Free Radical Scavenging and Antioxidant Potential of Ethanolic Leaf Extract of Diodia sarmentosa on High Fat Fed Wistar Rats

Abstract

Diodia sarmentosa (Sw) commonly known as Zimbabwe flora or Tropical button weed is a straggling or procumbent perennial herb which grows in evergreen forest, riverine vegetation and bush land. It has been used traditionally for the treatment of ulcer, diabetes and other ailments. This study investigated the Free radical scavenging and antioxidant potential of ethanolic leaf extract of Diodia sarmentosa on high fat fed wistar rats. Thirty (30) male wistar rats (150 g-200 g) were divided into five (5) groups: Negative control rats, Positive control rats, Low dose extract rats treated with 250 mg/kg, High dose extract rats treated with 500mg/kg of the extract, and Standard antihyperlipidaemic drug rats treated with 5 mg/kg of Simvastatin. High fat diet was fed to the rats with Ghee and Coconut oil in the ratio of 3:1 for six (6) weeks, and administration of the treatments started from the 3rd week till the 6th week. The free radical scavenging and antioxidant potentials of Diodia sarmentosa was determined by assessing parameters like nitric oxide radical, hydroxyl radical, malondialdehyde (MDA), Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx) and Glutathione S-transferase (GST) in the serum of the test rats. Diodia sarmentosa scavenged free radicals In vitro by inhibiting Nitric oxide and Hydroxyl radicals in a concentration-dependent manner, showing an inhibitory concentration at 50% (IC50) of 907.17 µg/ml ± 45.36 and 2173.44 µg/ml ± 100.11 respectively. Results obtained showed antioxidant enzymes like SOD, GPx and CAT in the serum of the test rats were significantly increased (p<0.05) by both doses of the extract when compared to the PC group and was similar to the standard drug used. GST activity was decreased in the serum by both doses of the extract, this decrease was not significant (p>0.05), while Malondialdehyde level was significantly decreased (p<0.05) by both doses of the extract in the serum of the tests rats. Diodia sarmentosa has antioxidants potentials because of its ability to scavenge free radicals, replenish antioxidant enzymes and reduce lipid peroxidation.