Protective effect of Centella asiatica extract and powder on oxidative stress in rats

The effect of Centella asiatica extract and powder in reducing oxidative stress in SpraqueDawley rats was evaluated. Lipid peroxidation was monitored by measuring malonaldehyde (MDA) level in blood. Activities of free radical-scavenging enzymes (superoxide dismutase and catalase) were determined using H₂O₂ decomposition and nitrobluetetrazolium reduction, respectively. Results showed that administration of H₂O₂ (0.1%) in drinking water of the rats, for 25 weeks, increased the malonaldehyde levels in erythrocytes of all the rats. However, rats receiving C. asiatica extract, powder and α-tocopherol had lower MDA levels than did the other rats, which indicates, decrease lipid peroxidation in these rats. Increase in catalase activity of the rats appears to be a response to H₂O₂ accumulation. The decrease in the activity of superoxide dismutase in C. asiatica- and α-tocopherol supplemented rats suggested a lower requirement for the enzyme and this indicates the protective effect of the plant in combating oxidative stress undergone by the rats. Results revealed that C. asiatica extract and powder may ameliorate H₂O₂-induced oxidative stress by decreasing lipid peroxidation via alteration of the antioxidant defence system of the rats.     

Protective effect of Funalia trogii crude extract on deltamethrin-induced oxidative stress in rats

In this study the protective effects of cold buffer extract of Funalia trogii ATCC 200800 (FtE) and vitamin E (VitE) on oxidative stress induced with deltamethrin using oral administration in rats were investigated. Deltamethrin treatment caused an increase in liver enzyme activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) (p < 0.05); however, it caused a decrease in activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GRd) when compared to control group (p < 0.05). Activities of AST, ALT, ALP enzymes and level of thiobarbituric acid reactive substances (TBARS) decreased significantly after VitE administration (p < 0.05). Both enzyme activities and TBARS levels were found similar in VitE and FtE treated rats shortly after pesticide administration (p < 0.05). In conclusion, it appears that FtE prepared in cold buffer has capability to prevent the liver damage like VitE against the toxic effect of deltamethrin.     

Protective effect of Spirulina platensis enriched in phenolic compounds against hepatotoxicity induced by CCl4

Phenolic compounds make up the major secondary metabolites with high pharmaceutical potential. Microalgae were reported to contain low amounts of phenolic compounds. The present study aimed to investigate the hepatoprotective potential of biomass of Spirulina platensis enriched in phenolic compounds. The protective effects of the biomass of S. platensis with low amounts of phenolics (SP1) and with high amounts of phenolics (SP2) against CCl₄-induced acute hepatotoxicity were evaluated in rats. The increased levels of ALT, AST and MDA along with decreased activities of SOD and CAT were significantly (p < 0.01) ameliorated by SP2. Histological examinations revealed that SP2 was more potent than SP1 in protecting the liver from toxic injury of CCl₄ and preserving the hepatocyte ultrastructure. The lesions including necrosis, lymphocyte infiltration, ballooning degeneration and hepatocyte injury as irregular lamellar organisation, dilations in endoplasmic reticulums and the presence of great number of cytoplasmic vacuolization were healed by SP2.     

Protective effect of extracts of Perilla frutescens treated with sucrose on tert-butyl hydroperoxide-induced oxidative hepatotoxicity in vitro and in vivo

Perilla frutescens leaves are often used in East Asian gourmet food. In this study, we investigated the hepatoprotective effects of P. frutescens leaves grown in different concentrations of sucrose (0, 115, 175 and 235 mM sucrose) leading to four samples of perilla leaf extracts (PLEs). Based on caffeic acid level and antioxidant activities, further experiments were conducted using perilla leaf extracts treated with 6% sucrose compared with non-treated perilla leaf extracts as a control. Oral intubation with non-treated perilla leaf extracts or perilla leaf extracts treated with 6% sucrose (1000 mg/kg b.w. rat) for 5 days was conducted before treatment with a single dose of tert-butyl hydroperoxide (0.5 mmol/kg b.w., i.p.) led to a significant reduction of hepatic toxicity in the perilla leaf extracts treated with 6% sucrose. We demonstrated that P. frutescens with higher contents of caffeic acid was produced, and that sucrose could play a role in the induction of this secondary metabolite. Sucrose-treated perilla leaves, which had better antioxidant activities than untreated leaves, can be used as a potential dietary source.     

