Assessing the efficacy of Stemona collinsiae roots extract against third-stage larvae of Gnathostoma spinigerum and its safety profiles

Gnathostomiasis, caused by the advanced third-stage larvae of <i>Gnathostoma spinigerum</i>, demands novel treatment avenues. The ethanolic root extract of <i>Stemona collinsiae</i> has been postulated to have anthelminthic properties, suggesting its potential as an alternative remedy. In this study, <i>S. collinsiae</i> roots were collected, identified, and extracted with 95 % ethanol. The crude extracts were standardized using didehydrostemofoline as chemical marker. The efficacy of the <i>S. collinsiae</i> root extract against third-stage larvae of <i>G. spinigerum</i> and its toxicity to Wistar rats were evaluated. Both <i>in vitro</i> and <i>in vivo</i> tests were performed, where the <i>in vitro</i> tests assessed the anthelminthic potential of <i>S. collinsiae</i> extract against <i>G. spinigerum</i> larvae, while <i>in vivo</i> tests examined the extract's efficacy against <i>G. spinigerum</i> larvae in infected Wistar rats and the efficacy was compared with albendazole. Parallelly, Wistar rats underwent acute and sub-chronic toxicity tests to establish the safe dosage of the extract. The <i>in vitro</i> tests showcased significant anthelminthic activity, marked by discernible morphological alterations in the exposed larvae. Acute toxicity proved fatal at 2000 mg/kg body weight, while a dose of 300 mg/kg proved non-toxic. Using the Globally Harmonized Classification System, an LD50 of 500 mg/kg was determined. <i>In vivo</i> trials revealed a pronounced decline in <i>G. spinigerum</i> larvae among rats treated with the <i>S. collinsiae</i> extract. The larvae were also observed to be encysted post-treatment, while those treated with albendazole were not encysted. The <i>S. collinsiae</i> extract, with its noteworthy <i>in vitro</i> efficacy and favorable safety metrics in rodents, can be a potential anthelminthic agent. The diminished inflammatory response compared to albendazole hints at <i>S. collinsiae</i> being a safer gnathostomiasis treatment alternative. The promising results in these preliminary trials warrant a deeper investigation to determine the root extract's optimal dosing, suitable delivery methods, and its broader clinical implications.