Antifilarial activity of azadirachtin fuelled through reactive oxygen species induced apoptosis: a thorough molecular study on Setaria cervi

Abstract

Efficacious therapeutic strategies against lymphatic filariasis are always sought after. However, natural products are a promising resource for developing effective antifilarial agents. Azadirachtin, a significant tetranortriterpenoid phytocompound found in Azadirachta indica, was evaluated in vitro for antifilarial potential against the filarial parasite Setaria cervi. Dye exclusion and MTT assay confirmed the antifilarial potential of azadirachtin against S. cervi with a median lethal dose (LC50) of 6.28 μg/ml for microfilariae (mf), and 9.55 μg/ml for adult parasites. Morphological aberrations were prominent in the histological sections of the azadirachtin-exposed parasites. Moreover, alterations in the reactive oxygen species (ROS) parameters in treated parasites were evident. Induction of apoptosis in treated parasites was confirmed by DNA laddering, acridine orange (AO)/ethidium bromide (EtBr) double staining and in situ DNA fragmentation. The downregulation of anti-apoptotic CED-9 and upregulation of proapoptotic EGL-1, CED-4 and CED-3 at both the transcription and translation levels confirmed apoptosis execution at the molecular level. Changes in the gene expressions of nuc-1, cps-6 and crn-1 further clarified the molecular cause of DNA degradation. Furthermore, azadirachtin was found to be non-toxic in both in vitro and in vivo toxicity analyses. Therefore, the experimental evidence detailed the pharmacological effectiveness of azadirachtin as a possible therapeutic agent against filariasis.

Polyphenol enriched ethanolic extract of Cajanus scarabaeoides (L.) Thouars exerts potential antifilarial activity by inducing oxidative stress and programmed cell death

“…After complete fixation, dehydration in graded alcohol was done and finally embedded in molten paraffin. 5μm of adult parasite tissue sections were prepared for hematoxylin-eosin staining [18, 22].…”

Use of medicinal plants as a remedy against lymphatic filariasis: Current status and future prospect

“…This inspired a study reporting on the efficacious therapeutic activity of Azadirachtin against LF. It further indicated that a significant tetranortriterpenoid phytocompound found in Azadirachta indica , showed efficacies against the filarial parasite Setaria cervi in vitro 34 . Thus, remedies for LF pathology should be directed towards interventions that are known to invoke less or moderate inflammation.…”

Research progress of meliaceous limonoids from 2011 to 2021

“…Azadirachtin effectively inhibits the development of S. frugiperda by inducing apoptosis. 429,430 By inhibiting larval feeding, and reducing the digestion and absorption of nutrients in the midgut, azadirachtin inhibits the larval growth and development of Spodoptera litura and Bactrocera dorsalis. 431,432 By exerting immunosuppressive effects, azadirachtin inhibits the growth of Sarcophaga (Liopygia) argyrostoma and esh ies.…”