Andrographolide and kalmegh (Andrographis paniculata) extract: in vivo and in vitro effect on hepatic lipid peroxidation.

Single or repeated (for 15 consecutive days) oral administration of kalmegh leaf extract (500 mg/kg) or its bitter principle, andrographolide (5 mg/kg), to adult male albino rats (b.wt. 125-150 g) produced no significant change in NADPH induced hepatic microsomal lipid peroxidation. Carbontetrachloride (5 ml/kg) induced hepatic microsomal lipid peroxidation was decreased when the rats were pretreated (for 4 hr), but only with a single dose and not with long term administration of kalmegh or andrographolide. In vitro carbontetrachloride (1 microliter) induced hepatic microsomal lipid peroxidation was completely normalized by kalmegh leaf extract (0.5 and 5.0 micrograms/mg protein) or andrographolide (0.5 and 5.0 micrograms/mg protein). At the higher concentration of carbontetrachloride (2 microliter), hepatic microsomal lipid peroxidation remained significantly increased (25 %) in the presence of andrographolide (0.5 microgram/mg protein), but not in the presence of kalmegh extract (0.5 microgram/protein). These results suggest that kalmegh leaf extract has more protective action on carbontetrachloride-induced hepatic toxicity than its bitter principle, andrographolide.