Abstract

*Anju MP, Favas IR, Favas Kaprakkadan, Shahana CK, Shahnas PK, Shamna

ABSTRACT

Background: Pediculosis capitis, which is caused by pediculus humanus capitis, continues to be a common ectoparasitic infestation, especially among children of school age. The extended and indiscriminate use of synthetic pediculicides like permethrin and lindane has led to the emergence of resistance, decreased effectiveness, and adverse effects including scalp irritation and neurotoxicity. These drawbacks have heightened the quest for safer, more effective, and environmentally friendly alternatives. Medicinal plants that are abundant in bioactive phytochemicals have attracted significant interest as potential natural agents head lice. Methods: This study aimed to assess the in vitro activity of Annona muricata leaves extracts against pediculus humanus Capitis under controlled laboratory conditions. Plant materials were gathered, verified, shade-dried, and extracted with appropriate solvents (ethanol) following standard extraction protocols. Phytochemical screening was conducted to identify major secondary metabolites. Adult lice were collected and maintained under controlled conditions. The pediculicidal activity was evaluated using combined contact and fumigation bioassay methods at different concentrations such as 250, 500, and 750µg/mL. Mortality rates were recorded at predetermined intervals. Results: The findings indicated a time and concentration-dependent increase in the mortality rate of head lice. Higher extract concentrations produced a rapid pediculicidal effect and significantly shortened the survival time. Complete mortality of adult lice was noted at elevated concentrations within a shorter exposure duration compared to lower doses. Phytochemical analysis identified the presence of bioactive components such as alkaloids, flavonoids, terpenoids, phenolic compounds, and acetogenins, which may work together to produce the observed pediculicidal effects. Conclusion: The results from this investigation indicate that the Annona muricata leaves extract studied shows promising pediculicidal activity against pediculus humanus capitis and may represent a viable natural alternative to traditional synthetic pediculicides. Given its efficacy, plant- based origin, and anticipated safety, the extract could be further developed into an herbal formulation for pediculicidal use. However, further studies in vivo and clinical trials are necessary to confirm its safety, effectiveness, and formulation stability prior to therapeutic use.