The Effects of Tannic Acid on Serum Lipid Parameters and Tissue Lipid Peroxides in the Spontaneously Hypertensive and Wistar Kyoto Rats

Abstract

The effects of tannic acid or its vehicle (normal saline) on blood pressure, blood lipid parameters, liver and kidney malonaldehyde (MDA) levels were investigated in the spontaneously hypertensive rats (SHR) and the normotensive Wistar Kyoto rats (WKY). When tannic acid dissolved in normal saline, was injected intraperitoneally (i.p.) twice a week at a single dose of 15mg/rat/injection (30mg/week) for a period of 10 weeks to the SHR, the serum total cholesterol (TC), low density lipoprotein cholesterol (LDLC), and triglycerides (TG) were significantly lower compared to the vehicle-treated SHR. However, there was no significant difference in the high density lipoprotein cholesterol (HDLC) concentration. Administration (i.p.) of tannic acid to the WKY did not cause any significant effects on the serum TC, LDLC, and TG levels. The HDLC concentration of the tannic acid-treated WKY was significantly higher than in the vehicle-treated WKY. The LDLC/HDLC ratio was significantly lowered compared to their respective controls for both strains of rats. When tannic acid was administered (i.p.) by osmotic pumps over a 13 day period (30 mg tannic acid/week), the kidney MDA level in the SHR was found to be significantly lower than in the vehicle-treated SHR. The liver MDA level was not significantly different between the treated and control rats. In the WKY, MDA was detected in trace amounts in the kidneys of both the control and treated rats. There were appreciable amounts of MDA detected in the liver of the control and treated rats but these were not significantly different from one another. For both strains of rats, administration (i.p.) of tannic acid by osmotic pumps did not affect the systolic blood pressure and serum lipid parameters significantly.

Key words

Tannic acid - serum lipids - malonaldehyde - SHR