A standardized topical preparation of Solanum lycocarpum fruit glycoalkaloids effectively heals Cutaneous Leishmaniasis

Leishmaniasis continues to be a major worldwide health problem with an annual mortality of about 60,000 people. The growing resistance to currently used therapeutic drugs is a major challenge. Two glycoalkaloids, solamargine and solasonine, initially identified as major components of the Brazilian plant Solanum lycocarpum were tested for leishmanicidal activity. Both alkaloids killed intracellular and extracellular L. mexicana parasites more efficiently than the reference drug sodium stibogluconate. Ten µM of each individual alkaloid significantly reduced parasite counts in infected macrophages and dendritic cells. In vivo treatment of C57BL/6 mice with a topical preparation containing glycoalkaloid extract (45.1% solamargine and 44.4% solasonine) gave a significant reduction in lesion sizes and parasite counts recovered from lesions. The two alkaloids exert activity by different intracellular pathways in macrophages and dendritic cells. We conclude that this topical preparation made from a semi purified extract (a potential Botanical Drug) is effective and a potential new and inexpensive treatment for cutaneous leishmaniasis.