The prebiotic effect ofAnoectochilus formosanusand its consequences on bone health

Abstract

The present study evaluated the prebiotic effect of a standardised aqueous extract of Anoectochilus formosanus (SAEAF) and its effects on osteoporosis in ovariectomised (OVX) rats. The OVX rats were randomly divided into five groups and orally treated with water, SAEAF (200 and 400 mg/kg daily) and inulin (400 mg/kg daily) for 12 weeks. The sham group was orally treated with water. The SAEAF treatment enhanced the number of faecal bifidobacteria in OVX rats. The results of a Ca-balance experiment showed that SAEAF increased apparent Ca absorption and retention. The OVX rats were killed after SAEAF treatment lasting 12 weeks. The SAEAF decreased the caecal pH values and increased the caecal wall weight, caecal mucosa calbindin-D9k mRNA expression, free-Ca concentration and levels of SCFA in the caecum. The mineral content, density and biomechanical strength of bones were lower in OVX rats than the sham group, but these bone losses were prevented by SAEAF administration. Microtomography scanning showed that the SAEAF-treated rats had higher trabecular bone volume than the OVX rats. These results suggest that SAEAF prevented bone loss associated with ovarian hormone deficiency in the rats.Key words: Anoectochilus formosanus: Prebiotics: Calcium balance studies: Osteoporosis Prebiotics are non-digestible food ingredients that benefit the host by selectively stimulating the favourable growth and/or activity of one or more indigenous probiotic bacteria that could deliver potential beneficial health effects (1) .Microbial fermentation products of prebiotics, such as SCFA, are responsible for an increase in Ca absorption in the large intestine. A high concentration of SCFA in the caecum leads to decreased caecal pH, which increases the concentration of soluble Ca (2) . In addition, butyrate, a SCFA, belongs to a new class of anti-osteoporotic agents that may be useful in treating bone loss (3 -5) . Furthermore, several reports have indicated that the ingestion of prebiotics such as inulin and fructo-oligosaccharides might help prevent osteoporosis (2,6) .Anoectochilus formosanus (Orchidaceae) is an orchidaceous perennial herb, of which the entire plant has been used as a folk medicine for treating underdevelopment in children in Taiwan. This traditional use of the herb suggests that it might enhance Ca absorption (7) . Several studies in rats have found that A. formosanus ameliorated the osteoporosis induced by ovariectomy (OVX) (8,9) . Masuda et al. (9) have shown that ethanolic extracts of A. formosanus suppress the bone loss otherwise caused by oestrogen deficiency, by inhibiting osteoclast formation. Our previous study has shown that aqueous extracts of A. formosanus ameliorated bone loss caused by OVX by stimulating bone formation (8) .A bioactivity-guided fractional study of the use of A. formosanus in mice has shown that the ethyl acetate fraction enhances hepatitis induced by carbon tetrachloride (10) . The present study developed a dietary supplement from A. formosanus to prevent bone loss. A standard...

Prebiotic and Probiotic Regulation of Bone Health: Role of the Intestine and its Microbiome

“…Similarly, GOS dose dependently increased rat tibia and femur strength (44,45). In addition, Anoecthochilus formosanus , a prebiotic herb, and inulin also increase bone strength in 12-week-old OVX rats (46). This effect on bone strength was observed in the absence of a significant change in bone volume, suggesting that prebiotics could change the extracellular matrix material properties.…”

“…Models for how prebiotics could increase calcium absorption include the involvement of fermentation of the prebiotics to release SCFA. It has been demonstrated that many prebiotic fibers (i.e., soluble corn fiber or fiber dextrin, inulin, FOS, agave fructans) increase the cecal content of SCFA such as acetate, propionate, butyrate, isobutyrate, valerate and isovalerate (23,34,46). SCFA can affect calcium absorption via two mechanisms.…”

“…This can be measured as an increase in cecum weight and/or histologically by increased cecal villi structures that maximize surface area and absorption (50). There could also be increased paracellular calcium transport under these conditions and increased calcium binding protein expression (46,50). Secondly, production of SCFA increases acidity in the lumen of the cecum and colon.…”

Anti‐inflammatory and anti‐insulin resistance activities of aqueous extract from Anoectochilus burmannicus

“…Anoectochilus genus such as Anoectochilus roxburghii, Anoectochilus formosanus, Anoectochilus elwesii, and Anoectochilus setaceus are used widespread in China, Vietnam, Sri Lanka, and Taiwan because of their medicinal properties (Yang, Wu, Lu, & Lin, 2013). They have remarkable curative effects of clearing heat and cooling blood, removing dampness, detoxification, antioxidative stress (Shih, Wu, & Lin, 2002; Wang et al., 2005), and anti‐inflammation (Hsieh, Hsiao, & Lin, 2010).…”

A Type II Arabinogalactan fromAnoectochilus formosanusfor G-CSF Production in Macrophages and Leukopenia Improvement in CT26-Bearing Mice Treated with 5-Fluorouracil

“…A. formosanus exhibits hepatoprotective activity [1], antitumor and immunomodulatory effects [2, 3], asthma treatment effects [4], antihyperglycemic activity [5], prebiotic effects [6], and antiosteoporosis activity [7, 8]. The polysaccharide isolated from A. formosanus juice is a type II arabinogalactan with an average molecular weight of 29 kDa, and it is a prebiotic that increases the growth of probiotics in vivo and in vitro [6].…”