Phytochemical investigation and In vitro antioxidant activity of an indigenous medicinal plant Alpinia nigra B.L. Burtt

Abstract

Objective: To investigate antioxidant potential of methanol extract of Alpinia nigra leaves. Methods: The study was done by using various in vitro methods such as 1,1-diphenyl-2picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), nitric oxide and hydrogen peroxide radical scavenging assays. Phytochemical constituents, total phenolic content and total flavonoid content of the extract at different concentrations (10-500 µg/ mL) were determined. Results: Alpinia nigra leaves showed high free radical scavenging activity as evidenced by the low IC 50 values in DPPH (64.51 µg/mL), in ABTS (28.32 µg/mL), in nitric oxide (80.02 µg/mL) and in H 2 O 2 (77.45 µg/mL) scavenging assays. Furthermore the TPC and TFC of the extract were found to be 69.25 mg gallic acid equivalent per gram of extract and 78.84 mg quercetin equivalent per gram of extract respectively. Conclusions: The results of present comprehensive analysis demonstrated that Alpinia nigra leaves possess high phenolic, flavonoid contents and potential antioxidant activity, and could be used as a viable source of natural antioxidants and might be exploited for functional foods and neutraceutical applications.

Exploring the antidiabetic and anti‐obesity properties of Samanea saman through in vitro and in vivo approaches

“…Whereas scavenging activity of H 2 O 2 by the extract may be attributed to its phytoconstituents, that can donate electrons to H 2 O 2 thereby, neutralizing it into H 2 O. The electron donation potential and antioxidant activity are directly proportional . The results as shown in the Table , extract also demonstrated hydrogen peroxide activity in a concentrated dose‐dependent manner with an IC50 value of (61.36 µg/mL).…”

Evaluation of the analgesic, anti-inflammatory, anti-oxidant, phytochemical and toxicological properties of the methanolic leaf extract of commercially processed Moringa oleifera in some laboratory animals

“…In the case of ABTS, the principle is based on the ability of the assay to inhibit the absorbance of radical cation, ABTS + , by anti-oxidants at a characteristic wavelength of 734 nm. The principle behind the technique involves the reaction between the ABTS and potassium per sulfate to produce the radical which is a blue green chromogen [43]. In the study, the food supplements exhibited anti-oxidant properties by inhibiting and scavenging for free radicals as shown by the 80% and 86.3% performance by the 10 and 20 mg concentrations on ABTS.…”

Comparative Evaluation of Crude Extract Fractions of the Whole Plant of Taxillus heyneanus and Dalechampia indica for Antioxidant Activity, Total Phenolic and Flavonoid Content

“…The ethanolic fraction of T.heyneanus extract showed highest flavonoid content (89.41±1.21mg RE/g dry extract) against other fractions (CTH, EDI, CDI) whose flavonoid content reported as 52.27±2.44,64.51±1.94 & 28.51±0.52 mg RE/g of dried weight, respectively. The results were seen in Table 1 & Fig 1D. Flavonoids are polyphenolic plant metabolites that perform different functions and provide various potential health benefits to humans because of their antioxidant nature, anti-inflammatory, anticancer, antiviral, antibacterial, vasodilatory and immune stimulating activity [27] .Flavonoids mediate their antioxidant effects by scavenging free radicals or by chelating metal ions or by inhibiting generation of free radicals [28] .…”