Antimicrobial Activities of Cucurbita moschata Leaves Water Extracts Against Selected Bacteria and Their Compound Determination

In Malaysia, high-value cash crops such as pumpkin (Cucurbita moschata) are cultivated, but their production generates significant agricultural waste. Discarded fruits, stems, and leaves are waste materials with multiple potential uses. Therefore, this study aimed to examine the antibacterial properties and determine the types of phytochemical components available in water extracts from pumpkin (C. moschata) leaves as an agricultural waste extract. Microwave-assisted extraction (MAE) is used to extract the plants' leaves due to its ease of use, quick extraction time, affordability, and increased yield. The leaves are obtained from Kampus Tembila, Universiti Sultan Zainal Abidin (UniSZA), Besut, Terengganu. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were run to visualise and determine the minimum concentration of pumpkin leave water extract that inhibits the six selected bacteria strains related to the gastrointestinal system of small ruminants which are Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis, Salmonella enterica, and Acinetobacter baumannii. Thin Layer Chromatography (TLC) was used for the phytochemical screening, and reagents such as Vanillin, Anisaldehyde, Dragendorff's, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methanol solution were sprayed to identify the type of compound's presence in the aqueous extracts of both leaves. C. moschata leaves show inhibition activity against all microbes tested except B. subtilis, and the lowest IC50 inhibition was 8 mg/ml against A. baumannii and 20 mg/ml for E. faecalis, respectively. In the meantime, the aqueous extracts of C. moschata leaves contain natural compounds such as triterpenes, alkaloids, tannins and antioxidants, as indicated by coloured spots derived from the TLC visualization method.