Hydroxycoumarin Scopoletin Inhibits Bone Loss through Enhancing Induction of Bone Turnover Markers in a Mouse Model of Type 2 Diabetes

Integrated chemical characterization, metabolite profiling, and pharmacokinetics analysis of Zhijun Tangshen Decoction by UPLC-Q/TOF-MS

Diabetic nephropathy (DN) is the main cause of end-stage renal disease worldwide and a major public issue affecting the health of people. Therefore, it is essential to explore effective drugs for the treatment of DN. In this study, the traditional Chinese medicine (TCM) formula, Zhijun Tangshen Decoction (ZJTSD), a prescription modified from the classical formula Didang Decoction, has been used in the clinical treatment of DN. However, the chemical basis underlying the therapeutic effects of ZJTSD in treating DN remains unknown. In this study, compounds of ZJTSD and serum after oral administration in rats were identified and analyzed using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). Meanwhile, a semi-quantitative approach was used to analyze the dynamic changes in the compounds of ZJTSD in vivo. UPLC-Q/TOF-MS analysis identified 190 compounds from ZJTSD, including flavonoids, anthraquinones, terpenoids, phenylpropanoids, alkaloids, and other categories. A total of 156 xenobiotics and metabolites, i.e., 51 prototype compounds and 105 metabolites, were identified from the compounds absorbed into the blood of rats treated with ZJTSD. The results further showed that 23 substances with high relative content, long retention time, and favorable pharmacokinetic characteristics in vivo deserved further investigations and validations of bioactivities. In conclusion, this study revealed the chemical basis underlying the complexity of ZJTSD and investigated the metabolite profiling and pharmacokinetics of ZJTSD-related xenobiotics in rats, thus providing a foundation for further investigation into the pharmacodynamic substance basis and metabolic regulations of ZJTSD.

Scopoletin: a review of its pharmacology, pharmacokinetics, and toxicity

Scopoletin is a coumarin synthesized by diverse medicinal and edible plants, which plays a vital role as a therapeutic and chemopreventive agent in the treatment of a variety of diseases. In this review, an overview of the pharmacology, pharmacokinetics, and toxicity of scopoletin is provided. In addition, the prospects and outlook for future studies are appraised. Scopoletin is indicated to have antimicrobial, anticancer, anti-inflammation, anti-angiogenesis, anti-oxidation, antidiabetic, antihypertensive, hepatoprotective, and neuroprotective properties and immunomodulatory effects in both in vitro and in vivo experimental trials. In addition, it is an inhibitor of various enzymes, including choline acetyltransferase, acetylcholinesterase, and monoamine oxidase. Pharmacokinetic studies have demonstrated the low bioavailability, rapid absorption, and extensive metabolism of scopoletin. These properties may be associated with its poor solubility in aqueous media. In addition, toxicity research indicates the non-toxicity of scopoletin to most cell types tested to date, suggesting that scopoletin will neither induce treatment-associated mortality nor abnormal performance with the test dose. Considering its favorable pharmacological activities, scopoletin has the potential to act as a drug candidate in the treatment of cancer, liver disease, diabetes, neurodegenerative disease, and mental disorders. In view of its merits and limitations, scopoletin is a suitable lead compound for the development of new, efficient, and low-toxicity derivatives. Additional studies are needed to explore its molecular mechanisms and targets, verify its toxicity, and promote its oral bioavailability.

Knockdown of LOX-1 ameliorates bone quality and generation of type H blood vessels in diabetic mice

Our previous studies have shown that lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) is expressed in liver sinusoidal endothelial cells, and oxidized low-density lipoprotein induces liver sinusoidal dysfunction and defenestration through the LOX-1/ROS/NF-kB pathway, revealing that LOX-1 can mediate liver sinusoidal barrier function, involved in the regulation of non-alcoholic fatty liver disease. Here, we investigated whether, in the context of bone metabolic diseases, LOX-1 could affect bone quality and type H blood vessels in diabetic mice. We used db/db mice as model and found that LOX-1 knockdown can ameliorate bone quality and type H blood vessel generation in db/db mice. This further verifies our hypothesis that LOX-1 is involved in the regulation of bone quality and type H blood vessel homeostasis, thus inhibiting osteoporosis progression in db/db mice.

Water Extract of Angelica dahurica Inhibits Osteoclast Differentiation and Bone Loss

Angelica dahurica radix has a long history of traditional use in China and Korea for treating headaches, cold-damp pain and skin diseases. Despite various pharmacological studies on A. dahurica, its impact on bones remains unclear. Hence, this study investigated the inhibitory effect of A. dahurica's radix water extract (WEAD) on osteoclast differentiation. In vitro experiments showed that WEAD effectively suppresses osteoclast differentiation. Treatment of an osteoclast precursor with WEAD significantly suppressed the expression of nuclear factor of activated T-cells 1 (NFATc1), essential transcription factor for osteoclastogenesis, while increasing the expression of negative regulators, interferon regulatory factor 8 (Irf8) and v-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MafB). Consistent with the in vitro findings, the oral administration of WEAD (100 and 300 mg/kg/day) to mice subjected to surgical ovariectomy for a duration of six weeks alleviated bone loss, while also mitigating weight gain and liver fat accumulation. In addition, we also identified phytochemicals present in WEAD, known to regulate osteoclastogenesis and/or bone loss. These results suggest the potential use of WEAD for treating various bone disorders caused by excessive bone resorption.

