Investigation of anaesthetic potentials of various extracts of Annona muricata (sour sop) in Wister albino rat and dog

Abstract

ObjectivesLocal and general anaesthetics currently used in clinical practice are not absolutely safe and efficacious. Hence two or more drugs are used for induction and maintenance of general anaesthesia. MethodsIn view of this, local and general anaesthetic potentials of Annona muricata extracts were investigated prospectively in laboratory using rat and dog. A total of 15 animals comprising 6 rats (3 males; 3 females) and 9 dogs (5 males; 4 females) were used. Secondary metabolites in root bark, leaf, stem bark and seed of Annona muricata were qualitatively and quantitatively determined. Methanol and water extracts were tested for induction and maintenance of surgical anaesthesia in rat and dog. The dose of the extracts (1250 mg/kg body weight of rat) that produced deep anaesthesia in rats was translated to 150, 170 and 150 mg/kg of root bark methanol extract (RBME), stem bark water extract (SBWE) and seed water extract (SWE), respectively. Each extract was administered to female and male dog for induction and maintenance of anaesthesia. Laparatomy was carried out via linea alba, and the length of small intestine (220 cm) and large intestine (32 cm) were measured using measuring ruler. ResultsPhenols and tannins were significantly lower (p < 0.05) as compared to saponins, flavonoids, alkaloids and glycosides. The median lethal dose (LD50) of methanol extract was < 5000 mg/kg in female and > 5000 mg/kg in male rats, respectively. Sedation, anaesthesia, male mounting and death were observed within 4 days of extract administration in the female rats, However, 12.5 mg/kg showed significant (p < 0.05) local anaesthesia on the test surgical sites. The male administered 170 mg/kg of SBWE showed salivation, significantly decreased respiratory rate, and loss of palpebral reflex, excretion, urination that characterized plane III; stage III of anaesthesia (deep anaesthesia) which lasted for 67 min. ConclusionsAqueous extract of Annona muricata have very potent local and general anaesthetic effects for a period of over 1 h. The observed effects may be due to presence of secondary metabolites.