Calcium antagonistic activity of Bacopa monniera in guinea-pig trachea.

OBJECTIVE: To demonstrate the calcium antagonistic property of ethanol extract of Bacopa monniera in guinea-pig trachea. MATERIALS AND METHODS: The dose response curves of CaCl(2) (1 × 10(-5) to 1 × 10(-1) M) were constructed in the absence and presence of ethanol extract of Bacopa monniera (100, 500 and 700 μg/ml) or nifedipine (1 × 10(-6) M) in guinea-pig trachea in calcium free high K(+)-MOPS-PSS (3-(N-morpholino)-propanesulphonic acid physiological salt solution). The data was analyzed by ANOVA followed by least significant difference test or by Student's 't' test for unequal variance when appropriate. A probability of at least P < 0.05 was considered statistically significant. RESULTS: The plant extract (500 and 700 μg/ml) significantly (P < 0.05) depressed and shifted the calcium concentration-response curves (1 × 10(-3)- 1 × 10(-1) M) to rightward similar to that of nifedipine. CONCLUSIONS: Bacopa monniera extract exhibited calcium channel blocking activity in guinea-pig tracheal smooth muscles that may rationalize its relaxant action on guinea-pig trachea and its traditional use in respiratory disorders.