The antioxidant potential of Sutherlandia frutescens

One of the best-known multi-purpose medicinal plants in Southern Africa, Sutherlandia frutescens subsp. microphylla (family: Fabaceae/Leguminosa), is used for a wide range of conditions, including cancer, viral diseases and inflammatory conditions. Little scientific data has been documented on the mechanism by which Sutherlandia frutescens acts on the immune system. Phagocyte derived reactive oxygen species, such as hydrogen peroxide and superoxide radicals, are responsible for the pathogenesis of various inflammatory conditions. Anti-inflammatory properties of various medicinal-plant extracts have been explained, at least in part, by their antioxidant activities. We investigated the effects of a hot water extract of Sutherlandia frutescens on both luminol and lucigenin enhanced chemiluminescence of neutrophils stimulated with L-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) as well as its superoxide and hydrogen peroxide scavenging properties in a cell free system. The results indicate that Sutherlandia frutescens extract possesses superoxide as well as hydrogen peroxide scavenging activities at concentrations as low as 10 microg/ml, which could account for some of the anti-inflammatory properties that have been described.     

Sutherlandia frutescens extracts can induce apoptosis in cultured carcinoma cells

Sutherlandia frutescens popularly known as cancer bush is endemic to Southern Africa. Whole plant parts have been used and traditional healers claim that it can treat cancer. In this study it is shown that a crude aqueous Sutherlandia frutescens whole plant extract induced cytotoxicity in neoplastic cells (cervical carcinoma) and CHO (Chinese Hamster Ovary cells) cell lines. Morphological observation and monitoring with other biological assays involving chromatin condensation as well as phosphotidyl serine externalisation point to apoptotic responses. Further biochemical assays showed similar DNA fragmentation patterns induced by Sutherlandia frutescens extracts compared to other inducers of apoptosis such as staurosporine and ceramide. Furthermore, Sutherlandia frutescens extracts induced apoptosis was confirmed by flow cytometric analysis. These findings warrant further research with a view to develop Sutherlandia frutescens extracts for use in anti-cancer therapy.     

Anti-diabetic effects of Sutherlandia frutescens in Wistar rats fed a diabetogenic diet

Sutherlandia frutescens has been marked as a potential hypoglycaemic agent for the treatment of type 2 diabetes. We investigated the effects of Sutherlandia frutescens in bringing about hypoglycaemia and promoting glucose uptake in pre-diabetic rats. Crushed Sutherlandia frutescens leaves in drinking water were administered to rats fed a high fat diet. Positive control rats received only metformin. Glucose uptake experiments were undertaken using [(3)H] deoxy-glucose. Various physiological parameters were also measured. Rats receiving Sutherlandia frutescens displayed normoinsulinaemic levels, after 8 weeks medicational compliance, compared to the fatty controls. There was a significant increase in glucose uptake into muscle and adipose tissue, and a significant decrease in intestinal glucose uptake (p<0.001 at 60min) in rats receiving the plant extract. The Sutherlandia frutescens plant extract shows promise as a type 2 anti-diabetes medication because of its ability to normalize insulin levels and glucose uptake in peripheral tissues and suppress intestinal glucose uptake, with no weight gain noted. The exact mechanism of action and the extract's efficacy in humans need further confirmation.     

In vitro culture studies of Sutherlandia frutescens on human tumor cell lines

Sutherlandia frutescens is a South African herb used traditionally by the natives to treat cancer, and more recently to improve the overall health in HIV/AIDS patients. Gas chromatography/mass spectrometer profiling and liquid chromatographic/mass spectral investigation confirmed and quantified the presence of canavanine, GABA and arginine in the herbal preparation used in this study. In vitro study demonstrated a concentration dependent effect of Sutherlandia on several tumor cell lines, with 50% inhibition (IC50) of proliferation of MCF7, MDA-MB-468, Jurkat and HL60 cells at 1/250, 1/200, 1/150 and 1/200 dilutions, respectively. Sutherlandia treatment did not induce HL60 differentiation along the macrophage/monocyte or granulocyte lineage. It demonstrated antioxidant activity in reducing free radical cations with an estimated activity of 0.5 microl of Sutherlandia extract equivalent to that of 10 microM of Trolox. However, it did not significantly suppress lipopolysaccharide stimulated nitric oxide production by murine macrophage/monocyte RAW 264.7 cells, nor did it significantly inhibit IL-1beta and TNF-alpha mRNA expression in RAW 264.7 cells. In conclusion, Sutherlandia ethanolic extract showed a concentration dependent antiproliferative effect on several human tumor cell lines but did not show significant antioxidant effects. Further studies are needed to explore the activities of this multipurpose South African herbal preparation.     

