Antioxidant, antibacterial, cytotoxic and thrombolytic activities of flowers of Mirabilis jalapa L: Possible role of phenolics and flavonoids

Mirabilis jalapa L. belongs to Nyctaginaceae family is an ornamental plant and domestically known as Sandhamaloti in Bangladesh. In this report we evaluated phenol and flavonoid content of cold methanol extractives of flower of M. jalapa and their role in antioxidant, antibacterial, cytotoxic and thrombolytic potentials. This study utilized HPLC to identify qualitative phenolic and flavonoid compounds. Gallic acid and Kaempferol were employed as standards for phenolic and flavonoid identification, respectively. Consequently, evaluating the overall phenolic and flavonoid content in the plant extract was considered a logical step. Flower of M. jalapa is an abundant source of phenols and flavonoids. The antioxidant activities in the phosphomolybdenum assay are differed in distinct extractives and have been found as 334.78 ± 0.62, 142.53 ± 0.51, 398.04 ± 0.81, 470.29 ± 0.55 and 480.90 ± 0.59 mg of ascorbic acid equivalent per gm of crude methanol extract (MSF), petroleum ether fraction (PSF), carbon tetrachloride fraction (CTF), chloroform fraction (CSF) and ethyl acetate fraction (ESF), respectively. The IC50 values for DPPH radical scavenging have been evaluated to be 13.70 ± 0.32, 49.05 ± 0.47, 6.76 ± 0.22, 9.30 ± 0.41 and 6.94 ± 0.31 μg/mL for MSF, PSF, CTF, CSF and ESF, respectively. The cytotoxicity was evaluated against brine shrimp lethality bioassay and LC50 values of MSF, PSF, CTF, CSF and ESF have been found 11.83 ± 0.32, 35.50 ± 0.54, 5.00 ± 0.18, 11.30 ± 0.30 and 4.61 ± 0.15 μg/mL, respectively in comparison to a standard vincristine sulphate 2.50 ± 0.11 μg/mL. Plant polyphenols and flavonoids having antioxidant properties exhibit potential antibacterial activity and our results revealed that the entire tested fractions of vegetation of M. jalapa exhibit potential antibacterial activity. On this observation, the thrombolytic activity, is the first strive in M. jalapa to investigate for more modern thrombolytic and its ethyl acetate fraction was shown to substantial (53.81 ± 0.52%) thrombolysis property. A high correlation was observed between antioxidant, cytotoxicity, thrombolytic and antibacterial activity with polyphenol and flavonoid contents (r2 = 0.903 to 0.996, p < 0.05). These data suggest the role of polyphenols and flavonoids in the bioactivities. Further study of this plant may lead to isolation of bioactive polyphenols and flavonoids which will be effective in the management of many chronic diseases.