Purpose: Body adiposity is negatively correlated with hepatic iron status, and Korean pine nut oil (PNO) has been reported to reduce adiposity. Therefore, we aimed to study the effects of PNO on adiposity, hepatic mineral status, and the expression of genes and proteins involved in iron absorption. Methods: Five-week-old male C57BL/6 mice were fed a control diet containing 10% kcal from PNO (PC) or soybean oil (SBO; SC), or a high-fat diet (HFD) containing 35% kcal from lard and 10% kcal from PNO (PHFD) or SBO (SHFD). Hepatic iron, copper, and zinc content; and expression of genes and proteins related to iron absorption were measured. Results: HFD-fed mice had a higher white fat mass (2-fold; p < 0.001), lower hepatic iron content (25% lower; p < 0.001), and lower hepatic Hamp (p = 0.028) and duodenal Dcytb mRNA levels (p = 0.037) compared to the control diet-fed mice. Hepatic iron status was negatively correlated with body weight (r = −0.607, p < 0.001) and white fat mass (r = −0.745, p < 0.001). Although the PHFD group gained less body weight (18% less; p < 0.05) and white fat mass (18% less; p < 0.05) than the SHFD group, the hepatic iron status impaired by the HFD feeding did not improve. The expression of hepatic and duodenal ferroportin protein was not affected by the fat amount or the oil type. PNO-fed mice had significantly lower Slc11a2 (p = 0.022) and Slc40a1 expression (p = 0.027) compared to SBO-fed mice. However, the PC group had a higher Heph expression than the SC group (p < 0.05). The hepatic copper and zinc content did not differ between the four diet groups, but hepatic copper content adjusted by body weight was significantly lower in the HFD-fed mice compared to the control diet-fed mice. Conclusion HFD-induced obesity decreased hepatic iron storage by affecting the regulation of genes related to iron absorption; however, the 18% less white fat mass in the PHFD group was not enough to improve the iron status compared to the SHFD group. The hepatic copper and zinc status was not altered by the fat amount or the oil type.

BACKGROUND/OBJECTIVES: Korean pine nut oil (PNO) has been reported to suppress appetite by increasing satiety hormone release. However, previous studies have rendered inconsistent results and there is lack of information on whether dietary Korean PNO affects the expression of satiety hormone receptors and hypothalamic neuropeptides. Therefore, our study sought to evaluate the chronic effects of Korean PNO on the long-term regulation of energy balance.MATERIALS/METHODS: Five-week-old male C57BL/6 mice were fed with control diets containing 10% kcal fat from Korean PNO or soybean oil (SBO) (PC or SC) or high-fat diets (HFDs) containing 35% kcal fat from lard and 10% kcal fat from Korean PNO or SBO (PHFD or SHFD) for 12 weeks. The expression of gastrointestinal satiety hormone receptors, hypothalamic neuropeptides, and genes related to intestinal lipid absorption and adipose lipid metabolism was then measured. RESULTS: There was no difference in the daily food intake between PNO- and SBO-fed mice; however, the PC and PHFD groups accumulated 30% and 18% less fat compared to SC and SHFD, respectively. Korean PNO-fed mice exhibited higher messenger RNA (mRNA) expression of Ghsr (ghrelin receptor) and ,Agrp (agouti-related peptide) (P < 0.05), which are expressed when energy consumption is low to induce appetite as well as the appetitesuppressing neuropeptides Pomc and Cartpt (P = 0.079 and 0.056, respectively). Korean PNO downregulated jejunal Cd36 and epididymal Lpl mRNA expressions, which could suppress intestinal fatty acid absorption and fat storage in white adipose tissue. Consistent with these findings, Korean PNO-fed mice had higher levels of fecal non-esterified fatty acid excretion. Korean PNO also tended to downregulate jejunal Apoa4 and upregulate epididymal Adrb3 mRNA levels, suggesting that PNO may decrease chylomicron synthesis and induce lipolysis. CONCLUSIONS In summary, Korean PNO attenuated body fat accumulation, and appeared to prevent HFD-induced dysregulation of the hypothalamic appetite-suppressing pathway.

