Tae Woong Lee

Effect of magnesium lithospermate B in rats with sodium-induced hypertension and renal failure

To evaluate the antihypertensive effect of magnesium lithospermate B isolated from Salviae miltiorrhizae radix, determinations of blood pressure and urinary excretions of sodium, potassium, prostaglandin E2 (PGE2) and kallikrein, which have been proposed to play an important role in the regulation of blood pressure, were made in rats with sodium-induced hypertension and renal failure. In rats given magnesium lithospermate B, blood pressure was significantly decreased, whereas urinary excretion of electrolytes was significantly increased. Urinary PGE2 excretion following administration of magnesium lithospermate B increased as the dose of the compound was stepped up. The activity of kallikrein in urine was also increased by the treatment. From these results, the blood pressure-lowering action of magnesium lithospermate B may be due in part to enhancement of the kallikrein-prostaglandin system.

Augmentation of renal response by magnesium lithospermate B.

Magnesium lithospermate B and adenine were given simultaneously to rats p.o. in order to investigate their renal effects. In rats given magnesium lithospermate B at a dose of 5 mg/kg body weight/day for 12 or 24 days, glomerular filtration rate, renal plasma flow and renal blood flow were increased significantly. A significant increase in renal function parameters was also found in rats given 10 mg of magnesium lithospermate B. Urinary excretion of prostaglandin E2 was increased by administration of magnesium lithospermate B, while those of 6-keto-prostaglandin F1 alpha and thromboxane B2 were unaffected at a dose of 5 mg or 10 mg/kg body weight/day for 12 or 24 days. The activity of kallikrein in urine increased markedly and significantly in rats given 5 or 10 mg of magnesium lithospermate B for 12 or 24 days. From these results, it seems that magnesium lithospermate B increases renal function by improving the renal circulatory state through activation of kallikrein and promotion of prostaglandin E2 production.

Renal responses to magnesium lithospermate B

Abstract— Renal responses to magnesium lithospermate B isolated from Salviae miltiorrhizae radix were examined in normal rats. Urinary sodium, potassium, prostaglandin E2 and kallikrein excretion was significantly increased after magnesium lithospermate B administration, whereas excretion of urinary 6‐keto‐prostaglandin F1α and thromboxane B2 was unchanged. Rats administered with the drug also revealed a slight elevation of plasma renin activity and the levels of angiotensins I and II. Plasma aldosterone was decreased slightly. No significant changes were observed in angiotensin‐converting enzyme or blood pressure.