Molluscicidal properties of wild sunflower (Tithonia diversifolia) leaf extract fractions against invasive golden apple snail (Pomacea canaliculata)

Pomacea canaliculata is a serious invasive pest in the rice farms of the Philippines. Using botanical molluscicide is much favored for human health and environmental reasons. Crude leaf extracts of Tithonia diversifolia , also an invasive plant, were observed to have molluscicidal properties. This study aimed to fractionate the different bioactive compounds in the T. diversifolia crude leaf extract using solvent extraction and test these fractions for molluscicidal properties. The results showed that the alkaloid and saponin fractions exhibited an LC50 of 6000 ppm and 3000 ppm, respectively, at 24 h. Histological analyses of tissues from the test organisms showed deteriorated epidermal and subepidermal layers of the foot, highly vacuolated and deciliated epithelium of the gill filaments and osphradial leaflets, and deteriorated lining of the primary ducts of the digestive glands. These results are attributed to the presence of alkaloids and saponins in the different extracts, which are reported from literature to have detergent properties that can disrupt cell membranes and inhibit acetylcholinesterase activities in animals.