Comparison of the Content of Phenolic Compounds, Flavonoids, and Antioxidant Activity of Six Different Medicinal Plants under Extraction Conditions with Different Solvents

In the present study, the solvent effect (aqueous and hydroalcoholic) of the extraction on the content of phenol, flavonoid, and the antioxidant activity of six medicinal plants, including Persian oak fruit hull (Quercus brantii), Zataria multiflora, German Matricaria chamomilla, Teucrium polium, Rosa foetida Herrm, and mountain barberry (Berberis integerrima) was investigated.

To measure phenol and flavonoid content, folin ciocaltio and aluminum chloride reagents were used, respectively, and to measure the antioxidant potential, the DPPH method was used. The content of phenol and flavonoid compounds was calculated as mg equivalent of gallic acid and catechin per gram of dry weight of the plant, respectively. The collected data was analyzed in SPSS software (version 14).

According to the obtained results, the amount of phenol and flavonoid in the hydroalcoholic extract of oak fruit hull Quercus brantii, Zataria multiflora, German Matricaria chamomilla, and mountain barberry was more than the aqueous extract, and this difference was statistically significant (P<0.001). The highest content of phenol and flavonoid were related to the hydroalcoholic extract of oak by 310.2 ± 2.5 mg/g and 241.2 ± 1 mg/g, respectively, and the lowest amounts were related to the aqueous extract of Matricaria chamomilla (53.1±1.1 mg/g) and the aqueous extract of acorn (23.9±1.5 mg/g), respectively. The highest antioxidant activity (IC50) was related to oak fruit-hull hydroalcoholic extract (39.1±4.4 µg/ml), and the lowest was related to the aqueous extract of Matricaria chamomilla (315.3±3.3 µg/ml).

The findings of this study showed that the solvent used to extract plants is a significant factor in separation of phenol and flavonoid compounds as well as their antioxidant activity.