翁布中酚性化合物体外抗氧化活性的研究

目的 研究藏药翁布中13种酚性化合物的体外抗氧化活性.方法 采用DPPH自由基清除活性试验、FRAP法、ABTS法和酪氨酸酶活性抑制法评价13种酚性化合物的自由基清除能力及抗氧化活性.结果 没食子酸、3,5-二羟基-4-甲氧基苯甲酸清除DPPH自由基的半数抑制浓度(IC50)低于维生素C;FRAP法测定结果中,化合物阿魏酸、阿魏酸葡糖苷、咖啡酸、对羟基桂皮酸、没食子酸、3,5-二羟基-4-甲氧基苯甲酸的总抗氧化值均高于阳性对照Trolox;ABTS法测定结果中,化合物阿魏酸、松柏醇、阿魏酸葡糖苷、咖啡酸、对羟基桂皮酸、没食子酸、4-羟基-α-甲基苯丙醇、4-羟基-3-甲氧基苯甲酸的总抗氧化值相对于Trolox标准溶液均大于0.01 mmol· L-1;13种酚性化合物对酪氨酸酶均具抑制活性,但IC50均高于阳性对照曲酸.结论 阿魏酸、阿魏酸葡糖苷、咖啡酸、对羟基桂皮酸、没食子酸、3,5-二羟基-4-甲氧基苯甲酸具有较强的抗氧化活性.     

Antioxidant and antimicrobial phenolic compounds from extracts of cultivated and wild-grown Tunisian Ruta chalepensis

The antioxidant and antibacterial activities of phenolic compounds from cultivated and wild Tunisian Ruta chalepensis L. leaves, stems, and flowers were assessed. The leaves and the flowers exhibited high but similar total polyphenol, flavonoid, and tannin content. Moreover, two organs showed strong, although not significantly different, total antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl scavenging ability, and reducing power. Investigation of the phenolic composition showed that vanillic acid and coumarin were the major compounds in the two organs, with higher percentages in the cultivated organs than in the spontaneous organs. Furthermore, R. chalepensis extracts showed marked antibacterial properties against human pathogen strains, and the activity was organ- and origin-dependent. Spontaneous stems had the strongest activity against Pseudomonas aeruginosa. From these results, it was concluded that domestication of Ruta did not significantly affect its chemical composition and consequently the possibility of using R. chalpensis organs as a potential source of natural antioxidants and as an antimicrobial agent in the food industry.     

Characterization of increased phenolic compounds from fermented Bokbunja (Rubus coreanus Miq.) and related antioxidant activity

This study examined the changes in the phenolic acid-content and antioxidant activity of Rubi Fructus (RF), the fruit of Rubus coreanus Miq., after fermentation with yeast (Saccharomyces cerevisiae). The phenolic acids were fractionated into three forms, free (Fr. A), ester (Fr. B), and insoluble-bound phenolic acids (Fr. C) and quantified by high performance liquid chromatography with a diode array detector (HPLC-DAD). This method was validated and allowed the successful identification of 11 phenolic acids in the RF extracts. HPLC-DAD analysis of the samples showed substantial increases in the levels of protocatechuic, vanillic and p-coumaric acid as the result of yeast fermentation. The total phenolic content (TPH) was also increased by fermentation. The total phenolics in Fr. A and Fr. B increased from 117 to 173 mg GAE/100 g and from 488 to 578 mg GAE/100 g, respectively. The total phenolics in Fr. C decreased from 264 to 175 mg GAE/100 g. The antioxidant activity of the fermented RF was measured as the 1,1-diphenoly-2-picrylhydrazyl (DPPH) radical scavenging capacity, which is expressed as the IC₅₀. The IC₅₀ for Fr. A and Fr. B decreased from 5.9 to 4.0 mg/ml (mg of dried RF equiv./ml) and from 1.2 to 0.8 mg/ml, respectively. In Fr. C, the IC₅₀ value increased from 2.1 to 2.8 mg/ml. In summary, the fermented RF had a higher total phenolic content and better DPPH radical-scavenging activity than the unfermented material.     

Biological activity and microscopic characterization of Lythrum salicaria L

Background

There are several plants have been used worldwide in the folk medicine with high incidence for treatment of human disorders, of which Lythrum salicaria belongs to the Lythraceae family has traditionally reputation for some medicinal usage and recently many biological and pharmacological activity of the plant have been studied.

