reduced the elevated levels of ROS and p38 phosphorylation and increased the reduced glutathione (GSH) content induced by UVA. The extract showed substantial anti-inflammatory activities in vivo: It diminished the edema thickness in carrageenan-induced hind-paw edema rat model and lowered the leukocyte migration into the peritoneal cavity. In rats, central and peripheral anti-nociceptive properties were also observed: The extract reduced the number of writhing in acid induced writhing and increased the latency time in hot plate test. Furthermore, adequate antipyretic effects were observed: The extract reduced the elevated rectal temperature in rats after intraperitoneal injection of Brewer's yeast. Moreover, the extract possessed robust anti-diabetic activity in streptozotocin (STZ) -diabetic rats: It markedly reduced the elevated serum glucose and lipid peroxidation levels and increased the insulin concentration in serum with higher potency than the positive control, glibenclamide. These effects might be associated with the interaction of PSM with the conserved amino acid residues of human pancreatic α-amylase (HPA), maltase glucoamylase (MGAM-C) and aldose reductase (ALR2) revealing considerable binding affinities. CONCLUSION: A plethora of substantial pharmacological properties indicates that Eugenia uniflora is a good antioxidant and a sustainable by-product with solid therapeutic potential for treating diabetes, inflammation, pain and related oxidative stress diseases.

Validation of the antihyperglycaemic and hepatoprotective activity of the flavonoid rich fraction of Brachychiton rupestris using in vivo experimental models and molecular modelling.

Oxidative stress leads to many disorders as diabetes mellitus and liver diseases. This study evaluates the antihyperglycemic and hepatoprotective activities of Brachychiton rupestris (Malvaceae). The antihyperglycemic activity of the total methanol extract of B. rupestris leaves (BRT) and its ethyl acetate fraction (BRE) was evaluated using streptozotocin induced diabetic rats. The hepatoprotective activity was assessed using carbon-tetrachloride induced hepatotoxicity. Oral administration of 50 mg/kg b.wt (body weight) of BRT and BRE to Streptozotocin -diabetic rats caused a notable decrease in serum glucose by 39.38 and 42.09% with 35.62 and 15.44% increase in serum insulin, respectively, compared with Streptozotocin-diabetic rats. Oral administration of BRT and BRE to carbon-tetrachloride -treated rats (50 mg/kg b.wt) resulted in reduction in serum aspartate transaminase (AST) (28.88 and 27.2%, respectively) and alanine transaminase (ALT) (8 and 13.56%) levels, respectively. They also ameliorated oxidative stress in both models as evidenced from oxidative stress markers. Liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) analysis of the most active fraction (BRE) identified nine compounds including flavonoids and phenolic acids. Molecular modelling of the identified compounds was performed on human pancreatic α-amylase (HPA) and human α-glucosidase (HAG) using Discovery Studio 2.5. Quercetin-3-O-(6″-O-α-l-rhamnopyranosyl)-ß-D-glucoside showed the greatest affinity towards both HPA and HAG. Thus, this study provided scientific evidence on the antihyperglycemic and hepatoprotective activities of Brachychiton rupestris.

Hepatoprotective and hypoglycemic effects of a tannin rich extract from Ximenia americana var. caffra root.

