Preparation and Optimization of Peppermint (Mentha pipertia) Essential Oil Nanoemulsion with Effective Herbal Larvicidal, Pupicidal, and Ovicidal Activity against Anopheles stephensi

Objectives: The Plasmodium parasite is transmitted directly to humans through the Anopheles mosquito bite and causes vector-borne malaria, leading to the transmission of the disease in Southeast Asia, including India. The problem of persistent toxicity, along with the growing incidence of insect resistance, has led to the use of green pesticides to control the spread of the disease in a cost-effective and environment-friendly manner. Based on this objective, this work investigated the larvicidal, pupicidal, and ovicidal activity of Mentha pipertia using a natural nanoemulsion technique. Methods: GC-MS characterized essential oils of Mentha pipertia leaves were formulated as a nanoemulsion for herbal larvicidal, pupicidal, and ovicidal activities. Size of the nanoemulsion was analyzed by photon correlation spectroscopy. The herbal activities against Anopheles Stephensi of nanoemulsion were evaluated in terms of the lethal concentration for 50% (LC50) and 90% (LC90) to prove low cost, pollution free active effective formulation. Results: Chiral, keto, and alcohol groups are obtained from Mentha pipertia leaves' essential oil, and the nanoemulsions have demonstrated good results in the larvicidal probit analysis, with values of LC50=09.67 ppm and LC90=20.60 ppm. Activity results of the most stable nano formulation with 9.89 nm size showed a significant increase when compared to the bulk. Conclusion: The nanoemulsion of Mentha pipertia leaves can be a promising eco-friendly widely available, low-cost herbicide against the Anopheles mosquito.