Beneficial effect of dietary geranylgeraniol on glucose homeostasis and bone microstructure in obese mice is associated with suppression of proinflammation and modification of gut microbiome

One-step ultrasound-assisted recovery of yellow-orange-red natural coloring from defatted annatto seeds: A cleaner processing alternative

The interest in natural colorants derived from sustainable processes has prompted research into obtaining bixin from defatted annatto (Bixa orellana L.) seeds. Bixin is a compound that imparts yellow-orange-red coloration, known for its high biodegradability, low toxicity, and wide industrial applicability. Meanwhile, high-intensity ultrasound (HIUS) technology has emerged as a promising method for extracting natural colorants, offering higher yields through shorter processes and minimizing thermal degradation. Although some studies have demonstrated the efficiency of HIUS technology in bixin extraction, research on the effects of acoustic cavitation on the properties of the colorant remains limited. Therefore, this study aimed to investigate the influence of HIUS-specific energy levels (0.02, 0.04, 0.12, and 0.20 kJ/g) on the chemical, physical, and morphological characteristics of annatto extracts containing bixin and geranylgeraniol. Single-step extractions of bixin using ethanol as a solvent were evaluated at various acoustic powers (4.6, 8.5, 14.5, and 20 W) and extraction times (0.5, 1, 3, and 5 min) to determine their impact on the yield of natural colorant extraction. Increasing the acoustic power from 4.6 to 20 W and extending the extraction time from 0.5 to 5 min resulted in higher yields of natural colorant, likely due to the effects of acoustic cavitation and increased heat under more intense conditions. However, elevated levels of mechanical and thermal energy did not affect the chemical properties of the colorant, as indicated by UV-Vis and FTIR spectra. Conversely, higher specific energies yielded colorants with a more intense red hue, consistent with increased bixin content, and altered the microstructure and physical state, as observed in X-ray diffractograms. Nevertheless, these alterations did not impact the solubility of the colorant. Therefore, employing a cleaner extraction procedure aided by one-step ultrasound facilitated the recovery of natural colorants and contributed to the biorefining of annatto seeds, enabling the production of a rich geranylgeraniol colorant through a sustainable approach.

Sex-specific effects of Fat-1 transgene on bone material properties, size, and shape in mice

Western diets are becoming increasingly common around the world. Western diets have high omega 6 (ω-6) and omega 3 (ω-3) fatty acids and are linked to bone loss in humans and animals. Dietary fats are not created equal; therefore, it is vital to understand the effects of specific dietary fats on bone. We aimed to determine how altering the endogenous ratios of ω-6:ω-3 fatty acids impacts bone accrual, strength, and fracture toughness. To accomplish this, we used the Fat-1 transgenic mice, which carry a gene responsible for encoding a ω-3 fatty acid desaturase that converts ω-6 to ω-3 fatty acids. Male and female Fat-1 positive mice (Fat-1) and Fat-1 negative littermates (WT) were given either a high-fat diet (HFD) or low-fat diet (LFD) at 4 wk of age for 16 wk. The Fat-1 transgene reduced fracture toughness in males. Additionally, male BMD, measured from DXA, decreased over the diet duration for HFD mice. In males, neither HFD feeding nor the presence of the Fat-1 transgene impacted cortical geometry, trabecular architecture, or whole-bone flexural properties, as detected by main group effects. In females, Fat-1-LFD mice experienced increases in BMD compared to WT-LFD mice; however, cortical area, distal femur trabecular thickness, and cortical stiffness were reduced in Fat-1 mice compared to pooled WT controls. However, reductions in stiffness were caused by a decrease in bone size and were not driven by changes in material properties. Together, these results demonstrate that the endogenous ω-6:ω-3 fatty acid ratio influences bone material properties in a sex-dependent manner. In addition, Fat-1 mediated fatty acid conversion was not able to mitigate the adverse effects of HFD on bone strength and accrual.

Diets intervene osteoporosis via gut-bone axis

Osteoporosis is a systemic skeletal disease that seriously endangers the health of middle-aged and older adults. Recently, with the continuous deepening of research, an increasing number of studies have revealed gut microbiota as a potential target for osteoporosis, and the research concept of the gut-bone axis has gradually emerged. Additionally, the intake of dietary nutrients and the adoption of dietary patterns may affect the gut microbiota, and alterations in the gut microbiota might also influence the metabolic status of the host, thus adjusting bone metabolism. Based on the gut-bone axis, dietary intake can also participate in the modulation of bone metabolism by altering abundance, diversity, and composition of gut microbiota. Herein, combined with emerging literatures and relevant studies, this review is aimed to summarize the impacts of different dietary components and patterns on osteoporosis by acting on gut microbiota, as well as underlying mechanisms and proper dietary recommendations.

