Antitumor, antioxidant and antimicrobial activities of Bersama engleriana (Melianthaceae)

The aim of this study was to evaluate the antitumor, antioxidant and antimicrobial activities as well as the phytochemical composition and the acute toxicity of the methanolic extracts from the roots (BER), stem bark (BEB), leaves (BEL) and wood (BEW) of Bersama engleriana. The crown gall tumor and DPPH radical scavenging assays were used to detect respectively the antitumoral and oxidant activities. Agar diffusion and liquid dilution were used for antimicrobial tests and the phytochemical assays were conducted according to Harbone methods. The single-dose oral toxicity test was performed in accordance with the OPPTS 870.1100 and OECD 401 guidelines. The phytochemical tests indicated the presence of flavonoids, phenols, triterpenes and anthraquinones in all extracts. Pronounced tumor reducing activity was observed with the extracts from the roots (69.32%) and leaves (65.42%). The DPPH scavenging activity showed that the extract from the leaves was the most active with 93.71% inhibition rate at the 1000 microg/ml. The results of antimicrobial activity showed that all tested extracts were active against all tested microbial species, including Gram-positive, and negative bacteria, the two Candida species and mycobacteria. The MIC values obtained ranged from 9.76 to 156.25 microg/ml. Under the conditions of the studied toxicity, all extracts were found to be non-toxic. The overall results of this study indicates that the extracts from the roots, stem bark, leaves and wood have interesting antioxidant properties and represent a potential source of medicine for the treatment of infectious diseases and cancer.     

罗汉果植株不同器官的抗氧化活性

目的:采用二苯基苦基苯肼(DPPH)法研究罗汉果植株茎、叶和果实的抗氧化活性。方法:采用超声提取法分别对罗汉果植株茎、叶和果实进行乙醇提取;采用分光光度法测定各提取物对DPPH的清除能力。结果:罗汉果植株茎、叶、果实对DPPH的半清除率(IC50值)分别为0.756,0.119,0.358 g.L-1。结论:罗汉果植株3个器官均有抗氧化活性。其中,叶的抗氧化能力最强。     

Antimicrobial, antioxidant, antitumour-promoting and cytotoxic activities of different plant part extracts of Garcinia atroviridis griff. ex T. anders

Crude extracts (methanol) of various parts, viz. the leaves, fruits, roots, stem and trunk bark, of Garcinia atroviridis were screened for antimicrobial, cytotoxic, brine shrimp toxic, antitumour-promoting and antioxidant activities. The crude extracts exhibited predominantly antibacterial activity with the root extract showing the strongest inhibition against the test bacteria at a minimum inhibitory dose (MID) of 15.6 microg/disc. Although all the extracts failed to inhibit the growth of most of the test fungi, significant antifungal activity against Cladosporium herbarum was exhibited by most notably the fruit (MID: 100 microg), and the leaf (MID: 400 microg) extracts. None of the extracts were significantly cytotoxic, and lethal towards brine shrimps. The root, leaf, trunk and stem bark extracts (except for the fruits) showed strong antioxidant activity exceeding that of the standard antioxidant, alpha-tocopherol. Antitumour-promoting activity (>95% inhibition) was shown by the fruit, leaf, stem and trunk bark extracts.     

菊花、叶、茎抗氧化活性比较

目的:研究菊花、叶和茎的体外抗氧化活性,为菊花、叶、茎资源的充分利用提供科学依据。方法:以绿原酸为对照组(CHA),分为菊花水提物组(JH-S),菊花醇提物组(JH-C),菊叶水提物组(JY-S),菊叶醇提物组(JY-C),菊花茎水提物组(JJ-S),菊花茎醇提物组(JJ-C),分别测定提取物的还原能力及对羟基自由基(·OH),二苯代苦味酰基自由基(DPPH·),脂自由基和超氧阴离子(O-2·)的清除率,研究其体外抗氧化活性。结果:菊花,叶,茎提取物和绿原酸的抗氧化作用与浓度呈正相关。菊花、叶、茎的水、醇提取物(0.20 g·L-1)和绿原酸相比,还原能力分别为2.260,2.270,2.261,2.260,2.261,2.272,2.256均无差异,且各醇提物和水提物之间也无差异;对·OH,O-2·均具较强的清除作用,且水提物的作用均好于其醇提物,尤其抗O-2·作用明显强于绿原酸清除DPPH·,脂自由基方面效果均优于水提物,菊茎醇提取物对DPPH·清除率略高于绿原酸,相同浓度下菊叶清除脂自由基作用胜于菊花。结论:菊花、叶和茎提取物均有较强的抗氧化活性,菊叶抗氧化作用与菊花相当。菊叶和茎作为天然抗氧化剂有较好的开发利用价值。     

