Backiam Arockia Doss Susai, Duraisamy Senbagam, Karuppaiya Palaniyandi, Balakrishnan Senthilkumar, Sathyan Aswathy, Kumarasamy Anbarasu, Raju Amutha
Department of Microbiology, Vivekanandha College of Arts and Science for Women (Autonomous), Tiruchengode, Tamil Nadu, India.
Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Chengalpattu, Tamil Nadu, India.
Biotechnol Appl Biochem. 2023 Dec;70(6):2038-2051. doi: 10.1002/bab.2508. Epub 2023 Aug 28.
The interest in bioactives especially from botanicals to treat vancomycin-resistant enterococcal (VRE) infections is increased. Many species of Ocimum have a long history in folk medicinal and food industries. Nevertheless, their bioactive compounds remain unexplored. This study is aimed to assess the antimicrobial and antioxidant activity of basil leaf extract prepared using ethanol, methanol, and water. The ethanol and methanol extract have all the phytochemicals (alkaloids, flavonoids, phenolic compounds, tannins, saponins, quinones, carbohydrates, and proteins) except steroids and terpenoids. In addition to steroids and terpenoids, tannin was also absent in the aqueous extract. Total phenolic and flavonoid content was high in ethanol and followed by methanol and aqueous extract. Similarly, ethanol and methanol extract showed strong antimicrobial activity against VRE and MTCC strains at a concentration of 20 mg/mL than aqueous extract. Among the 10 indicators, Staphylococcus aureus is highly susceptible to ethanol extract at a concentration of 8 mg/mL and followed by other MTCC strains. Vancomycin-resistant enterococci pathogens were inhibited at the minimum inhibitory concentration of 14, 16, and 20 mg/mL of ethanol, methanol, and aqueous extract. Further, on the basis of determining the absorbing material (nucleic acid and protein) at 260 nm and scanning electron microscopic, it was confirmed that the loss of cell membrane integrity and cell membrane damage were the effective mechanisms of plant extract antimicrobial activity. All three solvents have shown remarkable antioxidant activity. Gas chromatography-mass spectrometry analysis of basil leaves ethanol extract identified 19 compounds with various therapeutic and food applications.
人们对生物活性物质尤其是来自植物的生物活性物质治疗耐万古霉素肠球菌（VRE）感染的兴趣日益增加。许多罗勒属植物在民间医药和食品工业中有着悠久的历史。然而，它们的生物活性化合物仍未得到充分研究。本研究旨在评估用乙醇、甲醇和水制备的罗勒叶提取物的抗菌和抗氧化活性。乙醇和甲醇提取物含有除甾体和萜类化合物外的所有植物化学物质（生物碱、黄酮类化合物、酚类化合物、单宁、皂苷、醌类、碳水化合物和蛋白质）。水提取物除了不含甾体和萜类化合物外，也不含单宁。乙醇提取物中的总酚和黄酮含量较高，其次是甲醇提取物和水提取物。同样，乙醇和甲醇提取物在浓度为20mg/mL时对VRE和MTCC菌株的抗菌活性比水提取物强。在10种指示菌中，金黄色葡萄球菌在浓度为8mg/mL时对乙醇提取物高度敏感，其次是其他MTCC菌株。耐万古霉素肠球菌病原体在乙醇、甲醇和水提取物的最低抑菌浓度分别为14、16和20mg/mL时受到抑制。此外，通过在260nm处测定吸收物质（核酸和蛋白质）以及扫描电子显微镜观察，证实细胞膜完整性丧失和细胞膜损伤是植物提取物抗菌活性的有效机制。所有三种溶剂都表现出显著的抗氧化活性。罗勒叶乙醇提取物的气相色谱-质谱分析鉴定出19种具有各种治疗和食品应用的化合物。
