For γH2AX assay, remaining 2 mL of blood was reconstituted with 18 mL of RPMI-1640 culture medium and equally aliquoted into four sterile vials. Decoction at a concentration of 100 μg/mL was then added to two vials (decoction control and test) and all vials were incubated at 37°C in 5% CO2 for 3 hrs. At the end of the 3rd hour, bleomycin at a concentration of 40 μg/mL was added to (a) a vial containing the decoction (test) and (b) a vial without the decoction (positive control). Subsequently, all vials were incubated for further 2 hrs and lymphocytes were isolated by layering 4 mL aliquot from each vial on to 2 mL of Histopaque–1077 and centrifuged at 1000g for 5 min at room temperature.