Biomed Pharmacother. 1990 ; 44(1): 13-6.

Differential inhibition of the activities of reverse transcriptase and various cellular DNA polymerases by a traditional Kampo drug, sho-saiko-to.

Ono K, Nakane H, Fukushima M, Chermann JC, BarrÃ©-Sinoussi F.

Laboratory of Viral Oncology, Aichi Cancer Center Research Institute, Nagoya, Japan.

A traditional Kampo drug, Sho-saiko-to, composed of several herb extracts, differentially inhibited the activities of reverse transcriptase and human cellular DNA polymerase alpha and beta. Reverse transcriptases from murine leukemia virus and human immunodeficiency virus were inhibited by over 80% and 50%, respectively, in the presence of 100 micrograms/ml Sho-saiko-to, whereas DNA polymerase alpha was much less sensitive to inhibition by this drug than were the reverse transcriptases. DNA polymerase gamma was not inhibited by this drug at concentrations of up to 500 micrograms/ml. Only DNA polymerase beta was moderately inhibited by Sho-saiko-to. Thus, it has been shown that the inhibition by Sho-saiko-to is relatively specific for reverse transcriptase and that the drug contains as yet unidentified inhibitory substance(s) for reverse transcriptase.