Methods

In this study, microscopic characterizations of the aerial parts of the plant were determined. Moreover, the plant extract (aqueous methanol 80%) was subjected to an anti-diabetic activity test (in a rat model of streptozocin induced diabetes), anti-Helicobacter pylori (using disc diffusion method) along with antioxidant activity against DPPH (stable free radical) tests. Besides, total flavonoids, phenols, tannins, as well as polysaccharides contents have been assessed using spectroscopic methods.

Results

The microscopic properties of the plant fragments revealed anomocytic stomata, conical shape trichomes, and abundant spherical pollen grains as a characteristic pattern for the aerial parts of the plant. The extract of the plant at concentration of 15 g/kg showed mild lowering activity on blood glucose level to 12.6% and 7.3% after 2 and 3 h of administration. Additionally, clinically isolated H. pylori strain was inhibited with the plant extract at concentration of 500 mg/mL (zone of inhibition: 17 ± 0.08 mm). Moreover, IC₅₀ values for DPPH inhibition of the plant extract, vitamin E, BHA were examined as 13.5, 14.2, and 7.8 μg/mL, respectively. Total flavonoids, phenols, tannin, and polysaccharides contents of the extract were successfully evaluated as 5.8 ± 0.4 μg QE/mg EXT, 331 ± 3.7 μg GAE/mg EXT, 340 ± 2.3 μg TAE/mg EXT, 21 ± 0.2 μg GE/mg EXT, respectively.

Conclusions

The results suggested that L. salicaria has low anti-diabetic and anti-Helicobacter pylori effects, but high antioxidant activity, just the same as positive standard (vitamin E), which might be attributed to the high content of phenolic compounds in the extract.     

Prospective neurobiological effects of the aerial and root extracts and some pure compounds of randomly selected Scorzonera species

Context: Scorzonera L. species (Asteraceae) are edible and as medicinal plants are used for various purposed in folk medicine.

Objective: The methanol extracts of the aerial parts and roots from 27 Scorzonera taxa were investigated for their possible neurobiological effects.

Materials and methods: Inhibitory potential of the Scorzonera species was tested against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase (TYRO) at 100?µg?mL^?1 using ELISA microtiter assay. Antioxidant activity of the extracts was tested with radical scavenging activity, metal-chelation capacity, ferric- (FRAP), and phosphomolibdenum-reducing antioxidant power (PRAP) assays. Chlorogenic acid, hyperoside, rutin, and scorzotomentosin-4-O-β-glucoside were also screened in the same manner. Total phenol and flavonoid quantification in the extracts were determined spectrophotometrically.

Results: The aerial parts of Scorzonera pisidica (40.25?±?0.74%) and chlorogenic acid (46.97?±?0.82%) displayed the highest TYRO inhibition, while the remaining samples showed only trivial inhibition against cholinesterases (2.08?±?1.35%–25.32?±?1.37%). The same extract of S. pisidica was revealed to be the most potent in scavenging of all three radicals and FRAP assay.

Discussion and conclusion: Out of 27 taxa, S. pisidica, in particular, may deserve further investigation for its neuroprotective potential.     

Comparing ultrasonic- and microwave-assisted methods for extraction of phenolic compounds from Kabkab date seed (Phoenix dactylifera L.) and stepwise regression analysis of extracts antioxidant activity

This study aimed to extract bioactive compounds (phenolics and flavonoids and condensed tannins) from roasted date seed (Phoenix dactylifera L. cv Kabkab) using various solvent systems (W: water, AE: aqueous-ethanol, AA: aqueous-acetone) and extraction method (ultrasonic-assisted (UAE), microwave-assisted (MAE) and the combination of these two methods (UMAE) maceration (ME) and Decoction-Infusion (DIE) Extraction). Moreover, the feasibility of antioxidant activity prediction was investigated based on stepwise regression analysis and phytochemical properties. Extraction yield, Total phenolic content (TPC), total flavonoid content (TFD) and antioxidant activity (DPPH*, ABTS*⁺, FRAP and averaged antioxidant activity: AAA) of the extracts were evaluated. The main effect of solvent systems and extraction methods on phytochemical compounds and antioxidant activity were significant (P < 0.01). Water and aqueous-ethanol solvents extracted higher phytochemical compounds than aqueous-acetone (P < 0.05). Although the highest extraction performance was observed for the ME method, the novel methods show an acceptable result in a much shorter time. Among novel methods, the highest and lowest performances were recorded for UAE and MAE. There was no significant difference between novel-green methods (e.g., UAE and UMAE). Although the lowest phytochemical yield was obtained for MAE, this performance was obtained in less than 5 min. The highest and lowest correlation between the phytochemical compositions and antioxidant activity parameters were for DPPH* and AAA, respectively. Stepwise-regression analysis showed the weakest and strongest prediction models for AAA (10-fold S = 0.098 and 10-fold R² = 87.07) and ABTS*⁺ (10-fold S = 0.129 and 10-fold R² = 78.25), respectively.     

