Decreasing the Ratio of Dietary Linoleic to α-Linolenic Acid from 10 to 4 by Changing Only the Former Does Not Prevent Adiposity or Bone Deterioration in Obese Mice

Incorporation of Whole or Milled Dry Edible Beans into a High-Fat Diet Improves Bone Structure in Obese Mice

BACKGROUND

Pulses, a healthy diet component, have many bone-beneficial nutrients.

OBJECTIVES

This study investigated whether incorporation of dried pulses to a high-fat diet improves bone metabolism in obese mice.

METHODS

Male C57BL/6 mice at 4-wk-old were randomly assigned to 4 diet groups (n = 22-24/group) for 12 wk: a normal-fat (NF; 4.1 kcal/g and 16% energy as fat), a HF (4.9 kcal/g and 48% energy as fat), or a HF containing either whole beans (HFWB) or milled bean flour (HFMB) at 15% wt/wt. Diets containing beans had similar total energy, protein, and fiber content as the HF without beans. Bone structure and related biomarkers were measured. Data were analyzed using a 1-way analysis of variance followed by Tukey-Kramer post hoc contrasts.

RESULTS

Mice fed the HFWB or HFMB but not the HF had higher lean mass than those fed the NF (P < 0.05, 9.1% and 8.7%, for HFWB and HFMB, respectively). Mice fed the HF, HFWB, or HFMB had 23%, 14%, and 12% lower tibial bone volume/total volume (P < 0.05), respectively, than those on the NF. Mice fed the HF but not the HFWB or HFMB had 9.2% lower bone volume/total volume in the second lumbar vertebrae than those fed the NF (P < 0.05). Pooled HF with bean groups had 18%, 14%, 27%, 17%, and 15% greater body weight, fat mass, plasma concentrations of tartrate-resistant acid phosphatase, C-terminal telopeptide of type 1 collagen, blood glucose than the HF alone, respectively (P < 0.05). Milled bean flour had a greater impact on body weight, fat mass, tibial structural model index, circulating leptin, and glucose than whole bean relative to the HF alone.

CONCLUSIONS

These data indicate that the incorporation of dry edible beans into a HF mitigates but does not fully prevent bone deterioration in obese mice.

Effect of Fatty Acids on Backfat Quality in Beijing Black Pigs

The quality of pig backfat affects both pork quality and consumer preferences. Fatty acids (FAs) are crucial in determining the backfat quality. This study assessed the effect of FAs on the backfat quality and identified candidate genes associated with these FAs. The differential fatty acids (DFAs) were compared in pigs with varying backfat firmness and four DFAs-caproic acid, stearic acid, linoleic acid and alpha-linolenic acid-were selected based on T-tests (p < 0.05), fold changes (FC > 2 or FC < 0.5), and variable importance (VIP > 1). Genome-wide association studies on the DFAs and linoleic acid/alpha-linolenic acid ratios in 413 Beijing Black pigs identified 22 single-nucleotide polymorphisms significantly associated with one or more traits. The genes PLPP3, MGLL, CYP27A1 and UBE3C were identified as candidates associated with these traits influencing the backfat quality. These findings enhance our understanding of the backfat quality in Beijing Black pigs and provide a basis for further research.

ω-9 monounsaturated fatty acids in Sapindus mukorossi seed oil enhance calcium deposition expression of Wharton's jelly mesenchymal stem cells

Promoting osteogenesis is crucial to improve successful bone regeneration in bone tissue engineering. Several studies on osteogenesis have reported positive effects of ω-9 monounsaturated fatty acids (MUFA) on bone regeneration. This study examined the potential of ω-9 monounsaturated fatty acid abundant seed oil mechanically extracted from Sapindus mukorossi (S. mukorossi) fruit to improve osteogeneses. After showing the presence of ω-9 MUFA in S. mukorossi seed oil (SM oil) through GC-MS spectrum analysis, the proliferation and differentiation of human umbilical cord Wharton's jelly mesenchymal stem cells (WJMSCs) under SM treatment was evaluated. Our results indicate that WJMSC differentiation was induced by adding an osteogenesis-induced medium combined with SM oil. A high level of calcium deposition expression in WJMSCs induced by SM oil appears to be due to the effect of oleic acid and eicosenoic acid, both of which are ω-9 monounsaturated fatty acids. In addition, we found major contributors of SM oil-promoted WJMSC osteogenesis to be extracellular signal-regulated kinase (ERKs), c-Jun N-terminal kinase (JNKs), and the p38 MAPK pathway. The enhancement of WJMSC osteogenesis via ERK/MAPK pathways as demonstrated by qPCR analysis indicates the promise of SM oil for stem cell-based bone tissue engineering applications.

