Biochemical validation for the therapeutic use of Plumeria rubra in coagulation disorders: a study combining in silico, in vitro, and in vivo approaches

Abstract

Local healers in South Asia use Plumeria rubra Linn. leaves to treat various coagulation disorders in animals and humans. This study (in silico, in vitro, and in vivo) aimed to explore the pharmacological basis for the possible thrombolytic and anticlotting properties of the leaf extract of P. rubra. Phytoconstituents of P. rubra were dock against coagulation proteins: prothrombin, thromboplastin, and fibrin using in silico approach. Phytochemical screening, HPLC, and antioxidant, anticoagulant, and thrombolytic potential were evaluated using in vitro approach. Healthy male rabbits were divided into five groups (six rabbits each). Groups 1-3 were treated with aqueous-methanolic (30:70%) extract of P. rubra at 200, 300, and 600 mg/mL respectively groups in contrast to the positive and negative control groups. Thrombolytic activity was assessed at doses of 200, 300, and 600 µg/mL in comparison with standard urokinase (600 µg/kg). Platelet adhesion was evaluated at a dose of 200, 300, and 600 µg/mL against adrenaline (2 µM) and acute oral dose toxicity was assessed using in vivo approach. In silico study resulted in an excellent binding affinity and showed significant interaction with coagulation proteins. Phytochemical analysis showed a range of phytochemical classes: alkaloids, tannins, flavonoids, glycosides, anthraquinones, and saponins. HPLC analysis confirmed the phytoconstituents plumericin, rutin, kaempferol, and isoquercetin already reported for coagulation disorders. P. rubra showed excellent antioxidant potential and was assessed using DPPH, NO, and SOD assays. The activated partial thromboplastin time (APTT), bleeding time (BT), prothrombin time (PT), and clotting time (CT) all went up with increasing doses in the aqueous-methanolic extract (p ≤ 0.05). Comparing the plant extract to urokinase, the plant extract demonstrated considerable (p ≤ 0.05) clot lysis. Additionally, it dose-dependently delayed the ADR-induced platelet adhesion dose-dependently (p ≤ 0.05). The outcome of this study justifies its therapeutic utility in coagulation disorders and can be used as an alternative medicine.

Keywords: Plumeria rubra; Coagulation; Medicinal herbs; Thrombosis; Urokinase; Warfarin.