Parasitol Int. 2001 Mar; 50(1): 33-9.

A potent antimalarial activity of Hydrangea macrophylla var. Otaksa leaf extract against Plasmodium yoelii 17XL in mice.

Ishih A, Ikeya C, Yanoh M, Takezoe H, Miyase T, Terada M.

Department of Parasitology, Hamamatsu University School of Medicine, 3600 Handa-cho, 431-3192, Hamamatsu, Japan. [email protected]

The antimalarial activity of the hot-water extract of Hydrangea macrophylla var. Otaksa leaves was evaluated against Plasmodium yoelii 17XL in mice. Non-treated control mice died from 6 to 7 days after infection, but mice treated with the leaf extract survived during the experiment. Mice given the extract orally showed low parasitemia levels during administration. Following a transient recrudescence of malaria parasites in the bloodstream of treated mice, no parasites could be detected by a microscopic examination. Furthermore, the 30% MeOH aq. eluate and 50% MeOH aq. eluate from dried leaves of H. macrophylla var. Otaksa showed an antimalarial activity in vivo. Sulfamonomethoxine was orally given to infected mice to compare with the antimalarial activity of the hot-water extract of leaves. Sulfamonomethoxine given orally reduced parasitemia, but no complete cure of mice was observed.