Arecoline

Natural products are important sources of insecticidal lead compounds and are central to the development of green pesticides. Arecoline, the primary alkaloid in betel nut, shows insecticidal activity against Aedes aegypti . This study aimed to synthesize arecoline benzyl ester derivatives with improved activity and to investigate how they act by interfering with hormone signaling pathways and chitin metabolism in Ae. aegypti .

This study synthesized 22 arecoline benzyl ester derivatives and evaluated for insecticidal activity against fourth‐instar Ae. aegypti larvae. Among these, compound 4r (3‐phenoxy) exhibited the highest potency (median lethal concentration (LC 50 ) = 64.21 mg/L), significantly surpassing arecoline (LC 50  = 100.82 mg/L). Mechanistic studies indicate that compound 4r significantly reduces 20‐hydroxyecdysone (20E) levels in larvae, down‐regulated the expression of the early‐late transcription factor Hr3 induced by ecdysone receptor (EcR) and ultraspiracle (USP), thereby disrupting the 20E‐ EcR/USP ‐ Hr3 hormonal signaling axis. This, in turn, suppressed key downstream chitin‐metabolism genes, including CHS‐2 , CHT10 and CHIA , reduced chitinase activity and total chitin content, and ultimately led to disruption of chitin homeostasis and blockage of normal larval development.

Arecoline benzyl ester 4r is a promising insecticidal lead that perturbs 20E signaling via EcR/USP and Hr3 and dysregulates downstream chitin synthase and chitinase genes, thereby disrupting chitin homeostasis and larval development in Ae. aegypti . These findings provide a scientific basis for further optimization of arecoline‐based mosquito control agents targeting the chitin pathway. © 2026 Society of Chemical Industry.

Areca nut is classified as a Group 1 carcinogen by the International Agency for Research on Cancer. It is a widely consumed psychoactive substance with profound cultural roots in regions including Hunan, Hainan, and Taiwan of China. Its key bioactive components include alkaloids (e.g. arecoline and arecaidine) and areca nut-specific nitrosamines, that induce DNA damage, reactive oxygen species bursts, and chronic inflammation in oral tissues. Coupled with mechanical trauma from chewing, these insults drive the malignant progression of oral submucous fibrosis to oral cavity carcinomas. This review systematically outlines the pathological progression from normal oral mucosa to invasive oral cavity carcinomas, highlighting two core mediators of oral submucous fibrosis carcinogenesis: immune microenvironment reprogramming and oncogenic signaling activation. Furthermore, this review elaborates the molecular mechanisms of areca nut-induced oral cancer, providing a theoretical foundation for biomarker discovery and the development of novel therapeutic strategies. It also provides actionable guidance for reducing the incidence of areca nut-related oral cavity carcinomas and improving patient prognosis.