Anti-Inflammatory and Anti-Osteoclastogenesis Activities of Different Kinds of Zanthoxylum bungeanum Seed Oil in Vitro.

Our previous study has exhibited that one kind of Zanthoxylum bungeanum seed oil (ZSO), extracted from Zanthoxylum bungeanum seed, had inhibitory effects on osteoclastogenesis. However, the anti-osteoclastogenesis activities of different kinds of ZSO are scarcely reported. Since inflammation is related to bone loss and osteoporosis, in this study, three kinds of ZSO, Zanthoxylum schinifolium Siebold et Zucc seed oil (ZSSO), Zanthoxylum armatum DC. seed oil (ZDSO) and Zanthoxylum bungeanum maximum seed oil (ZBSO), were obtained with Soxhlet extraction and their fatty acid constituents were detected by GC-FID. RAW264.7 macrophages induced by lipopolysaccharide (LPS) were used to evaluate the inhibitory effects of three kinds of ZSO on inflammation via detecting the expression levels of inflammatory factors by RT-qPCR. Moreover, RANKL-induced osteoclastogenesis was applied to demonstrate the anti-osteoclastogenesis activities of them through tartrate-resistant acid phosphatase (TRAP) staining and RT-qPCR. The GC-FID results exhibited that the highest constituent in ZSSO and ZDSO was oleic acid (OA) and palmitoleic acid (PLA), respectively. While linoleic acid (LA) and α-Linolenic acid (ALA) in ZBSO were dominant. At the concentration of 0.5 µL/mL, all three kinds of ZSO could decrease the expression levels of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1ß) in LPS-induced macrophages. At the concentration of 0.25 µL/mL, only ZSSO could decrease the expression levels of iNOS and COX-2, which implied the inhibitory effects of ZSSO were stronger than other ZSOs. The number of RANKL-induced osteoclasts and the expressions of nuclear factor kappa-B (NF-κB), TNF-α and IL-6 in the cells were decreased after being treated with ZSOs at the concentration of 0.5 µL/mL, while the number of RANKL-induced osteoclasts after treated with ZBSO were less than those treated with other ZSOs, this indicated that the anti-osteoclastogenesis effect of ZBSO were stronger than other ZSOs. In conclusion, the fatty acid compositions of three major kinds of ZSO were compared and the content of unsaturated fatty acids especially ω-3 polyunsaturated fatty acids in ZBSO were the highest among them. All ZSOs tested had anti-inflammatory and anti-osteoclastogenesis activities. And their anti-osteoclastogenesis effects might be related to the suppression of the NF-κB pathway.

α-Linolenic Acid Inhibits RANKL-Induced Osteoclastogenesis In Vitro and Prevents Inflammation In Vivo.

Inflammation is an important risk factor for bone-destroying diseases. Our preliminary research found that Zanthoxylum bungeanum seed oil (ZBSO) is abundant in unsaturated fatty acids and could inhibit osteoclastogenesis in receptor activator of nuclear factor κB ligand (RANKL)-induced RAW264.7 cells. However, the key constituents in ZBSO in the prevention of osteoclastogenesis and its possible mechanism related to inflammation are still unclear. Therefore, in this study, oleic acid (OA), linoleic acid (LA), palmitoleic acid (PLA), and alpha-linolenic acid (ALA) in ZBSO, havingthe strongest effect on RANKL-induced osteoclastogenesis, were selected by a tartrate-resistant acid phosphatase (TRAP) staining method. Furthermore, the effects of the selected fatty acids on anti-inflammation and anti-osteoclastogenesis in vitro and in vivo were assessed using RT-qPCR. Among the four major unsaturated fatty acids we tested, ALA displayed the strongest inhibitory effect on osteoclastogenesis. The increased expression of free fatty acid receptor 4 (FFAR4) and ß-arrestin2 (ßarr2), as well as the decreased expression of nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), nuclear factor of activated T-cells c1 (NFATc1), and tartrate-resistant acid phosphatase (TRAP) in RAW264.7 cells after ALA treatment were observed. Moreover, in ovariectomized osteoporotic rats with ALA preventive intervention, we found that the expression of TNF-α, interleukin-6 (IL-6), interleukin-1ß (IL-1ß), NFATc1, and TRAP were decreased, while with the ALA therapeutic intervention, downregulated expression of NF-κB, NFATc1, TRAP, and transforming growth factor beta-activated kinase 1 (TAK1) were noticed. These results indicate that ALA, as the major unsaturated fatty acid in ZBSO, could inhibit RANKL-induced osteoclastogenesis via the FFAR4/ßarr2 signaling pathway and could prevent inflammation, suggesting that ZBSO may be a promising potential natural product of unsaturated fatty acids and a dietary supplement for the prevention of osteoclastogenesis and inflammatory diseases.

High-altitude exposure decreases bone mineral density and its relationship with gut microbiota: Results from the China multi-ethnic cohort (CMEC) study.