Protective effect of HV-P411, an herbal mixture,on carbon tetrachloride-induced liver fibrosis

This study was performed to examine the anti-fibrotic activity of HV-P411, an herbal mixture of seeds of Vitis vinifera, Schisandra chinensis and Taraxacum officinale extract, against carbon tetrachloride (CCl₄)-induced liver fibrosis. Hepatic fibrosis was induced by intraperitoneal injection of CCl₄ (0.5 ml/kg, twice weekly) for 8 weeks. Rats were treated orally with HV-P411 at 50, 100, 200, and 400 mg/kg once a day. After chronic exposure to CCl₄, the levels of hydroxyproline were markedly increased; these were significantly reduced by HV-P411 at all dose levels. The level of serum aminotransferases and lipid peroxidation were increased after the CCl₄ treatment, while reduced glutathione was decreased. These changes were attenuated by HV-P411. In addition, HV-P411 attenuated CCl₄-induced raised serum concentration of transforming growth factor-β1, and the levels of matrix metalloprotease-2 and tissue inhibitor of metalloprotease-1 mRNAs. Our results suggest that HV-P411 may prevent liver fibrosis by modulating fibrogenesis and fibrolysis.     

Hepatoprotective effect of 2,3-dehydrosilybin on carbon tetrachloride-induced liver injury in rats

The aim of this study was to investigate the protective effect of 2,3-dehydrosilybin (DHS) against carbon tetrachloride (CCl₄)-induced liver injury in rats. Administration of DHS significantly attenuated the levels of serum aspartate aminotransferase, alanine aminotransferase, and liver lipid peroxidation in CCl₄-treated rats. Moreover, we showed that DHS prevented DNA damage and decreased the protein levels of γ-H2AX, which is a specific DNA damage marker, in CCl₄-treated rat livers. DHS also markedly increased the activity of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase in CCl₄-treated rat livers. Furthermore, we found that DHS significantly inhibited the production of serum nitric oxide as well as the levels of serum IL-6, IFN-γ, and TNF-α in CCl₄-treated rats. Additionally, DHS significantly suppressed iNOS expression on the protein levels in CCl₄-treated rat livers. Collectively, the present study suggests that DHS protects the liver from CCl₄-induced hepatic damage via antioxidant and anti-inflammatory mechanisms.     

Hepatoprotective effect of the root extract of Decalepis hamiltonii against carbon tetrachloride-induced oxidative stress in rats

Decalepis hamiltonii, a climbing shrub, grows in the forests of peninsular India and is consumed for its health promoting properties. The hepatoprotective activity of the aqueous extract of the roots of D. hamiltonii with known antioxidant constituents was studied against carbon tetrachloride (CCl₄)-induced oxidative stress and liver injury in rats. Pretreatment of rats with aqueous extract of the roots of D. hamiltonii, single (50, 100 and 200 mg/kg b.w.) and multiple doses (50 and 100 mg/kg b.w. for 7 days) significantly prevented the CCl₄ (1 ml/kg b.w.) induced hepatic damage as indicated by the serum marker enzymes (AST, ALT, ALP, and LDH). Parallel to these changes, the root extract also prevented CCl₄-induced oxidative stress in the rat liver by inhibiting lipid peroxidation and protein carbonylation, and restoring the levels of antioxidant enzymes (SOD, CAT, GPx, GR, and GST) and glutathione. The biochemical changes were consistent with histopathological observations suggesting marked hepatoprotective effect of the root extract in a dose dependent manner. Protective effect of the aqueous extract of the roots of D. hamiltonii against CCl₄-induced acute hepatotoxicity could be attributed to the antioxidant constituents.     

Antioxidant activity of Nyctanthes arbor-tristis leaf extract

Nyctanthes arbor-tristis (Harsingar) leaf extracts are extensively used in Indian traditional medicine. The acetone-soluble fraction of its ethyl acetate extract showed impressive antioxidant activity as revealed by several in vitro experiments, e.g., DPPH, hydroxyl and superoxide radicals, as well as H₂O₂ scavenging assays. Moreover, its preventive capacity against Fe(II)-induced lipid peroxidation of liposomes and γ-ray-induced DNA damage also confirmed this. The strong reducing power and high phenolics and flavonoids contents could be responsible for the antioxidant activity.     

Beneficial effect of Ficus religiosa Linn. on high-fat-diet-induced hypercholesterolemia in rats

Ficus religiosa Linn. (Moraceae) was evaluated as a hypolipidaemic and antioxidant agent. Ethanol and hexane leaves extracts were examined for inhibition of β-hydroxy-β-methylglutaryl coenzyme A reductase and DPPH free radical elevation. The ethanol extract was evaluated for its effect against hypercholesterolaemia in rats, compared with the standard hypolipidaemic lipanthyl. Cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), phospho and total lipids were estimated. Malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) were measured. Administration of rats with 30 mg cholesterol five times per week for nine consecutive weeks caused a significant increase in lipid profile, MDA and SOD, while HDL-C and GSH showed significant decreases. Treatment with plant extract (500 mg/kg body weight) or lipanthyl drug (50 mg finofibrate/kg body weight) for the same duration recorded improvement in lipid profile, antioxidant levels, liver function enzymes and hepatic architecture. In conclusion, ethanol extract of F. religiosa exerted hypolipidaemic and antioxidant effects.     

