Phytochemical Analysis, Antioxidant and Antibacterial Activities of Aqueous Extract of Hybanthus enneaspermus Leaves

The popular medicinal plant, Hybanthus enneaspermus, is found across tropical and subtropical regions and has been used in the management of several diseases. Therefore, this study aimed to screen the leaves of Hybanthus enneaspermus for phytochemicals qualitatively and quantitatively and to investigate the antibacterial and antioxidant properties of aqueous extract of the leaves. The in vitro assessment of the antioxidant potential of the extract was conducted using the DPPH free radical scavenging activity assay procedure. For antibacterial testing, the agar-well diffusion technique was used. Gas chromatography-mass spectroscopy (GC-MS) was employed to characterize the extract and analyze its chemical composition. The presence of phenols, tannins, flavonoids, alkaloids, and saponins in varying concentrations was revealed by phytochemical analysis of the extract while DPPH scavenging activity revealed significantly (p ≤ 0.05) higher values of % inhibition than quercetin at the respective concentrations used. The examined bacterial species' growth was seen to be inhibited by the extract. A minimum inhibitory concentration of 30 mg/mL was observed against Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis. In the case of Staphylococcus aureus, an MIC of 20 mg/mL was observed while it was 10 mg/mL against both Streptococcus pneumoniae and Salmonella typhi. In the broth cultures, significantly (p ≤ 0.05) lower growth rates were observed in the MIC and 2X MIC treatments compared to the untreated setups. The major compounds revealed from the GC-MS analysis were n-hexadecanoic acid, 9,12-octadecadienoic acid (Z, Z)-, tetradecanoic acid, caryophyllene and 10,10-dimethyl-2,6 dimethylenebicyclo [7.2.0] undecan-5β-ol to be dominant. The findings of this study revealed that the aqueous extract of Hybanthus enneaspermus leaves possesses good antioxidant and antibacterial properties; this should necessitate further investigations that could potentially lead to commercialization.