Effect of Alstonia scholaris (Linn.) R. Br. on stress and cognition in mice.

Effect of stress and its modulation by methanolic extract of bark of Alstonia scholaris was studied using acute restraint stress model in mice. The extract was also evaluated for nootropic and antioxidant potential to support anti-stress activity testing. Acute restraint stress resulted in significant increase of plasma corticosterone, glucose, protein, cholesterol and triglyceride levels in stress group of animals. Methanolic extract pretreatment at 100, 250 and 500 mg/kg for 7 days displayed promising anti-stress effect by normalizing these stress-induced biochemical perturbations in plasma of mice. Effect on cognitive functions was evaluated using passive avoidance model and elevated plus maze model. Pretreatment with extract at 100, 250 and 500 mg/kg augmented acquisition and retention of memory of learned task as evidenced by increased step-down and shortened-transfer latency in passive avoidance model and elevated plus maze model, respectively. Diazepam (2 mg/kg, ip) and piracetam (200 mg/kg, po) were used as standard drugs for anti-stress and nootropic activity testing. Further, the extract at 200 microg/ml showed maximum scavenging of stable radical 1,1-diphenyl, 2-picryl hydrazyl at 90.11% and nitric oxide radical at 62.77%. The present study, thus, provided scientific support for anti-stress (adaptogenic), antioxidant and nootropic activities of methanolic extract of bark of Alstonia scholaris.

Formulation of the Extract of the Stem Bark of Alstonia Boonei as Tablet Dosage Form

Purpose: To formulate the extracts of the stem bark of Alstonia boonei; an important antimalarial herb; into tablet dosage form. Methods: Tablets were formulated using direct compression and wet granulation methods. The mechanical properties of the tablets were assessed using crushing strength and friability and the crushing strength:friability ratio (CSFR) while drug release properties were evaluated using disintegration and dissolution times. Results: There were statistically significant (p0.01) differences in the CSFR values and drug release properties of A. boonei tablets prepared by both methods. The differences depended on the type and concentration of excipient and binder employed in the formulation. Conclusions: The method of preparation of the A. boonei tablets needs to be carefully selected to ensure the production of tablets with adequate bond strength to withstand the rigours of handling and at the same time release the active compound (s) for biological action