Gabonese flora abounds in a significant reserve of plants in medical matter. Thus, medicinal plants occupy a significant place in African pharmacopeia. Aim of this work was to evaluate the antimicrobial, antioxidant, anti-inflammatory and cytotoxic properties of extracts of Guibourtia tessmanii (Harms) J. Léonard. The test for sensitivity to microorganisms was performed by the diffusion method, while the MICs and MBCs were evaluated by the microdilution technique. Antioxidant tests were performed by scavenging the DPPH and ABTS radicals. Anti-inflammatory activity was determined by protein denaturing and membrane stabilization methods. The cytotoxicity was evaluated on the tadpoles of the green frog. The antibacterial activity shows that the Gt F2 fraction and the water-acetone extract produced the greatest inhibitions. The water, water-ethanol and water-acetone extracts exhibited bactericidal effects on the majority of bacteria. In the case of trapping of the DPPH radical, the IC50 values varied from 6.92 ± 0.48 to 16.64 ± 0.20 μg/mL. For the decolouration of ABTS, oxidation was mainly inhibited by the water-acetetone, water-ethanol extracts and some fractions. The water and water-acetone extracts showed good inhibition of denaturation. The hemolysis test confirmed the good activities of the extracts. The lethal test showed that the LC50 drops from 171.37 ± 9.25 to 58.25 ± 7.21 μg/mL after 24 and 96 h of exposure. In tadpoles exposed to 7.81 μg / mL of extracts, the first mortalities (12.5%) were observed on the second day of exposure. From the ninth day, the mortality rate increased (25%) until the 16th day. Our results show that Guibourtia tessmanii may be a promising product for the isolations of molecules responsible for biological activities.

中文翻译：

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加蓬的杜鹃花（Journey J.Léonard）提取物的抗微生物，抗氧化，抗炎和细胞毒性研究

加蓬植物区系盛产大量的药用植物。因此，药用植物在非洲药典中占有重要地位。这项工作的目的是评估吉百特（Gourbourtia tessmanii）（Harms）J。Léonard提取物的抗微生物，抗氧化，抗炎和细胞毒性特性。对微生物的敏感性测试通过扩散法进行，而MIC和MBC通过微稀释技术进行评估。通过清除DPPH和ABTS自由基进行抗氧化剂测试。通过蛋白质变性和膜稳定化方法确定抗炎活性。在绿色青蛙的the上评估了细胞毒性。抗菌活性表明，Gt F2馏分和水-丙酮提取物产生最大的抑制作用。水 水-乙醇和水-丙酮提取物对大多数细菌表现出杀菌作用。在捕获DPPH自由基的情况下，IC50值从6.92±0.48到16.64±0.20μg/ mL不等。对于ABTS的脱色，氧化主要受到水-丙酮，水-乙醇提取物和某些馏分的抑制。水和水-丙酮提取物显示出良好的变性抑制作用。溶血试验证实了提取物的良好活性。致死测试表明，暴露24小时和96小时后，LC50从171.37±9.25μg/ mL下降至58.25±7.21μg/ mL。在暴露于7.81μg/ mL提取物的t中，在暴露的第二天观察到第一次死亡（12.5％）。从第9天开始，死亡率一直提高（25％），直到第16天为止。