بررسی فعالیت آنتی اکسیدانی و آنتی باکتریایی عصاره های الکلی گل و ریشه گیاه سیاه گینه روی برخی باکتری های بیماریزای انسانی

Introduction & Objective: With increasing the information about the dangerous side effects of synthetic antibiotics , the demand for natural alternative of these drugs has increased. The purpose of this study is to investigate the antibacterial and antioxidant properties of root and flower extracts of the medicinal plant of Dendrostellera lesserti against some human pathogenic bacteria. Materials & Methods: In this experimental study, Dendrostellera lesserti was collected from Hamadan province in 2013. After identification, the extracts were prepared by maceration method. Antibacterial activities were determined by the agar well diffusion method, MIC (serial dilution method) and MBC. Antioxidant properties by DPPH method and amount of phenolic and flavonoid were measured by Folin-ciocalteu and aluminum chloride methods , respectively. The data were analyzed using sas software version 9.2 (P<0.05). Results: The largest growth inhibition zone with diameter of 21.33±.66 mm was seen in Salmonella typhi culture against root methanolic extract. MIC and MBC of root extract was lower in comparison with flower. Methanolic extract of flower in at concentration of 0.8 mg/ml had the highest scavenging percentage of free radical. The higher amount of phenol and flavonoid was related to methanol extract of root, 111.8±2.69 mgGAE/g and 2.25±0.35 mgQ/g, respectively Conclusion: According to the obtained results, the root and flower methanolic extracts of Dendrostellera lesserti contain compounds with antibacterial and antioxidant properties.