Evaluation of pharmacological activities, cytotoxicity and phenolic composition of four Maytenus species used in southern African traditional medicine to treat intestinal infections and diarrhoeal diseases.
Evaluation of pharmacological activities, cytotoxicity and phenolic composition of four Maytenus species used in southern African traditional medicine to treat intestinal infections and diarrhoeal diseases.
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DOI：
10.1186/1472-6882-13-100
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发表时间：
2013-05-11
影响因子：
--
通讯作者：
Eloff JN
中科院分区：
文献类型：
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作者：
Ahmed AS;McGaw LJ;Eloff JN
微生物感染以及由此产生的炎症和氧化应激是胃肠道（GIT）疾病的常见发病机制。在南非，美登木属的几个物种在传统医学中用于治疗各种传染病。以前的大部分工作都集中在非极性提取物的根和树皮。在这项研究中，评价了有柄美登木、平卧美登木、塞内加尔美登木和undata美登木的极性提取物的叶提取物的抗微生物、抗炎和抗氧化活性，以确定它们作为GIT病症的治疗剂的功效。通过用酸化的70%甲醇提取和溶剂-溶剂分级制备富含酚的叶提取物和级分。采用连续微孔板稀释法测定了各组分对金黄色葡萄球菌、铜绿假单胞菌、大肠杆菌和粪肠球菌以及烟曲霉、白色念珠菌和新型隐球菌临床分离株的活性。采用1，1-二苯基-2-苦基肼（DPPH）、2，2 '-连氮双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）、羟自由基（OH）清除试验和亚油酸过氧化抑制试验，测定其抗氧化活性。使用各种标准方案评价了粗提物的酚类成分以及对Vero细胞系的细胞毒性。抗微生物活性集中在己烷、二氯甲烷和乙酸乙酯的非极性级分中（MIC 19-312 μg/ml）。粗提物和极性组分（丁醇和水）具有中等至较差的抗微生物活性（MIC 312至高于2500 μg/ml）。粗提物和极性组分具有较好的抗氧化活性（对DPPH、ABTS和OH的EC_（50）分别为1.22 ~ 607 μg/ml、1.71 ~ 312 μg/ml和23 ~ 284 μg/ml）。粗提取物的亚油酸过氧化抑制EC 50值范围为27至39 μg/ml，对Vero细胞系的毒性相对较低（IC 50值87至187 μg/ml）。具有低活性的粗提物的分级分离可导致具有更有效活性的级分。这项研究证明了传统的使用叶粗提取物和馏分从这四种植物，以补救胃肠道疾病引起的感染，炎症和氧化应激并发症。该研究还为使用具有相同有益效果的叶提取物代替不可持续的根和树皮收获提供了理论基础。
Microbial infections and resulting inflammation and oxidative stress are common pathogenesis of gastrointestinal tract (GIT) disorders. In South Africa, several species of the genus Maytenus are used in traditional medicine to treat various infectious diseases. Most of the previous work on this genus was focused on nonpolar extracts from the root and bark. In this study, leaf extracts of polar extracts of Maytenus peduncularis, Maytenus procumbens, Maytenus senegalensis and Maytenus undata were evaluated for antimicrobial, anti-inflammatory and antioxidant activities to determine their efficacy as therapeutic agents in GIT disorders. Phenolic-enriched leaf extracts and fractions were prepared by extracting with acidified 70% methanol and solvent-solvent fractionation. The activities of the fractions against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis as well as clinical isolates of Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans were determined using a serial microplate dilution method. Antioxidant activities were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH) radical scavenging and linoleic acid peroxidation inhibitory assays. The phenolic composition as well as the cytotoxicity against Vero cell lines of the crude extracts was evaluated using various standard protocols. The antimicrobial activities were concentrated in the non-polar fractions of hexane, dichloromethane and ethyl acetate (MICs 19–312 μg/ml). The crude extracts and polar fractions (butanol and water) had moderate to poor antimicrobial activity (MICs 312 to above 2500 μg/ml). The crude extracts and polar fractions had good antioxidant activity (EC50 values varied from 1.22 to 607 μg/ml, 1.71 to 312 μg/ml and 23 to 284 μg/ml for DPPH, ABTS and OH respectively. Linoleic acid peroxidation inhibition EC50 values of the crude extracts ranged between 27 and 39 μg/ml with relatively low toxicity against Vero cell lines (IC50 values 87 to 187 μg/ml). Fractionation of a crude extract with low activity could lead to fractions with more potent activity. This study justifies the traditional use of leaf crude extracts and fractions from these four plants to remedy gastrointestinal disorders resulting from infection, inflammation and oxidative stress complications. The study also provides rationale for the use of leaf extracts with same beneficial effects in place of unsustainable root and bark harvest.