Protein glycation inhibitory activities of Lawsonia inermis and its active principles.

The protein glycation inhibitory activity of ethanolic extract of Lawsonia inermis (henna) plant tissues was evaluated in vitro using the model system of bovine serum albumin and glucose. Protein oxidation and glycation are posttranslational modifications that are implicated in the pathological development of many age-related disease processes. This study investigated the effects of Lawsonia inermis ethanolic extract and its components, on protein damage induced by a free radical generator in in vitro assay system. We found that alcoholic extract of Lawsonia inermis can effectively protect against protein damage and showed that its action is mainly due to Lawsone. In addition, the presence of gallic acid also plays an important role in the protective activity against protein oxidation and glycation. Two known compounds, namely, Lawsone and gallic acid previously isolated from this plant were subjected to glycation bioassay for the first time. It was found that the alcoholic extract, lawsone (1) and gallic acid (2) showed significant inhibition of Advanced Glycated End Products (AGEs) formation and exhibit 77.95%, 79.10% and 66.98% inhibition at a concentration of 1500 microg/mL, 1000 microg/mL and 1000 microM respectively. Lawsonia inermis, compounds 1 and 2 were found to be glycation inhibitors with IC(50) 82.06 +/- 0.13 microg/mL, 67.42 +/- 1.46 microM and 401.7 +/- 6. 23 microM respectively. This is the first report on the glycation activity of these compounds and alcoholic extract of Lawsonia inermis.