Abstract

Background of study: Annona muricata; commonly known as sour sop has been reported to possess ethno medicinal values including anti-tumor and antioxidant activity.
Aim: This research was aimed at evaluating the phytochemical composition and the phytoestrogenic, hypocholesterolemic and antioxidant activity of Annona muricata seed extract in 7, 12-dimethylbenzeneanthracene (DMBA) treated female wistar rats.
Methodology: Ethanolic extract of A. muricata seed was prepared following crude extraction protocol. Qualitative and quantitative screening for the phytochemical constituents was done using standard methods. A total of thirty rats were randomly divided into six groups with five rats in each group. Group I served as the control group fed on food and water only; group II rats received A. muricata seed extract (200 mg/kg per body weight) intraperitoneally (i.p) daily for two weeks; rats in group III were treated with DMBA i.p (20 mg/kg pbw) twice weekly for two weeks; group IV rats were pre-treated with DMBA (20 mg/kg pbw) i.p for two weeks followed by i.p injection of tamoxifen (20 mg/kg pbw); group V rats were pre-treated with DMBA (20 mg/kg pbw) i.p for two weeks followed by i.p treatment with A. muricata seed extract (100 mg/kg pbw) for two weeks while rats in group VI received i.p injection of DMBA (20 mg/kg pbw) twice weekly for two weeks followed by i.p treatment with A. muricata seed extract (200 mg/ kg pbw) for two weeks. Blood samples were collected at the end of the experiment. Serum levels of estradiol and cholesterol were determined by standard methods. Levels of antioxidant parameters superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were also estimated from the serum using standard methods.
Results: Phytochemical screening revealed the presence of phenol (26.74 mg/100 g), tannin (21.95 mg/100 g), flavonoids (27.52 mg/100 g), alkaloid (19.25 mg/100 g) and steroid (20.23 mg/100 g). Results obtained from the serum samples of experimental animals showed that there was a significant (P<0.05) increase in the estradiol, SOD and CAT levels while there was a significant (P<0.05) decrease in MDA and cholesterol levels of the treated rats as compared to the control groups.
Conclusion: The results obtained in the study suggest the phytoestrogenic, hypocholesterolemic and antioxidant activity of A. muricata extract in DMBA-treated rats.

Keywords: Phytoestrogen; DMBA; Antioxidant; Hypocholesterolemic; Annona muricata