Hypocholesterolemic and antioxidant effects of aqueous extracts from the dried calyx of Hibiscus sabdariffa L. in hypercholesterolemic rats.
The present study was designed to investigate the hypolipidemic effects and antioxidant effects of Hibiscus sabdariffa L. (roselle) with regard to protection of LDL oxidation in vivo and ex vivo in rats made hypercholesterolemic by continuous cholesterol feeding. Administering the dried calyx extracts of roselle at doses of 500 and 1,000 mg/kg together with continuous cholesterol feeding to hypercholesterolemic rats for 6 weeks significantly decreased serum cholesterol level by 22% and 26%, respectively (p<0.001); serum triglycerides level by 33% and 28%, respectively (p<0.05); serum LDL level by 22% and 32%, respectively (p<0.05). However, serum HDL level was not affected. LDL was extracted from plasma of the hypercholesterolemic rats and the effects of the dried calyx extracts of roselle on the oxidation of LDL in vivo and ex vivo were examined. Six-week treatment with 250, 500 and 1,000 mg/kg of the extracts significantly decreased thiobarbituric acid reactive substances (TBARs) formation (p<0.05) while the formation of conjugated dienes during the oxidation of LDL induced by CuSO(4) was reduced, but not significantly different. These lines of evidence suggest that the aqueous extracts from the dried calyx of roselle possess both antioxidant effects against LDL oxidation and hypolipidemic effects in vivo. However, its mechanism(s) of action remains to be elucidated.
Hirunpanich
Vilasinee
V
Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Sriayudhaya Road, Rajadhevi, Bangkok 10400, Thailand.
Utaipat
Anocha
A
Morales
Noppawan Phumala
NP
Bunyapraphatsara
Nuntavan
N
Sato
Hitoshi
H
Herunsale
Angkana
A
Suthisisang
Chuthamanee
C
D000818:Animals; D000924:Anticholesteremic Agents / Q000302:isolation & purification / Q000627:therapeutic use*; D000975:Antioxidants / Q000302:isolation & purification / Q000627:therapeutic use*; D031584:Hibiscus; D006937:Hypercholesterolemia / Q000188:drug therapy*; D008077:Lipoproteins, LDL / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010084:Oxidation-Reduction / Q000187:drug effects; D008517:Phytotherapy; D010936:Plant Extracts / Q000302:isolation & purification / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000924:Anticholesteremic Agents; D000975:Antioxidants; D008077:Lipoproteins, LDL; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances