Polyacetylenes from Bidens pilosa Linn., promising insecticides with anti-inflammatory effects on HaCaT cells

Abstract

Over the years, plant-derived substances have been developed as effective substitutes for synthetic insecticides because of their safety and environmental friendliness. In this study, we investigated the insecticidal properties of four polyacetylenes isolated from Bidens pilosa, a traditional edible herb, against Plutella xylostella (L.), Spodoptera litura, Mythimna separata (Walker), Spodoptera exigua (Hübner), Helicoverpa armigera and Ostrinia furnacalis (Guene’e). The polyacetylenes 1-4 showed potent insecticidal activities with LD50 values ranging from 0.133 to 4.084 μg/larva in the contact toxicity assay and with LC50 values ranging from 0.070 to 2.561 mg/mL in the stomach toxicity assay. Among these four compounds, compound 1 exhibited the highest insecticidal activity, comparable with the activity of commercial pesticide pyrethrins. The results of in vitro glutathione S-transferases (GSTs) and acetylcholinesterase (AChE) assays indicated these polyacetylenes exerted inhibitory effects on GSTs or (and) AChE in P. xylostella. Meanwhile, their anti-inflammatory properties were investigated using the q-PCR assay. These compounds proved to be non-cytotoxic against human keratinocytes (HaCaT) in MTT assay. These findings suggested that compounds 1-4 have the potential to be developed as skin-safe insecticidal agents.