Antioxidant and Anti-inflammatory Activities of Organic and Aqueous Extracts of Northeast Algerian Marrubium vulgare

Marrubium vulgare (Lamiaceae) is frequently used in traditional medicine to treat many illnesses from ancient times. Its beneficial effects include antibacterial, antioedematogenic, and analgesic activities. This study was designed to evaluate the antioxidant and anti-inflammatory activities of organic and aqueous extracts of the leaves, the flowers, the stems, and the roots of Marrubium vulgare. The total phenolic and flavonoid contents as well as the antioxidant and the anti-inflammatory effects of methanol, chloroform, ethyl acetate, and aqueous extracts have been investigated by using different in-vitro methods. It was found that the ethyl acetate extract from Marrubium vulgare stems had the highest total phenolic content, while the ethyl acetate extract from the leaves yielded a high concentration of flavonoids. The ethyl acetate extract from the stems exhibited the highest activity in scavenging of 2,2-diphenyl- 1-picrylhydrazyl (DPPH), as well as in protecting erythrocytes. The leaves aqueous extract exhibited the highest ferrous chelating activity and its methanolic extract was found to be the strongest inhibitor of lipid peroxidation in β-carotene bleaching assay. The leaves chloroform extracts as well as the flowers methanol, chloroform, and ethyl acetate extracts were found to decrease the pro-inflammatory tumor necrosis factor alpha (TNF-α) cytokine levels in a dose-dependent manner. On the other hand, the flowers methanolic extract and the leaves methanol, ethyl acetate, and aqueous extracts decreased the interleukin-1 beta (IL- 1β) release. It was also found that the methanol extract from the flowers and the chloroform extract from the stems of Marrubium vulgare inhibited interleukin-8 (IL-8) release. This study provides a scientific basis for the traditional use of Marrubium vulgare as an anti-inflammatory agent and for the plant to be considered as an important resource of natural antioxidants.