Enzyme inhibition,antioxidant and immunomodulatory activities,and brine shrimp toxicity of extracts from the root bark,stem bark and leaves of Terminalia macroptera

Ethnopharmacological relevance

The root bark, stem bark and leaves of Terminalia macroptera have been traditionally used against a variety of ailments such as wounds, hepatitis, malaria, fever, cough, and diarrhea as well as tuberculosis and skin diseases in African folk medicine. Boiling water extracts of Terminalia macroptera, administered orally, are the most common preparations of this plant used by the traditional healers in Mali. This study aimed to investigate the inhibition of the activities of α-glucosidase, 15-lipoxygenase and xanthine oxidase, DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of different extracts obtained by boiling water extraction (BWE) and by ASE (accelerated solvent extraction) with ethanol, ethanol–water and water as extractants from different plant parts of Terminalia macroptera.

Materials and methods

27 different crude extracts were obtained by BWE and ASE from root bark, stem bark and leaves of Terminalia macroptera. The total phenolic and carbohydrate contents, enzyme inhibition activities (α-glucosidase, 15-lipoxygenase and xanthine oxidase), DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of these extracts were evaluated. Principal component analysis (PCA) was applied for total biological activities evaluation.

Results

Several of the extracts from root bark, stem bark and leaves of Terminalia macroptera obtained by BWE and ASE showed potent enzyme inhibition activities, radical-scavenging properties and complement fixation activities. None of the extracts are toxic against brine shrimp larvae in the test concentration. Based on the results from PCA, the ASE ethanol extracts of root bark and stem bark and the low molecular weight fraction of the 50% ethanol–water extract of leaves showed the highest total biological activities. The boiling water extracts were less active, but the bark extracts showed activity as α-glucosidase inhibitors and radical scavengers, the leaf extract being less active.

Conclusion

The observed enzyme inhibition activities, radical scavenging properties and complement fixation activities may explain some of the traditional uses of this medicinal tree, such as in wound healing and against diabetes.     

In vitro antioxidant and antimicrobial activity of extracts from Morus alba L. leaves, stems and fruits

In this study, the aqueous and ethanolic extracts (leaves, stems and fruits) from Morus alba L., a traditional Chinese medicine, were evaluated for their antioxidant and antimicrobial properties. Ethanolic extracts showed higher contents of both total phenolics and flavonoids than aqueous extracts. The total phenolic content was in the order of: leaf extracts > fruit extracts > stem extracts, whereas the total flavonoids was: leaf extracts > stem extracts > fruit extracts. Using DPPH assays, the concentrations providing 50% inhibition (IC(50)) values of aqueous extracts from leaves, stems and fruits were 7.11 ± 1.45 mg/ml, 86.78 ± 3.21 mg/ml and 14.38 ± 2.83 mg/ml, respectively, whereas the IC(50) values of ethanolic extracts were 3.11 ± 0.86 mg/ml, 14.62 ± 2.45 mg/ml and 12.42 ± 2.76 mg/ml, respectively. In sum, the antioxidant activities of ethanolic extracts from M. alba L. were stronger than the aqueous extracts, and in the order of: leaf extracts > fruit extracts > stem extracts. The ethanolic extracts exhibited moderate antimicrobial activities, whereas the aqueous extracts showed poor antimicrobial properties in our test system. This study validated the medicinal potential of M. alba L.     

