Capsaicin preferentially inhibits slow-inactivation sodium currents in insects.

IF 2.6 4区医学 Q2 PHARMACOLOGY & PHARMACY Toxicon Pub Date : 2025-01-29 DOI:10.1016/j.toxicon.2025.108264

Masashi Kamezaki, Hisashi Nishiwaki

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引用次数: 0

Abstract

Capsaicin, a pungent ingredient found in chili peppers, exhibits various pharmacological activities including inhibiting voltage-gated sodium channels (VGSCs) in mammals, suppressing sodium currents. Although capsaicin shows insecticidal activity, its underlying mechanism of action on insect VGSCs remains unclear. Here, we evaluated the effects of capsaicin on insect nerve cords and VGSCs using neurophysiological techniques. Capsaicin injection immediately induced paralysis in American cockroaches (Periplaneta americana). Extracellular recordings of their nerve cords revealed that capsaicin inhibited the allethrin-induced excitation of nerve cord activity. Furthermore, in Xenopus oocytes expressing VGSCs of German cockroaches (Blattella germanica), capsaicin inhibited the steady-state activation of VGSCs, with an IC₅₀ value of 130.6 μM. Capsaicin significantly shifted the half-inactivation potential of the inactivation curve of insect VGSCs in a slow-inactivated state from -44.61 to -48.92 mV. Although the state dependency of sodium current inhibition by capsaicin remains unknown, based on its effective concentration, capsaicin may preferentially inhibit sodium currents by acting on insect VGSCs in a slow-inactivated state. This unique profile may serve as a foundation for the creation of novel insecticides based on capsaicin properties.

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来源期刊

Toxicon 医学-毒理学

CiteScore

4.80

自引率

10.70%

发文量

358

审稿时长

68 days

期刊介绍： Toxicon has an open access mirror Toxicon: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review. An introductory offer Toxicon: X - full waiver of the Open Access fee. Toxicon''s "aims and scope" are to publish: -articles containing the results of original research on problems related to toxins derived from animals, plants and microorganisms -papers on novel findings related to the chemical, pharmacological, toxicological, and immunological properties of natural toxins -molecular biological studies of toxins and other genes from poisonous and venomous organisms that advance understanding of the role or function of toxins -clinical observations on poisoning and envenoming where a new therapeutic principle has been proposed or a decidedly superior clinical result has been obtained. -material on the use of toxins as tools in studying biological processes and material on subjects related to venom and antivenom problems. -articles on the translational application of toxins, for example as drugs and insecticides -epidemiological studies on envenoming or poisoning, so long as they highlight a previously unrecognised medical problem or provide insight into the prevention or medical treatment of envenoming or poisoning. Retrospective surveys of hospital records, especially those lacking species identification, will not be considered for publication. Properly designed prospective community-based surveys are strongly encouraged. -articles describing well-known activities of venoms, such as antibacterial, anticancer, and analgesic activities of arachnid venoms, without any attempt to define the mechanism of action or purify the active component, will not be considered for publication in Toxicon. -review articles on problems related to toxinology. To encourage the exchange of ideas, sections of the journal may be devoted to Short Communications, Letters to the Editor and activities of the affiliated societies.