has been an enhanced focus on exploring indigenous medicinal plants with
antidiabetic potential so that a low cost, safer, and effective alternative strategy to
insulin and other synthetic compounds for diabetes management can be realized.
Hypoglycemic effects of several plants used to treat diabetes are already known and
the underlying mechanisms of the observed affects are also being worked out (Patel
et al. 2012 ). Recently, Mohammed et al. ( 2016 ), in a comprehensive study, eval-
uated antidiabetic activity ofCoccinia grandisagainst streptozotocin-induced dia-
betic rats. Treatment of diabetic rats withCoccinia grandisleaf ethanolic extract
(500 mg/kg) for 21 days showed significant reduction in blood glucose level,
increase in body weight and serum insulin in a dose dependent manner. Diabetes
induced hypercholesteremia and hypertriglyceridemia, which can lead to secondary
complications, were also found to be significantly improved as a result of treatment.
Marked recovery was also recorded in liver and kidney function tests of diabetic
rats. The study demonstrated a strong antioxidant activity of the ethanolic leaf
extract of the plant. It should be pointed out here that oxidative stress is a natural
consequence of chronically elevated blood glucose level and thus, compliments
diabetes (Rahimi et al. 2005 ). Baldea et al. ( 2010 ) evaluated antidiabetic activity of
crude ethanolic extract of 17 Boreal forest medicinal plants by in vitro on Caco-2
human enterocylic cell lines and in vivo on normal rats by oral administration of
250 mg/kg body weight of extract. In in vitro experiments, of the 17 plants, 13
showed approximately 40% decreased glycaemia and another 2 plants showed
reduction in intestinal glucose absorption in rats. Similarly, antidiabetic activity of
Allium cepa,Allium sativum, andZingiber officinaleaqueous extract was evaluated
against alloxan-induced diabetic rats. All three plant extracts showed decrease in
blood glucose level in treated diabetic rats as compared to control rats (Eyo et al.
2011 ). A comprehensive list of studies of the last 5–6 years on antidiabetic activ-
ities of plant/plant extracts demonstrating the interest and scope in thefield is given
in Table10.3.
10.4.1 Antidiabetic Compounds from Fungal Endophytes
Dhankar et al. ( 2013 ) demonstrated the antidiabetic and hypolipidemic activity of
endophytic fungi,Aspergillussp. andPhomasp. isolated fromSalvadora oleoides
(Salvadoraceae). The study showed that 2,6-di-tert-butyl-p-cresol and Phenol,
2,6-bis [1,1-dimethylethyl]-4-methyl, isolated from the broth extract of endophytic
fungi, significantly reduce blood glucose level in glucose loaded, fasting and al-
loxan-induced diabetic Wistar albino rats. Bioactivity-guided fractionation of the
culturefiltrate of an endophytic fungus,Dendryphion nanum,isolated fromFicus
religiosayielded a compound herbarine 1 and its analogue herbaridine A2 showing
promising antidiabetic activities. Both of them were found to be naphthaquinones
(Mishra et al. 2013 ).
Berberine from several medicinal plants is a compound known for its cardio-
protective, antidiabetic, antibiotic, and antitumor roles (Sun et al. 2009 ). Recently, it
222 S.I. Mohammed et al.