Inhibitory Activity of Avicennia marina, a Medicinal Plant in Persian Folk Medicine, against HIV and HSV

Avicennia marina (Avicenniaceae) is a species of mangrove tree used for treatment of small pox lesions in Persian folk medicine. The antiviral activity of methanol, ethanol, water, chloroform and n-hexane extracts was evaluated against HIV-1 and HSV. Methanol extract had the highest antiviral activity and the most polar fraction of this extract (fraction D) inhibited HSV with TI and SI values of 57.1 and 133; however, it showed mild activity against HIV with SI value of 6.25 (fraction 3). The anti-HSV activity of active fraction was confirmed using FLASH-PCR. Phytochemical investigation revealed that fraction D encompasses flavonoids compounds. The time-of-addition study demonstrated that fraction D disturbs viral replication after penetrating to the cell. A. marina was endowed with fragments by which found to be able to inhibit replication of HSV after entry but did not show significant potency against HIV-1. This promotes further investigation in anti-HSV drug discovery.