Antioxidant, Total Phenolic and Flavonoid Content of Selected Nigerian Medicinal Plants

Abstract

Plant phenolics and flavonoids play a great role in scavenging free radicals in the body and act as antioxidants. Thus their determination is sometimes nedded. Total antioxidant capacity, total phenolic and flavonoid contents of the extracts of 10 medicinal plants (Lochnera rosea, Allamanda cathartica, Asplenium platyneuron, Euphorbia prostrate, Baphia nitida, Crotolaria retusa, Zapoteca portoricensis, Platycerium bifurcatum, Mussaenda afzelii and Craterosiphon scandens) from 7 botanical families growing in the tropical rainforest of Nigeria were included in this study. The total antioxidant capacity of the extracts was assessed by using the phosphomolybdate method. The phenolic content was determined by using Folin-Ciocalteau assay, while the total flavonoid was determined by the aluminium chloride colorimetric assay. The results obtained showed that the total antioxidant capacity for all the extracts were in the range of 0.888 ± 0.75 to 0.938 ± 0.00 mg EAA/g. The results showed that E. prostrate, P. bifurcatum and A. platyneuron were found to be the richest source of phenolic (97.77 ± 0.77, 87.62 ± 1.22 and 82.33 ± 0.30 mg GAE/g) while B. nitida and M. afzelii had the least total phenolic content (11.67 ± 0.09 and11.18 ± 0.30 mg GAE/g). The highest total flavonoid content was revealed in P. bifurcatum (648.67 ± 12.3 mg QE) while M. afzelii also had the least total flavonoid content (3.67 ± 0.00 mg QE/g). The ratio of flavonoid to the phenolic in each extract was also determined to ascertain extracts that are rich in flavonoids.

Comparative Analysis of Nutritional and Bioactive Properties of Aerial Parts of Snake Gourd (Trichosanthes cucumerinaLinn.)

“…The procedure described by Agbo et al [13] was followed with slight modifications. A volume of 0.5 mL of aqueous extract was taken in to a test tube and 2 mL of distilled water was added followed by the addition of 0.15 mL of sodium nitrite (NaNO 2 , 5%, w/v) and allowed to stand for 6 min.…”

Gallic Acid Derivatives (GADs) from Loranthus micranthus Linn. Parasitic on Hevea brasiliensis with Antioxidative Capacity

“…Antioxidant assay. The antioxidant assay of the compounds was performed according to the procedure described by Agbo et al 8 Compounds 1-2 were dissolved in methanol to give a concentration of 1 mg/1000 μl stock solution. Ten microliter (10 μl) of these solutions was added to 490 μl DPPH solution (4.5 mg/100 mL) in an ependorf vial.…”

Antimicrobial and Antioxidant Activities of Novel Marine Bacteria (Bacillus 2011SOCCUF3) Isolated from Marine Sponge (Spongia officinalis)

“…The total antioxidant capacities (TAC) of the samples were determined by the phosphomolybdate method as described by Agbo et al 17 with slight modification. Then 0.1 mL of various concentrations of the samples (10 -100 mg/mL) were mixed with 1 mL of reagent solution (600 mm tetraoxosulphate (VI) acid, 28 mm sodium phosphate and 4 mm ammonium molybdate 1:1:1) in an Eppendorf vial.…”