Katsukunya Jonathan, Makurira Rumbidzai, Mukanganyama Stanley
Department of Biotechnology and Biochemistry, University of Zimbabwe, P.O. Box MP 167, Mt. Pleasant, Harare, Zimbabwe.
Biochem Res Int. 2021 Oct 29;2021:5599129. doi: 10.1155/2021/5599129. eCollection 2021.
Treatment of infections caused by has become a challenge due to the emergency of resistant strains. root extracts have been used in traditional medicine to treat throat and chest pains in Zimbabwe. The objective of the study was to determine the effects of root bark extracts on the production of extracellular proteases by . The root barks were collected, dried, and crushed into powder. To obtain different phytoconstituents, plant extractions were performed. Extractions were carried out using two solvent mixtures: ethanol : water (50 : 50 v/v) and dichloromethane : methanol (50 : 50 v/v). Serial exhaustive extractions were also performed using methanol, ethanol, dichloromethane, acetone, ethyl acetate, hexane, and water. The broth microdilution assays were used to assess the antibacterial effects of the root bark extracts against . Ciprofloxacin was used as a positive control. Qualitative screening for extracellular protease production by on BCG-skim milk agar plates using the most potent extract was carried out. The proteolytic zones were measured and expressed as the ratio of the diameter of the colony to the total diameter of the colony plus the zone of hydrolysis ( values). The ethyl acetate extract was found to be the most potent inhibitor of the growth of with 99% inhibition and a minimum inhibitory concentration (MIC) of 100 g/mL. Inhibition of extracellular protease production was directly proportional to the concentration of the extract. At 100 g/mL, the ethyl acetate extract had a value of 0.84, indicative of mild proteolytic activity. A value of 0.94 was observed at a concentration of 200 g/mL and signified weak proteolytic activity. In conclusion, the extract inhibited the production of extracellular proteases in . Further work on the isolation and purification of bioactive compounds responsible for inhibiting the production of extracellular proteases is of importance in the discovery of agents with antivirulent effects on .
由于耐药菌株的出现，由……引起的感染治疗已成为一项挑战。在津巴布韦，……根提取物已被用于传统医学中治疗咽喉和胸痛。本研究的目的是确定……根皮提取物对……产生细胞外蛋白酶的影响。收集根皮，干燥并粉碎成粉末。为了获得不同的植物成分，进行了植物提取物的制备。使用两种溶剂混合物进行提取：乙醇∶水（50∶50 v/v）和二氯甲烷∶甲醇（50∶50 v/v）。还使用甲醇、乙醇、二氯甲烷、丙酮、乙酸乙酯、己烷和水进行了连续彻底提取。采用肉汤微量稀释法评估……根皮提取物对……的抗菌作用。环丙沙星用作阳性对照。使用最有效的提取物在卡介苗脱脂乳琼脂平板上对……产生细胞外蛋白酶进行定性筛选。测量蛋白水解区并表示为菌落直径与菌落直径加水解区总直径的比值（……值）。发现乙酸乙酯提取物是对……生长最有效的抑制剂，抑制率为99%，最低抑菌浓度（MIC）为100μg/mL。细胞外蛋白酶产生的抑制作用与提取物浓度成正比。在100μg/mL时，乙酸乙酯提取物的……值为0.84，表明有轻度蛋白水解活性。在200μg/mL浓度下观察到……值为0.94，表明蛋白水解活性较弱。总之，该提取物抑制了……中细胞外蛋白酶的产生。进一步开展负责抑制细胞外蛋白酶产生的生物活性化合物的分离和纯化工作对于发现对……具有抗毒力作用的药物具有重要意义。
