Identification of polyphenols in white mugwort (Artemisia lactiflora Wall.) ethanolic extracts and their anti-inflammatory and anti-adipogenic activity potential

Abstract

White mugwort (Artemisia lactiflora Wall.) is known as a medicinal herb containing phytochemicals with antioxidant and bio-activity. The optimal concentration of ethanol was investigated for extracting polyphenols from the fresh aerial part and dried powder of white mugwort as expressed by total phenolic content (TPC), phenolic compounds, antioxidant, anti-inflammatory, and anti-adipogenic activity. Among various ethanol concentrations (0, 25, 50 or 95%) used in the extraction process, the freeze-dried extract from fresh aerial part (FE) extracted with 95% ethanol expressed the highest antioxidant activity (DPPH radical scavenging IC50 of 0.817 ± 0.06 μl/mg dry weight (DW) and FRAP value of 11.40 ± 0.86 mmol Fe(II)/g DW) and the highest TPC (61.46 ± 3.09 mgGAE/g DW). While, the freeze-dried extract from dried powder (PE) exhibited the prominent antioxidant properties (DPPH radical scavenging IC50 of 0.975 ± 0.03 μl/mg DW and FRAP value of 07.60 ± 0.22 mmol Fe(II)/g DW), TPC (48.11 ± 1.45 mgGAE/g DW) when extracted with 50% ethanol. Seven phenolic compounds—two phenolic acids (gallic acid and tannic acid) and five flavonoids (apigenin, isoquercetin, quercetin, rutin, and catechin) were identified in FE and PE using HPLC-DAD/MS. The inflammatory genes were down-regulated in lipopolysaccharide-stimulated THP-1 monocytes treated with PE, suggesting anti-inflammatory activity. Lipid accumulation in 3T3-L1 adipocytes treated with FE at 60 μ gGAE/mL decreased to 12.8%, while the decrease of 36.8% was detected in PE. Hence, flavonoids were suggested to be responsible for the stronger bioactivity of PE over FE. Moreover, this work originally revealed the investigation of the anti-inflammatory and anti-adipogenic activity of white mugwort on THP-1 and 3T3-L1 cells.