2.2. Plant material and extract preparation
The T. chebula fruits were collected from a local
market of Ahmedabad, India, during January 2012 and
were taxonomically identified and authenticated as T.
chebula fruits by Dr. Yogesh T. Jasrai, Department of
Botany, Gujarat University, India. A voucher specimen
was deposited in the herbarium for future reference (Ref.
No. GU/2013/53).
The T. chebula fruits were thoroughly cleaned,
dried under the shade and coarsely powdered. The
polyphenolic-rich extract was prepared according to a
previously reported method [20]. The powdered plant
material was mixed with 70% methanol and stored at
room temperature for 5 days. After 5 days, it was filtered
and the solvent was evaporated. The residue was dissolved
in water, and the aqueous layer was washed with
petroleum ether several times until a clear upper layer of
petroleum ether was obtained. The lower layer was then
treated with ethyl acetate containing glacial acetic acid
(10 mL/L). Extraction of the polyphenols was performed
for 36 h at room temperature, and the combined ethyl
acetate layer was then concentrated. The residue was
lyophilised. The extract obtained was dried and stored in
an airtight container at 4 ◦C. The yield of the dry polyphenolic
extract was 30.5% (w/w). The dried extract was
dissolved in Milli-Q water and used for further study.