Scientists from Korea have administered bitter orange (Jigak in Korean) to mice fed a high-fat diet to study it as a potential therapeutic target for obesity management.
The findings were published in the journal Nutrients.
Mice were fed with a 60% kcal high fat diet (HFD) for four weeks to induce obesity.
They were divided into two groups (n=5) and fed for eight additional weeks with either HFD or HFD + CA (100mg/kg/day).
A control group was fed a normal diet (ND) for 12 weeks.
The weight of the mice were measured twice a week, and blood were taken to measure HDL, LDL, and total cholesterol.
CA effect on body weight gain
The research reported that the body weights of HFD and HFD + CA group (50.31 ± 0.84g vs. 40.91 ± 0.91 g, respectively) were significantly different after 12 weeks.
The researchers said this could suggest CA can regulate the weight of HFD-fed mice.
CA was also found to reduce adipose tissue weight in CA-treated obese mice, decreasing significantly by 35% (p = 0.0143).
The total cholesterol level was also significantly reduced by CA in HFD-fed mice (p < 0.05).
The researchers said CA might directly suppress adipogenesis of white adipocytes and regulate thermogenesis of brown adipocytes which were both attractive targets of anti-obese strategy.
The findings showed that CA (1000 μg/ml) could suppress lipid accumulation, and reduce mRNA expression involved in white adipogenesis.
Adipocyte differentiation or adipogenesis is the process by which pre-adipocytes become adipocytes (lipocytes or fat cells).
White adipose tissue are mostly used for storing excess calories.
“In addition, CA treatment reduced levels of PPARγ and C/EBPα, which are both well-known key regulators of adipocyte differentiation,” they said.
The paper also reported that CA could regulate thermogenesis of brown adipocytes. According to the researchers, brown fat specialise in energy expenditure to reduce weight gain through thermogenesis (heat producing).
They said, “Our findings revealed that administration of CA significantly reduced body weight in obese mice, suggesting that CA may be a potential option as an intervention to fight obesity.”
Potential of CA
Also known as sour orange or marmalade orange, CA is available on the market as a beverage and dietary supplement.
There are many studies on its anti-cancer and anti-oxidant effects of CA, but until this paper there were no studies on CA’s mechanism on improving obesity.
“Bitter Orange (Citrus aurantium Linné) Improves Obesity by Regulating Adipogenesis and Thermogenesis through AMPK Activation”
Authors: Park, et al.