BACKGROUND: Liver diseases and diabetes are serious health disorders associated with oxidative stress and ageing. Some plant polyphenols can lower the risk of these diseases. PURPOSE: We investigated the phytochemical profiling of a root extract from Ximenia americana var. caffra using HPLC-PDA-ESI-MS/MS. The antioxidant activities in vitro were investigated. The hepatoprotective activities were studied in rat models with d-galactosamine (d-GaIN)-induced hepatotoxicity and the antidiabetic activities in STZ-diabetic rats were also investigated. MATERIALS AND METHODS: HPLC-PDA-ESI-MS/MS was used to identify plant phenolics. The antioxidant activities in vitro were determined using DPPH and FRAP assays. The in vivo hepatoprotective activities were determined for d-GaIN-induced hepatotoxicity in rats. We determined the liver markers alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT), liver peroxidation product malondialdehyde (MDA), glutathione content (GSH), albumin and total bilirubin concentration. The histopathological changes in rat liver were also studied. The antidiabetic activities were also investigated in STZ-diabetic rats and serum glucose, serum insulin hormone, and lipid peroxides were determined. RESULTS: The root extract is rich in tannins with 20 compounds including a series of stereoisomers of (epi)catechin, (epi)catechin-(epi)catechin, (epi)catechin-(epi)catechin-(epi)catechin, and their galloyl esters. Promising antioxidant potential was observed in vitro in DPPH assay with EC50 of 6.5 µg extract / 26 µg raw material and in FRAP assay with 19.54 mM FeSO4 compared with ascorbic acid (EC50 of 2.92 µg/ml) and quercetin (FeSO4 24.04 mM/mg), respectively. Significant reduction of serologic enzymatic markers and hepatic oxidative stress markers such as ALT, AST, MDA, GGT, and total bilirubin, as well as elevation of GSH and albumin were observed in rats with d-galactosamine-induced liver damage treated with the extract. These findings agree with a histopathological examination suggesting a hepatoprotective potential for the root extract. The root extract can mediate an antidiabetic effect by reducing elevated blood glucose and serum lipid peroxides levels and by increasing insulin in STZ-diabetic rats by -107, -31.1, +11.3%, respectively. CONCLUSIONS: The results of this study suggest that the tannin-rich extract from Ximenia americana var. caffra could be an interesting candidate for the treatment of several health disorders associated with oxidative stress such as hepatocellular injury and diabetes.

Antihyperglycaemic activity of the methanol extract from leaves of Eremophila maculata (Scrophulariaceae) in streptozotocin-induced diabetic rats.

OBJECTIVES: This study was designed to evaluate the antihyperglycaemic activity of the methanol leaf extract of Eremophila maculata (EMM) both in vitro and in vivo. METHODS: The antihyperglycaemic activity was assessed in vitro using differentiated 3T3-L1 adipocytes, whereas in-vivo effect was evaluated in streptozotocin-induced diabetic rats. Chemical profiling of EMM was done using LC-ESI-MS techniques. Molecular modelling experiments of the identified compounds were performed using C-Docker protocol. KEY FINDINGS: Eremophila maculata slightly enhanced cellular glucose uptake and utilization in vitro by 3.92% relative to the untreated control. A stronger in-vivo effect was observed for EMM and its dichloromethane fraction. A pronounced elevation in serum insulin by 88.89 and 66.67%, respectively, accompanied by an apparent decline in fasting blood glucose (FBG) level by 65.60 and 70.37% comparable to streptozotocin-induced diabetic rats was observed. This effect was stronger than that of the reference drug glibenclamide (GLB). Chemical profiling of EMM revealed that leucoseptoside A, verbascoside, syringaresinol-4-O-ß-D-glucopyranoside, pinoresinol-4-O-ß-D-glucopyranoside and pinoresinol-4-O-[6″-O-(E)-feruloyl]-ß-D-glucopyranoside are the major compounds. Molecular modelling showed that martynoside, verbascoside and phillygenin exhibited the highest inhibition to human pancreatic α-amylase (HPA), maltase glucoamylase (MGAM) and aldose reductase (AR), respectively. CONCLUSION: Eremophila maculata offers an interesting relatively safer antihyperglycaemic candidate comparable to synthetic analogues.

Eremophila maculata-Isolation of a rare naturally-occurring lignan glycoside and the hepatoprotective activity of the leaf extract.

