Phytochemical profile of cansanção nettle extracts and their bioactivities on cabbage caterpillar

Abstract: The objective of this work was to evaluate the phytochemical profile and bioactivity of extracts of Brazilian stinging (“cansanção”) nettle (Cnidoscolus urens) on cabbage caterpillar (Ascia monuste orseis). Mortality, larval stage duration, pupal viability and mass, percentage of deformed pupae, and feeding preference were evaluated. The constituent classes of the ethanolic extracts were also identified by analytical thin-layer chromatography (TLC). Ethanolic extracts of leaves and roots at 2% (m/v) and aqueous extract of roots at 20% (m/v) prolonged the larval phase of the insect. The ethanolic extract of leaves at 2% reduced pupal viability, and pupae from all treatments showed reduced masses and generated deformed adults. Except for the ethanolic extract of stem at 2% (m/v), all other extracts showed a deterrent effect on A. monuste orseis larvae. The phytochemical analysis of ethanolic extracts showed the major presence of phenolic compounds, naphthoquinones, anthraquinones, coumarins, anthracene derivatives, terpenes, and steroids, as well as tannins. Aqueous extracts at 20% concentration and ethanolic extracts at 2% of leaves, stems, and roots of cansanção nettle cause larval mortality and also reduce leaf consumption, pupal viability, and pupal mass of A. monuste orseis.