In vitro antioxidant activity and total phenolic content of endophytic fungi isolated from Eugenia jambolana Lam.

ObjectiveTo elucidate the antioxidant activity and total phenolic content (TPC) of ethyl acetate extracts of endophytic fungi isolated from Eugenia jambolana by three different antioxidant assays.MethodsTwenty one different endophytic fungal extracts were screened for presence of various phytochemicals, TPC and in vitro antioxidant activity. TPC was tested by Folin-Ciocalteau reagent based assay. DPPH free radical scavenging, hydrogen peroxide scavenging and reducing power assays were used to evaluate the antioxidant activity.ResultsAlkaloids, phenols, flavonoids, saponins, and terpenes were the main phytochemicals presents in all 21 endophytes. A significant positive correlation was found between antioxidant activity and TPC in fungal extracts. There is 36% endophytic extracts having high phenolic content exhibited potent antioxidant activity. Chaetomium sp., Aspergillus sp., Aspergillus peyronelii and Aspergillus niger strain showed the highest antioxidant activity ranging from 50% to 80% having 58 mg/g to 60 mg/g GAE total phenolics. Ascorbic acid used as a standard showed 90% reducing potential.ConclusionsThe results reveal that metabolites produced by endophytic fungi isolated from Eugenia jambolana can be a potential source of novel natural antioxidant compounds.     

楮实提取物体外抗氧化活性的研究

目的 探讨楮实提取物的体外抗氧化活性.方法 先用80%乙醇,然后用蒸馏水对楮实进行提取.其中醇提取物依次用石油醚、氯仿、乙酸乙酯、正丁醇萃取,水提部分经醇沉、干燥后得到楮实粗多糖.运用羟基(·OH)自由基体系、二苯代苦味基肼(DPPH·)自由基体系和对Fe~(3+)的还原能力实验,比较楮实各提取物的抗氧化活性.结果 楮实提取物对·OH自由基和DPPH·自由基均有较好的清除作用,其中总醇提取物对·OH自由基的清除能力最强,其IC_(50)值为0.28 mg/ml;乙酸乙酯提取物对DPPH·自由基的清除效果最好,其IC_(50)值达到0.08 mg/ml;各提取物对Fe~(3+)均有较强的还原能力,乙酸乙酯提取物还原效果最为明显.结论 楮实提取物具有一定的抗氧化活性,在抗衰老方面有广泛的应用前景.     

仙茅提取物体外抗氧化活性研究

目的 探讨仙茅提取物的抗氧化活性.方法 先用80%乙醇,然后用蒸馏水对仙茅进行提取,其中醇提浸膏依次用石油醚、氯仿、乙酸乙酯、正丁醇萃取;水提部分经醇沉,制备仙茅粗多糖.分别观察仙茅各提取物对羟基自由基 (·OH)、1,1-二苯基-2-苦基苯肼自由基(DPPH·)的清除率以及对Fe~(3+)还原力.结果 与抗坏血酸比较,仙茅提取物对自由基均有较强清除作用,对·OH的清除率乙酸乙酯萃取物>正丁醇萃取物>粗多糖>总醇提物,IC_(50)值分别为0.247、0.358、0.796和0.871 mg/ml;对DPPH·的清除率乙酸乙酯萃取物>正丁醇萃取物>总醇萃取物>氯仿萃取物>石油醚萃取物>粗多糖,其IC_(50)值分别为0.026、0.055、0.620、0.071、0.122和0.275 mg/ml.不同提取物对Fe~(3+)有较强还原能力,还原力大小为:乙酸乙酯萃取物>正丁醇萃取物>总醇提物>氯仿萃取物>石油醚萃取物>粗多糖.结论 仙茅具有明显的抗氧化活性,在抗衰老方面有广泛的应用前景.     

