In vitro Leishmanicidal and Cytotoxic Activities of the Glycoalkaloids from Solanum lycocarpum (Solanaceae) Fruits

Abstract

Leishmaniasis is an infection caused by a protozoan parasite of the genus Leishmania and is the second most prevalent parasitic protozoal disease after malaria in the world. We report the in vitro leishmanicidal activity on promastigote forms of Leishmania amazonensis and cytotoxicity, using LLCMK2 cells, of the glycoalkaloids from the fruits of Solanum lycocarpum, determined by colorimetric methods. The alkaloidic extract was obtained by acid-base extraction; solamargine and solasonine were isolated by silica-gel chromatography, followed by reversed-phase HPLC final purification. The alkaloidic extract, solamargine, solasonine, as well as the equimolar mixture of the glycoalkaloids solamargine and solasonine displayed leishmanicidal activity against promastigote forms of L. amazonensis, whereas the aglycone solasodine was inactive. After 24 and 72 h of incubation, most of the samples showed lower cytotoxicities (IC50 6.5 to 124 μM) as compared to leishmanicidal activity (IC50 1.1 to 23.6 μM). The equimolar mixture solamargine/solasonine was the most active with an IC50 value of 1.1 μM, after 72 h. Likewise, solamargine was the most active after 24 h with an IC50 value of 14.4 μM, both in comparison with the positive control amphotericin B.

Photodynamic Therapy With Bengal Rose and Derivatives Against Leishmania amazonensis

“…The IC 50 for RBMET (9.83 μM) approximate the IC 50 against L. amazonensis for amphotericin B (14.9 μM and 6.1 μM) found by Miranda et al, 15 and Almeida et al, 16 respectively. In contrast, to the IC 50 for RBBUT (45.08 μM) which was higher than the amphotericin B.…”

A New Antileishmanial Preparation of Combined Solamargine and Solasonine Heals Cutaneous Leishmaniasis through Different Immunochemical Pathways

“…In particular, the glycoalkaloids from this plant present potent antimicrobial activity (11,13,(16)(17)(18). We recently demonstrated that the more abundant S. lycocarpum alkaloids present strong toxicity to extracellular L. amazonensis in vitro (9). In this work, our in vitro experiments showed that L. mexicana promastigotes are equally susceptible to solasonine and solamargine.…”

“…Solamargine and solasonine (Fig. 1A) are heterosidic steroids isolated from Solanum lycocarpum fruits, as described previously (9,10). Figure 1B shows a typical HPLC chromatogram of the standardized plant extract containing solamargine and solasonine and an internal standard (veratraldehyde).…”

“…Drug resistance is a major problem associated with the failure of treatment of human infections caused by this type of parasite and underscores the importance of the development of novel drugs (21)(22)(23). Plant products have long been used in traditional medicine to treat different types of illnesses (2,(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) and are now considered a good alternative for drug discovery. There are promising compounds originally isolated from plants with leishmanicidal properties, which could be antileishmanial drugs with commercial potential.…”

“…Preparations from this plant also display cytotoxic, antimicrobial, immunomodulatory, and antimutagenic activities (9)(10)(11)(12)(13)(14)(15)(16)(17)(18). We showed that alkaloids from this plant are lethal to Leishmania amazonensis promastigotes (9). In this work, we studied the role of the alkaloidal extract of S. lycocarpum in the in vitro and in vivo destruction of L. mexicana parasites.…”