Abstract:
Morinda citrifolia, better known as Mengkudu in Malaysia, or Noni in the western world has been used traditionally to treat many ailments including asthma, diabetes, high blood pressure, irregular menstruation and is believed to have anticoagulant, analgesic, anti-inflammatory, antioxidant, antiseptic, antibiotic, anticancer and immunomodulating activities. Research findings with the fruit juice (Tahitian Noni Juice) supported some of these claims. This study determines the effect of the hot water extract of the fruits of Morinda citrofolia (McHWE) on human blood coagulation, in vitro. Various concentrations of the lyophilized extract was used to study the effect on clotting time, coagulation profile and platelet aggregation with PBS (phosphate buffer) and EDTA used as the negative and the positive controls respectively. The data obtained, was analyzed using the ‘paired T-test’ and the ‘Wilcoxon Singed Ranks test’ (non-parametric test). All tested concentrations of McHWE (10mg/ml, to 150mg/ml) significantly increased clotting time compared to control (p<0.001). Prolongation in clotting time between the subsequent concentrations tested was also shown to be statistically significant (p<0.001) where a concentration dependent effect was demonstrated. The increase in concentration produces increase in response. Blood did not clot even after 24 hours with concentrations of McHWE higher than 150mg/ml. The various concentrations of McHWE (100mg/ml to 250mg/ml) affected the coagulation profile assay, with significant prolongation of the activated partial thromboplastin time (APTT), prothrombin time (PT), and the thrombin time (TT) respectively (p<0.001). A concentration dependent pattern was exhibited with all coagulation profile assays tested. The platelet aggregation assay, which showed a statistical significant decrease in platelet aggregation (p<0.001) with McHWE (concentrations 5mg/ml and 25mg/ml) for agonist, collagen, ristocetin and arachidonic acid, suggested that McHWE was most sensitive to the collagen test where a statistical significant decrease in platelet aggregation (p<0.001) was seen with concentration as low as 0.5mg/ml. Partial fractionation of crude McHWE was carried out with various solvents of n-butano1 and ethyl acetate. Both soluble and insoluble in ethyl acetate (which showed anticoagulant activity) was fractionated using silica gel column chromatography, with 3 different solvent systems: dichloromethane-acetic acid-methanol-water (64:32:12:8) {solvent system 1}, methanol-ethyl acetate (8:2) {solvent system 2} and Methanol-water (8:2) {Solvent system 3} with fractions of solvent system 1 showing highest anticoagulant activity (determined with the clotting time assay). Determination of the active compound(s) present was carried out using TLC and phytochemical analysis which suggested the presence of alkaloids, anthraquinones and saponins.
