Arecanut (Areca catechu L.) Seed Polyphenol-Ameliorated Osteoporosis by Altering Gut Microbiome via LYZ and the Immune System in Estrogen-Deficient Rats

Abstract

Polyphenol can improve osteoporosis and is closely associated with gut microbiota, while the mechanism and the relationship among polyphenol, osteoporosis, and gut microbiota colonization remain unclear. Here, an osteoporosis rat model established by ovariectomy was employed to investigate the improving mechanism of arecanut (Areca catechu L.) seed polyphenol (ACP) on osteoporosis by regulating gut microbiota. We analyzed the bone microstructure, Paneth cells, regulating microbial protein (lysozyme (LYZ)), proinflammatory cytokines, macrophage infiltration levels, and gut microbial communities in a rat. ACP improved the trabecular microstructure compared to OVX, including the increased trabecular number (Tb.N) (P < 0.01) and trabecular thickness (Tb.Th) (P < 0.001) and decreased trabecular separation (Tb.Sp) (P < 0.01). At the phylum level, Bacteroidetes was increased after ovariectomy (P < 0.001) and Firmicutes and Proteobacteria were increased in ACP (P < 0.001). Antiosteoporosis groups with lower LYZ and Paneth cells (P < 0.001) showed that the microbiota Alistipes, which have a negative effect on bone metabolism were decreased in ACP (P < 0.001). Altogether, these studies showed that the estrogen deficiency could induce the shedding of Paneth cells, which leads to the decrease of LYZ, while ACP could increase the LYZ expression by maintaining the population of Paneth cells in an estrogen-deficient host, which were implicated in gut microbiota regulation and improved osteoporosis by controlling the inflammatory reaction.

The Human Gut Microbiota: A Key Mediator of Osteoporosis and Osteogenesis

“…Studies in rodents show promising results for the addition of high-fiber diets and the resultant increase in the gut microbiome production of short-chain fatty acids (SCFA), particularly butyrate [14], the primary metabolites of microbial fermentation in the gut [29]. SCFAs appear to protect against postmenopausal and inflammatory bone loss, repair intestinal barriers, and prevent the development of osteoporosis in mice [30][31][32]. These results seem to translate to studies in human populations, where an association between increased dietary fiber consumption and bone mineral density has been demonstrated [33,34].…”

Tilapia Head Protein Hydrolysate Attenuates Scopolamine-Induced Cognitive Impairment through the Gut-Brain Axis in Mice

“…The qRT-PCR experiment was performed basing on the previously reported methods with slight modification [ 36 , 37 , 38 ]. In brief, total RNA was extracted from brain tissues homogenized of mice by Eastep R Super Total RNA Extraction Kit (Promega Biotechnology Co., Ltd., Shanghai, China).…”

“…To determine the expression of the gut microbiota flora associated with cognitive impairment, 16s high-throughput sequencing was used to study the changes in the intestinal flora. The method of genomic DNA amplification was the same as in the previous research [ 38 ]. Briefly, the microbial DNA in mouse feces was extracted using QIAamp DNA Stool Mini Kit (Qiagen, Hilden, Germany), and then the purity and concentration of DNA were detected by agarose gel electrophoresis.…”

Anti-Osteoporotic Mechanisms of Polyphenols Elucidated Based on In Vivo Studies Using Ovariectomized Animals

“…A relatively short-term study (8 days) involving the use of dietary purified blueberry polyphenols, which are rich in anthocyanin, revealed that polyphenols enhance calcium absorption in ovariectomized rats [ 49 ]. As an interesting anti-osteoporotic mechanism, it was recently reported that arecanut ( Areca catechu L.) seed polyphenol promotes bone formation by altering gut microbiota along with controlling inflammatory reactions [ 50 ]. The seed has also been used in osteoporosis therapy in the field of Chinese medicine.…”