The present study aimed to investigate the effects of
Hsian-tsao (Mesona procumbens Hemsl.) and its active compound on blood pressure, lipid peroxidation and total
antioxidant status of spontaneously hypertensive rats (SHRs). Male SHRs were orally administrated either a water extract of
Hsian-tsao (WEHT) (1.0 g/kg) or
caffeic acid (CA) [0.1 g/kg of
body weight (BW)] on a daily basis for 6 weeks. The results indicated that both hepatic and plasmatic
malondialdehyde concentration were increased and total liver
glutathione (GSH) levels and
antioxidant enzyme activities were decreased in SHRs when compared to the control Wistar Kyoto rats at the end of the trail. In SHRs,
oral administration of WEHT or CA for 6 weeks reduced blood pressure as well as plasma and hepatic
malondialdehyde levels and increased hepatic
antioxidant enzyme activities when compared to SHRs control rats.
Reverse transcriptase-polymerase chain reaction results indicated that the changes in hepatic
antioxidant enzyme mRNA levels by WEHT or CA were similar to those noted in the
enzyme activity levels. The hepatic levels obtained from WEHT or CA-administrated rats had significantly greater
oxygen radical absorbance capacity values and total GSH levels than those of control rats. Following
oral administration of CA,
phenolic acid was detected in the plasma, and C(max) value after 1.0 h administration was 0.92 micromol/L. These findings indicate that a supplement of
Hsian-tsao may prevent development of increased blood pressure and enhance the total
antioxidant status in vivo.