Assessment of antioxidant, anti-inflammatory, anti-cholinesterase and cytotoxic activities of Henna (Lawsonia inermis) flowers

Lawsonia inermis flowers were evaluated for chemical and biological properties for the first time. Extracts were prepared successively by hexane, chloroform and methanol. Phenolics (7.8-239.0g gallic acid equivalent/kg of dry mass), tannins (12.5148.5mg cathechin equivalent/kg of dry mass) and flavonoids (36.2-43.75mg quercetin equivalent/kg of dry mass) were quantified. Methanol extract has a high antioxidant activity (IC50=8.5mg/L by DPPH assay and IC50=5mg/L by ABTS assay) and a good anti-inflammatory activity against 5-Lipoxygenase (IC50=49.33mg/L) compared to references. However, extracts exhibited a poor anti-Alzheimer and antidiabetic activities. Chloroform extract exhibited a higher anticancer activity (IC50=20mg/L). We observed high correlations between phenolics and flavonoids with antioxidant and anti-inflammatory activities (0.75<R2<0.97). Finally, a very good correlation between anti-inflammatory activity and antioxidant activity with R2=0.99. It may be interpreted that the greatest anti-inflammatory activity was excreted by the best antioxidants extracts, which contain the high amounts of total phenolics.