ANTITHOMBOTIC ACTION OF MORINDA CITRIFOLIA FRUIT EXTRACT: MECHANISM OF ACTION AND CHEMICAL CHARACTERIZATION.

Abstract

Background: A previous study on the effects of hot water extract of Morinda citrifolia (M. citrifolia) fruits on human blood coagulation suggested anticoagulant effects in vitro. This study was carried out to determine the effective extraction method of the fruit producing highest anticoagulant activity, along with the aim to identify its effective fraction exhibiting highest anticoagulant activity and its mechanism of action, and to chemically characterize this effective fraction. This study, which involved in vitro and in vivo methods, compared M. citrifolia extracts to antiplatelet/anticoagulant drugs, aspirin and warfarin (positive controls), and three known compounds of the M. citrifolia fruit (scopoletin, quercetin and rutin) with distilled water (vehicle) as the negative control. Methods: Phase I identified the best method of extraction to produce highest anticoagulant activity, while the phase II, determined the effective fractions of this identified extract, with highest anticoagulant activity using bioassay guided fractionation. Phase III of the study, revealed the mechanism of anticoagulant action via various antiplatelet and anti-coagulation cascade pathways. The effect on biochemisbtry, hematology and histology of treated animals as well as the interaction between warfarin and the M. citrifolia were also examined. Differences between groups were compared using the one-way analysis of variance (ANOVA), and students’t-test with SPSS. In Phase IV the effective anticoagulant fraction was chemically characterized. Result and discussion: The results suggests, crushed fruit extract (CE) as the most effective extract with dose dependent anticoagulant activity via coagulation profile in vitro. The water (McWF) and methanol (McMF) fractions of the M. citrifolia extract were identified as the most effective fractions, exhibiting highest anticoagulant activity, while phase III suggested significant inhibitory effects of theses fractions on platelets and the coagulation cascade. The interaction study of M. citrifolia with warfarin showed significant reduction of warfarin’s antiplatelet and anticoagulant activity. The biochemical studies saw increased liver enzymes while histological findings suggested liver degeneration with M. citrifolia. The LCMS profiling of the M. citrifolia effective fraction (McWF) showed the presence rutin which was quantified. Conclusion: M. citrifolia fruit extract exhibited anticoagulant and anti-platelet activity, in vitro and in vivo. The McWF was identified the most effective fraction, though the crude extract still remained more potent. M. citrifolia reduced the anticoagulant activity of warfarin. The prospects of using M. citrifolia as a possible anticoagulant requires further verification on its dose dependent, reversible and the safety index of its anticoagulant action and possible liver toxicity.