The Alkaloid Fraction from Melicope latifolia Leaves Inhibits Hepatitis C Virus

Introduction: Hepatitis C Virus (HCV) is a major health problem, which infects approximately 170 million people among worldwide population. Moreover, there is no vaccine available to prevent HCV infection and the current anti-HCV drugs have not covered all the various genotypes and subtypes. Meanwhile, medicinal plants have been widely used to treat a variety of infectious disease. Our previous study reported that ethanol extract of Melicope latifolia has been shown to exert anti-HCV activity towards a number of different virus genotypes with mainly inhibition mechanism at the entry step. Further separation was needed to purify and identify the active anti-HCV constituent using bioactivity-guided isolation method. Materials and Methods: In vitro Anti-HCV assay was performed using hepatocyte cell line (Huh7it) and HCV genotype 2a (JFH1). The purification of M. latifolia ethanol extract (B1F) was done by liquid-liquid fractionation, vacuum liquid chromatography (VLC), and high-performance liquid chromatography (HPLC). The active fraction was further identified by thin layer chromatography (TLC) and the major constituent was determined by nuclear magnetic resonance (NMR) spectra data analysis. Results: The fractionation of M. latifolia leaves ethanol extract resulted an alkaloid fraction (B1F D2H.3) containing a major constituent N-methylflindersine. This alkaloid fraction was active to reduce HCV JFH1 with an inhibition concentration (IC₅₀) value of 6.21 µg/mL, a cytotoxicity concentration (CC₅₀) value of 82.64 µg/mL, and a selectivity index value of 13.31. Conclusion: An alkaloid fraction of M. latifolia (B1F D2H.3) was known to have major compound named N-methylflindersine. This alkaloid fraction exhibited strong anti-HCV against JFH1 in vitro. The results indicated that this alkaloid fraction may a good candidate for anti-HCV agent.