Efficacy of Emu Oil Transfersomes for Local Transdermal Delivery of 4-OH Tamoxifen in the Treatment of Breast Cancer

Oral tamoxifen used in the prevention and treatment of ductal carcinoma in situ (DCIS) (estrogen-positive) patients has limited acceptance, due to its adverse side effects. The efficacy of tamoxifen is related to its major metabolite, 4-hydroxytamoxifen. Local transdermal therapy of 4-hydroxytamoxifen to the breast might avert the toxicity of oral tamoxifen, while maintaining efficacy. We aim to study the skin irritancy, as well as to evaluate the efficacy of the developed transfersome formulations, with/without emu oil, using a syngeneic mouse model of breast cancer. We also quantified tamoxifen/4-hydroxytamoxifen concentrations in blood plasma and performed histopathology. The skin irritancy test showed that the pure emu oil and transfersome formulations with or without the emu oil did not cause skin irritancy in the animals studied. A sensitive and specific LC–MS/MS method for the quantification of tamoxifen and 4-hydroxytamoxifen was developed and validated. Studies on tumor volume and necrosis (histopathology) using the breast cancer mouse model showed that the 4-OHT transfersomal formulations, with and without emu oil, showed comparable efficacy with that of orally administered tamoxifen. However, the transfersomal formulations, with and without emu oil, resulted in significantly lower (10.24 ± 0.07 and 32.45 ± 0.48 ng/mL, respectively) plasma concentrations of 4-hydroxytamoxifen, compared to the oral tamoxifen (TAMX) group (634.42 ± 7.54 ng/mL). This study demonstrated the potential use of emu oil in a local transdermal formulation for the treatment of breast cancer and its reduced adverse effects.

The influence of age and gender on emu (Dromaius novaehollandiae) fat

Studies were carried out to determine the influence of age and sex on two types of fat (back fat and abdominal fat) in the emu, as these are factors that influence the composition of animal tissues. The material involved 26 emus at the age 1 (6 males), 3 (6 males) and 15 years (8 females and 6 males), kept on the same farm and fed the feed of the same nutritional value. The basic chemical composition, cholesterol and mineral content, as well as fatty acid profile of back and abdominal fat of emu were determined. Abdominal fat was characterized by higher content of fat and ash, as well as Mn and Ba. Back fat, on the other hand, showed a higher level of protein, cholesterol, C16:1 and the elements K, P, Si, Na, Ca, Mg, Fe, Zn, Se and Cu. With age, regardless of the type of fat tissue, fat content decreased and water content increased. The highest content of protein, ash, cholesterol, some fatty acids (C18:0, C18:1n9c, C18:2n6c), generally higher content of MUFA, PUFA and the elements K, P, Ca, Mg, Fe, Zn, Pb, Se, Cr, Cd, were found in the fatty tissue of 15-year-old emus. Sex did influence the content of Si, Ca, Cu, Sr, which was higher in the fatty tissue of males. The composition of emu storage fat is determined by factors such as age, sex and the location of the fat tissue in the body.