Phytochemical screening and biological assays of ethanolic leaf extract of Senna rugosa

Abstract Senna rugosa (Fabaceae) is a common specie of the Brazilian territory, especially in the Cerrado biome. It is widely used in the popular medicine although not yet adequately investigated as to its phytoconstituents and pharmacological activities. In this study, the preliminary phytochemical analysis of ethanolic leaf extract of S. rugosa was performed and its cytotoxicity, antitumoral and antimicrobial activities (antibacterial, antifungal, anti-Trypanosoma and anti-Leishmania) were evaluated. The crude extract was analyzed in HPLC-DAD and fractions were also characterized using GC-MS and ESI-MS techniques. Results indicate phenolic compounds majority presence, including flavonol, anthraquinone and anthrones derivatives. Relative antimicrobial activities were detected against Staphylococcus aureus, Pseudomonas aeruginosa, Candida famata, Candida krusei and Candida tropicalis. As well as, a weak anti-trypanosomatids activity against M2269 strain and BH46 strain of Leishmania sp. A relative antitumoral activity was also identified but in counterpoint were also observed a toxicity in fibroblast cells (L929). Phytochemically, results provide evidence that phenolic compounds in S. rugosa leaves might be the responsible for its antimicrobial activity and cell toxicity inferred in our research.

摘要：皱叶决明（Senna rugosa，豆科（Fabaceae））是巴西本土常见物种，尤其广泛分布于塞拉多（Cerrado）生物群落。该物种虽已广泛应用于民间医药，但目前针对其植物化学成分与药理活性的研究仍未得到充分开展。本研究对皱叶决明的乙醇叶片提取物开展了初步植物化学分析，并对其细胞毒性、抗肿瘤活性及抗菌活性（涵盖抗细菌、抗真菌、抗锥虫及抗利什曼原虫活性）进行了评价。本研究采用高效液相色谱-二极管阵列检测器（HPLC-DAD）对粗提物进行分析，并通过气相色谱-质谱联用（GC-MS）与电喷雾电离质谱（ESI-MS）技术对提取物组分进行了表征。分析结果显示，提取物中主要成分为酚类化合物，包括黄酮醇、蒽醌及蒽酮类衍生物。研究检测到该提取物对金黄色葡萄球菌（Staphylococcus aureus）、铜绿假单胞菌（Pseudomonas aeruginosa）、法马假丝酵母（Candida famata）、克柔假丝酵母（Candida krusei）及热带假丝酵母（Candida tropicalis）具有一定抗菌活性。此外，该提取物对利什曼原虫属（Leishmania sp.）的M2269株与BH46株表现出较弱的抗锥虫体活性。本研究同时检测到一定的抗肿瘤活性，但与此同时也观察到其对成纤维细胞（L929）具有毒性。从植物化学角度来看，本研究结果表明，皱叶决明叶片中的酚类化合物可能是其抗菌活性与细胞毒性的主要来源。