Isolation and biological activity of compounds from Garcinia preussii

Context: Plants of the genus Garcinia (Clusiaceae) are traditionally used to relieve stomachaches, toothaches, and as a chew stick.

Objective: In order to determine which compounds were responsible for these activities, a phytochemical investigation of the fruits and leaves of Garcinia preussii Engl. was pursued.

Materials and methods: Plants were extracted by solvents of various polarities. Compounds isolation was then carried out using chromatography methods (medium- and high-pressure liquid chromatography, open column and thin-layer chromatography). The isolated compounds were identified and characterized by using 1D and 2D NMR spectroscopies. The antioxidant activity was evaluated using DPPH^?, ABTS^??, ALP, and ORAC assays. The antimicrobial activity was assayed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis by determining the minimum inhibitory concentration (MIC) value. The cytotoxic activity of most of the isolated compounds was evaluated on a small panel of human cancer cell lines (DU145, HeLa, HT-29, and A431) using the XTT method.

Results: The phytochemical investigation of G. preussii led to the isolation of eight known compounds, six benzophenones and two flavonoids. These compounds were tested for their biological activities. 1, 2, 3, 4, 7 and 8 demonstrated a high free radical scavenging activity with ER₅₀ ranging from 0.1 to 0.7. The antimicrobial activity was shown only against Gram-positive bacteria for 1, 4, and 5. A moderate cytotoxic activity with IC₅₀ ranging from 7 to 50?µM was observed, except for 6 which was not active.

Conclusion: These results appear to support some of the properties reported for Garcinia species.     

Walnut (Juglans regia L.) leaves: phenolic compounds, antibacterial activity and antioxidant potential of different cultivars.

Different cultivars of walnut (Juglans regia L.) leaves (Cv. Lara, Franquette, Mayette, Marbot, Mellanaise and Parisienne) grown in Portugal, were investigated in what concerns phenolic compounds and antimicrobial and antioxidant properties. Phenolics analysis was performed by reversed-phase HPLC/DAD and 10 compounds were identified and quantified: 3- and 5-caffeoylquinic acids, 3- and 4-p-coumaroylquinic acids, p-coumaric acid, quercetin 3-galactoside, quercetin 3-pentoside derivative, quercetin 3-arabinoside, quercetin 3-xyloside and quercetin 3-rhamnoside. The antimicrobial capacity was screened against Gram positive (Bacillus cereus, B. subtilis, Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans). Walnut leaves selectively inhibited the growth of Gram positive bacteria, being B. cereus the most susceptible one (MIC 0.1mg/mL). Gram negative bacteria and fungi were resistant to the extracts at 100mg/mL. Lara walnut leaves were also submitted to antibacterial assays using 18 clinical isolates of Staphylococcus sp. Antioxidant activity was accessed by the reducing power assay, the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and beta-carotene linoleate model system. In a general way, all of the studied walnut leaves cultivars presented high antioxidant activity (EC(50) values lower than 1mg/mL), being Cv. Lara the most effective one.     

Biological activity of HPLC-characterized ethanol extract from the aerial parts of Haplophyllum tuberculatum

Context: The search for new sources of natural antioxidants from plant material may have beneficial therapeutic potential for those diseases associated with oxidative stress. The medicinal plant Haplophyllum tuberculatum (Forsskal) A. Juss. (Rutaceae) contains phenolic compounds as main phytochemicals; however, there are no reports on its antioxidant properties.

Objective: To evaluate antioxidant and cytoprotective potential of ethanol extract of Haplophyllum tuberculatum aerial parts.