Direct and indirect antimicrobial effects and antioxidant activity of Cordia gilletii De Wild (Boraginaceae)

Cordia gilletii De Wild (Boraginaceae) root bark is traditionally used in Democratic Republic of Congo (DRC) for the treatment of various disorders, including malaria, diarrhea, wounds and skin diseases; part of these activities may rely on antimicrobial and antioxidant properties. Successive extracts of root barks powder with n-hexane, dichloromethane, ethyl acetate, methanol and water were tested for antimicrobial activity, both direct and indirect (antibiotic resistance reversal), against 10 strains of bacteria and 1 strain of fungi by broth microdilution and agar diffusion methods. The eventual synergy between plant extracts and antibiotics was investigated by the determination of the fractional inhibitory concentration index (FIC index). The methanol extract showed direct antimicrobial activity against all tested microorganisms with minimum inhibitory concentrations (MIC) ranging between 125 and 1000 microg/ml, whereas the ethyl acetate and the dichloromethane extracts showed activity on four and three strains, respectively. 200 microg/ml of n-hexane and dichloromethane extracts decreased the MICs of penicillin and streptomycin 4-64-fold for methicillin-resistant Staphylococcus aureus. A synergistic effect was found between the methanol extract and tetracycline, whereas additive effects were observed for the other combinations tested. The methanol and dichloromethane extracts showed the greater antioxidant activity by scavenging the free radical DPPH with IC(50) values of 3.2 and 8.1 microg/ml, respectively. These results support the use of the plant in the treatment of infectious diseases and wounds; they warrant further studies as to the nature of active compounds.     

暴马丁香不同部位乙醇提取物抑菌及清除DPPH自由基作用

目的以暴马丁香树皮、叶、枝和花蕾的75%乙醇提取物为材料,研究其抑菌及抗氧化的活性。方法采用滤纸片法测定暴马丁香不同部位乙醇提取物对2种常见细菌的生长抑制活性、最低抑菌浓度。采用DPPH自由基法,利用分光光度法测定不同部位乙醇提取物在不同质量浓度下清除DPPH自由基的能力。结果暴马丁香乙醇提取液对沙门氏菌的抑制效果大小顺序为枝花蕾叶树皮,对枯草芽孢杆菌的抑制效果大小为叶枝树皮花蕾。暴马丁香树皮乙醇提取物抗氧化能力最强,其余各部位的抗氧化能力大小依次是花蕾枝叶。结论暴马丁香枝和叶的抑菌能力较好,其树皮、花蕾的抗氧化能力较强,确定枝和花蕾具有较好的应用价值。     

Evaluation of antioxidant and antimicrobial properties of Soymida febrifuga leaf extracts

The present study was designed to evaluate the antioxidant and antimicrobial properties of hexane (LH), methanol (LM) and aqueous (LA) extracts of Soymida febrifuga (Maliaceae) leaves, which is a traditional folk medicine in India. No pharmacological evaluation of this plant (except antiplasmodial activity) has been reported to date. Antioxidant activity of different extracts was evaluated by DPPH free radical scavenging activity, taking total phenolic content (TPC) as an index. Antimicrobial activity was tested against six bacterial and five fungal strains using the agar hole diffusion method and the minimum inhibitory concentrations (MIC) and minimum microbicidal concentration (MMC) were determined for all the test organisms against the extracts. The results showed that the methanol and aqueous extracts of leaf had a higher antioxidant activity and total phenolic content than the hexane extract. The antioxidant activity and TPC of the extracts were highly correlated. Extracts also showed several degrees of antimicrobial activity against different microbes. The methanol extract was more potent against Aspergillus fumigatus and Candida tropicana. The lowest MIC values obtained for LM, LA and LH were 78, 156, 625 microg/mL against A. fumigatus, C. tropicana and C. albicans, respectively. Hence, this study confirms that Soymida febrifuga leaves possess potent antioxidant and antimicrobial activity.     

