Effects of pine needle extract on differentiation of 3T3-L1 preadipocytes and obesity in high-fat diet fed rats

The present study examined the anti-obesity effects of pine needle extract (PNE) in 3T3-L1 preadipocytes and in vivo studies. PNE treatment suppressed both glycerol-3-phosphate dehydrogenase activity and expression of peroxisome proliferator-activated receptor (PPAR) gamma in cultured 3T3-L1 adipocytes. To investigate the effect of PNE on obesity in rats fed high-fat diet, four types of diet, which included a normal diet (ND), high-fat diet (HFD), ND+PNE, and HFD+PNE diets, were fed to the rats ad libitum for 6 weeks. The PNE supplement significantly decreased body weight gain and visceral fat mass compared to the HFD group. The total cholesterol, TG, and leptin levels in the plasma were significantly reduced by PNE supplementation compared with those of the HFD group. Histological findings in liver tissue showed that PNE supplementation alleviated steatosis induced by HFD. In conclusion, PNE treatment suppressed differentiation of 3T-L1 adipocytes, in part by down-regulating expression of PPAP gamma mRNA, and reduced adipose tissue mass, hyperlipidemia, and hepatic steatosis in obese rats fed HFD. Therefore, pine needle water extract may be considered for use in therapy to control obesity.