Phytochemical analysis, toxicity and antibacterial activities of morinda citrifolia leaves / Nur Syakirah Kamarulzaman

The rapid emergence of various diseases caused by bacterial infections are becoming a concern and have threatened human health. The most common diseases caused by bacterial infections are skin diseases. There are many plants have been identified with the properties of antimicrobial activity that has potential to combat bacteria. The main objective of this study is to evaluate the antibacterial activity of Morinda citrifolia leaves towards Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeroginosa. Besides, the aim of this study is to identify the compounds present in Morinda citrifolia leaves by phytochemical analysis using gas chromatography and mass spectrometry (GC-MS) analysis. Another purpose of this study is to evaluate the toxicity properties of M. citrifolia leaves by using brine shrimp lethality bioassay (BSLA). Methods used for this study were plant extraction to obtain the methanolic extract of leaves, disc diffusion method to test the antibacterial activity of Morinda citrifolia leaves extract towards skin infection bacteria, Gas Chromatography-Mass Spectrometry Analysis (GC-MS) to identify the compounds present in Morinda citrifolia leaves and Brine Shrimp Lethality Bioassay (BSLA) to evaluate the toxicity properties of Morinda citrifolia leaves. The results of antibacterial activity screening have revealed that plant extract extract has antibacterial potential on all bacteria tested. GC-MS analysis has revealed major compounds such as are hydroxymethylfurfural (HMF), 4H-Pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl (DDMP), propanoic acid, 2-Methoxy-4-vinylphenol, oleic acid, ascorbic acid, 3-Methoxyacetophenone, 2,3,4,6-Tetramethylphenol, 2-Tetrazene,1,1-diethyl-4,4-dimethyl and sarcosine anhydride. Each compound contains beneficial properties such as antibacterial, antioxidant, anti-inflammatory, analgesic and anticancer activities. The calculated LC50 value is 583.45 μg/ml which is considered low toxic to brine shrimps. In conclusion, M. citrifolia leaves have great potential as new sources of antibacterial agent that are fundamental to combat bacteria that cause skin infections.