Oxidant/antioxidant status of plasma samples from patients with rheumatoid arthritis

This study aims to elucidate plasma oxidant/antioxidant status in patients with rheumatoid arthritis (RA). Fasting blood samples were obtained from 24 patients with RA and 20 control subjects. Antioxidant potential (AOP) value, nonenzymatic superoxide radical scavenger activity (NSSA), and malondialdehyde (MDA) levels were measured to establish plasma oxidant/antioxidant status in the patient and control groups. Patients with RA had lower AOP and NSSA but higher MDA levels than those of the control subjects, which was an indication of reduced antioxidant capacity and oxidant stress in these patients. Results suggest that the antioxidant system is impaired and peroxidation reactions are accelerated in patients with RA. We suppose that therapeutic use of some antioxidants may be beneficial in this regard. Received: 26 April 1999 / Accepted: 2 August 1999     

Analysis of antioxidant prenylflavonoids in different parts of Macaranga tanarius,the plant origin of Okinawan propolis

Objective:To analyze the antioxidant prenylilavonoids in different parts of Macaranga tanarius(M.tanarius)(Euphorbiaceae)including the leaf,petiole,stem,leaflet,flower and fruit(only in female plant),and to evaluate their antioxidant properties.Methods:Methanol extracts of each part of M.tanarius were prepared and five prenylilavonoids in them were quantitatively analyzed using HPLC.The fruits from female plant were further separated into seed,pericarp,and glandular trichome.After the quantitative analyses of prenylflavonoids in each part of M.tanarius,antioxidant activity of the extracts was evaluated by 2,2-diphenyl-l-picryI-hydrazyl(DPPH)radical scavenging assay.Results:The leaf of M.tanarius contained two prenylflavonoids as main components in both male and female plants.Both flowers(male and female)contained five kinds of prenylflavonoids.In the petiole,stem and leaflet of both male and female plants,the prenylflavonoids were not delected or their amounts were very low.Five kinds of prenylflavonoids were detected in the seed,pericarp and glandular trichome of female M.tanarius.In particular,the glandular trichome had the highest level of total prenylflavonoids(235 mg/g of fresh plant).DPPH radical scavenging activity of all parts was more than 30%.Conclusions:We found that different parts of M.tanarius contained antioxidant prenylflavonoids.In particular,not only the glandular trichome but also the leaf contained prenylflavonoids,which indicated that M.tanarius may be developed as a functional plant,because the leaves of this plant can be easily collected.     

光枝勾儿茶提取物的抗氧化活性

目的 探讨光枝勾儿茶提取物的抗氧化活性.方法 采用80%乙醇进行回流提取,其中醇提浸膏依次用石油醚、乙酸乙酯、正丁醇萃取.分别考察光枝勾儿茶各提取物对羟基自由基 (·OH)、二苯代苦味基肼自由基(DPPH·)的清除率以及对Fe3+的还原力.结果 与抗坏血酸(Vc)比较,光枝勾儿茶提取物对自由基均有较强清除作用,对·OH的清除率Vc>乙酸乙酯萃取物>石油醚萃取物>正丁醇萃取物>水层部分,半清除率浓度(IC50,mg/ml)分别为0.061、0.099、0.344、0.770、1.709;对DPPH·的清除率Vc>正丁醇萃取物>乙酸乙酯萃取物>水层部分>石油醚萃取物,其半清除率浓度(IC50,mg/ml)分别为0.004 6、0.011 1、0.019 2、0.028 3、0.058 6.不同提取物对Fe3+有较强还原能力,还原力大小为:Vc>乙酸乙酯萃取物>正丁醇萃取物>石油醚萃取物>水层部分.结论 光枝勾儿茶具有明显的抗氧化活性,在抗衰老方面有广泛应用前景.     

Hepatoprotective and antioxidant capacity of Melochia corchorifolia extracts

ObjectiveTo evaluate hepato protective and antioxidant capacity of Melochia corchorifolia (M. corchorifolia) aerial part extracts.MethodsAntioxidant activity was evaluated by using three free radicals (Superoxide, Hydroxyl and DPPH) and hepatoprotective activity was assessed against CCl₄ induced liver intoxication in rats.ResultsThe extracts produced concentration dependent percentage protection in decrease of serum enzymes and percentage inhibition on free radicals. Among all extracts methanol extract showed better activity with percentage protection of SGOT (78.98%), SGPT (79.65%), ALP (82.48%) and total bilirubin (80.0%) levels against CCl₄ liver intoxication and also methanolic extract showed better activity with IC₅₀ values on superoxide, hydroxyl and DPPH radicals were 127 μ g, 240 μ g and 179 μ g.ConclusionsFrom the results obtained during the study it could be concluded that M. corchorifolia aerial part extracts have antioxidant and hepatoprotective components. Further study is necessary for isolation and characterization of bioactive molecules which are responsible for hepatoprotective and antioxidant activity.     

