Test materials
T. tuberculata Beumee plants used in this study were obtained from
the Herbal Garden of Universiti Putra Malaysia (02°59′ N, 101°43′ E
and 64mabove sea level), Selangor,Malaysia.Mature plants (excluding
roots) were harvested, cleaned several times with tap water and airdried
for 3 weeks. The plants were separated and bulked into the two
major parts, leaf and stem. Both bulked plant parts were then ground
into a fine powder in a laboratory blender and sieved through a
40 mesh sieve.