BACKGROUND: Geographic altitude is a potent environmental factor for human microbiota and bone mineral density. However, little evidence exists in population-based studies with altitude diversity ranges across more than 3000 m. This study assessed the associations between a wide range of altitudes and bone mineral density, as well as the potential mediating role of microbiota in this relationship. METHODS: A total of 99,556 participants from the China Multi-Ethnic Cohort (CMEC) study were enrolled. The altitude of each participant was extracted from global Shuttle Radar Topography Mission (SRTM) 4 data. Bone mineral density was measured by calcaneus quantitative ultrasound index (QUI). Stool samples were collected for 16S rRNA gene sequencing (n = 1384). The metabolites of gut microbiota, seven kinds of short-chain fatty acids (SCFAs), were detected by gas chromatography-mass spectrometry (GC-MS, n = 128). After screening, 73,974 participants were selected for the "altitude-QUI" analysis and they were placed into the low-altitude (LA) and high-altitude (HA) groups. Additionally, a subgroup (n = 1384) was further selected for the "altitude-microbiota-QUI" analysis. Multivariate linear regression models and mediation analyses were conducted among participants. RESULTS: A significant negative association between high-altitude and QUI was obtained (mean difference = -0.373 standard deviation [SD], 95% confidence interval [CI]: -0.389, -0.358, n = 73,974). The same negative association was also observed in the population with microbiota data (mean difference = -0.185 SD, 95%CI: -0.360, -0.010, n = 1384), and a significant mediating effect of Catenibacteriumon on the association between altitude and QUI (proportion mediated = 25.2%, P = 0.038) was also noticed. Additionally, the acetic acid, butyric acid, and total amount of seven SCFAs of the low-altitude group were significantly higher than that of the high-altitude group (P < 0.05). CONCLUSION: High-altitude exposure may decrease bone mineral density in adults, thus increasing the risk of osteoporosis. The modulation of gut microbiota may be a potential strategy for alleviating the decrease of bone mineral density.

Association between residential greenness and gut microbiota in Chinese adults.

BACKGROUND: A growing body of studies have reported the health benefits of greenness. However, less is known about the potential beneficial effects of residential greenness on gut microbiota, which is essential to human health. In this study, we aim to examine the association between residential greenness and gut microbiota in a population-based cohort study. METHODS: We included 1758 participants based on the China Multi-Ethnic Cohort (CMEC) study and collected their stool samples for 16S sequencing to derive gut microbiota data. Residential greenness was estimated using the satellite-based data on enhanced vegetation index (EVI) and the normalized differential vegetation index (NDVI) in circular buffers of 250 m, 500 m, and 1000 m. The relationships between residential greenness levels and the composition of gut microbiota, measured by standardized α-diversity and taxonomic composition, were assessed using linear regression and Spearman correlation weighted by generalized propensity scores. RESULTS: Higher greenness levels were significantly positively associated with standardized α-diversity. Per interquartile range (IQR) increase of EVI and NDVI in the circular buffer of 250 m were associated with the increments of 0.995(95% confidence interval (CI): 0.212-1.778) and 0.653(95% CI: 0.160-1.146) in the standardized Shannon index. For the taxonomic composition of gut microbiota, higher greenness levels were significantly correlated with 29 types of microbial taxonomic composition. NDVI in the circular buffer of 250 m was associated with increased Firmicutes (r = 0.102, adjusted p value = 0.004), which was the dominant composition in the gut microbiota. CONCLUSIONS: Increased amounts of residential greenness may support healthy gut microbiota by benignly altering their composition. These findings suggested that green spaces should be designed to support diverse gut microbiota and ultimately optimize health benefits.

Comparative Study of Oral Bacteria and Fungi Microbiota in Tibetan and Chinese Han Living at Different Altitude.

Knowledge about the impact of altitude and ethnicity on human oral microbiota is currently limited. To obtain the baseline of normal salivary microbiota, we analyzed the bacteria and fungi composition in Tibetan (HY group) and Han population (CD group) living at different altitudes by using next-generation sequencing (NGS) technology combined with PICRUSt and FUNGuild analyses. There were significant differences in oral microbiota composition between the two groups at phylum and genus levels. At the phylum level, the HY group had higher relative abundances of Firmicutes and Ascomycota, whereas the Bacteroidetes and Basidiomycota in the CD group were richer. These changes at the phylum level reflected different dominant genus compositions. Compared with the Han population, Candida, Fusarium, Zopfiella, Streptococcus, Veillonella and Rothia in Tibetan were higher. Surprisingly, the Zopfiella was found almost exclusively in the Tibetan. The PICRUSt and FUNGuild analysis also indicated that the function of the bacterial and fungal communities was altered between the two groups. In conclusion, our results suggest that there are significant differences in oral microbial structure and metabolic characteristics and trophic modes among Tibetan and Han population living at different altitudes. We first established the oral microbiota framework and represented a critical step for determining the diversity of oral microbiota in the Tibetan and Han population.