Antioxidant activity of ethanolic extract of Cortex fraxini and use in peanut oil

Cortex fraxini was extracted with 95% ethanol to obtain a crude antioxidant extract. The antioxidant activity was evaluated using the linoleic acid peroxidation method and the free radical scavenging assays, namely 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Cortex fraxini extract (CFE) showed high inhibition of peroxidation of linoleic acid when compared with butylated hydroxytoluene (BHT). CFE also exhibited excellent scavenging activity on DPPH and hydroxyl radicals. Total antioxidant activity was measured by the reduction of Mo(VI) to Mo(V) by the extract, and subsequent formation of a green phosphate/Mo(V) complex at acid pH. CFE had significant total antioxidant activity and the effects were increased with increasing reaction time. The total phenolic content of the sample, analyzed by using Folin–Ciocalteu’s reagent, was 91.33 mg/g dry weight expressed as pyrocatechol equivalents. Then the suitability of CFE as an antioxidant was determined in peanut oil, and the decrease of lipid oxidation was monitored using thiobarbituric acid-reactive substances (TBARS) assay. CFE treatment significantly (P < 0.05) reduced lipid oxidation in peanut oil compared to the control. No significant differences (P = 0.05) in lipid oxidation were detected between CFE antioxidant and BHT antioxidant samples.     

Antioxidant and free radical scavenging activity of an aqueous extract of Coleus aromaticus

The leaves of Coleus aromaticus Benth., (Lamiaceae), commonly called Indian Borage, are often eaten raw with bread and butter. The chopped leaves are also used as a substitute for sage (Salvia officinalis Linn.) in stuffing. In the present study, the antioxidant potency of freeze-dried aqueous extract of C. aromaticus was investigated, employing various established in vitro systems, such as the β-carotene-linoleate model system, 1,1-diphenyl-2-picrylhydrazyl (DPPH)/superoxide/nitric oxide radical scavenging, reducing power, and iron ion chelating activity. Freeze-dried aqueous extract of C. aromaticus (CAE) showed notable inhibitory activity in the β-carotene-linoleate model system. Furthermore, CAE exhibited a moderate concentration-dependent inhibition of the DPPH radical. The multiple antioxidant activity of CAE was evident as it showed significant reducing power, superoxide scavenging ability, nitric oxide-scavenging activity and also ferrous ion chelating potency. The data obtained in the in vitro models clearly establish the antioxidant potency of freeze-dried extract of C. aromaticus.     

Quantification of the polyphenolic fraction and in vitro antioxidant and in vivo anti-hyperlipemic activities of Hibiscus sabdariffa aqueous extract

In the present study the quantification of the polyphenolic fraction, anthocyanins and other polar compounds, the antioxidant capacity and the anti-hyperlipemic action of the aqueous extract of Hibiscus sabdariffa has been achieved. Seventeen compounds were successfully quantified either by HPLC-DAD or HPLC-ESI-TOF-MS. Six of them were directly quantified by their corresponding standards, whereas the rest were indirectly quantified as equivalents using standards of similar compounds. The antioxidant capacity have also been estimated by comparing different assays, i,e, Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and measurement of thiobarbituric acid reacting substances (TBARS). H. sabdariffa showed high reducing capacity in FRAP assay and significant capability to scavenge peroxyl radicals in the ORAC assay. Nevertheless, the extract exhibited poor efficacy to inhibit peroxyl radicals in lipid systems. The plant extract also exhibited the capacity to decrease serum triglyceride concentration on hyperlipemic mouse model.     

Antioxidant properties of Agaricus blazei, Agrocybe cylindracea, and Boletus edulis

Three mushrooms are currently available in Taiwan, including Agaricus blazei, Agrocybe cylindracea, and Boletus edulis. Their ethanolic and hot water extracts were prepared and antioxidant properties studied. Ethanolic extracts from three mushrooms were more effective than hot water extracts in antioxidant activity using the conjugated diene method and scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals whereas hot water extracts were more effective in reducing power, scavenging ability on hydroxyl radials and chelating ability on ferrous ions as evidenced by their lower EC₅₀ values. Overall, for both extracts, B. edulis was more effective among antioxidant properties assayed. Naturally occurring antioxidant components including total tocopherols (3.18-6.18 mg/g) and total phenols (5.67-5.81 mg/g) were found in the extracts and their contents were associated (r=0.636-0.907) with EC₅₀ value of antioxidant properties. Based on the results obtained, both extracts from these three mushrooms were effective in antioxidant properties.     

