Evaluation of Antibacterial Activity of Essential Oils of Melaleuca cajuputi Powell

Phytochemical Analysis and Antibacterial Activities of Kyllinga nemoralis Extracts against the Growth of some Pathogenic Bacteria

This study aimed to screen the phytochemical contents and investigate antibacterial activities of the aqueous and methanolic extracts of Kyllinga nemoralis. Extraction was done using the whole plant of K. nemoralis except the root. The phytochemical screening was carried out on both aqueous and methanolic extracts of K. nemoralis. The aqueous extract showed the presence of saponin and high amount of steroid, while the methanolic extract showed high amount of terpenoid and steroid. The antibacterial activities of K. nemoralis extracts were tested against five Gram positive bacteria (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Streptococcus pyogenes, and Bacillus thuringiensis) and four Gram negative bacteria (Escherichia coli, Shigella sonnei, Salmonella Typhi and Klebsiella pneumoniae). K. nemoralis extracts were subjected to testing of their antibacterial activities by the disk diffusion method. Furthermore, the minimum inhibitory concentrations of the extracts were determined. The results indicate that the aqueous extract of K. nemoralis exhibits more antibacterial activities than the methanolic extract. The aqueous extract of K. nemoralis showed efficacy against S. aureus and MRSA while the methanolic extract of K. nemoralis was found to exert antibacterial activity against MRSA. The results proved the potency of K. nemoralis extracts as natural antibacterial and supported the potential of use in the medication of the diseases caused by the tested bacteria.

Antimicrobial Secondary Metabolites from the Mangrove Plants of Asia and the Pacific

Microbes such as the White Spot Syndrome Virus account for severe losses in the shrimp farming industry globally. This review examines the literature on the mangrove plants of Asia and the Pacific with antibacterial, antifungal, or antiviral activities. All of the available data published on this subject were collected from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and a library search from 1968 to 2022. Out of about 286 plant species, 119 exhibited antimicrobial effects, and a total of 114 antimicrobial natural products have been identified including 12 with MIC values below 1 µg/mL. Most of these plants are medicinal. The mangrove plants of Asia and the Pacific yield secondary metabolites with the potential to mitigate infectious diseases in shrimp aquaculture.