Antioxidant activity and total phenolic compound content of certain medicinal plants

Abstract

Aqueous extracts were prepared from eight medicinal plants and other plants were prepared as essential oils.The radical-scavenging ability of each plant extract was determined by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay. The total phenolic content of plants was determined by the Folin-Ciocalteu reagent in terms of gallic acid equivalents. The DPPH scavenging potential of the aqueous extracts ranged from 17 to 79%, whereas the essential oils showed inhibition of the DPPH activity in the 12-88% range. The highest inhibition of DPPH radicals was observed for Pinus halepensis extract. Meanwhile, amongst the essential oils, the greatest antioxidant potential was exhibited by Nigella sativa. The Bauhinia variegate extract had the highest phenolic content (149.18 mg/g gallic acid equivalents), followed by Albizzia lebbeck (148.00 mg/g) and Pinus halepensis (145.67 mg/g), whereas, amongst the essential oils, the highest phenolic content (98.57 mg/g) was found for Thymus vulgaris. The lowest contents were observed for Kigelia africana and Rosmarinus officinalis.The antioxidant activity had a positive correlation (R=0.654) with the phenolic content of most aqueous extracts, whereas it had a weak correlation using the essential oils (R=0.335). This confirms that the phenolic content of aqueous extracts may contribute towards their antioxidant properties.

Effects of Ethanol Extracts of Origanum vulgare and Thymus vulgaris on the Mycotoxin Concentrations and the Hygienic Quality of Maize (Zea mays L.) Silage

“…The TPC of the ethanol-extracted oregano and thyme was determined by colorimetric spectrophotometry following the Follin-Ciocalteu method [ 37 ] with some modifications. For the analysis, 1 mL of each herbal plant extract was mixed separately with 5 mL of the Folin-Ciocalteu reagent (diluted ten-fold).…”

Comparative analysis of antioxidant potential in leaf, stem, and root of Paederia foetida L.

“…The absorbance of reaction solutions was measured at 765 nm against a blank sample. Quantification was done according to the formula of Abdul-Hafeez et al (2014). The measurements were compared to a standard curve of gallic acid solutions and expressed as micrograms of gallic acid equivalents per gram dry mass (µg g -1 ).…”

“…The plant extracts were supposed to showing DPPH radical scavenging activity by following the method of Abdul-Hafeez et al (2014). Ascorbic acid was used to make a reference solution.…”

Ethnomedicinal Use, Phytochemistry, and Other Potential Application of Aquatic and Semiaquatic Medicinal Plants

“…Potential antioxidant compounds are identified from the extracts of Centella asiatica , Ipomea aquatic, Nelumbo nucifera, Nasturtium officinale, and Ludwigia adscendens . Phytochemical compounds with antioxidant properties were found in aquatic and semiaquatic plant species such as Persicaria hydropiper, Rotula aquatic, Sphaeranthus indicus, Polygonum glabrum, Ammannia baccifera, Ipomea aquatic, Nymphaea nouchali, Acorus calamus, Hedychium coronarium, Heliotropium indicum, Marsilea minuta, and Vetiveria zizanioides [ 107 , 148 – 151 ].…”