Evaluation of the analgesic, anti-inflammatory and anti-diabetic properties of Sclerocarya birrea (A. Rich.) Hochst. stem-bark aqueous extract in mice and rats.
In order to appraise some of the ethnomedical uses of Sclerocarya birrea (A. Rich.) Hochst., subspecies caffra (Sond.) Kokwaro [family: Anacardiaceae], the present study was undertaken to investigate the analgesic, anti-inflammatory and anti-diabetic properties of the plant's stem-bark aqueous extract in experimental models of pain, inflammation and diabetes mellitus. The analgesic effect of Sclerocarya birrea stem-bark aqueous extract was evaluated in mice, while its anti-inflammatory and anti-diabetic effects were investigated in rats. Diclofenac (DIC, 100 mg/kg p. o.) and chlorpropamide (250 mg/kg p. o.) were used respectively as reference analgesic, anti-inflammatory and anti-diabetic agents for comparison. Like diclofenac (DIC, 100 mg/kg p. o.), Sclerocarya birrea stem-bark aqueous extract (SBE, 100-800 mg/kg p. o.) produced dose-dependent, significant protection (p < 0.05-0.001) against electrical heat-induced pain. The plant extract (SBE, 25-800 mg/kg p. o.) also produced dose- and time-related, sustained and significant reductions (p < 0.05-0.001) in the fresh egg albumin-induced acute inflammation of the rat hind paw oedema. However, the analgesic and anti-inflammatory effects of the plant's extract were found to be approximately 10-15 times less than that of diclofenac. In one set of experiments involving hypoglycaemic/antidiabetic evaluation of the plant's extract, graded doses of Sclerocarya birrea stem-bark aqueous extract (SBE, 25-800 mg/kg p. o.) were separately administered to groups of fasted normal and fasted diabetic rats. In another set of experiments, a single dose of the plant's aqueous extract (SBE, 800 mg/kg p. o.) was used. The hypoglycaemic effect of this single dose of Sclerocarya birrea stem-bark aqueous extract (SBE, 800 mg/kg p. o.) was compared with that of chlorpropamide (250 mg/kg p. o.) in both fasted normal and fasted streptozotocin (STZ)-treated diabetic rats. Following acute treatment, relatively moderate to high doses of Sclerocarya birrea stem-bark aqueous extract (SBE, 25-800 mg/kg p. o.) produced dose-dependent, significant reductions (p < 0.05-0.001) in the blood glucose concentrations of both fasted normal and fasted diabetic rats. Chlorpropamide (250 mg/kg p. o.) also produced significant reductions (p < 0.05-0.001) in the blood glucose concentrations of the fasted normal and fasted diabetic rats. Administration of the single dose of Sclerocarya birrea stem-bark aqueous extract (SBE, 800 mg/kg p. o.) significantly reduced (p < 0.01-0.001) the blood glucose levels of both fasted normal (normoglycaemic) and fasted STZ-treated, diabetic rats. The results of this experimental animal study indicate that Sclerocarya birrea stem-bark aqueous extract possesses analgesic, anti-inflammatory and hypoglycaemic properties. These experimental findings lend pharmacological support to the suggested folkloric uses of the plant's stem-bark in the management and/or control of pain, inflammatory conditions, and adult-onset, type-2 diabetes mellitus in some communities of South Africa.
Department of Pharmacology, University of Durban-Westville, Durban 4000, South Africa. ojewolej@ukzn.ac.za
John A O
JA
Ojewole
D027926:Anacardiaceae; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001786:Blood Glucose / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000517:prevention & control; D003924:Diabetes Mellitus, Type 2 / Q000139:chemically induced / Q000517:prevention & control; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000139:chemically induced / Q000517:prevention & control; D004527:Egg Proteins; D005260:Female; D006358:Hot Temperature; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010146:Pain / Q000517:prevention & control; D010147:Pain Measurement / Q000187:drug effects; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D018547:Plant Stems; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin
D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001786:Blood Glucose; D004527:Egg Proteins; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D013311:Streptozocin