BACKGROUND: The Australian plant Eremophila maculata F. Muell (Scrophulariaceae) is cultivated worldwide as an ornamental plant. PURPOSE: This study was designed to assess the antioxidant and hepatoprotective activities of a methanol extract from E. maculata leaves (EMM) both in vitro and in vivo (rats) experiments. Detailed phytochemical study was done on the extract followed by molecular docking experiments on TNF-α ascertain the efficacy of the isolated compounds. METHODS: The antiproliferative activity was evaluated in the human cancer cell lines A-495, PC3 and HepG2 cells using the SRB method. The antioxidant activitywas evaluated in vitro using the DPPH• assay while the hepatoprotective properties were investigated by determining the amelioration of CCl4-induced cytotoxicity and oxidative stress in HepG2 cells. The activity was confirmed in vivo by studying tamoxifen-induced hepatotoxicity in rats. An in-depth phytochemical investigation of a methanol extract was performed using 1D and 2D NMR experiments. In silico molecular modeling studies of the isolated compounds on TNF-α (PDB ID 2AZ5) were carried out using Discovery Studio 2.5 software applying C-Docker protocol. RESULTS: The IC50 values of EMM were >500µg/ml for both PC3 and HepG2 cells indicating its safety. Similar to the standard drug silymarin, EMM could restore AST, ALT values; replenish GSH level, SOD activity and TAC in vitro. The hepatoprotective activity was confirmed in vivo in which the extract (20mg/kg body weight) decreased ALT and AST levels by 45.23 and 45.79%, respectively as compared to the tamoxifen treated groups. Oxidative stress was reduced by lowering of thiobarbituric acid reactive substances by 28.57%. Additionally, hepatocyte inflammation was improved by reducing the pro-inflammatory mediator TNF-α by 54.29%. Phytochemical investigation resulted in the isolation of a rare naturally-occurring lignan glycoside, namely pinoresinol-4-O-[6″-O-(E)-feruloyl]-ß-D-glucopyranoside for the first time from the Scrophulariaceae in addition to 12 known compounds.Pinoresinol-4-O-[6''-O-(E)-feruloyl]-ß-D-glucopyranoside was the strongest inhibitor of TNF-α as evidenced from its higher fitting scores comparable to lead compound. CONCLUSIONS: These findings highlighted for the first time that EMM could be an interesting candidate as a safe, natural liver supplement for relieving of various hepatic disorders and counteracting the effect of many xenobiotics.

Cytotoxic activity of methanolic extract of Mentha longifolia and Ocimum basilicum against human breast cancer.

Labiatae family is represented in Saudi Arabia. The aim of the present study was to go insight to investigate the anticancer activity and antioxidative potentials of methanolic extracts of Mentha longifolia L. (ML) and Ocimum basilicum L. (OB) that grown in Madina province, western region, Saudi Arabia. OB exhibited the greater phenolic contents as mg gallic acid equivalent/g weight (mg GAE/g) for a value of 105 +/- 5.5 mg GAE/g. On the other hand, ML produced 29 +/- 3.12 mg GAE/g. The standard antioxidant vitamin E used in this experiment elicited a value of total phenolic contents equal 22 +/- 2.2 mg GAE/g. The percentage scavenging activity of against diphenylpicrylhydrazyl (DPPH) was 850 and 160% for OB and ML extracts, respectively. Vitamin E elicited% scavenging activity of against DPPH equal to 198%. Brine shrimp cytotoxic assay clearly indicated the cytotoxic effects of either ML or OB extract. The brine shrimp survival is inversely proportional to the concentration of either ML or OB extract used with LD50 191.23 and 235.50 ppm, respectively. Toxic effects on brine shrimps indicated the anticancer potential of ML or OB extract. The ML or OB extract was unable to produce pbluescript (pBS) plasmid DNA damage, while the plasmid DNA treated with EcoRI produced a single band as a result of DNA damage. Also, both ML and OB extract exhibited marked cytotoxic activity against MCF-7 cells at various concentrations (20, 40, 80, 160 and 320 microg mL(-1)). The 160 and 320 microg mL(-1) showed more cytotoxic effect against MCF-7 cells. Based on results achieved, we can concluded that, OB and ML extracts have the potency to act as powerful antioxidants and protect against DNA damage and have cytotoxic activity against MCF-7 cell line.

