Antihyperlipidemic, Antioxidant and Cytotoxic Activities of Methanolic and Aqueous Extracts of Different Parts of Star Fruit.
BACKGROUND
Star fruit (Averrhoa carambola) is a well-known plant in Malaysia which bears a great significance in traditional medicine.


OBJECTIVE
This study aimed to evaluate the antihyperlipidemic effect, antioxidant potential and cytotoxicity of aqueous and methanolic extracts of ripe and unripe fruits, leaves and stem of A. carambola.


METHODS
Antihyperlipidemic activity was assessed in poloxamer-407 (P-407) induced acute hyperlipidemic rat's model. The antioxidant activity was assessed in vitro using 2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging, 1-diphenyl-2-dipicrylhydrazyl radical scavenging (DPPH) and ferric reducing antioxidant power (FRAP) assays. In addition, cytotoxicity of A. carambola extracts was assessed using MTS assay on four leukemic cell lines (human colon cancer, human promyeloid leukemia, erythroid leukemia, acute myeloid leukemia) and one normal cell (human umbilical vein endothelial cells).


RESULTS
Methanolic extract of leaves had the most potent antihyperlipidemic activity in P-407 model, whereby it significantly reduced serum levels of total cholesterol (P<0.01), triglycerides (P<0.01), low-density lipoprotein (P<0.05), verylow- density lipoprotein (P<0.01) and atherogenic index (P<0.01). On the other hand, methanolic extracts of A. carambola stem and leaves showed the strongest antioxidant activity. Total phenolic and flavonoid contents of the extracts exhibited significant correlations with antioxidant but not with antihyperlipidemic activities. All plant parts showed no cytotoxic effect on the selected cancer or normal cell lines.


CONCLUSIONS
Antihyperlipidemic activity of different parts of A. carambola is greatly affected by extraction solvents used. Methanolic extract of A. carambola leaves exhibited higher antihyperlipidemic and antioxidant potentials compared to other parts of the plant.
Sultan A M
SA
Saghir
Amirin
A
Sadikun
Fouad S R
FS
Al-Suede
Amin M S A
AM
Majid
Discipline of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang, Malaysia. vicky@usm.my.
Vikneswaran
V
Murugaiyah
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D065826:Averrhoa; D005419:Flavonoids / Q000494:pharmacology; D005638:Fruit; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D008077:Lipoproteins, LDL; D008297:Male; D008519:Medicine, Traditional; D010636:Phenols / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D020442:Poloxamer / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley
D000975:Antioxidants; D005419:Flavonoids; D000960:Hypolipidemic Agents; D008077:Lipoproteins, LDL; D010636:Phenols; D010936:Plant Extracts; D020442:Poloxamer