A simple, cost-effective, and environmentally friendly method is needed for synthesizing metal nanoparticles, including gold nanoparticles (AuNPs). In this study, AuNPs were synthesized with Lignosus rhinocerotis sclerotial extract (LRE) and chitosan (CS) as reducing and stabilizing agents, respectively. Different LRE concentrations from cold and hot water extraction (CWE and HWE, respectively) were used to reduce chloroauric acid (HAuCl4) to form AuNPs. Positively charged chitosan stabilized AuNPs (CS-AuNPs) mediated by LRE exhibited a surface plasmon resonance (SPR) band at 533 nm. The CS-AuNPs synthesized using CWE had a smaller particle size (49.5 ± 6.7-82.4 ± 28.0 nm) compared to that of the HWE samples (80.3 ± 23.4-125.3 ± 41.5 nm), depending on LRE concentration. FTIR results suggested protein and polysaccharides in LRE were the sources of reducing power, reducing gold ions to AuNPs. CS-AuNPs were mostly spherical with higher LRE concentrations, whereas some triangular, pentagonal, irregular, and rod shaped AuNPs were observed at lower LRE concentrations. CS-AuNPs mediated by LRE displayed effective antibacterial activity against gram-negative (Pseudomonas aeruginosa and Escherichia coli) and gram-positive bacteria (Staphylococcus aureus and Bacillus sp.). Thus, the biosynthesized AuNPs using LRE and chitosan provide opportunities for developing stable and eco-friendly nanoparticles with effective antibacterial properties.

Hyperhidrosis is a condition characterized by excessive sweating that affects at least 5% of the world’s population. It is normally associated with unpleasant body odour which requires continuous maintenance throughout life. Antiperspirants and deodorants are the first-line treatments for hyperhidrosis. However, association of this class of product with the risk of other diseases has increased the search for an effective antiperspirant from natural sources. This study aimed to investigate the antibacterial and antiperspirant activities of Curcuma xanthorrhiza Roxb. Using an in vitro microbial assay against specific bacteria responsible for body odour and rat foot pad analysis. Quality control of the fractionated extract was conducted using reversed-phase HPLC based on two active markers: xanthorrhiza and curcumin. Toxicity tests were conducted based on the OECD guidelines (50–2000 mg/kg). Inhibition zone, MIC, and MBC values of the hexane fraction of C. xanthorrhiza showed equivalent antibacterial activity to positive control (p > 0.05). No swelling, redness, or rashes were observed at the injection area throughout the study. Treatment with 40, 80, and 160 mg/kg of the extract significantly decreased the sweat excretion up to 79.34% (p < 0.05) after 15 min compared to negative control. Histopathology analysis showed the reduced size of the secretory units in plantar sweat glands post treatment compared to negative control. In conclusion, the hexane fraction of C. xanthorrhiza is able to reduce sweat excretion in a rat model and inhibit the growth of bacteria causing body odour.