Comparison of antioxidant and antimicrobial activities of plant extracts Centaury (Hypericum montbretii and Hypericum bupleuroides) and Blackthorn (Paliurus spina-christi Mill) in Artvin, Giresun region of Turkey

Abstract Antioxidant activity 13 different samples of medicinal and aromatic plants of Centaury ( Hypericum montbretii) , Centaury ( Hypericum bupleuroides ), Blackthorn ( Paliurus spina-christi Mill), including leaf, flower and stem, was investigated using DPPH, FRAP and CUPRAC methods. Total flavonoid, total phenolic amount and the antibacterial features of extracts from these herbs were also determined. According to the obtained of antioxidant datas, except for the result of total polyphenol assay, the dried leaves of Centuary ( Hypericum montbretii ) had the best antioxidant property that was realized in all results. Accordingly test of total polyphenol, the content of yellow flower of Centuary (Hypericum montbretii) herb was measured as of 22.48±0.66 mg GAE /g dry herb sample and so this herb had the highest total phenolic content. Antimicrobial activity tests were carried out using disc diffusion methods with 12 microbial species and the most of them displayed good-moderate antimicrobial and antifungal activity .