Materials and methods: Total phenol content was determined using Folin–Ciocalteu reagent; antiradical activity was measured using ORAC assay and the analysis of the major polyphenols was carried out using a HPLC-MS method. The antioxidant and cytoprotective effect were also investigated by the MTT assay and DCFH–DA method. The human astrocytoma U373-MG cell line was pretreated with ethanol extract (from 0.025 to 250?µg/mL) for 24?h, prior to 1?mM H₂O₂ exposure (30?min).

Results and conclusion: Total phenol content was 46.2?mg gallic acid/g sample and ORAC value was 1.283?µmol TE/mg sample. Chemical constituents were methoxyflavones, flavonols (mainly quercetin derivatives), cinnamic acids and benzoic acids. In cell system model of oxidative stress, pretreatments with ethanol extract at the concentrations of 2.5, 0.25 and 0.025?µg/mL significantly attenuated H₂O₂-induced loss in viability by 13.5, 17 and 20.5%, respectively. Furthermore, these ethanol extract concentrations markedly inhibited intracellular ROS production with IC₅₀ 0.026?µg/mL. These findings demonstrate the beneficial properties of ethanol extract of Haplophyllum tuberculatum aerial parts, rich in phenolic compounds, as antioxidant and radical scavenger ameliorating ROS-related processes and diseases such as several neurodegenerative disorders.     

Natural compounds from danshen suppress the activity of hepatic stellate cells

Danshen is an herbal medication frequently used in oriental medicine to treat liver or kidney malfunction. In the course of our studies, we observed that compounds purified from Danshen exhibit an inhibitory activity against Discoidin Domain Receptor 2 (DDR2) tyrosine kinase. Through this inhibition, these compounds also inhibited the growth of HSC T6 cells and suppressed the expression of alpha-smooth muscle actin and MMP2, as well as collagen synthesis, all of which are increased in activated liver stellate cells. Given that activation of liver stellate cells is the hallmark of liver fibrosis and that DDR2 plays a critical role in this activation, these results suggest that one of the pharmacological activities of Danshen extract that protects the liver is the inhibition of key cell-signaling kinases, such as DDR2, in liver stellate cells.     

Structural characterization and antioxidant activity of a heteropolysaccharide isolated from Hedysarum polybotrys

A water-soluble polysaccharide (HPS3aS) with a molecular mass of 1.22 × 10⁴ Da was isolated from Hedysarum polybotrys using anion-exchange and gel-permeation chromatography. HPS3aS exhibits a globular-shaped conformation in 0.1 M NaNO₃ by size exclusion chromatography with multi-angle laser light scattering (SEC-MALLS). The investigation of the structural features of this heteropolysaccharide through a combination of chemical and instrumental analyses revealed that the backbone of HPS3aS is composed of α-d-(1 → 4)-linked glucopyranose residues, which occasionally branched at O-6. The branches are composed of (1 → 4)-linked galactopyranose residues and terminated with glucopyranose residues. HPS3aS possesses good in vitro antioxidant activity, as evaluated by scavenging assays with 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and superoxide radicals, which suggests that HPS3aS could be a potential antioxidant.     

Bioactive compounds from endemic plants of Southwest Portugal: Inhibition of acetylcholinesterase and radical scavenging activities

Context: Natural products are reported to have substantial neuroprotective activity due to their radical scavenging capacity, and also acetylcholinesterase (AChE) inhibitory capacity, both activities important in neurodegeneration.

Objective: The undesirable side effects of compounds in pharmacological use make it important to identify natural neuroprotective molecules. This work assesses the potential of five endemic Portuguese plants as sources of neuroprotective compounds.

Materials and methods: Antioxidant capacity for peroxyl radical was determined by Oxygen Radical Absorbance Capacity method and for hydroxyl by Electron Paramagnetic Resonance, as well as AChE inhibitory capacity of the plant hydroethanolic extracts. The molecules responsible for these valuable properties were also tentatively identified by HPLC.