Protective effect of dietary flavonoid quercetin against lipemic-oxidative hepatic injury in hypercholesterolemic rats.

CONTEXT: Quercetin, a dietary-derived flavonoid, is ubiquitous in fruits and vegetables and plays important roles in human health by virtue of its antioxidant activity. OBJECTIVE: This study was conducted to investigate the possible modulatory effect of quercetin against hepatic lipemic-oxidative injury in rats fed with a high cholesterol diet (HCD), and to highlight the underlying mechanisms of such effect. MATERIALS AND METHODS: Different groups of male Sprague-Dawley rats were used; one group was treated by gavage with HCD cocktail (1 mL/100 g) whereas another group was orally administered HCD-enriched with quercetin (15 mg/kg). Corresponding control animals were also used. RESULTS: Quercetin administration significantly decreased liver triglycerides (24%), liver total cholesterol (TC) (22%), serum TC (20%), serum low-density lipoprotein cholesterol (31%), and duplicated serum high-density lipoprotein cholesterol (HDL-C). This study also revealed that quercetin administration significantly reduced the activity of serum alanine aminotransferase (41%), aspartate aminotransferase (51%), and γ-glutamyl transpeptidase (G-GT) (35%). Significant inhibition of thiobarbituric acid-reacting substances (40%), together with a valuable enhancement of reduced glutathione (GSH) content (53%) in the liver homogenates, was observed. In addition, quercetin-treated hypercholesterolemic animals exhibited a reasonable improvement of hepatic antioxidant enzymes. Moreover, serum and liver content of nitric oxide (NO) were markedly decreased in this model (26 and 25%, respectively), and were almost normalized following quercetin administration. DISCUSSION AND CONCLUSION: These data revealed that quercetin has the ability to ameliorate HCD-induced lipemic-oxidative injury in rat liver possibly through its antioxidant potential and/or increased NO bioavailability.

Antioxidant activity of Artocarpus heterophyllus Lam. (Jack Fruit) leaf extracts: remarkable attenuations of hyperglycemia and hyperlipidemia in streptozotocin-diabetic rats.

The present study examines the antioxidative, hypoglycemic, and hypolipidemic activities of Artocarpus heterophyllus (jack fruit) leaf extracts (JFEs). The 70% ethanol (JFEE), n-butanol (JFBE), water (JFWE), chloroform (JFCE), and ethyl acetate (JFEAE) extracts were obtained. Both JFEE and JFBE markedly scavenge diphenylpicrylhydrazyl radical and chelate Fe+2 in vitro. A compound was isolated from JFBE and identified using 1D and 2D 1H- and 13C-NMR. The administration of JFEE or JFBE to streptozotocin (STZ)-diabetic rats significantly reduced fasting blood glucose (FBG) from 200 to 56 and 79 mg%, respectively; elevated insulin from 10.8 to 19.5 and 15.1 µU/ml, respectively; decreased lipid peroxides from 7.3 to 5.4 and 5.9 nmol/ml, respectively; decreased %glycosylated hemoglobin A1C (%HbA1C) from 6.8 to 4.5 and 5.0%, respectively; and increased total protein content from 2.5 to 6.3 and 5.7 mg%, respectively. Triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), VLDL-C, and LDL/HDL ratio significantly declined by -37, -19, -23, -37, and -39%, respectively, in the case of JFEE; and by -31, -14, -17, -31, and -25%, respectively, in the case of JFBE; as compared to diabetic rats. HDL-C increased by +37% (JFEE) and by +11% (JFBE). Both JFEE and JFBE have shown appreciable results in decreasing FBG, lipid peroxides, %HbA1C, TC, LDL-C, and TG levels, and increasing insulin, HDL-C, and protein content. The spectrometric analysis confirmed that the flavonoid isolated from JFBE was isoquercitrin. We can conclude from this study that JFEE and JFBE exert hypoglycemic and hypolipidemic effects in STZ-diabetic rats through an antioxidative pathway that might be referred to their flavonoid contents.

