highly significantp < 0.01
Significant levels were considered at p < 0.05 and highly significant level at p < 0.01 comparing with control group. 2.5 Mass spectrometric analysis of the selected cytotoxic fractions 2.5.1 Sample fractionation Individual selected fractions were fractionated based on their molecular size using Macrosep® 3 K, 10 K and 50 K Omega centrifugal devices (Pall Life Sciences, USA) into four sub-fractions: lower than 3 kDa, between 3 and 10 kDa, between 10 and 50 kDa, and larger than 50 kDa sub-fractions.