Leishmanicidal and Anti-Microbial Effects of MgO–ZnO Bimetallic Nanocomposites, Fabricated with Curcuma zedoaria Oil

The oily extract of Curcuma zedoaria was employed to fabricate MgO-ZnO nanocomposites, using metals in different ratios (Mg₁:Zn₁, Mg₁:Zn₂, and Mg₂:Zn₁). Initially confirmed through infra-red spectroscopy, the nanocomposites were found to be crystalline, as evident from X-ray diffraction analysis, with crystallites sizes ranging between 4.01 and 8.12 nm. Additionally, it was observed that the nanocomposites were thermally stable. Comparative analysis of the anti-microbial potentials of the crude oily fraction and nanocomposites revealed higher activity for the nanocomposites. The Mg₁Zn₂ and Mg₂Zn₁ composites were characterized to be the most effective against Staphylococcus aureus (zone of inhibition = 35 mm, at 25 µg/mL, for both). Mg₂Zn₁ exhibited highest activity (35 mm) against Pseudomonas aeruginosa and Enterobacter cloacae (30 mm), at a higher concentration (75 µg/mL). The Mg₁Zn₂ composite (75 µg/mL) was found to be the most active against the fungal strain, Fusarium graminearum (35 mm). The composites also showed good Leishmanicidal activity, with IC₅₀ of 46.27 ± 2.73, 50.47 ± 3.589, and 72.11 ± 3.14 µg/mL, for Mg₁Zn₁, Mg₁Zn₂, and Mg₂Zn₁, respectively.