Abstract:
Diabetic Foot Ulcer (DFU) is a complication of diabetes mellitus that can be worsened by
microbial infections. Although antibiotics are used, antimicrobial resistance can lead to the
progression of disease. Therefore, silver nanoparticles (AgNPs) could be useful as a potential
novel therapeutic agent due to their antimicrobial activities. Kaempferia galanga (Iguru
Piyali), which is used in Ayurvedic medicine, was used to biosynthesise AgNPs. Antimicrobial
properties of plant crude extracts, extract-coated AgNPs, and uncoated AgNPs were screened
in vitro against standard bacterial strains Staphylococcus aureus (ATCC 25923), Pseudomonas
aeruginosa (ATCC 27853), and the fungal strain Candida albicans (ATCC 10231). Rhizomes
of Kaempferia galanga were used to prepare crude extracts and were used to synthesise extractcoated
AgNPs. Uncoated AgNPs were synthesised using a vitamin C solution. Antimicrobial
activities of crude extracts, extract-coated AgNPs, and uncoated AgNPs were screened using
the broth micro dilution method (CLSI, 2025). As positive controls, gentamicin and fluconazole
were used. Each formulation’s minimum inhibitory concentration (MIC), minimum bactericidal
concentration (MBC), and half-maximal inhibitory concentration (IC50) were evaluated. IC50
was calculated using Prism 10.0 (GraphPad Software Inc., La Jolla, CA). Extracts-coated Ag-
NPs of Kaempferia galanga showed higher activity compared to the crude extracts and uncoated
AgNPs. It showed considerable activity against all three tested microorganisms. Kaempferia
galanga extracts-coated AgNPs exhibited excellent antifungal activity and also the lowest MIC
value of 0.078 mg/mL against C. albicans MBC and IC50 values were also obtained for each
microorganism. It can be concluded that, Kaempferia galanga extracts-coated AgNPs exhibited
in vitro antimicrobial activity against S. aureus, P. aeruginosa, and C. albicans, than plant crude
extracts and uncoated AgNPs. Moreover, it has shown higher antifungal activity against C. albicans.
Further studies are needed to evaluate the pharmacological and antimicrobial activity of
Kaempferia galanga plant crude extracts, and extract-coated AgNPs as a topical antimicrobial
agent for DFU.
