**6. Conclusions**

Chemotherapy has become the only option for treating leishmaniasis due to a lack of effective medicines. However, these medications have increased degrees of toxicity, treatment costs, and resistance development against leishmanial parasites, as well as other side effects. Furthermore, due to leishmanial antigen variations and varied immunological responses to the treatment, the efficacy of medicines differs from species to species. Biogenic nanomaterials have been suggested as helpful alternatives to formulate nanovaccines since they are nontoxic, biocompatible, cost effective, and have high targeted drug-loading potentials. Nanoformulations can be used to overcome targeted medication transport hurdles, resulting in increased parasiticidal efficacy. Moreover, plant-derived natural compounds (such as berberine, 7,8-dihydroxyflavone, E-caryophyllene, essential oil constituents, -terpineol, glycosides, tannins, and anthraquinone flavonoids) have been shown to have leishmanicidal activities in various studies, which can further integrate beneficial outcomes. Furthermore, the majority of leishmanicidal investigations revealed only the most basic results, such as determining the influence of test medications (crude extract, extracted bioactive components, essential oil, and purified fraction) on parasite growth. Few of them are able to determine the right formulation as well as the effect on the sandfly promastigote stage (vector). Plants include a range of bioactive chemicals, and the majority of them have been recognized for their medicinal qualities, according to the literature. As a result, standardization may lead to the identification of a specific component that has leishmanicidal properties. Biosynthesized nanoparticles mostly remove infection by triggering the host's immunomodulatory response or, in rare cases, directly by causing parasitic cell vacuolization, resulting in parasite death. Nanovaccines are a relatively new concept in *Leishmania* treatment, and while no vaccine is currently available, research is ongoing to find effective nanovaccines. Although nanotechnology has given hope for better and more successful eradication of neglected tropical diseases, a complete understanding of the molecular mechanisms responsible is still needed.
