Type 2 diabetes mellitus has become one of the most com-
mon endocrine diseases in clinics worldwide, and accounts for
90% of the overall incidence of diabetes [1]. A significant number
of people diagnosed with Type 2 diabetes will develop complica-
tions secondary to hyperglycemia. The importance of developing
methods for managing and treating diabetes is becoming more
urgent. If appropriate therapy is not available, people will face
more serious health and social problems. Plants have been an
exemplary source of pharmaceutical treatment for diabetes, and
many of the currently available drugs have been derived directly
or indirectly from them. It is reported that about 800 plants may
possess anti-diabetic potential [2]. For example, Ning Yang et al.
[3] have demonstrated that polysaccharides of Opuntia monacantha
cladode (POMC) extract have beneficial hypoglycemic properties
in streptozotocin-induced diabetic rats, the mechanism of which
might be similar to that of the anti-diabetic agent dimethyl-
biguanide. Wang et al. [4] have confirmed the anti-diabetic effect of