Influence of Sutherlandia frutescens extracts on cell numbers, morphology and gene expression in MCF-7 cells

Sutherlandia frutescens is a well-known South African herbal remedy traditionally used for stomach problems, internal cancers, diabetes, various inflammatory conditions and recently to improve the overall health in cancer and HIV/AIDS patients. The influence of crude Sutherlandia frutescens extracts (prepared with 70% ethanol) was investigated on cell numbers, morphology, and gene expression profiles in a MCF-7 human breast adenocarcinoma cell line. Time-dependent (24, 34, 48 and 72 h) and dose-dependent (0.5-2.5 mg/ml) studies were conducted utilizing spectrophotometrical analysis with crystal violet as DNA stain. A statistically significant decrease to 50% of malignant cell numbers was observed after 24 h of exposure to 1.5 mg/ml Sutherlandia frutescens extract when compared to vehicle-treated controls. Morphological characteristics of apoptosis including cytoplasmic shrinking, membrane blebbing and apoptotic bodies were observed after 24h of exposure. A preliminary global gene expression profile was obtained by means of microarray analysis and revealed valuable information about the molecular mechanisms and signal transduction associated with 70% ethanolic Sutherlandia frutescens extracts.     

The influence of Sutherlandia frutescens on adrenal steroidogenic cytochrome P450 enzymes

AIM OF THE STUDY: The aim of this study was to investigate whether Sutherlandia frutescens, subsp. microphylla (family: Fabaceae/Leguminosa), which is traditionally used to treat symptoms of chronic stress generally associated with increased circulating glucocorticoids, influences the biosynthesis of these glucocorticoids. METHODS: We investigated the interaction of Sutherlandia frutescens with cytochrome P450 enzymes, CYP17 and CYP21, which catalyse key reactions in glucocorticoid biosynthesis. The binding of progesterone and pregnenolone to these enzymes and their metabolism were assayed in the presence of extracts and the bioactive compounds, l-canavanine, pinitol, GABA, flavonoids and triterpenoid glucosides present in the shrub. RESULTS: While the aqueous and methanol extracts inhibited the type I progesterone-induced difference spectrum (p<0.05), inhibition of pregnenolone binding (p=0.25) was negligible, with the aqueous extract exhibiting greater inhibition. The triterpenoid fraction inhibited both the type I pregnenolone- and progesterone-induced difference spectra and elicited a type II difference spectrum in the absence of substrate. Both pregnenolone and progesterone metabolism were inhibited by the aqueous extract, the inhibition of CYP21 being greater than that of CYP17, influencing the flux through glucocorticoid precursor pathways. CONCLUSION: This attenuation of adrenal P450 enzymes may thus demonstrate a possible mechanism by which Sutherlandia frutescens reduces glucocorticoid levels and alleviates symptoms associated with stress.     

Evaluation of the mutagenic and antimutagenic effects of South African plants

Dichloromethane and 90% methanol extracts of 42 South African plants were screened for mutagenicity and antimutagenicity using the Salmonella/microsome mutagenicity assay (Ames) against Salmonella typhimurium TA98 and TA100 bacterial strains in the presence and absence of metabolic activator S9. The methanol extracts from whole plants of Helichrysum simillimum, Helichrysum herbaceum and Helichrysum rugulosum indicated mutagenicity. These are the first reported tests on the mutagenicity of Helichrysum species. Six species indicated antimutagenic properties, all in the presence of S9: methanol leaf extract of Bauhinia galpinii, and dichloromethane leaf extracts of Bauhinia galpinii, Clerodendrum myricoides, Datura stramonium, Buddleja saligna, Millettia sutherlandii and Sutherlandia frutescens.     

SPME-GC-MS联用分析紫苏挥发性成分

目的 采用SPME-GC-MS联用的方法检测紫苏中挥发性成分.方法 先采用固相微萃取器萃取紫苏挥发油,再用气质联用仪检测挥发油中的有效成分.结果 从紫苏中分离出56种成分,主要成分为2-己酰基呋喃,单萜,倍半单萜,脂肪酸等,其中2-己酰基呋喃占69.88%,这可能是造成紫苏强烈气味的主要原因.结论 SPME-GC-MS方法能简便、敏感、快捷的检测紫苏中挥发性成分.     

