Humulus lupulus L. Extract Prevents Ovariectomy-Induced Osteoporosis in Mice and Regulates Activities of Osteoblasts and Osteoclasts.

OBJECTIVE: To systematically evaluate the protective effects of Humulus lupulus L. extract (HLE) on osteoporosis mice. METHODS: In vivo experiment, a total of 35 12-week-old female ICR mice were equally divided into 5 groups: the sham control group (sham); the ovariectomy with vehicle group (OVX); the OVX with estradiol valerate [EV, 0.2 mg/(kg•d)] the OVX with low- or high-dose HLE groups [HLE, 1 g/(kg•d) and 3 g/(kg•d)], 7 in each group. Treatment began 1 week after the ovariectomized surgery and lasted for 12 weeks. Bone mass and trabecular bone mircoarchitecture were evaluated by micro computed tomography, and bone turnover markers in serum were evaluated using enzyme-linked immunosorbent assay (ELISA) kits. In vitro experiment, osteoblasts and osteoclasts were treated with HLE at doses of 0, 4, 20 and 100 µg/mL. Biomarkers for bone formation in osteoblasts and bone resorption in osteoclasts were analyzed. RESULTS: Compared with the OVX group, HLE exerted bone protective effects by the increase of estradiol (P<0.05), the improvement of cancellous bone structure, bone mineral density (P<0.01) and the reduction of serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), bone gla-protein, c-terminal telopeptides of type I collagen (CTX-I) and deoxypyridinoline levels (P<0.01 for all). In vitro experiment, compared with the control group, HLE at 20 µg/mL promoted the cell proliferation (P<0.01), and increased the expression of bone morphogenetic protein-2 and osteopontin levels in osteoblasts (both P<0.05). HLE at 100 µg/mL increased the osteoblastic ALP activities, and HLE at all dose enhanced the extracellular matrix mineralization (both P<0.01). Furthermore, compared with the control group, HLE at 20 µg/mL and 100 µg/mL inhibited osteoclastic TRAP activity (P<0.01), and reduced the expression of matrix metalloproteinase-9 and cathepsin K (both P<0.05). CONCLUSION: HLE may protect against bone loss, and have potentials in the treatment of osteoporosis.

Metabolomics profiling provides valuable insights into the underlying mechanisms of Morinda officinalis on protecting glucocorticoid-induced osteoporosis.

Morinda officinalis (MO) has long been used as a traditional herbal medicine for the treatment of bone fractures and joint diseases in China. Monotropein (Mon) and rubiadin-1-methyl ether (Rub) are major bioactive components in MO. Ample evidence shows that MO and its chemical constituents can prevent osteoporosis induced by estrogen-deficiency and ageing. However, there is no study reporting glucocorticoid-induced osteoporosis (GIOP). The aim of the present study was to explore the protective effect of MO on GIOP modeled rats and osteoblasts, and elucidate the underlying mechanisms via UHPLC-Q-TOF/MS based metabolomics profiling. Eight weeks after dexamethasone (DEX) injection and MO treatment in female SD rats aged 12 weeks, bone mineral density (BMD), the micro-architecture of the trabecular bone, serum level of bone metabolism markers, and urine metabolomics were assayed in vivo. Cultured osteoblasts were injured with DEX, and the effects of MO, Mon and Rub on osteoblastic proliferation, differentiation and mineralization were examined in vitro. The results showed that MO was able to increase BMD, improve the micro-architecture and intervene bone metabolism via regulating alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP) and c-terminal telopeptides of type I collagen (CTX-I) levels in DEX-treated rats. The in vitro experiment showed that MO, Mon and Rub all increased the cell proliferation and ALP activity, and enhanced extracellular matrix mineralization in DEX-injured osteoblasts. Metabolomics profiling identified a total of 37 differential metabolites in DEX group vs. the control group, of which 20 were reversed significantly after MO treatment. Further metabolic pathway enrichment and Western blotting analysis showed that MO prevented bone loss mainly by interfering with arachidonic acid metabolism. These results suggested MO had a notable anti-GIOP effect, and the underlying mechanisms might be related to arachidonic acid metabolism.

Metabolomics Profiling Reveals Rehmanniae Radix Preparata Extract Protects against Glucocorticoid-Induced Osteoporosis Mainly via Intervening Steroid Hormone Biosynthesis.

Rehmanniae Radix Preparata (RR), the dry rhizome of Rehmannia glutinosa Libosch., is a traditional herbal medicine for improving the liver and kidney function. Ample clinical and pharmacological experiments show that RR can prevent post-menopausal osteoporosis and senile osteoporosis. In the present study, in vivo and in vitro experiments, as well as a UHPLC-Q/TOF-MS-based metabolomics study, were used to explore the preventing effect of RR on glucocorticoid-induced osteoporosis (GIOP) and its underlying mechanisms. As a result, RR significantly enhanced bone mineral density (BMD), improved the micro-architecture of trabecular bone, and intervened in biochemical markers of bone metabolism in dexamethasone (DEX)-treated rats. For the in vitro experiment, RR increased the cell proliferation and alkaline phosphatase (ALP) activity, enhanced the extracellular matrix mineralization level, and improved the expression of runt-related transcription factor 2 (RUNX2) and osteopontin (OPN) in DEX-injured osteoblasts. For the metabolomics study, a total of 27 differential metabolites were detected in the DEX group vs. the control group, of which 10 were significantly reversed after RR treatment. These metabolites were majorly involved in steroid hormone biosynthesis, sex steroids regulation, and amino acid metabolism. By metabolic pathway and Western blotting analysis, it was further ascertained that RR protected against DEX-induced bone loss, mainly via interfering steroid hormone biosynthesis, as evidenced by the up-regulation of cytochrome P450 17A1 (CYP17A1) and aromatase (CYP19A1), and the down-regulation of 11ß-hydroxysteroid dehydrogenase (HSD11B1). Collectively, these results indicated that RR had a notable preventing effect on GIOP, and the action mechanism might be related to steroid hormone biosynthesis.

[Research progress of chemical constituents and pharmacological activities in Humulus lupulus].

Hops, the female inflorescences of the hop plant (Humulus lupulus), are widely used in the brewing industry to add bitterness and aroma to beer. Combining with the relevant literature, the chemical composition(resinae, volatile oil, polyphenol and polysaccharide) in hops and their pharmacological effects are reviewed in this paper so as to present some sights for further application research and development.