ANTI-NUTRITIONAL CONSTITUENT OF COLOCASIA ESCULENTA ...

decreased by sitosterols as a result of their affect on membrane fluidity (Silva et al.,
2005). Increased Na+JK+-ATPase activity generates an inward sodium ion gradient that
leads to increased glucose translocation across the cell membrane (Omoruyi, 1991). A
reduction in ATPase activity can result in lowered glucose translocation from the
intestine into blood. This could be useful in the treatment of diabetics (McAnuff et al.,
2005).
When rats fed with beta-sitosterol were compared with rats fed the oleic-acid and/or
distilled water control diet, a significant inhibitory change was observed. Upper intestinal
sucrase and maltase and both proximal and distal intestinal lactase activity showed a
significant inlnbitory effect (p>O.05). The dissemination of disaccharidase activities
among mammals is extremely diverse (Martinez del Rio and Stevens, 1988). The
distnbution pattem of the disaccharidases along the small intestine is also significantly
influenced by the locus of disaccharide hydrolysis because the location of optimum
activity presumably reflects the site of absorption. A number of mammals have showed
this inconsistent distrIbution of disaccharidase activity along the small intestine
(Dahlqvist, 1964; Malhotra and Philip, 1964, 1965).
This non-uuiform distribution of disaccharidase activity along the small intestine was
also observed in this study. The modified changes in enzyme activity of the small
intestine depend on various exogenous factors (McCarthy et aI., 1980). These
disaccharide mucosal enzymes are physiologically necessary in the digestion of food
consumed for assimilation. They provide essential nutrients for maintenance and rapid
growth (Lee et aI., 2003). Reduced disaccharidase activity is indicated by reduced blood
glucose levels from less absorbable glucose formed from carbohydrate digestion
(McAnuff et aI., 2005). There are other factors that can influence disaccharidase
activities, such as obesity and age (Flores et aI., 1990), hormones (Raul et al., 1984) and
a decrease ofluminal proteases (Zarling and Mobarhan, 1987). Thus, with a decrease in
the blood-glucose levels of the rats treated with beta-sitosterol, the decreasing effect on
the activities ofthe disaccharidase and ATPase could suggest the value ofbeta-sitosterol
an as anti-diabetic (hypoglycemic) agent.
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