Polyphenols content, antioxidant and antiviral activities of leaf extracts of Marrubium deserti growing in Tunisia

Marrubium deserti de Noé is used in traditional medicine, for example as a remedy for asthma and diabetes, and was also found to have antibacterial properties. It is of particular interest in Tunisia and this is why we continued research on this plant. We here report on an investigation of its antioxidant and antiviral activities of petroleum ether, ethyl acetate, chloroform, butanol and methanol extracts. Total phenolic content of the extracts was determined by the Folin–Ciocalteu colorimetric method. The antioxidant activity was evaluated with the DPPH assay, the ABTS test and ammonium thiocyanate method. The antiviral activity was evaluated against human cytomegalovirus (HCMV) strain AD-169 (ATCC Ref. VR 538) and Coxsackie B virus type 3 (CoxB-3) using a cytopathic effect (CPE) reduction assay. With regards to IC50 values (50% inhibitory concentration) of scavenging abilities of the DPPH radical, methanol extract exhibited important antioxidant activities with IC50 of 0.150 mg/ml. The ethyl acetate extract showed the highest antioxidant activity using the linoleic acid emulsion system (79.23%). The butanol, methanol and ethyl acetate extracts showed significant antiviral activity against Coxsackie B3 virus. In conclusion, these results can be considered very promising and justify further research, amongst others on the identification of antioxidant and antiviral components in the active extracts.