Effects of extraction solvent system, time and temperature on total phenolic content of henna (Lawsonia inermis) stems.

Abstract

Henna plant (
\nLawsonia inermis
\n) is an Indian medicinal plant used in traditional medicine for
\nthe treatment of various diseases, besides its popularity as a natural dye to colour hand and hair.
\nResearch in the recent past has accumulated enormous evidence revealing henna plant to be
\nan excellent source of antioxidants such as total phenolics. In this study, the extraction of total
\nphenolics from henna stems was evaluated using the Folin-Ciocalteu assay. A set of single factor
\nexperiments was carried out for identifying the optimum condition of each independent variable
\naffecting total phenolic content (TPC) extraction efficiency of henna stems, namely the solvent
\ntype, solvent concentration (v/v, %), extraction time (min) and extraction temperature (
\no
\nC).
\nGenerally, high extraction yield was obtained using aqueous acetone (about 40%) as solvent
\nand the extraction yield could further be increased using a prolonged time of 270 min and a
\nhigher incubation temperature of 55°C. Under these optimized conditions, the experimental
\nmaximum yield of TPC of 5554.15 ± 73.04 mg GAE/100 g DW was obtained.