Amelioration of tamoxifen-induced liver injury in rats by grape seed extract, black seed extract and curcumin.

Liver injury was induced in female rats using tamoxifen (TAM). Grape seeds (Vitis vinifera) extract (GSE), black seed (Nigella sativa) extract (NSE), curcumin (CUR) or silymarin (SYL) were orally administered to TAM-intoxicated rats. Liver histopathology of TAM-intoxicated:rats showed pathological changes. TAM-intoxication elicited declines in liver antioxidant enzymes levels (glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase), reduced glutathione (GSH) and GSH/GSSG ratio plus the hepatic elevations in lipid peroxides, oxidized glutathione (GSSG), tumor necrosis factor-alpha (TNF-alpha) and serum liver enzymes; alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase and gamma glutamyl transferase levels. Oral intake of NSE, GSE, CUR or SYL to TAM-intoxicated rats, attenuated histopathological changes and corrected all parameters mentioned above. Improvements were prominent in case of NSE (similarly SYL) > CUR > GSE. Data indicated that NSE, GSE or CUR act as free radicals scavengers and protect TAM-induced liver injury in rats.

Caffeic acid phenethyl ester protects against tamoxifen-induced hepatotoxicity in rats.

Tamoxifen (TAM) is widely used in the treatment and prevention of breast cancer. Adverse effects of TAM include hepatotoxicity. Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been used in folk medicine for diverse ailments. In the current study, the protective effects of CAPE against TAM-induced hepatotoxicity in female rats were evaluated. TAM (45 mg/kg/day, i.p., for 10 consecutive days) resulted in an elevation of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), depletion of liver reduced glutathione (GSH) and accumulation of oxidized glutathione (GSSG) and lipid peroxidation (LPO). Also, TAM treatment resulted in inhibition of hepatic activity of glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT). Further, it raised liver tumor necrosis factor-alpha (TNF-alpha) level and induced histopathological changes. Pretreatment with CAPE (2.84 mg/kg/day; i.p., for 20 consecutive days, starting 10 days before TAM injection) significantly prevented the elevation in serum activity of the assessed enzymes. CAPE significantly inhibited TAM-induced hepatic GSH depletion and GSSG and LPO accumulation. Consistently, CAPE normalized the activity of GR, GPx, SOD and CAT, inhibited the rise in TNF-alpha and ameliorated the histopathological changes. In conclusion, CAPE protects against TAM-induced hepatotoxicity.

Aqueous garlic extract attenuates hepatitis and oxidative stress induced by galactosamine/lipoploysaccharide in rats.

Injection of D-galactosamine and lipopolysaccharide (DGaIN/LPS) is useful as an experimental model of acute hepatic damage. Juvenile rats were used for investigation. The hepatoprotective activity of aqueous garlic (Allium sativum) extract (AGE) at a dose of 300 mg/kg body weight for 14 days, intraperitoneal (i.p.) prior to the induction of DGalN/LPS, was investigated against DGalN/LPS-induced hepatitis in rats. DGalN/LPS (300 mg/kg body weight/30 microg/kg body weight, i.p.), induced hepatic damage that was manifested by a significant increase in the activities of marker enzymes [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma glutamyl transferase (gamma GT)], bilirubin, lipid peroxides (LPO), tumor necrosis factor (TNF-alpha) and myeloperoxidase (MPO) activity level in serum. Also, the lipid profile in serum and liver homogenate including total cholesterol, triglycerides, free fatty acids and phospholipids were significantly deteriorated. The antioxidant enzyme activities (superoxide dismutase, SOD; reduced glutathione, GSH; catalase, CAT and glutathione peroxidase, GPX) in liver homogenate were significantly decreased in the DGalN/LPS. Pretreatment of rats with AGE reversed these altered parameters near to normal control values. Results of this study revealed that AGE could afford a significant protection in the alleviation of DGalN/LPS-induced hepatic damage.

