Anti-HIV activity of alkaline extract from pine seed shells (Pinus koraiensis).

The alkaline extracts from pine seed shells (Pinus koraiensis) suppressed the human immunodeficiency virus (HIV)-induced cytopathicity using HIV (HTLV-III) infected MT-4 cells in vitro, and showed extremely low cytotoxicity. The active substances were acid polysaccharides containing uronic acids. No animal died and no harmful effect was observed at a concentration of 1.05 g per kg body weight. We also studied the clinical effects of alkaline extracts on the protection of feline immunodeficiency virus (FIV) infection. Protection against infection by FIV was achieved by oral administration of the alkaline extracts with usual food.