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Six sesquiterpenes: germacrone (1), zederone (2), dehydrocurdione (3), curcumenol (4), zedoarondiol (5) and isocurcumenol (6) were isolated from rhizomes of Curcuma aeruginosa Roxb. (Zingiberaceae). They inhibited 5α-reductase which converts testosterone to dihydrotestosterone (DHT). Germacrone (1) was the most potent (IC(50)=0.42±0.05 mg/mL). Compound 1 was anti-androgenic in LNCaP cells when proliferation was testosterone-induced. The growth of flank gland of male Syrian hamsters is dependent on circulating androgen and when maintained with testosterone, 1 (3, 30, 100μg) inhibited growth but was ineffective against DHT. The similar activity profile was observed on the 5α-reductase inhibitor, finasteride (100 μg) treatment group. The androgen receptor binding assay showed that 1 did not bind to the androgen receptor. In conclusion, 1 showed anti-androgenic effect on in vitro and in vivo assays. One of the possible mechanisms was inhibition 5α-reductase activity. Thus, 1 is a potential lead compound for treatment of androgen-dependent disorders.

The ethanolic extract from stems of a Thai medicinal plant, Alstonia macrophylla Wall. ex G. Don (Apocynaceae) showed a significant inhibitory effect on acetylcholinesterase (AChE) determined by using Ellman assay. Four compounds i.e., a bisindole alkaloid, macralstonine (1), a new bisindole alkaloid, thungfaine (2), a secoiridoid glycoside, sweroside (3) and a new secoiridoid glycoside, naresuanoside (4) were isolated. Compound 4 showed moderate AChE and butyrylcholinesterase (BChE) inhibitory effects. Interestingly, compound 4 inhibited cell growth on human androgen-sensitive prostate cancer cell line (LNCaP) but no effect on viability of human foreskin fibroblast cells (HF).