The anti-snake venom activities of the methanolic extract of the bulb of Crinum jagus (Amaryllidaceae)

Abstract

The anti-snake venom activities of the methanolic extract of the bulb of Crinum jagus plant (Amaryllidaceae) were investigated in vitro and in vivo against the venoms of three notable snake species: Echis ocellatus, Bitis arietans and Naja nigricollis. The extract was prepared by cold marceration in 50% methanol at 37 °C with intermittent shaking for 48 h. An yield of 12.8% w/w dry extract was obtained. Oral administration of C. jagus extract (1000 mg/kg) protected 50% of mice, while injection of a 30 min pre-incubated mixture of the same dose of extract and venom gave 100% protection against the lethal effects of E. ocellatus venom (10 mg/kg, i.m.). The intraperitoneal administration of the extract at 250 mg/kg, 30 min before the injection of E. ocellatus venom (10 mg/kg, i.m.), significantly ( p<0.05) prolonged the death time of poisoned mice. C. jagus extract (500 mg/kg, per os), gave 50% protection against B. arietans venom (9.5 mg/kg, i.m.) in mice while the pre-incubation of a mixture of the same dose of venom and extract (500 mg/kg), prior to injection (i.p.) of the mixture, gave only 33.3% protection. The pre-incubation of 500 mg/kg of C. jagus extract with N. nigricollis venom (6 mg/kg) prior to i.p. injection of the mixture protected 50% of the treated mice. There were generally no significant differences in the death times of mice that were given the same dose of the extract orally 30 min before injection of the venoms and those administered with the pre-incubated mixtures of venom and extract. The pre-incubation of the extract and E. ocellatus venom (5 mg/kg) for 30 min, before the i.m. injection of the mixture, significantly reduced infiltration of inflammatory cells to the site of injection 4 h post treatment. The concentrations of plasma creatine kinase in poisoned mice were significantly ( p<0.01 or p<0.05) reduced after the injection (i.p.) of C. jagus extract (1000 mg/kg) pre-incubated with E. ocellatus (5 mg/kg) or B. arietans (7 mg/kg) venom, respectively. The bulb extract of C. jagus blocked the haemorrhagic activity of a standard haemorrhagic dose (2.8 mg/ml) of E. ocellatus venom at various concentrations (1.7, 3.3 and 6.7 mg/ml). The methanolic bulb extract of C. jagus was therefore able to significantly protect mice from death, myonecrosis and haemorrhage induced by the lethal effects of venoms of notable snake species in Nigeria.