Antimicrobial and antioxidant properties of the essential oils and methanol extract from Mentha longifolia L. ssp. longifolia

This study was designed to evaluate antimicrobial and antioxidant activities of the essential oil and methanol extract from Mentha longifolia ssp. longifolia. The essential oil showed strong antimicrobial activity against all 30 microorganisms tested whereas the methanol extract almost remained inactive. In contrast, the extract showed much better activity than the essential oil in antioxidant activity assays employed, e.g. in the inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene/linoleic acid systems. In the former, the extract was able to reduce the stable free radical DPPH with an IC₅₀ of 57.4 μg/ml while that of the oils was 10 700 μg/ml. When compared to BHT, a synthetic antioxidant, both showed weaker antioxidative potential. Similarly, in β-carotene/linoleic acid assay, these samples were not effectively able to inhibit the linoleic acid oxidation; exhibiting only 24% and 36% inhibitions at 2 mg/ml, respectively; both were far below than that of BHT. Total phenolic constituent of the extract was 4.5 g/100 g as gallic acid equivalent. GC–MS analysis of the oil resulted in the identification of 45 constituents, cis-piperitone epoxide, pulegone and piperitenone oxide being the main components.     

大蒜提取物对四氯化碳诱导肝损伤小鼠的保护作用研究

该实验研究了大蒜提取物对四氯化碳诱导肝损伤小鼠的保护作用。将76只6周龄ICR小鼠随机分为6组：空白对照组,模型组,大蒜提取物低、中、高剂量组,水飞蓟宾阳性对照组。连续给药14 d,末次给药后,使用四氯化碳对模型组及各给药组建模。对小鼠血清及肝脏中的总蛋白（TP）、白蛋白ALB）、谷胱甘肽（GSH）、谷草转氨酶（AST）、谷丙转氨酶（ALT）、乳酸脱氢酶（LDH）、胆碱酯酶（CHE）七个指标进行测定。结果表明,大蒜提取物可以抑制四氯化碳导致的小鼠血清及肝脏中AST、ALT、LDH活力升高,并提高TP、ALB、GSH含量及CHE活力,说明大蒜提取物对四氯化碳诱导的肝损伤具有保护作用。     

Determination of antioxidative potential of lichen Usnea ghattensis in vitro

The study was aimed at evaluating the antioxidant activities of extract of Usnea ghattensis. The antioxidant activity, reducing power, superoxide anion radical scavenging and free radical scavenging activities were studied. The antioxidant activity increased with the increasing amount of extracts (2-20 mg/ml) added to the linoleic acid emulsion. Lipid peroxidation upto 73.3% was inhibited by the extract of 20 mg/ml and 39.2% by α-tocopherol at the same concentration. These effects were statistically significant (r²=0.876,P<0.01) when compared with control. However, the extract had no significant effect on superoxide anion scavenging by the PMS/NADH-NBT method. Like antioxidant activity, the reducing power and free radical scavenging activity of extract depends on concentration and increasing with increased amount of sample. The reducing power and DPPH radical-scavenging activity of U. ghattensis extract were found greater than the BHA and BHT. The results obtained in the present study indicate that U. ghattensis is a potential source of natural antioxidant.     

In vitro antioxidant and antimicrobial activities of the extract of Pericarpium Citri Reticulatae of a new Citrus cultivar and its main flavonoids

To provide the base for the application of a new cultivar of Citrus reticulata Blanco, whose family is Rutaceae, a flavonoid extract of Pericarpium Citri Reticulatae (FEPCR), the dried rind of the ripe citrus, was obtained with 80% aq. ethanol. Total flavonoid content of FEPCR was determined by a colorimetric method. Total phenol content was estimated as gallic acid equivalents. The major constituents of FEPCR, including Hesperidin, Nobiletin and Tangeretin, were determined by HPLC analysis. The antioxidant activities of FEPCR, Hesperidin, Nobiletin and Tangeretin were evaluated by various antioxidant assays, including DPPH scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and reducing power. All samples showed antioxidant activities to some degree in all the tested methods. In addition to the antioxidant activity, the antimicrobial assay was measured as well. Six strains of microorganisms including Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Salmonella typhi and Enterobacter cloacae were used in the tests. FEPCR and Hesperidin displayed a broad antimicrobial spectrum and exerted antimicrobial effects in antimicrobial tests. But Tangeretin and Nobiletin exhibited low antimicrobial activities.