Comparing antioxidant activity along with total phenols and flavonoids contents of four different Marrubium spp. extracts in East Azarbaijan habitats

Marrubium genus belongs to the family Lamiaceae which is one of the precious genara native to Iran. Phytochemical studies upon Marrubium spp. are so limited so we decided to study four species of genus Marrubium native to Iran. The aerial parts of four Marrubium spp. (M. crassidens, M. persicum, M. propinquum, and M. parviflorum) were collected during their flowering stages from Varzeghan and Marand provinces from Azarbaijan, Iran in 1395. Dried plant materials were solvent extracted separately with petroleum ether, chloroform and methanol via maceration method. Afterwards, the antioxidant activities of the extracts were evaluated through scavenging the free DPPH radicals. Besides, the total phenolic and flavonoid contents of the extracts were verified based on colorimetric relative techniques. The antioxidant evaluation established the lowest RC50 of 11.1μg/mL for the 40% Sep-Pak fraction of the M. crassidens methanol extract. Moreover, petroleum ether extracts revealed no antioxidant activity. The most total phenolics and flavonoids content of the extracts were for M. crassidens methanol extract with 512.6 mg gallic acid equivalent and 212.7 mg quercetin equivalent both in 100 g dried plant material. In the study, presence of phenollics and flavonoids in different levels alongside prominent antioxidant activities were detected for the four Marrubium spp. native to East Azerbaijan. Overall, M. crassidens possessed higher phenolic and flavonoid contents resulting in superior antioxidant activity compared to other three species.