Entomotoxic Activity of Prasiola crispa (Antarctic Algae) in Nauphoeta cinerea Cockroaches: Identification of Main Steroidal Compounds

Abstract

Prasiola crispa is a macroscopic green algae found in abundance in Antarctica ice free areas. Prasiola crispan-hexaneextract (HPC) induced insecticidal activity in Nauphoeta cinerea cockroaches after 24 h of exposure. The chemical analysis of HPC revealed the presence of the followingphytosterols: β-sitosterol, campesterol and stigmasterol. The incubation of cockroach semi-isolated heart preparations with HPC caused a significant negative chronotropic activity in the heartbeats. HPC affected the insect neuromuscular function by inducing a complete inhibition of the cockroach leg-muscle twitch tension. When the isolated phytosterols were injected at in vivo cockroach neuromuscular preparations, there was a progressive inhibition of muscle twitches on the following order of potency: β-sitosterol > campesterol > stigmasterol. HPC also provoked significant behavioral alterations, characterized by the increase or decrease of cockroach grooming activity, depending on the dose assayed. Altogether, the results presented here corroborate the insecticide potential of Prasiola crispa Antarctic algae. They also revealed the presence of phytosterols and the involvement of these steroidal compounds in the entomotoxic activity of the algae, potentially by modulating octopaminergic-cholinergic pathways. Further phytochemical-combined bioguided analysis of the HPC will unveil novel bioactive compounds that might be an accessory to the insecticide activity of the algae.

Algae and Their Metabolites as Potential Bio-Pesticides

“…The extracts and the aforementioned phytosterols also caused neuromuscular inhibition, which was reduced by the application of phentolamine, an octopamine receptor inhibitor. Altogether, these results suggested the involvement of octopaminergic-cholinergic pathways in the insecticidal activity of this Antarctic macroalga [217].…”

“…Extracts of the macroalga Prasiola crispa were shown to possess insecticidal properties in fruit fly (Drosophila melanogaster) and cockroach (Nauphoeta cinerea) [216]. In a follow-up study, Prasiola crispa extracts and its phytosterols, namely β-sitosterol, campesterol and stigmasterol (Figure 3), exhibited insecticidal activities in the cockroach Nauphoeta cinerea [217]. To understand the mechanism of action of the extracts and isolated compounds, the authors performed acetylcholinesterase activity assays, semi-isolated heart preparations to determine heartbeats, grooming activity assays, and cockroach neuromuscular function assays.…”

Phytochemical Profiling of Javanese Ginseng (Talinum paniculatum) Stem Extract Using GC-MS Analysis and Pharmacological Potential

“…This work is licensed under the Creative Commons Attribution 4.0 International License Antioxidant, 45 anti-inflammatory. 32 5 Campesterol Anticholinesterase, 38 anti-inflammatory, 37 anti-cancer. 39 6 Ethyl (9z,12z)-9,12-octadecadienoate Antioxidant, 46 anti-inflammatory.…”

“…36 Campesterol compounds have been reported to have anti-inflammatory activity. 37 Furthermore, they demonstrated anticholinesterase 38 and anti-cancer properties. 39 This shows that campesterol compounds have similar biological activity with the class they belong to, namely Ergostane Steroids.…”