响应面分析法优化白苏中总黄酮的超声提取工艺

目的:确定白苏总黄酮的最佳提取工艺条件。方法:以白苏总黄酮提取率为指标,采用响应面分析法优化超声提取工艺条件,考察乙醇浓度、固液比、提取次数等三因素对白苏总黄酮提取率的影响。结果:白苏总黄酮最佳提取工艺条件为,加60%乙醇超声提取4次,每次18 min,固液比为1∶15,总黄酮提取率为24.65 mg/g。结论:超声法对白苏总黄酮有较好的提取作用,工艺简单,易于工业化大生产。     

紫苏和鸭跖草抗菌活性的研究

采用系统溶剂提取法分别提取紫苏、白苏和鸭跖草的茎和叶,得到24个提取物,然后用滤纸扩散法测定这些提取物对枯草芽胞杆菌等8种菌株的抗菌活性,发现紫苏、白苏的抗菌活性比鸭跖草强,紫苏茎的乙酸乙酯提取物和白苏茎石油醚提取物对所测试的菌株表现出较好的生物活性,紫苏茎的乙酸乙酯提取物抑菌圈直径范围在7.0～11.0mm,白苏茎石油醚提取物抑菌圈直径范围在8.3～14.3mm,是该植物的抗菌活性部位,其抗菌范围广.     

DPPH法分析测定生地和熟地清除自由基的能力

目的:采用不同提取溶剂、不同提取方法提取生地和熟地,并对其进行抗氧化活性研究。方法:采用Folin-Ciocalteu方法测定生地和熟地不同提取物的总多酚含量,利用DPPH测定样品清除自由基的能力。结果:生地正丁醇提取物,熟地无水乙醇提取物的总多酚含量最高,ASE提取总多酚含量高。在DPPH实验中,生地正丁醇提取物和熟地丙酮提取物的清除自由基的能力最强,ASE法提取样品均具有很好清除DPPH自由基能力。结论:生地和熟地清除DPPH自由基能力的强弱与样品中的总多酚含量无关。     

半枝莲乙醇提取物体外抗氧化活性研究

目的分析半枝莲乙醇提取物及不同极性溶剂萃取后体外抗氧化活性。方法乙醇提取半枝莲黄酮类化合物,以石油醚、乙酸乙脂、正丁醇分别萃取得各部分化合物,200～750 nm吸收光谱扫描,进行ABTS+、羟自由基、DPPH自由基清除实验。结果半枝莲乙醇提取物具有明显抗ABTS+、羟自由基、DPPH自由基活性,不同极性溶剂萃取半枝莲黄酮对其抗氧化能力有不同程度影响。结论半枝莲乙醇提取物具有明显抗氧化活性,分类萃取可降低其抗氧化活性。     

车前子中苯乙醇苷化合物抗氧化活性研究

采用PCL和FRAP两种不同的抗氧化活性体外评价体系,对车前子80%乙醇提取物以及从中分离得到的两个苯乙醇苷单体化合物,麦角甾苷和异麦角甾苷的抗氧化活性进行了系统研究。研究结果表明:车前子80%乙醇提取物,麦角甾苷和异麦角甾苷都具有良好的抗氧化活性,而且证明车前子80%乙醇提取物的抗氧化活性主要来自这2个化合物的贡献。     

蚊子草抗氧化物提取工艺优选及抗氧化活性考察

目的:优选蚊子草抗氧化物的提取工艺并测定抗氧化提取物及其纯化物的抗氧化活性.方法:以总黄酮和总酚酸含量为指标,采用正交试验法优选蚊子草抗氧化物的提取工艺;采用DPPH法研究抗氧化提取物及其纯化物的体外抗氧化活性.结果:最佳提取工艺为10倍量65％乙醇加热回流提取3次,每次2.0h;抗氧化提取物及其纯化物的DPPH自由基清除率分别约为70％,90％.结论:优选的提取工艺稳定、可靠;蚊子草抗氧化物及其纯化物具有较强的体外抗氧化活性.     

