Paper Title
Investigation of Antioxidant Properties of Hypericum Heterophyllum Vent. as an Endemic St. John's Wort (Yellow Centaury) Species in Turkey

Abstract
The use of plants for pharmaceutical, food and cosmetic purposes has started with the existence of humans and has continued until today. Phytochemicals are considered as one of the cornerstones of pharmacy in the past. Today, more than 20,000 plants are included in drug formulations and are used for complementary treatment as well as clinical treatments. One of the plants used for this purpose is Hypericum perforatum (St. John's Wort or yellow centaury). Studies on the effects of many types of endemic species have not yet been made. In this study, it is aimed that investigation of antioxidant properties of Hypericum Heterophyllum Vent. as an endemic yellow centaur species in Turkey. Total antioxidant capacity (TAC), total oxidant capacity (TOC) of the plant species (Hypericum Heterophyllum Vent.) were analyzed. The oxidative stress index (OSI) was calculated to interpret the possible effect of the plant on the oxidative stress that may occur in organisms. TAC and TOC analyzes were carried out on the crude samples obtained after drying and homogenous decomposition of the leaves, branches and flower parts of the plant. The TAC levels of Hypericum Heterophyllum Vent. were found to be 2.22 mmolTroloxEquivalent/L and TOC levels were 42.41 ┬Ámol H2O2 Equiv./L. OSI levels were calculated as 1924 AU. These data indicate that Hypericum Heterophyllum Vent. have high antioxidant capacity. For this reason, antioxidant power can be shown as the reason for its use in various diseases. Keywords - Hypericum Heterophyllum Vent., St. John's Wort, antioxidant and oxidant activity