An extract of eastern Nigeria mistletoe, Loranthus micranthus Linn modulates dexamethasone-induced insulin resistance and exhibit potent osteogenic activity in vitro and in animal experimental model
Recently, we demonstrated potent in vitro osteogenic potentials of different mistletoe extracts and compounds. In the present study, we evaluated the ability of the extract to reverse the deterioration of bone functions occasioned by prolonged therapy with dexamethasone (200 µg/kg i.p) in mature Sprague-Dawley (SD) rats of both sexes. They were treated at doses of 100, 200 or 400 mg/kg daily for 16 – 21 days. The results demonstrated that rats treated with extracts alone had comparable growth rate to the vehicle and positive (Metformin) controls and at the dose of 400 mg/kg, significantly (**p < 0.01) reversed severe weight loss caused by dexamethasone. Dexamethasone treatment increased triglycerides levels by 98.75% compared to vehicle group and extract alone (p < 0.001) treated but in combination with extracts at 400 mg/kg caused a significant (p < 0.05) reduction (44.79%) in amount of circulating triglycerides in serum and preserved serum calcium levels. Data derived from the microarchitectural determination of excised bones showed that the extract (400 mg/kg) in combination with dexamethasone showed better bone mineral density of 1.7532 ± 0.0002*** versus 1.6060 ± 0.0004 for vehicle at the weight-bearing L5 vertebrae. Mistletoe extracts therefore enhanced and preserved bone compactness (quality) of SD rats treated alone with extracts or in combination with 200 µg/kg dexamethasone. The present findings further support the use of mistletoe as an antidiabetic plant with osteogenic potentials.
 Osadebe, P.O. and Omeje, E.O. (2009). Comparative toxicities and immunomodulatory potentials of five Eastern Nigeria mistletoes, J. Ethnopharmacol., 126:287 – 293.