Results and discussion: Armeria rouyana and Thymus capitellatus presented some of the highest phenolic contents (76.60?±?7.19 and 12.82?±?0.24?mg GAE g^?1 dw, respectively) and antioxidant capacities (592?±?116 and 449?±?57 μmol TE g^?1 dw, respectively). The flavonoids were identified as the phytomolecules related to the antioxidant capacity of these plant extracts; in the case of A. rouyana, l-ascorbic acid also made an important contribution (3.27?±?0.26?mg g^?1 dw). Plant extracts clearly demonstrated effective AChE inhibitory activity (480?±?98 and 490?±?46 μg mL^?1, respectively), that could be associated to polyphenols.

Conclusions: The extracts of A. rouyana and T. capitellatus and their active components, especially polyphenols, demonstrate interesting neuroprotective potential. They, therefore, deserve further study as their phytomolecules are promising sources of either natural neuroprotective products and/or novel lead compounds.     

A novel strategy to improve the recovery of phenolic compounds from Pistacia lentiscus L. fruits using design-based statistical modeling for ultrasound-deep eutectic solvents extraction and the evaluation of their antioxidant potential

Recently, there has been increasing interest in using alternative green technologies for the isolation of bioactive metabolites from medicinal plants. This study was designed to select the optimal solvent for phenolic compounds (TPC) extraction from Pistacia lentiscus L. black fruits (PBF) and the development of an experimental model by response surface methodology using ultrasound-assisted deep eutectic solvents (UAE-DES). The characterization and the antioxidant capacity of PBF phytochemicals using a multi-test system in-vitro were investigated. The highest amount of phenolic compounds (TPC: 183.95 ± 0.01 mg GAE/Gdw) was obtained using choline chloride-acetic acid solvent DES, under the optimum extraction conditions: 28.3% of water percentage, 40 °C of extraction temperature, and 18 min of extraction time. Moreover, DES extract had a more important antioxidant capacity with no significant difference compared to the control (Ascorbic acid). Furthermore, HPLC-DAD and TLC analysis indicated the presence of rutin and Cyanidin-3-glycoside in fraction number 4 after fractionation using the HP-20 diaion resin column. This extraction media has proved to be an alternative approach for the extraction of bioactive compounds as a sustainable and safe extraction media for pharmaceutical and industrial applications.     

In vitro and in vivo antioxidant activity of Symplocos cochinchinensis S. Moore leaves containing phenolic compounds

Methanol extract of Symplocos cochinchinensis S. Moore leaves was evaluated for its in vitro and in vivo antioxidant activity. The total phenolic content of the extract was 230 mg of gallic acid equivalents/g extract. The extract showed very good scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC₅₀ 620.30 ± 0.14 μg/ml), hydroxyl (IC₅₀ 730.21 ± 1.05 μg/ml), nitric oxide (IC₅₀ 870.31 ± 0.19 μg/ml) radicals, as well as high reducing power. The extract also showed strong suppressive effect on lipid peroxidation. In in vivo study CCl₄ induced oxidative stress produced significant increase in SGOT, SGPT and LDH levels along with reduction in liver SOD, CAT, GSH and GPx levels. Pre-treatment of rats with the extract (250 and 500 mg/kg) for 7 days showed significant reduction in the levels of SGOT, SGPT and LDH compared to CCl₄ treated rats. SOD, CAT, GSH and GPx levels were increased significantly due to treatment with the extract. The activity of the extract was comparable to the standard drug, silymarin (25 mg/kg). The results suggest that the leaves of S. cochinchinensis are a source of natural antioxidants.     

Investigation on the elemental profiles of lip cosmetic products: Concentrations,distribution and assessment of potential carcinogenic and non-carcinogenic human health risk for consumer safety

Metal contamination of lip care products can cause potential adverse effects for consumers, hence assessment of human health risks associated with the consumption of these products is inevitable to ensure the consumers’ safety. In the presented study, the profiles of 18 elements in 37 of the most popular lip cosmetic products, of various types and brands, sold in the Saudi Arabian markets, were investigated and their associated potential carcinogenic and non-carcinogenic human health risks were assessed. The metal concentrations were determined using inductively coupled plasma mass spectrometry preceded by microwave digestion for sample preparation. In general, the concentrations of the investigated metals were lower than the safe permissible limits with the exception of Cd, Pb and Hg. The results found that Cd was regarded as the primary metal contaminant present in the analyzed lip products contributing to 66.3% of the total determined carcinogenic health risk. Overall, however it was observed that there was no significant non-carcinogenic (hazard index < 1) or carcinogenic (Risk_T < 10⁻⁴) health risks associated with the use of the investigated lip products. Although all the calculated values in this study were within the acceptable limits, special attention should be taken in order to prioritize minimizing the trace metals in lip products, especially for Cd, Pb, Ti and Hg. This study could provide vital data needed to ascertain the degree to which heavy metal exposure through cosmetics is prevalent.     