Effect of Dietary Geranylgeraniol and Green Tea Polyphenols on Glucose Homeostasis, Bone Turnover Biomarkers, and Bone Microstructure in Obese Mice

Previously, we demonstrated that the administration of either geranylgeraniol (GGOH) or green tea polyphenols (GTP) improved bone health. This study examined the combined effects of GGOH and GTP on glucose homeostasis in addition to bone remodeling in obese mice. We hypothesized that GGOH and GTP would have an additive or synergistic effect on improving glucose homeostasis and bone remodeling possibly in part via suppression of proinflammatory cytokines. Forty-eight male C57BL/6J mice were assigned to a high-fat diet (control), HFD + 400 mg GGOH/kg diet (GG), HFD + 0.5% GTP water (TP), or HFD + GGOH + GTP (GGTP) diet for 14 weeks. Results demonstrated that GTP supplementation improved glucose tolerance in obese mice. Neither GGOH nor GTP affected pancreas insulin or bone formation procollagen type I intact N-terminal, bone volume at the lumbar vertebrae, or bone parameters at the trabecular bone and cortical bone of the femur. There was an interactive effect for serum bone resorption collagen type 1 cross-linked C-telopeptide concentrations, resulting in no-GGOH and no-GTP groups having the highest values. GGOH increased trabecular number and decreased trabecular separation at the lumbar vertebrae. GTP increased trabecular thickness at lumbar vertebrae. The GG group produced the greatest connectivity density and the lowest structure model index. Only GTP, not GGOH, decreased adipokines concentrations (resistin, leptin, monocyte chemoattractant protein-1, and interleukin-6). In an obese male mouse model, individual GGOH and GTP supplementation improved glucose homeostasis, serum CTX, and trabecular microstructure of LV-4. However, the combined GGOH and GTP supplementation compromises such osteoprotective effects on serum CTX and trabecular bone of obese mice.

Sodium butyrate ameliorates thiram-induced tibial dyschondroplasia and gut microbial dysbiosis in broiler chickens

Thiram is a dithiocarbamate pesticide widely used in agriculture as a fungicide for storing grains to prevent fungal diseases. However, its residues have threatened the safety of human beings and the stability of the ecosystem by causing different disease conditions, e.g., tibial dyschondroplasia (TD), which results in a substantial economic loss for the poultry industry. So, the research on TD has a great concern for the industry and the overall GDP of a country. In current study, we investigated whether different concentrations (300, 500, and 700 mg/kg) of sodium butyrate alleviated TD induced under acute thiram exposure by regulating osteogenic gene expression, promoting chondrocyte differentiation, and altering the gut microbial community. According to the findings, sodium butyrate restored clinical symptoms in broilers, improved growth performance, bone density, angiogenesis, and chondrocyte morphology and arrangement. It could activate the signal transduction of the Wnt/β-catenin pathway, regulate the expression of GSK-3β and β-catenin, and further promote the production of osteogenic transcription factors Runx2 and OPN for restoration of lameness. In addition, the 16S rRNA sequencing revealed a significantly different community composition among the groups. The TD group increased the abundance of the harmful bacteria Proteobacteria, Subdoligranulum, and Erysipelatoclostridium. The sodium butyrate enriched many beneficial bacteria, such as Bacteroidetes, Verrucomicrobia, Faecalibacterium, Barnesiella, Rikenella, and Butyricicoccus, etc., especially at the concentration of 500 mg/kg. The mentioned concentration significantly limited the intestinal disorders under thiram exposure, and restored bone metabolism.

New Advances in Improving Bone Health Based on Specific Gut Microbiota

The gut microbiota has been shown to play an important role in the pathogenesis of various diseases, including metabolic diseases, cardiovascular diseases, and cancer. Recent studies suggest that the gut microbiota is also closely associated with bone metabolism. However, given the high diversity of the gut microbiota, the effects of different taxa and compositions on bone are poorly understood. Previous studies demonstrated that the mechanisms underlying the effects of the gut microbiota on bone mainly include its modulation of nutrient absorption, intestinal permeability, metabolites (such as short-chain amino acids), immune responses, and hormones or neurotransmitters (such as 5-hydroxytryptamine). Several studies found that external interventions, such as dietary changes, improved bone health and altered the composition of the gut microbiota. This review summarises the beneficial gut bacteria and explores how dietary, natural, and physical factors alter the diversity and composition of the gut microbiota to improve bone health, thereby providing potential new insight into the prevention of osteoporosis.

The Role of Geranylgeraniol in Managing Bisphosphonate-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (ONJ) is a rare but significant adverse side effect of antiresorptive drugs. Bisphosphonate-related ONJ (BRONJ) is the most prevalent condition due to the extensive use of the drug in cancer and osteoporosis treatment. Nitrogen-containing bisphosphonates suppress osteoclastic resorption by inhibiting farnesyl pyrophosphate synthase in the mevalonate pathway, leading to deficiency of the substrate for GTPase prenylation. The bone remodelling process is uncoupled, subsequently impairing bone healing and causing ONJ. Targeted administration of geranylgeraniol (GGOH) represents a promising approach to mitigate BRONJ because GGOH is a substrate for GTPase prenylation. In the current review, the in vitro effects of GGOH on osteoclasts, osteoblasts and other related cells of the jaw are summarised. We also present and appraise the current in vivo evidence of GGOH in managing BRONJ in animal models. Lastly, several considerations of using GGOH in the clinical management of BRONJ are highlighted. As a conclusion, GGOH is a promising topical agent to manage BRONJ, pending more research on an effective delivery system and validation from a clinical trial.