沙枣叶醇提物各组分清除DPPH自由基的研究

目的通过DPPH抗氧化活性体外评价体系测定沙枣叶醇提物各组分的抗氧化活性、清除自由基的能力。方法将沙枣叶乙醇提取物依次用石油醚,醋酸乙酯,正丁醇进行萃取,各组分都配置成适当倍数的的水溶液,通过DPPH法测定各组分的清除自由基的能力,并计算各组分的IC50。结果 萃取后的水层清除自由基的能力最强,IC50为0.70 mg/m l,其次是正丁醇层(IC50为3.47 mg/m l),醋酸乙酯层(IC50为13.9mg/m l)和石油醚层(IC50为63.6 mg/m l)。结论 沙枣叶醇提物各组分对DPPH·均具有一定清除作用,具有体外抗氧化性,可作为有效的天然自由基清除剂,具有很大的开发利用前景。     

Determination of antioxidant and radical scavenging activity of Basil (Ocimum basilicum L. Family Lamiaceae) assayed by different methodologies

The antioxidant properties of plants have been investigated, in the light of recent scientific developments, throughout the world due to their potent pharmacological activities and food viability. Basil (Ocimum basilicum L. Family Lamiaceae) is used as a kitchen herb and as an ornamental plant in house gardens. In the present study, the possible radical scavenging and antioxidant activity of the water (WEB) and ethanol extracts (EEB) of basil was investigated using different antioxidant methodologies: 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, scavenging of superoxide anion radical-generated non-enzymatic system, ferric thiocyanate method, reducing power, hydrogen peroxide scavenging and metal chelating activities. Experiments revealed that WEB and EEB have an antioxidant effects which are concentration-dependent. The total antioxidant activity was performed according to the ferric thiocyanate method. At the 50 microg/mL concentration, the inhibition effects of WEB and EEB on peroxidation of linoleic acid emulsion were found to be 94.8% and 97.5%, respectively. On the other hand, the percentage inhibition of a 50 microg/mL concentration of BHA, BHT and alpha-tocopherol was found to be 97.1%, 98.5% and 70.4% inhibition of peroxidation of linoleic acid emulsion, respectively. In addition, WEB and EEB had effective DPPH radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, reducing power and metal chelating activities. Additionally, these various antioxidant activities were compared with BHA, BHT and alpha-tocopherol as reference antioxidants. The additional total phenolic content of these basil extracts was determined as the gallic acid equivalent and were found to be equivalent.     

Antioxidant and 15-lipoxygenase inhibitory activities of the Malian medicinal plants Diospyros abyssinica (Hiern) F. White (Ebenaceae), Lannea velutina A. Rich (Anacardiaceae) and Crossopteryx febrifuga (Afzel) Benth. (Rubiaceae)

The African flora contains numerous medicinal plants whose biological and chemical properties are incompletely known. Antioxidant and radical scavenging properties of plants are subject to intensive research. In the work described here, we have investigated the antioxidant activity of the plants Diospyros abyssinica (root bark), Lannea velutina (root bark and stem bark) and Crossopteryx febrifuga (seeds). Extracts of different polarity were assayed for radical scavenging activity, using the stable free radical diphenylpicrylhydrazyl, and for inhibition of enzymatic lipid peroxidation mediated by soybean 15-lipoxygenase. All plants investigated showed activity, but there were large differences between plants and between extracts. In general, Diospyros abyssinica and Lannea velutina were richer in antioxidants than Crossopteryx febrifuga. Lipophilic extracts were not active as radical scavengers, but did inhibit 15-lipoxygenase. Semipolar extracts (80% aqueous ethanol and methanol) of Diospyros abyssinica and Lannea velutina showed the highest activity both as radical scavengers and lipoxygenase inhibitors, and also gave the highest extract yields. These plants therefore appear to be excellent sources of antioxidants.     

