Azadirachtin B, a limonoid derived from the seed kernels of Azadirachta indica, exhibits a broad spectrum of biochemical activities, including insecticidal, nematocidal, anticancer, anti-inflammatory, antiviral, and osteogenic effects. It is effective against the Epstein-Barr virus early antigen (EBV-EA), enhances alkaline phosphatase (ALP) activity, and promotes osteoblast differentiation[1][2][3].

Azadirachtin B increases expression of RunX-2 ～2.5 fold at 10 nM concentration, ALP expression ～2.8 fold at 10 nM and 100 pM concentration and OCN expression ～2.5 folds at 10 nM as compared with control[1]. Azadirachtin B (1 pM-100 μM; 48 hours; Osteoblast cells) treatment shows highest proliferation at 10 nM and 100 pM concentrations in osteoblast cells[1]. Azadirachtin B (compound 21) exhibits moderate or potent inhibitory effects (IC50 value of 384 mol ratio/32 pmol TPA) against the Epstein-Barr virus early antigen (EBV-EA) activation induced by tetradecanoylphorbol-13-acetate (TPA)[3]. Azadirachtin B (Compound 4) exhibits toxicity to the diamondback moth (Plutella xylostella) with an LD50 of 4.85-1.06 μg/g body weight, in 92 h[2].

On evaluation of Azadirachtin B (compound 21; oral administration) for its anti-tumor-initiating activity on the two-stage carcinogenesis of mouse skin tumor induced by peroxynitrite (ONOO-; PN) as an initiator and TPA as a promoter, this exhibited marked inhibitory activity[3].