Ken-ichi Furukawa (1), Kazuki Shibusawa (1), Nattaya Chairungsrilerd (1), Tomihisa Ohta (2), Shigeo Nozoe (2) and Yasushi Ohizumi (1)
(1) Department of Pharmaceutical Molecular Biology, Faculty of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980, Japan (2) Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980, Japan
Abstract: Alpha-Mangostin, the principal ingredient of the fruit hull of Garcinia mangostana, caused a concentration-dependent decrease in the activities of both Ca2+-ATPase and Ca2+-transport of the sarcoplasmic reticulum from rabbit skeletal muscle with an IC50 value of 5 microM. Neither Ca2+ release nor other enzyme activities were affected by alpha-mangostin. Kinetic analysis of the inhibitory effects of alpha-mangostin on Ca2+-ATPase suggests that the inhibition of the ATPase is a noncompetitive-type with respect to ATP or Ca2+. alpha-Mangostin may become a useful pharmacological tool for clarifying the physiological functions of Ca2+-pumping ATPase and sarcoplasmic reticulum.
alpha-Mangostin, Ca2+-pumping ATPase, Sarcoplasmic reticulum
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