Aims: Antimicrobial resistance (AMR) is a growing threat to public health, where treatments using conventional drugs are becoming ineffective. One viable but underexplored alternative is through the use of Dioscorea hispida, a wild plant that exhibits antimicrobial properties. This study aims to explore D. hispida effectiveness as an antibacterial and antibiofilm agent against selected pathogenic and non-pathogenic bacteria. Methodology and results: Different concentrations of D. hispida crude extracts (0 – 2.5 mg/mL) were tested against the growth of planktonic bacterial cells over 24 h incubation, and the half maximal effective concentration (EC50) obtained was used in the antibiofilm test over 24 and 48 h. All bacteria treated with D. hispida showed significant (P<0.05) reduction in planktonic cell and biofilm densities against the negative control starting at 0.3 mg/mL. However, in comparison to the antibiotic, only certain bacteria were significantly affected by D. hispida, implying the plant has a ‘moderate’ biocidal activity in general. Furthermore, Atomic Force Microscopy imaging of S. aureus biofilm with D. hispida revealed increased height and width of cell clusters despite reduction in volume compared to the negative control, suggesting unique biofilm resistance behaviour against the plant. Conclusion, significance and impact of study This study demonstrated D. hispida capability as a natural antimicrobial and antibiofilm agent. The plant could complement current antimicrobials to maximise killing efficiency and minimise occurrences of resistance. Unique biofilm behaviour against D. hispida also warrants further investigation on the effect of biocides towards biofilm structure. Overall, this research provides new insights into a traditional plant-based antimicrobial activity in combating infectious diseases and AMR.

Parasitic diseases represent one of the causes for significant global economic, environmental and public health impacts. The efficacy of currently available anti-parasitic drugs has been threatened by the emergence of single drug- or multidrug-resistant parasite populations, vector threats and high cost of drug development. Therefore, the discovery of more potent anti-parasitic drugs coming from medicinal plants such as Quercus infectoria is seen as a major approach to tackle the problem. A systematic review was conducted to assess the efficacy of Q. infectoria in treating parasitic diseases both in vitro and in vivo due to the lack of such reviews on the anti-parasitic activities of this plant. This review consisted of intensive searches from three databases including PubMed, Science Direct and Scopus. Articles were selected throughout the years, limited to English language and fully documented. A total of 454 potential articles were identified, but only four articles were accepted to be evaluated based on inclusion and exclusion criteria. Although there were insufficient pieces of evidence to account for the efficacy of Q. infectoria against the parasites, this plant appears to have anti-leishmanial, anti-blastocystis and anti-amoebic activities. More studies in vitro and in vivo are warranted to further validate the anti-parasitic efficacy of Q. infectoria.