Phytochemical screening,anti-oxidant activity and in vitro anticancer potential of ethanolic and water leaves extracts of Annona muricata (Graviola)

ObjectiveTo determine the phytochemical composition, antioxidant and anticancer activities of ethanolic and water leaves extracts of Annona muricata (A. muricata) from the Eastern Uganda.MethodsPhytochemical screening was conducted using standard qualitative methods and a Chi-square goodness of fit test was used to assign the relative abundance of the different phytochemicals. The antioxidant activity was determined using the 2, 2-diphenyl-2-picrylhydrazyl and reducing power methods whereas the in vitro anticancer activity was determined using three different cell lines.ResultsPhytochemical screening of the extracts revealed that they were rich in secondary class metabolite compounds such as alkaloids, saponins, terpenoids, flavonoids, coumarins and lactones, anthraquinones, tannins, cardiac glycosides, phenols and phytosterols. Total phenolics in the water extract were (683.69±0.09) μg/mL gallic acid equivalents (GAE) while it was (372.92±0.15) μg/mL GAE in the ethanolic extract. The reducing power was 216.41 μg/mL in the water extract and 470.51 μg/mL GAE in the ethanolic extract. In vitro antioxidant activity IC₅₀ was 2.0456 mg/mL and 0.9077 mg/mL for ethanolic and water leaves extracts of A. muricata respectively. The ethanolic leaves extract was found to be selectively cytotoxic in vitro to tumor cell lines (EACC, MDA and SKBR3) with IC₅₀ values of 335.85 μg/mL, 248.77 μg/mL, 202.33 μg/mL respectively, while it had no cytotoxic effect on normal spleen cells. The data also showed that water leaves extract of A. muricata had no anticancer effect at all tested concentrations.ConclusionsThe results showed that A. muricata was a promising new antioxidant and anticancer agent.     

Decreased oxidant profile and increased antioxidant capacity in naturally postmenopausal women

Recent works have shown a dual side of estrogens, and research on the relationship between oxidative stress and menopausal status remains unclear and has produced controversial results. In this work, we aimed to evaluate by sensitive methods the oxidant and antioxidant changes that develop after natural menopause. Thirty premenopausal and 28 naturally postmenopausal women volunteered for this study. Blood was collected and plasma used. 17-OH estradiol levels in plasma were estimated. Plasma levels of advanced oxidation protein products (AOPP), lipid peroxidation products (such as hydroperoxides and malondialdehyde (MDA)), and nitrites were measured, and total radical antioxidant parameter testing was performed to determine the oxidant and antioxidant profiles, respectively. Estrogen levels were significantly increased (p < 0.02) in premenopausal women (54.28 ± 9.34 pg/mL) as compared with postmenopausal women (18.10 ± 1.49 pg/mL). Postmenopausal women had lower levels of lipid hydroperoxide oxidation (p < 0.0001), lipid hydroperoxide levels evaluated by the area under the curve (AUC; 1,366,000 ± 179,400 AUC; p < 0.01), and hydroperoxides as measured by the ferrous oxidation-xylenol orange method (31.48 ± 2.7 μM; p < 0.0001). The MDA levels did not differ between pre- and postmenopausal women whether measured by thiobarbituric acid-reactive substances or high-performance liquid chromatography assays. No differences in AOPP and nitrite levels were observed between pre- and postmenopausal women. Postmenopausal women also exhibited a higher total radical antioxidant level (0.89 ± 0.08 μM Trolox; p < 0.0001). Postmenopausal women demonstrated lower levels of oxidative damage and a higher antioxidant capacity than premenopausal women.     

A comparative study of the in vitro antioxidant activity of statins

Background: Treatment of hypercholesterolemia with statins is remarkably effective in cardiovascular prevention. This has led to the hypothesis that these drugs may act on the atherosclerotic plaque by mechanism(s) independent of the reduction of serum cholesterol levels. The aim of this study was to assess the total antioxidant activity of the most prescribed statins: fluvastatin, atorvastatin, pravastatin and simvastatin. Methods: We measured the in vitro antioxidant activity of statins as their ability to antagonize the oxidation of -keto-γ-methiolbutyric acid by both hydroxyl and peroxyl radicals. The results are expressed as Total Oxyradical Scavenging Capacity (TOSC) units. Uric acid and Trolox were used as the reference antioxidants. Results: The scavenging capacity towards hydroxyl radicals was highest for simvastatin (3375±112 U/mg), a value 270.2% higher (P<0.0001) compared to uric acid (reference antioxidant vs. hydroxyl radicals, 1249±71 U/mg). Among the tested statins, fluvastatin exhibited the highest anti-peroxyl radical antioxidant capacity (8755±187 U/mg) which appeared 50% lower (P<0.0001) compared to Trolox (reference antioxidant vs. peroxyl radicals, 17 460±379 U/mg). Conclusions: All the statins tested have intrinsic antioxidant activity with both anti-hydroxyl and peroxyl radical activity. Simvastatin was the most effective as an anti-hydroxyl radical antioxidant and fluvastatin as an anti-peroxyl radical antioxidant.     