Huogu injection alleviates SONFH by regulating adipogenic differentiation of BMSCs via targeting the miR-34c-5p/MDM4 pathway

Although the precise pathogenesis of steroid-induced osteonecrosis of femoral head (SONFH) is not yet fully understood, evidence shows miRNAs-mediated posttranscription control directs the adipogenesis of bone marrow mesenchymal stem cells (BMSCs) and plays a pivotal role in the SONFH processes. Huogu injection formulated according to traditional Chinese medicine (TCM) theory has been used to treat SONFH by intra-articular injection. In this study, we asked whether the therapeutic effects of Huogu injection might depend on the inhibition of adipogenic differentiation of BMSCs, and if so, the pathway might be a therapeutic target to promote bone repair. Consequently, miR-34c-5p was upregulated in the dexamethasone (DEX)-treated BMSCs and might participate in the adipogenesis of BMSCs. TargetScan database and the luciferase reporter assay showed miR-34c-5p targeted on the MDM4 and negatively regulated its expression. Huogu injection in vitro inhibited the adipogenesis in the DEX-treated BMSCs by inhibiting the expression levels of PPARγ and C/EBPα, as well as reducing miR-34c-5p to prevent the degradation of MDM4. Moreover, miR-34c-5p mimic or MDM4 knockdown using shRNA neutralized the anti-adipogenesis of Huogu injection in BMSCs. In vivo, the results of X-ray imaging confirmed that Huogu injection alleviated the bone loss in rat SONFH. Consistent with results in vitro, Huogu injection reduced the lipid accumulation, removed the suppression of MDM4 by downregulating the expression of miR-34c-5p, and inhibited the expression of C/EBPα and PPARγ in bone tissues. When the lentivirus encoding miR-34c-5p was conducted by intra-articular injection, the overexpression of miR-34c-5p antagonized the therapeutic effects of Huogu injection. Our results underline the critical importance of the miR-34c-5p/MDM4 pathway in regulating the adipogenic outcome of BMSCs, suggesting the miR-34c-5p as a potentially effective therapeutic target in SONFH. These results further reinforce the potential of Huogu injection as an alternative approach in SONFH.

Dietary Collagen Hydrolysates Retard Estrogen Deficiency-Induced Bone Loss through Blocking Osteoclastic Activation and Enhancing Osteoblastic Matrix Mineralization

Osteoporosis manifest in postmenopausal women is an osteolytic disease characterized by bone loss, leading to increased susceptibility to bone fractures and frailty. The use of complementary therapies to alleviate postmenopausal osteoporosis is fairly widespread among women. The current study examined that Pangasius hypophthalmus fish skin collagen hydrolysates (fsCH) inhibited ovariectomy (OVX)-induced bone loss by conducting inter-comparative experiments for anti-osteoporotic activity among 206–618 mg/kg fsCH, 2 mg/kg isoflavone, 15 mg/kg glycine–proline–hydroxyproline (GPH) tripeptide, and calcium lactate. Surgical estrogen loss of mice for 8 weeks reduced serum 17β-estradiol levels with uterus atrophy, which was ameliorated by orally administering fsCH or isoflavone to mice. Similar to isoflavone, fsCH containing GPH-enhanced bone mineral density reduced levels of cathepsin K and proton-handling proteins, and elevated collagen 1 level in OVX bones. The treatment with fsCH and isoflavone enhanced the serum levels of collagen synthesis-related procollagen type 1 carboxy/amino-terminal propeptides reduced by OVX, whereas serum levels of osteocalcin and alkaline phosphatase, as well as collagen breakdown-related carboxy/amino-terminal telopeptides of type 1 collagen were reduced in OVX mice treated with fsCH, isoflavone, and calcium lactate. The trabecular bones were newly formed in OVX bones treated with isoflavone and fsCH, but not with calcium lactate. However, a low-dose combination of fsCH and calcium lactate had a beneficial synergy effect on postmenopausal osteoporosis. Furthermore, similar to isoflavone, 15–70 μg/mL fsCH, with its constituents of GPH and dipeptides of glycine–proline and proline–hydroxyproline, enhanced osteogenesis through stimulating differentiation, matrix mineralization, and calcium deposition of MC3T3-E1 osteoblasts. Accordingly, the presence of fsCH may encumber estrogen deficiency-induced bone loss through enhancing osteoclastogenic differentiation and matrix collagen synthesis. Therefore, fsCH may be a natural compound retarding postmenopausal osteoporosis and pathological osteoresorptive disorders.