Phytochemical analysis and biological activity of the phenolic rich extract of Impatiens noli-tangere and Symphytum officinalis

In the traditional medicine Impatiens noli-tangere (fam. Balsaminaceae) and Symphytum officinale L. (fam. Boraginaceae) are known for their antioxidative, anti-inflammatory, astringent, hemostatic and wound healing properties [1 – 3]. Only a limited number of studies have been made to evaluate the chemical composition and biological activity of I. noli-tangere extracts. Plant extracts were evaluated for phytochemical profile (phenolics, flavonoids), antioxidant (DPPH and reducing power assays), anti-inflammatory (lipoxygenase (LOX) and cyclooxygenase-1 (COX-1) inhibition) and anti-tyrosinase activities [4]. Hydro-alcoholic extracts of the two medicinal herbs were processed by microfiltration and ultrafiltration for concentrating the polyphenolic compounds. Rosmarinic acid and isoquercitrin were the dominant compounds in both extracts. The polyphenolic-rich extract from S. officinale exhibited the most potent DPPH radical scavenging (IC₅₀= 0.0829 mg/mL) and reducing power (EC₅₀= 0.649 mg/mL) activities. Both extracts showed a high inhibition of LOX (IC₅₀: 0.0846 mg/mL for I. noli-tangere and 0.1094 mg/mL for S. officinale) and of COX-1 (IC₅₀: 0.0426 mg/mL for I. noli-tangere and 0.0692 mg/mL for S. officinale). The studied extracts inhibited tyrosinase activity in a dose-dependent manner. The IC₅₀ value of the tyrosinase inhibitory effect was 2.09 mg/mL for the I. noli-tangere polyphenolic-rich extract, slightly higher than that of S. officinale polyphenolic-rich extract of 1.18 mg/mL. These results suggest that I. noli-tangere and S. officinale extracts may be used as a source of anti-inflammatory agents as well as a dietary complement for health promotion.

Acknowledgements: This work was supported by a grant of the Romanian National Authority for Scientific Research, CNDI-UEFISCDI, project no. PN-II-PT-PCCA-2013 – 4-0034.

Keywords: Impatiens noli-tangere, Symphytum officinale, antioxidant, anti-inflammatory, anti-tyrosinase.

References:

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