A 7-day profile of oxidative stress and antioxidant status in patients with acute liver failure

Purpose  Acute liver failure (ALF) is characterized by a rapid and massive destruction of hepatocytes. The role of oxidative stress in perpetuating the injury is undefined and may be a potential therapeutic target. Our aim was to study serial variation in oxidative stress and antioxidant status in patients with ALF. Methods  The study involved a prospective case–control study set in a tertiary care referral center. Thirty-two consecutive patients admitted with ALF were included with 23 healthy controls for comparison. Level of systemic oxidative stress as defined by superoxide dismutase (SOD), lipid peroxidation products (thiobarbituric acid reactive derivatives [TBARS]), and the total antioxidant capacity as the ferric reducing ability of plasma (FRAP) was measured at baseline on days 3 and 7. Results  The patients were aged 24 years (range 13–60 years) and included 20 females. Thirteen (40.6%) patients died. Patients with ALF had significantly increased systemic oxidative stress at presentation, as reflected by higher levels of SOD (P < 0.001) and TBARS (P < 0.001) than controls. Both TBARS levels and FRAP decreased progressively from admission to the end of first week among the survivors (P = 0.004 and 0.015, respectively). The antioxidant status reflected by FRAP (P = 0.001) was significantly lower in ALF patients than controls. No relation was found between the level of oxidative stress and the mortality or complications. Conclusion  A high level of systemic oxidative stress exists in ALF, with depletion of antioxidant reserves. Further studies are needed to define the clinical correlation of the large pro-oxidant burden.     

鲜壁虎不同部位提取液对小鼠H22肝癌体内外抑制作用

目的:探讨鲜壁虎不同部位提取液对培养的H22肝癌细胞体外抑制增殖作用和对H22实体型移植瘤小鼠的体内抑制作用,寻找有效的抗肿瘤活性成分.方法:MTT法检测高、低剂量的壁虎皮肤、头部、肌肉骨骼、内脏、尾部及全壁虎的提取液对H22肝癌细胞的体外杀伤作用.采用昆明小鼠H22移植瘤模型观察壁虎内脏高、低剂量组,去内脏壁虎高、低剂量组,全壁虎高、低剂量组的体内抑瘤活性及荷瘤小鼠胸腺和脾脏指数的变化.结果:体外实验结果显示,壁虎内脏提取液高剂量可显著抑制H22细胞的增殖,抑制率为61.6%,与其他部位的提取液相比有显著差异(P<0.01).体内抑瘤实验,5-FU组的抑瘤率为65.3%,内脏低剂量和高剂量组的抑瘤率为8.4%和16.8%,去内脏为26.3%和42.1%.全壁虎为31.6%和52.1%.去内脏壁虎的高、低剂量组和全壁虎的高、低剂量组的瘤重与模型组比较有统计学差异(P<0.05或P<0.01).全壁虎高剂量组与5-FU组的瘤重相比较无统计学差异.各壁虎组与模型组小鼠的胸腺重、胸腺指数,脾脏重、脾脏指数相比均没有明显差异.而5-FU组胸腺重、胸腺指数,脾脏重、脾脏指数较模型组和各壁虎组均明显降低(P<0.01).结论:壁虎具有良好的抗肝癌效果     

Phytochemical screening and comparative antimicrobial potential of different extracts of Stevia rebaudiana Bertoni leaves

ObjectiveTo evaluate in vitro antimicrobial potential and phytochemical screening of the crude extracts of leaves of Stevia rebaudiana Bertoni.MethodsThe essential oil and crude extracts were prepared by using different usual method. Antimicrobial and antifungal activities were measured by the well established methods.ResultsHighest antifungal index [(12.13±0.08) mm)] and lowest antifungal index [(9.13±0.04) mm] as well as highest antibacterial index [(11.89±0.07) mm] and lowest antibacterial index [(7.24±0.03) mm] were obtained for extracts B, H, A and F, respectively. Invariably extract C, E, I, J and H did not show antimicrobial activity. The extract F showed all antifungal and antibacterial activity except Bacillus cereus and Bacillus megaterium.ConclusionsThe above findings support the idea that plant extracts of Stevia rebaudiana Bertoni leaves may have a role to be used as pharmaceuticals or preservatives.     