A review of the taxonomy, ethnobotany, chemistry and pharmacology of Sutherlandia frutescens (Fabaceae)

Sutherlandia frutescens (tribe Galegeae, Fabaceae), a popular plant in traditional medicine, is indigenous to South Africa, Lesotho, southern Namibia and southeastern Botswana. It is chemically, genetically and geographically extremely variable and has been divided into three subspecies and several regional forms. A second species, Sutherlandia tomentosa, is localized along the Cape coast. Sutherlandia is sometimes treated as part of the genus Lessertia. There are numerous vernacular names and a wide diversity of uses, including poor appetite, indigestion, stomach complaints, dysentery, colds, influenza, kidney conditions, fever, diabetes, internal cancers, uterine troubles, liver conditions, backache, rheumatoid arthritis, urinary tract infections, stress and anxiety, dropsy and heart failure. Notable is the use as a bitter tonic ("blood purifier"), anti-stress medication ('musa-pelo) and, at least since 1895, specifically as a cancer tonic (both as treatment and as prophylaxis). Externally it is applied to haemorrhoids, inflamed wounds and eye infections. Recent in vitro and in vivo studies have shown antiproliferative, anti-HIV, anti-diabetic, anti-inflammatory, analgesic, antibacterial, anti-stress, anticonvulsant and antithrombotic activities. Aqueous extracts often differ in activity from organic solvent extracts. The presence of high levels of free amino acids, non-protein amino acids such as canavanine and GABA, the cyclitol pinitol, flavonols and triterpenes (including SU1, a cycloartane-type triterpene saponin) provide plausible hypotheses on how these compounds, individually or collectively, may be responsible for the reputed efficacy in a wide range of ailments. Results of animal studies, as well as a phase I clinical study, have shown no indications of toxicity. Sufficient preclinical data are now available to justify controlled clinical studies.     

Semecarpus anacardium L. nut extract administration induces the in vivo antioxidant defence system in aflatoxin B1 mediated hepatocellular carcinoma.

The antioxidant defence system which plays a critical role in carcinogenesis is severely altered in aflatoxin B1 induced hepatocellular carcinoma conditions. In order to assess the antitumour activity of Semecarpus anacardium nut extract, a flavonoid containing drug, non-enzymic antioxidant levels were analysed in control and experimental animals. Plasma was analysed for uric acid, vitamin E and vitamin C. Glutathione, total thiols, non-protein thiols, vitamin E, vitamin C and cytochrome P450 were estimated in liver and kidney homogenates. Depletion of all these antioxidants were recorded in cancer conditions. These deleterious effects are controlled by the administration of Semecarpus anacardium nut extract. Following drug administration, there was a marked increase in antioxidant levels and a dramatic elevation in cytochrome P450 content. It can be concluded that the observed anticancer property of Semecarpus anacardium nut extract may also be explained by its strong antioxidant capacity and capability to induce the in vivo antioxidant system.     

南非传统草药Sutherlandia 抗糖尿病作用的研究

目的：观察南非传统草药Sutherlandia水提物对糖脂代谢的影响。方法：腹腔注射链脲佐菌素（STZ）并高脂饲料喂养诱导2型糖尿病大鼠模型。随机分为正常组、模型组、吡格列酮组、Sutherlandia组。观察体质量、口服糖耐量试验（OGTT）、血甘油三酯（TG）、总胆固醇（TC）、低密度脂蛋白-胆固醇（LDL-C）、高密度脂蛋白-胆固醇（HDL-C）指标的改变,Western Blot法检测各组大鼠骨骼肌胰岛素受体底物（IRS-1）表达情况。结果：与正常组比较,模型组大鼠体质量降低,OGTT、TG、TC、LDL-C指标明显升高（P<0.05）,多饮、多食、多尿症状明显,IRS-1 蛋白表达明显降低（P<0.05）;治疗后,与模型组比较,Sutherlandia组及吡格列酮组的体质量未见明显增长,Sutherlandia组及吡格列酮组血糖、TG、TC均明显降低（P<0.05或P<0.01）,二者之间无统计学差异,Sutherlandia组及吡格列酮组骨骼肌中IRS-1蛋白表达明显升高（P<0.05）,二者之间无统计学差异。结论：腹腔注射STZ并高糖高脂饲料喂养诱导2 型糖尿病大鼠模型存在糖脂代谢紊乱;南非传统草药Sutherlandia可明显降低其血糖水平,改善血脂代谢,提高胰岛素水平;Sutherlandia可提高IRS-1骨骼肌中的表达水平,进而改善胰岛素抵抗,降低血糖,其确切的作用途径有待进一步深入研究。     

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。