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.

Hepatoprotective effect of green tea (Camellia sinensis) extract against tamoxifen-induced liver injury in rats.

Tamoxifen citrate (TAM), is widely used for treatment of breast cancer. It showed a degree of hepatic carcinogenesis. The purpose of this study was to elucidate the antioxidant capacity of green tea (Camellia sinensis) extract (GTE) against TAM-induced liver injury. A model of liver injury in female rats was done by intraperitoneal injection of TAM in a dose of 45mg Kg(-1) day(-1), i.p. for 7 successive days. GTE in the concentration of 1.5 %, was orally administered 4 days prior and 14 days after TAM-intoxication as a sole source of drinking water. The antioxidant flavonoid; epicatechin (a component of green tea) was not detectable in liver and blood of rats in either normal control or TAM-intoxicated group, however, TAM intoxication resulted in a significant decrease of its level in liver homogenate of tamoxifenintoxicated rats. The model of TAM-intoxication elicited significant declines in the antioxidant enzymes (glutathione-S-transferase,glutathione peroxidase, superoxide dismutase and catalase) and reduced glutathione concomitant with significant elevations in TBARS (thiobarbituric acid reactive substance) and liver transaminases; sGPT (serum glutamate pyruvate transaminase) and sGOT (serum glutamate oxaloacetate transaminase) levels. The oral administration of 1.5 % GTE to TAM-intoxicated rats, produced significant increments in the antioxidant enzymes and reduced glutathione concomitant with significant decrements in TBARS and liver transaminases levels. The data obtained from this study speculated that 1.5 % GTE has the capacity to scavenge free radical and can protect against oxidative stress induced by TAM intoxication. Supplementation of GTE could be useful in alleviating tamoxifen-induced liver injury in rats.

Hypoglycemic effect of Egyptian Morus alba root bark extract: effect on diabetes and lipid peroxidation of streptozotocin-induced diabetic rats.

The hypoglycemic activity of the flavonoids rich fraction of 70% alcohol extract of the Egyptian Morus alba root bark (MRBF-3) was evaluated after its oral administration to streptozotocin-induced diabetic rats. Diabetes was induced by injection of 60 mg kg(-1) i.p. The administration of MRBF-3 to streptozotocin (STZ)-diabetic rats for 10 days in a dose of 200 and 400 mg kg(-1)day(-1) was not significant. However, administration of MRBF-3 for 10 days (600 mg kg(-1)day(-1)) significantly reduced the amount of the glucose from control level (379+/-9 mg/dl) to a lower level (155+/-8 mg/dl) and significantly increased the insulin level from control (10.8+/-0.3 microU/ml) to a high level (15.6+/-0.3 microU/ml). The measurement of produced lipid peroxides (expressed as the amount of thiobarbituric acid (TBA) reactive substance, nmol TBARS/ml serum) indicated antiperoxidative activity of MRBF-3. The oral administration of MRBF-3 to STZ-diabetic rats significantly decreased the lipid peroxides from 6.3+/-0.8 to 5.1+/-0.7 nmol TBARS/ml serum. The phytochemical investigation of MRBF-3 resulted in the isolation of four hydrophobic flavonoids with one or two isoprenoid groups (log P=5-9): morusin, cyclomorusin, neocyclomorusin, and kuwanon E, a 2-arylbenzofuran, moracin M, and two triterpenes, betulinic acid and methyl ursolate. The data obtained from this study revealed that MRBF-3 may protect pancreatic beta cells from degeneration and diminish lipid peroxidation. However, this is the first biological screening of the Egyptian Morus alba root bark; further future merit studies including clinical study will be necessary in order to confirm the results obtained from this study.