Pharmacological properties of Bergenia ciliata synthesized green zinc sulfide nanoparticles (ZnS-NPs) and zinc oxide nanoparticles (ZnO-NPs).

The conventional physical and chemical synthesis of nanomaterials is associated with multiple disadvantages, such as high energy consumption, high cost, time consumption, and the use of toxic chemicals that are not only hazardous in the manufacturing setup but are also harmful to the environment. To overcome such limitations, phytofabrication, i.e., the use of plants for the synthesis of nanoparticles is considered preferred as it is an inexpensive, sustainable, non-toxic, eco-friendly, and green approach. The current study aims to explore and compare the biological properties of green synthesized zinc oxide and zinc sulfide nanoparticles. The materials are prepared using eco-friendly chemistry, using an aqueous herbal extract of Bergenia ciliata. The materials are then subjected to comprehensive characterization techniques and biological studies using antibacterial, antifungal, antiparasitic, anticancer, antioxidant, and biocompatibility studies. Our comprehensive evaluation reveals that green-synthesized ZnS-NPs demonstrate superior antibacterial and anticancer properties compared to ZnO-NPs. Specifically, ZnS-NPs induced significant zones of inhibition (ZOI) of 24 ± 1.2 and 22 ± 0.8 mm against B. subtilis and E. coli, respectively, with a minimum inhibitory concentration (MIC) of 1.125 mg/mL. In contrast, ZnO-NPs displayed better dispersion behavior, along with enhanced antioxidant, antiparasitic, and antidiabetic activities. Notably, ZnO-NPs significantly inhibited both amastigote and promastigote forms of Leishmania tropica (KWH23), with MICs of 112 and 135 µg/mL, respectively, highlighting their strong therapeutic potential against leishmaniasis. However, none of the samples exhibit antifungal properties as they fail to inflict any zone of inhibition against the tested fungal strains. We thus conclude that the B. ciliata synthesized green ZnS-NPs and ZnO-NPs exhibit distinct but excellent therapeutic properties and that both the synthesized materials have the potential to be further explored in in vitro and in vivo studies.