Biological and chemical characterization of the fraction with antiherpetic activity from Achyrocline flaccida.

The in vitro antiviral activity demonstrated by aqueous extract (AE) of Achyrocline flaccida on herpes simplex virus type-1 is exerted early during the viral replication, essentially during the viral adsorption to host cells. A bioguided purification process of the AE indicated that negatively charged polysaccharides were responsible for this antiviral activity.     

Formulation and clinical evaluation of the standardized Litchi chinensis extract for skin hyperpigmentation and aging treatments

IntroductionThe standardized litchi extract had been revealed on phytochemical actives, in vitro and cellular activities against aging and darkening of skin. However, a formulation containing the extract has never been developed as per clinical evaluated.Materials and methodsThe litchi serum was developed, safety and efficacy were clinically evaluated in human volunteers. The stable and none irritated 0.05 and 0.1% litchi serums were randomized-single blind placebo control clinical applied on the inner forearm of 29 volunteers for a consecutive 112 days and monitored by Mexameter® MX18, Cutometer® MPA 580 and Visioscan® VC 98.ResultsSkin lightening efficacy of the 0.1% and 0.05% litchi serum was significantly (P < 0.001 and P < 0.05) higher than the placebo. Skin elasticity and wrinkle reduction was significantly (P < 0.05 and P < 0.005) achieved by the 0.1% litchi serum. The efficacy of litchi serums was confirmed by a split-face, randomized, single-blind controlled that the 0.1% litchi serum was significantly (P < 0.05) better than the 0.05% one of all examined parameters.ConclusionSafety and efficacy of litchi extract are clinically confirmed for hyperpigmentation and aging of skin treatments.     

Subcritical water extraction of nutraceuticals with antioxidant activity from oregano. Chemical and functional characterization

In the present work, oregano leaves (Origanum vulgare L.) are explored as natural source of nutraceuticals with antioxidant activity. To do this, subcritical water extraction (SWE), a new environmentally friendly technique, is employed as extraction procedure and HPLC coupled to DAD is used for the chemical characterization of the extracts. Moreover, the radical scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the determination of the total phenolic content (measured with the Folin test) are applied to evaluate the antioxidant activity of the extracts. The extraction of antioxidants from oregano leaves by SWE is studied considering different temperatures (25, 50, 100, 150 and 200 °C) to investigate the selectivity of the process. The highest antioxidant activity is observed for the extract obtained at the highest temperature, 200 °C (EC₅₀ equal to 10 μg/ml). Moreover, the extraction yield was also the highest (54% dry weight) at these extraction conditions. The total phenolic content showed no differences among the different extracts, concluding that the amount of phenolic compounds extracted was similar but the type and structure of the phenolics was different, providing in this way different antioxidant activity. Some compounds could be tentatively identified, proposing some probable chemical structures for some of them, such as flavanones, dihydroflavonols, favonols and flavones.     

Antidiabetic and antioxidant activity of the methanol extract of Diospyros peregrina fruit on Type I diabetic rats

Chronic diabetes complications are mainly associated with augmented oxidative stress. Thus the present study evaluated the hypoglycemic, as well the antioxidant effect, of the methanol extract of Diospyros peregrina Gurke. (Ebenaceae) fruits on experimental diabetic rats. Oral administration of methanol extract at 150 and 300?mg/kg body weight per day to diabetic rats was found to have profound hypoglycemic activity in term of reduction of fasting blood glucose level. The diabetic rats showed lower activities of superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) content in hepatic and renal tissues as compared with normal rats. The activities of SOD, CAT, and GSH were found to be increased in extract-treated diabetic rats in selected tissues. The increased levels of lipid peroxidation (thiobarbituric acid reactive substances and hydroperoxides) in diabetic rats were also found to be reverted back to near-normal status in extract-treated groups. It was found that the extract is more effective at the dose of 300?mg/kg body weight and this effect is almost comparable to that of standard glibenclamide.