2.2. Preparation of plant extract
The leaves of M. piperita were washed thoroughly thrice with
distilled water and were shade dried for 5 days. The fine powder
was obtained from the dried leaves by using kitchen blender. The
leaf powder was sterilized at 121 ◦C for 15 min. 20 g of powder
was taken and mixed with 200 ml of Milli Q water and kept in
boiling water bath at 60 ◦C for 10 min. The extracts were filtered
with Whatman filter paper No 1. The filtered extract was stored in
refrigerator at 4 ◦C for further studies.