Effect of Lonicerae Flos extracts on reflux esophagitis with antioxidant activity

AIM： To observe the effects of traditional antiinflammatory medicine Lonicerae FIos （LF） on rat reflux esophagitis （RE） induced by pylorus and forestomach ligation compared with the well-known proton antioxidant, α-tocopherol. METHODS： Rats were pretreated with three different dosages of LF （500, 250 and 125 mg/kg） orally, once a day for 14 d before pylorus and forestomach ligation. Nine hours after pylorus and forestomach ligation, changes to the stomach and esophagus lesion areas, gastric volumes, acid and pepsin outputs, antioxidant effects, esophageal lipid peroxidation, superoxide dismutase （SOD）, catalase （CAT）, malondialdehyde （MDA）, myeloperoxidase and glutathione （GSH） levels, and collagen contents （marker of flexibility） were observed on the esophageal and fundic histopathology. The results were compared with an α-tocopherol （once orally, 1 h before operation, 30 mg/kg） treated group in which the effects on RE were already confirmed.RESULTS： Pylorus and forestomach ligations caused marked increases of gross esophageal and gastric mucosa lesion areas, which corresponded with histopathological changes. In addition, increases of esophageal lipid peroxidation, decreases of SOD, CAT, and GSH-free radical scavengers, increases of collagen were observed. However, these pylorus and forestomach ligation induced RE were dose-dependently inhibited by treatment of 500, 250 and 125 mg/kg of LF extract, mediated by antioxidant effects. RE at 250 mg/kg showed similar effects α-tocopherol. CONCLUSION： The results suggest that antioxidant effects of LF could attenuate the severity of RE and prevent the esophageal mucosal damage, and validate its therapeutic use in esophageal reflux disease.     

Evaluation of extracts and essential oil from Callistemon viminalis leaves: Antibacterial and antioxidant activities,total phenolic and flavonoid contents

ObjectiveTo investigate antioxidant and antibacterial activities of Callistemon viminalis (C. viminalis) leaves.MethodsThe essential oil of C. viminalis leaves obtained by hydro-distillation was analyzed by GC/MS. Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant (DPPH assay) and antibacterial (agar disc diffusion and 96-well micro-plates methods) actives.ResultsFourteen components were identified in the essential oil, representing 98.94% of the total oil. The major components were 1,8-cineole (64.53%) and α-pinene (9.69%). Leaf essential oil exhibited the highest antioxidant activity of (88.60±1.51)% comparable to gallic acid, a standard compound [(80.00±2.12)%]. Additionally, the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic (tetracycline). The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.ConclusionsIt can be suggested that C. viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis. The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C. viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.     

Comparative study of total phenolics,flavonoids contents and evaluation of antioxidant and antimicrobial activities of different polarities fruits crude extracts of Datura metel L.

ObjectiveTo determine the total phenolics and flavonoids and to evaluate antioxidant and antimicrobial activities of different extracts from fruits of Datura metel (D. metel).MethodsDifferent crude extracts from the fruits of D. metel were subjected to determination of total phenolics, flavonoids, antioxidant and antimicrobial activities by established methods.ResutlsThe total phenolics results showed that ethyl acetate extract was the most efficient (60.26%) compared to hexane, chloroform, butanol and methanol extracts which had phenolic contents of 50.08, 35.50, 52.54 and 26.49%, respectively. Almost similar results were obtained from the fruits crude extracts for total flavonoids and results found that methanol crude extract was the highest (1.71%) compared to other crude extracts. The antioxidant activity results showed that methanol extract acted the highest activity compared to other extracts and in the order of methanol>ethyl acetate>hexane>chloroform>butanol extract. All extracts were displayed moderate antibacterial potential against the tested bacteria such as Staphylococcus aureus, Escherichia coli and Pseudomonus aeruginosa in the range of 0%–10%.ConclusionsThe results of this present study clearly showed that the crude extracts of D. metel demenstrated antimicrobial and antioxidant activities and it may act as potential antioxidant sources for human biological system.     

