Antioxidant activity, acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum extracts

Abstract

In this study several investigations and tests were performed to determine the antioxidant activity and the acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum aqueous extracts (10% mass) and ethanolic extracts (10% mass and 70% ethanol), respectively. Moreover, for each type of the prepared extracts of P. officinalis and of C. umbellatum the content in the biologically active compounds - polyphenols, flavones and proanthocyanidins was determined. The antioxidant activity was assessed using two methods, namely the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and reducing power assay. The analyzed plant extracts showed a high acetylcholinesterase and tyrosinase inhibitory activity in the range of 72.24-94.24% (at the highest used dose - 3 mg/mL), 66.96% and 94.03% (at 3 mg/mL), respectively correlated with a high DPPH radical inhibition - 70.29-84.9% (at 3 mg/mL). These medicinal plants could provide a potential natural source of bioactive compounds and could be beneficial to the human health, especially in the neurodegenerative disorders and as sources of natural antioxidants in food industry.

Keywords: Acetylcholinesterase inhibitory activity; Antioxidant activity; Pulmonaria officinalis and Centarium umbellatum; Tyrosinase inhibitory activity.

Figure 1

Radical scavenging activity % p < 0.05 compared the activity of the ethanolic extracts with that of the aqueous extracts ^∗∗p < 0.01 compared the activity of the ethanolic extracts with that of the aqueous extracts; ^∗∗∗p < 0.001 compared the activity of the ethanolic extracts with that of the aqueous extracts; ^∗p < 0.05 compared polyphenol content of extracts with radical scavenging activity; ^∗p < 0.05 compared flavone content of extracts with radical scavenging activity.

Figure 2

Reducing power of Pulmonaria officinalis and Centarium umbellatum and aqueous and ethanolic extracts ^∗p < 0.05 compared polyphenol content of extracts with reducing power ^∗p < 0.05 compared flavone content of extracts with reducing power ^∗∗p < 0.01 compared the activity of the ethanolic extracts with that of the aqueous extracts.