Phytochemical and Pharmacological Investigations of Different Extracts of Dracaena spicata Roxb. Available in Bangladesh

Natural product-based drug discovery from plant sources has frequently been practiced for many years in the field of health research. The present study aimed to determine the phytochemicals, antioxidant, antibacterial, cytotoxic, and thrombolytic properties of different solvent extracts of Dracaena spicata Roxb. Secondary metabolites were isolated from the methanol extract of D. spicata using a series of chromatographic techniques and characterized by NMR spectral analysis. The antioxidant potential of all the extracts was determined using DPPH free radical scavenging assay besides determining their total phenolic and flavonoid contents. Antibacterial activity was tested using the disc diffusion method, and cytotoxicity was assessed using the brine shrimp lethality assay. The thrombolytic activity of all the extracts was also measured. Two secondary metabolites were isolated from the methanol extract and characterized as vanillic acid (1) and isovanillic acid (2). The methanol extract exhibited the highest free radical scavenging abilities (IC50 value = 47.38 ± 2.96 µg/mL), the highest concentrations of phenolic (244.73 ± 0.25 mg/g gallic acid equivalent) and flavonoid content (297.08 ± 2.58 mg/g quercetin equivalent) and it was also shown to be the most cytotoxic (LC50 = 38.79 ± 2.79 µg/mL). The dichloromethane extract exhibited the highest inhibitory activity against Vibrio mimicus, producing a 32.8 ± 0.8 mm zone of inhibition and was found to have the highest thrombolytic activity (29.01 ± 1.25%). The bioactivities of D. spicata validate the traditional use of this plant as well as urge further investigations to identify more bioactive compounds.