Quinine sulfate hydrate (2:1:4) is an orally active alkaloid extracted from cinchona bark and can be used in anti-malarial studies. Quinine sulfate hydrate (2:1:4) is a potassium channel inhibitor that inhibits WT mouse Slo3 (KCa5.1) channel currents evoked by voltage pulses to +100?mV with an IC50 of 169 μM[2].In Vitro: Quinine sulfate hydrate (150 μM, 30 min) inhibits the proliferation and cytostatic effects of DENV (Dengue virus) in human hepatocarcinoma HepG2 cell line.Quinine sulfate hydrate (37.5-150 μM, 24 hours) significantly reduces viral DENV RNA and protein levels in a dose-dependent manner in human hepatocarcinoma HepG2 cell line.In Vivo: Quinine sulfate hydrate (oral gavage, 12 or 15 mg/kg, every week, 16 weeks) has some tumor suppressing effect on skin cancer in Swiss albino mice[2].Quinine sulfate hydrate (oral gavage, 10 mg/kg, everyday, 8 weeks) causes a decrease in the antioxidant defense system of rat testicular tissue such as SOD, CAT and GSH enzyme activity in male adult albino rats.