The in vitro biological activity of selected South African Commiphora species

Ten South African Commiphora (Burseraceae) species were investigated to validate their use in traditional healing rites. The leaf and stem extracts of each species were analysed for the anti-oxidant (ABTS and DPPH assays), antimicrobial (MIC and death kinetic assays), anti-inflammatory (5-LOX assay), anticancer (SRB assay) properties, as well as the cytotoxic effects (tetrazolium-based assay). The best anti-oxidant activity (ABTS assay) was observed for the stem extracts of Commiphora tenuipetiolata IC(50)=5.10 microg/ml), Commiphora neglecta (IC(50)=7.28 microg/ml) and Commiphora mollis (IC(50)=8.82 microg/ml). Extracts generally exhibited poor anti-oxidant activity in the DPPH assay, with the exception of Commiphora schimperi (stem), Commiphora neglecta (stem), Commiphora tenuipetiolata (stem and leaf), and Commiphora edulis (stem), with IC(50) values ranging between 7.31 and 10.81 microg/ml. The stem extracts exhibited moderate to good 5-LOX inhibitory activity with Commiphora pyracanthoides (stem) displaying the greatest inhibitory effect (IC(50)=27.86+/-4.45 microg/ml). For the antimicrobial (MIC) assay, a greater selectivity was exhibited by the extracts against the Gram-positive bacteria (0.01-8.00 mg/ml) and the yeasts (0.25-8.00 mg/ml) than against the Gram-negative bacteria (1.00-8.00 mg/ml). Using death kinetic studies (time-kill studies), the rate at which Commiphora marlothii (stem) kills Staphylococcus aureus over a 24h period was determined. Mostly, a concentration-dependent antibacterial activity was observed beginning after ca. 30 min. All concentrations exhibited antibacterial activity, with complete bactericidal effect achieved by the 24(th) hour. The most active Commiphora species against the HT-29 cells (SRB anticancer assay) were Commiphora glandulosa (leaf and stem) and Commiphora marlothii (leaf). The MCF-7 cells (SRB anticancer assay) exhibited the highest sensitivity to indigenous Commiphora species, with Commiphora edulis (leaf and stem), Commiphora glandulosa (leaf and stem), Commiphora marlothii (leaf), Commiphora pyracanthoides (leaf and stem), Commiphora schimperi (stem), and Commiphora viminea (stem) all possessing a percentage inhibition greater than 80% at 100 microg/ml. Commiphora glandulosa (leaf and stem) and Commiphora pyracanthoides (leaf and stem) were the two most active species against the SF-268 cells (SRB anticancer assay), with IC(50) values ranging between 68.55+/-2.01 and 71.45+/-1.24 microg/ml. The majority of the Commiphora extracts were largely non-cytotoxic against Graham human kidney epithelial cells when investigated in the MTT assay.     

Influence of extracts of Stryphnodendron polyphyllum Mart. and Stryphnodendron obovatum Benth. on the cicatrisation of cutaneous wounds in rats

