In vitro Anthelmintic Effects of Citrus sinensis and Citrus nobilis Fruit Peel Extracts

A study was conducted to evaluate the in vitro anthelmintic effect of different crude extracts of Citrus sinensis (orange) and Citrus nobilis (mandarin) fruit peel. In vitro free radical scavenging activity of the different extracts was determined by the 2,2-azino bis (3-ethylbenzothiazoline-6-sulfonate) method. In vitro anthelmintic activity of different extracts was assessed against Haemonchus contortus by egg hatch assay (EHA) and larval mortality assay (LMA). C. sinensis had higher antioxidant activity as compared to C. nobilis. Poor embryonicidal effect was observed on H. contortus eggs by extracts of C. sinensis fruit peel. However, acetone extract of C. nobilis peel (@ 10 mg/ml) exhibited excellent embryonicidal effect (>90%). Though all the extracts of C. sinensis (except ethanol extract) and C. nobilis (except methanol extract) showed excellent inhibition of egg hatching at a minimum concentration of 0.15 mg/ml, among all the extracts acetone and hydroalcohol extracts were found to be the best for inhibition of egg hatching. In larval mortality assay, all the extracts of both fruit peels exhibited marked larvicidal activity at a minimum concentration of 0.63 mg/ml. The results indicated that acetone extract of both C. sinensis and C. nobilis fruit peels has potent ovicidal activity while all the extracts possessed larvicidal properties against H. contortus that need to be investigated in vivo for the management of this parasite.