Saponins molluscicidal activity

Saponins have been variously attributed with a diverse range of properties, some of which include both beneficial and detrimental effects on human health, piscidical, insecticidal and molluscicidal activity, allelopathic action, antinutri-tional effects, sweetness and bitterness, and as phytoprotectants that defend plants against attack by microbes and herbivores [2-11]. A more detailed understanding of the biochemical pathways and enzymes involved in saponin... 

Extracts from tamarind fruit pulp have shown molluscicidal activity against Bulinus trancatus snails. This is probably due to the presence of saponins in the fruit (Imbabi and Abu-Al-Futuh, 1992a, cited in (5)). 

Swartzia madagascariensis Devaux (Leguminosae) is one of the most promising plants for the potential control of schistosomiasis-transmitting snails in Africa. Aqueous extracts of the seed pods contain large amounts of saponins with high molluscicidal activity. These saponins have been characterised and field trials with extracts of the fruits have been performed in Tanzania [21], The most active saponins are glycosides of oleanolic acid. 

A saponin isolated from the Zimbabwean plant Phytolacca dodecandra, own to have molluscicidal activity, contains a P-Gal(l-+3)-P-Glc disaccharide unit. ... 

Anthospermum rigidum Eckl. Zeyh. [sambulela] (Rubiaceae) leaf infusion is also used for pubic lice. The leaf contains flavonoids, polyphenols and tannins (75). Studies have also shown that apart from the antibacterial properties of these plants, they also have additional medicinal values. The root bark of Andrachne ovalis shows insecticidal activity and is a remedy for snake bites and epilepsy (16,28). The alcohohc extract of the leaves is strongly molluscicidal and can be used in the vector control of hilharzia (67). The leaf decoction is used for persistent dizziness (11). The stem bark contains alkaloids, anthranoids, cardenolides and polyphenols. The root bark contains alkaloids, cardenohdes, polyphenols and saponins (50). 

Many active molluscicides are saponins (Farnsworth et al., 1987 Henderson et al., 1987 Marston and Hostettmann, 1991). These compounds are important because of the potential for controlling the snail vectors for schistosomiasis (bil-harzia), which affects about 300 million people worldwide. Four triterpenoid saponins with strong moUuscicidal activity are found in the fruits of ivy Hedera helix Araliacene), and others in the fruits of Lonicera japonica (Caprifoliaceae) (Hostettmann, 1986). 

---