Stem bark of the two species Stryphnodendron polyphyllum Mart. and Stryphnodendron obovatum Benth., Leguminosae, was investigated for wound healing, antibacterial and antioxidant activity. These plants contain 12 and 19% tannins in their stem bark, respectively, and are widely used in traditional medicine in Brazil. The total content of phenolics of the crude extract (CE) of Stryphnodendron obovatum was 76.95 +/- 2.98% (CV = 3.87%) and of the ethyl-acetate fraction (EAF) was 89.13 +/- 0.34% (CV = 0.38%); whereas in Stryphnodendron polyphyllum the CE phenolics content was 51.62+/-1.53% (CV = 2.96%) and the EAF phenolics content was 59.00 +/- 1.91% (CV = 3.24%). The tannin content of CE from Stryphnodendron obovatum [36.58 +/- 0.35% (CV = 0.98%)] was about 11% higher than in CE from Stryphnodendron polyphyllum [25.43 +/- 0.96% (CV = 3.77%)]. The difference between the species was even greater in the EAF: in Stryphnodendron obovatum the EAF phenolics content was 55.01 +/- 0.36% (CV = 0.65%), whereas in Stryphnodendron polyphyllum the content was 36.16 +/- 0.42% (CV = 1.16%). The healing effect of ointments containing 2.5% crude lyophilised extract (PCE) and 2.5% ethyl-acetate lyophilised fraction (PEA) of the stem bark of Stryphnodendron polyphyllum and Stryphnodendron obovatum was studied in cutaneous wounds of Wistar rats after 4, 7 and 10 days of treatment. Epithelial cell proliferation in the area of re-epithelialisation of the wounds was evaluated by counting the metaphases blocked by vincristine sulfate. With PCE an increase in epidermal growth was observed after 4 and 7 days of treatment with Stryphnodendron polyphyllum, and after 7 and 10 days of treatment with Stryphnodendron obovatum. Wounds treated with PEA of Stryphnodendron obovatum showed increased epidermal growth only 4 days after the treatment; for Stryphnodendron polyphyllum, epidermal growth was observed after 4 and 7 days of treatment. Both the CE and the EAF fractions of Stryphnodendron polyphyllum and Stryphnodendron obovatum showed antibacterial activity against Staphylococcus aureus with MIC values of 125 and 250 microg/ml, respectively. Gram-negative bacteria tested were not inhibited by extracts and fractions at concentrations > 1000 microg/ml. The antioxidant activity through reduction of the DPPH radical in TLC, confirmed the anti-radical properties of these extracts in both species. CE and EAF of both species showed a radical scavenging activity (RSA) and protected DPPH from discolouration, already at 0.032 microg/ml. The extract from Stryphnodendron polyphyllum were more effective than those Stryphnodendron obovatum, although the former had a lower tannin content.     

The antioxidant activity of Clitoria ternatea flower petal extracts and eye gel

Extracts of Clitoria ternatea (butterfly pea) flowers are used in Thailand as a component of cosmetics and the chemical composition of the flowers suggest that they may have antioxidant activity. In this study the potential antioxidant activity of C. ternatea extracts and an extract containing eye gel formulation was investigated. Aqueous extracts were shown to have stronger antioxidant activity (as measured by DPPH scavenging activity) than ethanol extracts (IC₅₀ values were 1 mg/mL and 4 mg/mL, respectively). Aqueous extracts incorporated in to an eye gel formulation were also shown to retain this activity, however, it was significantly less than a commercial antiwrinkle cream included for comparison. The total phenolic content was 1.9 mg/g extract as gallic acid equivalents. The data from this study support the use of C. ternatea extracts as antioxidant inclusions in cosmetic products. Copyright © 2009 John Wiley & Sons, Ltd.     

Antioxidant Activity of Moringa oleifera Tissue Extracts

Moringa oleifera is an important source of antioxidants, tools in nutritional biochemistry that could be beneficial for human health; the leaves and flowers are used by the population with great nutritional importance. This work investigates the antioxidant activity of M. oleifera ethanolic (E1) and saline (E2) extracts from flowers (a), inflorescence rachis (b), seeds (c), leaf tissue (d), leaf rachis (e) and fundamental tissues of stem (f). The radical scavenging capacity (RSC) of extracts was determined using dot‐blots on thin layer chromatography stained with a 0.4 mm 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) solution; spectrophotometric assays were recorded (515 nm). Antioxidant components were detected in all E1 and E2 from a, b and d. The best RSC was obtained with E1d; the antioxidants present in E2 reacted very slowly with DPPH. The chromatogram revealed by diphenylborinate‐2‐ethylamine methanolic solution showed that the ethanolic extract from the flowers, inflorescence rachis, fundamental tissue of stem and leaf tissue contained at least three flavonoids; the saline extract from the flowers and leaf tissue revealed at least two flavonoids. In conclusion, M. oleifera ethanolic and saline extracts contain antioxidants that support the use of the plant tissues as food sources. Copyright © 2012 John Wiley & Sons, Ltd.     