Effects of Sapindus mukorossi Seed Oil on Bone Healing Efficiency: An Animal Study

Natural products have attracted great interest in the development of tissue engineering. Recent studies have demonstrated that unsaturated fatty acids found in natural plant seed oil may exhibit positive osteogenic effects; however, few in vivo studies have focused on the use of plant seed oil for bone regeneration. The aim of this study is to investigate the effects of seed oil found in Sapindus mukorossi (S. mukorossi) on the osteogenic differentiation of mesenchymal stem cells and bone growth in artificial bone defects in vivo. In this study, Wharton-jelly-derived mesenchymal stem cells (WJMSCs) were co-cultured with S. mukorossi seed oil. Cellular osteogenic capacity was assessed using Alizarin Red S staining. Real-time PCR was carried out to evaluate ALP and OCN gene expression. The potential of S. mukorossi seed oil to enhance bone growth was assessed using an animal model. Four 6 mm circular defects were prepared at the parietal bone of New Zealand white rabbits. The defects were filled with hydrogel and hydrogel-S. mukorossi seed oil, respectively. Quantitative analysis of micro-computed tomography (Micro-CT) and histological images was conducted to compare differences in osteogenesis between oil-treated and untreated samples. Although our results showed no significant differences in viability between WJMSCs treated with and without S. mukorossi seed oil, under osteogenic conditions, S. mukorossi seed oil facilitated an increase in mineralized nodule secretion and upregulated the expression of ALP and OCN genes in the cells (p < 0.05). In the animal study, both micro-CT and histological evaluations revealed that new bone formation in artificial bone defects treated with S. mukorossi seed oil were nearly doubled compared to control defects (p < 0.05) after 4 weeks of healing. Based on these findings, it is reasonable to suggest that S. mukorossi seed oil holds promise as a potential candidate for enhancing bone healing efficiency in bone tissue engineering.

How high-fat diet affects bone in mice: A systematic review and meta-analysis

High-fat diet (HFD) feeding for mice is commonly used to model obesity. However, conflicting results have been reported on the relationship between HFD and bone mass. In this systematic review and meta-analysis, we synthesized data from 80 articles to determine the alterations in cortical and trabecular bone mass of femur, tibia, and vertebrae in C57BL/6 mice after HFD. Overall, we detected decreased trabecular bone mass as well as deteriorated architecture, in femur and tibia of HFD treated mice. The vertebral trabecula was also impaired, possibly due to its reshaping into a more fragmentized pattern. In addition, pooled cortical thickness declined in femur, tibia, and vertebrae. Combined with changes in other cortical parameters, HFD could lead to a larger femoral bone marrow cavity, and a thinner and more fragile cortex. Moreover, we conducted subgroup analyses to explore the influence of mice's sex and age as well as HFD's ingredients and intervention period. Based on our data, male mice or mice aged 6-12 weeks old are relatively susceptible to HFD. HFD with > 50% of energy from fats and intervention time of 10 weeks to 5 months are more likely to induce skeletal alterations. Altogether, these findings supported HFD as an appropriate model for obesity-associated bone loss and can guide future studies.

The review of alpha-linolenic acid: Sources, metabolism, and pharmacology

α-linolenic acid (ALA, 18:3n-3) is a carboxylic acid composed of 18 carbon atoms and three cis double bonds, and is an essential fatty acid indispensable to the human body. This study aims to systematically review related studies on the dietary sources, metabolism, and pharmacological effects of ALA. Information on ALA was collected from the internet database PubMed, Elsevier, ResearchGate, Web of Science, Wiley Online Library, and Europe PMC using a combination of keywords including "pharmacology," "metabolism," "sources." The following findings are mainly contained. (a) ALA can only be ingested from food and then converted into eicosapentaenoic acid and docosahexaenoic acid in the body. (b) This conversion process is relatively limited and affected by many factors such as dose, gender, and disease. (c) Pharmacological research shows that ALA has the anti-metabolic syndrome, anticancer, antiinflammatory, anti-oxidant, anti-obesity, neuroprotection, and regulation of the intestinal flora properties. (d) There are the most studies that prove ALA has anti-metabolic syndrome effects, including experimental studies and clinical trials. (e) The therapeutic effect of ALA will be affected by the dosage. In short, ALA is expected to treat many diseases, but further high quality studies are needed to firmly establish the clinical efficacy of ALA.

Do polyunsaturated fatty acids protect against bone loss in our aging and osteoporotic population?

Age-related bone loss is inevitable in both men and women and there will soon be more people of extreme old age than ever before. Osteoporosis is a common chronic disease and as the proportion of older people, rate of obesity and the length of life increases, a rise in age-related degenerating bone diseases, disability, and prolonged dependency is projected. Fragility fractures are one of the most severe complications associated with both primary and secondary osteoporosis and current treatment strategies target weight-bearing exercise and pharmacological intervention, both with limited long-term success. Obesity and osteoporosis are intimately interrelated, and diet is a variable that plays a significant role in bone regeneration and repair. The Western Diet is characterized by its unhealthy components, specifically excess amounts of saturated fat intake. This review examines the impact of saturated and polyunsaturated fatty acid consumption on chronic inflammation, osteogenesis, bone architecture, and strength and explores the hypothesis that dietary polyunsaturated fats have a beneficial effect on osteogenesis, reducing bone loss by decreasing chronic inflammation, and activating bone resorption through key cellular and molecular mechanisms in our aging population. We conclude that aging, obesity and a diet high in saturated fatty acids significantly impairs bone regeneration and repair and that consumption of ω-3 polyunsaturated fatty acids is associated with significantly increased bone regeneration, improved microarchitecture and structural strength. However, ω-6 polyunsaturated fatty acids were typically pro-inflammatory and have been associated with an increased fracture risk. This review suggests a potential role for ω-3 fatty acids as a non-pharmacological dietary method of reducing bone loss in our aging population. We also conclude that contemporary amendments to the formal nutritional recommendations made by the Food and Nutrition Board may be necessary such that our aging population is directly considered.