BACKGROUND/OBJECTIVES: Consumption of pine nut oil (PNO) was shown to reduce weight gain and attenuate hepatic steatosis in mice fed a high-fat diet (HFD). The aim of this study was to examine the effects of PNO on both intestinal and hepatic lipid metabolism in mice fed control or HFD. MATERIALS/METHODS: Five-week-old C57BL/6 mice were fed control diets containing 10% energy fat from either Soybean Oil (SBO) or PNO, or HFD containing 15% energy fat from lard and 30% energy fat from SBO or PNO for 12 weeks. Expression of genes related to intestinal fatty acid (FA) uptake and channeling (Cd36, Fatp4, Acsl5, Acbp), intestinal chylomicron synthesis (Mtp, ApoB48, ApoA4), hepatic lipid uptake and channeling (Lrp1, Fatp5, Acsl1, Acbp), hepatic triacylglycerol (TAG) lipolysis and FA oxidation (Atgl, Cpt1a, Acadl, Ehhadh, Acaa1), as well as very low-density lipoprotein (VLDL) assembly (ApoB100) were determined by real-time PCR. RESULTS: In intestine, significantly lower Cd36 mRNA expression (P < 0.05) and a tendency of lower ApoA4 mRNA levels (P = 0.07) was observed in PNO-fed mice, indicating that PNO consumption may decrease intestinal FA uptake and chylomicron assembly. PNO consumption tended to result in higher hepatic mRNA levels of Atgl (P = 0.08) and Cpt1a (P = 0.05). Significantly higher hepatic mRNA levels of Acadl and ApoB100 were detected in mice fed PNO diet (P < 0.05). These results suggest that PNO could increase hepatic TAG metabolism; mitochondrial fatty acid oxidation and VLDL assembly. CONCLUSIONS: PNO replacement in the diet might function in prevention of excessive lipid uptake by intestine and improve hepatic lipid metabolism in both control diet and HFD fed mice.
Animals ; Apolipoprotein B-48 ; Diet ; Diet, High-Fat ; Intestines ; Lipid Metabolism* ; Lipolysis ; Lipoproteins ; Liver ; Metabolism ; Mice* ; Nuts* ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Soybean Oil ; Triglycerides ; Weight Gain

Korean pine nut oil (PNO) has been reported to have favorable effects on lipid metabolism and appetite control. We investigated whether PNO consumption could influence weight gain, and whether the PNO-induced effect would result in an improvement of immune function in high-fat diet (HFD)-induced obese mice. C57BL/6 mice were fed control diets with 10% energy fat from either PNO or soybean oil (SBO), or HFDs with 45% energy fat from 10% PNO or SBO and 35% lard, 20% PNO or SBO and 25% lard, or 30% PNO or SBO and 15% lard for 12 weeks. The proliferative responses of splenocytes upon stimulation with concanavalin A (Con A) or lipopolysaccharide (LPS), Con A-stimulated production of interleukin (IL)-2 and interferon (IFN)-gamma, and LPS-stimulated production of IL-6, IL-1beta, and prostaglandin E2 (PGE2) by splenocytes were determined. Consumption of HFDs containing PNO resulted in significantly less weight gain (17% less, P < 0.001), and lower weight gain was mainly due to less white adipose tissue (18% less, P = 0.001). The reduction in weight gain did not result in the overall enhancement in splenocyte proliferation. Overall, PNO consumption resulted in a higher production of IL-1beta (P = 0.04). Replacement of SBO with PNO had no effect on the production of IL-2, IFN-gamma, IL-6, or PGE2 in mice fed with either the control diets or HFDs. In conclusion, consumption of PNO reduced weight gain in mice fed with HFD, but this effect did not result in the overall improvement in immune responses.
Adipose Tissue, White ; Animals ; Appetite ; Concanavalin A ; Diet ; Diet, High-Fat ; Dietary Fats ; Dinoprostone ; Interferons ; Interleukin-2 ; Interleukin-6 ; Interleukins ; Lipid Metabolism ; Mice ; Mice, Obese ; Nuts ; Obesity ; Soybean Oil ; Weight Gain