In vitro antiplasmodial activity of 18 plants used in Congo Brazzaville traditional medicine

Sixty-six extracts of 18 plants commonly used by traditional healers in Congo Brazzaville for the treatment of malaria have been investigated for in vitro antiplasmodial activity. Ethanolic and dichloromethane extracts of 7 among the 18 studied plants were moderately active (10 microg/ml相似文献   

五倍子中多酚类物质对DPPH自由基清除作用的电子自旋共振研究

目的研究五倍子提取物对活性氧自由基的清除作用。方法采用电子自旋共振(ESR)和自旋捕集技术直接测定不同浓度的五倍子两种方法提取物对DPPH自由基的清除作用。结果五倍子两种提取物具有良好的清除DPPH自由基的作用,在实验条件下,五倍子水提取物清除DPPH自由基的IC50为0.414 7 mg/L,五倍子醇提取物清除DPPH自由基的IC50为0.858 6 mg/L。结论五倍子中多酚类物质具有较强的抗氧化活性。     

The in vitro and ex vivo antioxidant properties, hypolipidaemic and antiatherosclerotic activities of water extract of Moringa oleifera Lam. leaves

Moringa oleifera is used in Thai traditional medicine as cardiotonic. Recent studies demonstrated its hypocholesterolaemic effect. However, to be clinically useful, more scientific data are needed. AIM OF THE STUDY: We investigated the antioxidant, hypolipidaemic and antiatherosclerotic activities of Moringa oleifera leaf extract. MATERIALS AND METHODS: Scavenging activity of the extract on 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), and the inhibitory effect on Cu(2+)-induced low-density lipoprotein (LDL) oxidation were determined in in vitro experiment. The effects of the extract on cholesterol levels, conjugated diene (CD) and thiobarbituric acid reactive substances (TBARS) and plaque formations in cholesterol-fed rabbits were investigated. RESULTS: We found that in scavenging DPPH radicals the extract and Trolox had IC(50) of 78.15+/-0.92 and 2.14+/-0.12microg/ml, respectively. The extract significantly (P<0.05) prolonged the lag-time of CD formation and inhibited TBARS formation in both in vitro and ex vivo experiments in a dose-dependent manner. In hypercholesterol-fed rabbits, at 12 weeks of treatment, it significantly (P<0.05) lowered the cholesterol levels and reduced the atherosclerotic plaque formation to about 50 and 86%, respectively. These effects were at degrees comparable to those of simvastatin. CONCLUSIONS: The results indicate that this plant possesses antioxidant, hypolipidaemic and antiatherosclerotic activities and has therapeutic potential for the prevention of cardiovascular diseases.     

野坝子体外清除自由基活性研究

目的:对野坝子Elsholtzia rugulosa Hemsl.乙醇提取物的不同极性萃取部位和AB-8大孔树脂柱色谱不同浓度甲醇洗脱部位清除自由基能力进行综合评价。方法:分别以维生素C和维生素E为对照,采用清除2,2-二苯基苦味酰基苯肼基(2,2-diphenyl-1-picrylhydrazyl,DPPH)和2,2′-连氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐[2,2′-azino-bis(3-ethylbenzthiazo-line-6-sulphonic acid)diammonium salt,ABTS]自由基的方法,通过计算半数抑制浓度评价野坝子的乙醇提取物的不同极性萃取部位和AB-8大孔树脂柱色谱不同浓度甲醇洗脱部位的清除自由基能力。结果:野坝子提取物不同极性萃取部位清除DPPH自由基和ABTS自由基的能力分别为:乙酸乙酯部位Vit C正丁醇部位水部位石油醚部位氯仿部位、乙酸乙酯部位Vit E正丁醇部位水部位氯仿部位石油醚部位。AB-8大孔树脂柱色谱不同浓度甲醇洗脱部位清除DPPH和ABTS自由基的能力分别为Vit C50%甲醇部位70%甲醇部位30%甲醇部位100%甲醇部位、50%甲醇部位70%甲醇部位30%甲醇部位Vit E100%甲醇部位。结论:野坝子乙醇提取物的乙酸乙酯萃取部位和30%,50%和70%甲醇洗脱部位都具有很好的清除自由基活性,是一种新型天然抗氧化物质来源。