Phytochemical screening and antioxidant capacity of the aerial parts of Thymelaea hirsuta L.

Objective

To assess antioxidant activities of different aerial parts of Thymelaea hirsuta (T. hirsuta) from west Algeria, and to search for new sources of safe and inexpensive antioxidants.

Methods

Samples of leaves, stems and flowers from T. hirsuta were tested for total phenolic content, flavonoids content, and evaluation its total antioxidant activity, were done using the spectrophotometric analyses.

Results

Results of preliminary phytochemical screening of leaf, flower and stem of T. hirsuta revealed the presence of tannins, alkaloids, steroids, saponins, coumarins, reducteurs compound and anthraquinones. The total phenolics and flavonoids were estimated. The aqueous extracts of the aerial parts of T. hirsuta showed potent in vitro antioxydant activities using various models viz, DPPH scavenging assay, ferric reducing antioxidant power (FRAP) and ABTS radical scavenging activity.

Conclusions

On the basis of the results obtained, T. hirsuta extracts are rich sources of natural antioxidants appears to be an alternative to synthetic antioxidants and this justifies its therapeutic usage.     

硒拮抗砷抑制体外人胚肺组织中抗氧化酶活性的研究

目的 观察硒和砷对组中抗氧化酶活性的影响及硒对砷的拮抗作用。方法 以体外培养人胚肺组织为靶组织,使其暴露于不同浓度的Ａｓ２Ｏ３和Ｎａ２ＳｅＯ３后检测其组织匀浆液中抗氧化酶ＧＳＨ－Ｐｘ（谷胱甘肽过氧化物酶）、ＣＡＴ（过氧化氢酶）、Ｍｎ－ＳＯＤ（锰－超氧化物歧化酶）和总ＳＯＤ活性变化。结果 ３０、５０、１００μｍｏｌ／Ｌ砷使各酶活性显著降低;０．１和１．０μｍｏｌ／Ｌ硒使ＧＳＨ－Ｐｘ及ＣＡＴ活性显著增     

Multicomponent exercise program improves blood lipid profile and antioxidant capacity in older women

This study intended to determine the effect of multicomponent exercise on blood lipid profile and on antioxidant capacity in older women. Forty women aged 60-80 years participated in a supervised multicomponent exercise program. Plasma contents of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-1 (Apo A-1) and apolipoprotein B (Apo B-100), total antioxidant status (TAS) and the enzymatic activities of glutathione reductase (GR) and glutathione peroxidase (GPx) were evaluated before and after 8-month training. The multicomponent exercise program induced a significant decrease in TG, TC/HDL-C and Apo B/Apo A-1 and a significant increase in HDL-C and Apo A-1 (p < 0.05). There was a significant increase in plasma TAS as well as GR and GPx enzyme activities. The present data show that an 8-month supervised moderate-intensity multicomponent exercise program resulted in beneficial improvements of blood lipid profile that were accompanied by positive modulation of antioxidant capacity.     

Total phenolic content,in vitro antioxidant activity and chemical composition of plant extracts from semiarid Mexican region

Objective:To determine the extraction suitable conditions of total phenolic content(TPC) by heat-reflux system,antioxidant activities and HPLC characterization of the aqueous-ethanolic extracts of Jatropha dioica(J.dioica)(Dragon's blood).Flourensia cernua(F.cernua)(Tar bush).Eucalyptus camaldulensis(E.camaldulensis)(Eucalyptus) and Turnera diffusa(T.diffusa)(Damiana).Methods:TPC was evaluated by the well-known colorimetric assay using FolinCiocalteu reagent.The antioxidant activities were assayed by three methods based on scavenging of DPPH,ABTS and by lipid oxidation inhibition.The chemical composition of the extracts obtained was subject to HPLC analysis.Results:TPC in the plant extracts ranged from 2.3 to14.12 mg gallic acid equivalents/g for J.dioica and E.camaldulensis,respectively.The plant extracts of F.cernua,E.camaldulensis and T.diffusa showed similar strong antioxidant activities on scavenging of DPPH and lipid oxidation inhibition.In contrast,J.dioica extracts had lowest potential antioxidant in three assays used.HPLC assay showed the presence of several phenolic compounds in the extracts used.Conclusions:The results obtained suggest that F.cernua,E.camaldulensis and T.diffusa are potential sources to obtain bioactive phenolic compounds with high antioxidant properties which can be used in the factories as antioxidant agents or for treatments in diseases.