Biphasic Dose–Response of Components From Coptis chinensis on Feeding and Detoxification Enzymes of Spodoptera litura Larvae

Abstract

Due to long-term coevolution, secondary metabolites present in plants apparently function as chemical defense against insect feeding, while various detoxification enzymes in insects are adaptively induced as a prosurvival mechanism. Coptis chinensis, a medicinal plant used in traditional Chinese medicine for a thousand years, was found to be less prey to insects in our earlier field observations. Herein, 4 crude extracts obtained from sequential partition of aqueous extract of Rhizoma coptidis with petroleum ether, ethyl acetate, and n-butanol exhibited antifeedant activity against Spodoptera litura (Fabricius) larvae at high doses and inducing activity at low doses. Furthermore, a similar biphasic dose–response of the antifeedant activity against S litura larvae was also observed for jateorhizine, palmatine, and obakunone in Coptis chinensis. Notably, the enzyme activities of glutathione-S-transferase and carboxyl esterase in S litura larvae affected by the different components (jateorhizine, palmatine, obakunone, berberine, and coptisine) of C chinensis also showed a biphasic dose–response with an increasing trend at low doses and a decreasing trend at high doses. Together, our study suggests that the components of C chinensis may play a chemical defensive role against S litura larvae in a hormetic manner.

Solanum nigrum Fruit Extract Modulates Immune System Activity of Mealworm Beetle, Tenebrio molitor L.

“…For this reason, the action of a low dose of EXT may be connected with the hormesis process—a biphasic dose response, whereby exposure to low doses of a stressor can stimulate biological processes [ 33 ]. This phenomenon has also been reported in pest insects exposed to low doses of a pesticide [ 34 , 35 ] and plant secondary metabolites, including essential oils and alkaloids [ 36 , 37 ].…”

Cordyceps militaris extracts and cordycepin ameliorate type 2 diabetes mellitus by modulating the gut microbiota and metabolites

“…Recent studies have highlighted that many ingredients from natural plants exhibited bifunction in model organisms by mediating hormesis ( Jiang et al, 2020a ). Hormesis is a biphasic dose-response relationship characterized by low dose stimulation and high dose inhibition, and is typically represented as a J-shaped or inverted U-shaped curve ( Sun H et al, 2020 ).…”

“…Three isoforms were found in different species: PPARα, PPARβ/δ, and PPARγ. PPARs are key regulators of glucose homeostasis and lipid metabolism, and also important targets for the development of modern anti-diabetic drugs to improve insulin sensitivity and blood glucose level by regulating target genes ( Jiang et al, 2020a ). PPARs regulate gene transcription by initially activating by binding to ligand fatty acids and their derivatives, forming heterodimers with retinoid X receptor, and then binding to DNA sites of specific sequences to induce target gene activation ( Chan and Wells, 2009 ), thereby regulating lipid metabolism, adipocyte differentiation, glycogenesis, ubiquitination, and inflammation ( Gross B et al, 2017 ).…”

Responses of Fungi Maggot (Bradysia impatiens Johannsen) to Allyl Isothiocyanate and High CO2

“…Insects detoxify the different numerous exogenous and endogenous compounds due to the production of detoxification enzymes, including GSTs, CarE, and Cyt-b5, and their activities are considered to be an effective indicator monitoring the development of insect resistance to pesticides ( Li et al, 2021 ; Bilal et al, 2020 ). The presence of insecticides is reported to stimulate the activities of detoxification enzymes due to the increased production of ROS ( Jiang et al, 2020 ). The present results show that the enzyme activities of GSTs, CarE, and Cyt-b5 in B. impatiens third larvae were induced by the sub-lethal concentrations of AITC (LC 25 ) after 24 h and significantly enhanced under high CO 2 .…”