Luteolin rescues postmenopausal osteoporosis elicited by OVX through alleviating osteoblast pyroptosis via activating PI3K-AKT signaling.

BACKGROUND: Recently, osteoblast pyroptosis has been proposed as a potential pathogenic mechanism underlying osteoporosis, although this remains to be confirmed. Luteolin (Lut), a flavonoid phytochemical, plays a critical role in the anti-osteoporosis effects of many traditional Chinese medicine prescriptions. However, its protective impact on osteoblasts in postmenopausal osteoporosis (PMOP) has not been elucidated. PURPOSE: This research aimed to determine the effect of Lut in ameliorating PMOP by alleviating osteoblast pyroptosis and sustaining osteogenesis. STUDY DESIGN: This research was designed to investigate the novel mechanism of Lut in alleviating PMOP both in cell and animal models. METHODS: Ovariectomy-induced PMOP models were established in mice with/without daily gavaged of 10 or 20 mg/kg body weight Lut. The impact of Lut on bone microstructure, metabolism and oxidative stress was evaluated with 0.104 mg/kg body weight Estradiol Valerate Tablets daily gavaged as positive control. Network pharmacological analysis and molecular docking were employed to investigate the mechanisms of Lut in PMOP treatment. Subsequently, the impacts of Lut on the PI3K/AKT axis, oxidative stress, mitochondria, and osteoblast pyroptosis were assessed. In vitro, cultured MC3T3-E1(14) cells were exposed to H2O2 with/without Lut to examine its effects on the PI3K/AKT signaling pathway, osteogenic differentiation, mitochondrial function, and osteoblast pyroptosis. RESULTS: Our findings demonstrated that 20 mg/kg Lut, similar to the positive control drug, effectively reduced systemic bone loss and oxidative stress, and enhanced bone metabolism induced by ovariectomy. Network pharmacological analysis and molecular docking indicated that the PI3K/AKT axis was a potential target, with oxidative stress response and nuclear membrane function being key mechanisms. Consequently, the effects of Lut on the PI3K/AKT axis and pyroptosis were investigated. In vivo data revealed that the PI3K/AKT axis was deactivated following ovariectomy, and Lut restored the phosphorylation of key proteins, thereby reactivating the axis. Additionally, Lut alleviated osteoblast pyroptosis and mitochondrial abnormalities induced by ovariectomy. In vitro, Lut intervention mitigated the inhibition of the PI3K/AKT axis and osteogenesis, as well as H2O2-induced pyroptosis. Furthermore, Lut attenuated ROS accumulation and mitochondrial dysfunction. The effects of Lut, including osteogenesis restoration, anti-pyroptosis, and mitochondrial maintenance, were all reversed with LY294002 (a PI3K/AKT pathway inhibitor). CONCLUSION: In summary, Lut could improve mitochondrial dysfunction, alleviate GSDME-mediated pyroptosis and maintain osteogenesis via activating the PI3K/AKT axis, offering a new therapeutic strategy for PMOP.

The correlation between the methylation of PTEN gene and the apoptosis of osteosarcoma cells mediated by SeHA nanoparticles.

The invasive spreading of residual osteosarcoma cells becomes a serious threat to human health, urgently needing new bone regenerative biomaterials for orthopedic therapy. Thus, in this work, selenite-substituted hydroxyapatite (SeHA) nanoparticles were prepared for both inhibiting the recurrence of the tumor and accelerating the regenerative repair of bone defect. Physicochemical characterization showed these synthetic nanoparticles were spherical poly-crystals with the shape of snowflakes. Such structure benefited them to inhibit the cellular viability of osteosarcoma cells by about (58.90 ± 14.37)% during 24 h co-culturing. The expression level of cell growth-related genes such as PTEN, MMP-9, Cyclin D1, Cyclin A2, Annexin A2 and CDC2 decreased. Bisulfite Sequence PCR of PTEN gene exhibited about (22.40 ± 5.39)%, (45.91 ± 6.36)% and (25.90 ± 5.36)% promoter methylation in control, HA and SeHA group. Animal experiment also proved the similar effects. Almost no recurrence were observed in SeHA group. Oppositely, the slowly recurrent growth of the remnant tumor appeared in purely surgical group. The overall survival and toxicity analysis showed that, in the usage dose of 0-0.1 g, the SeHA-0.01 exhibited higher inhibitory recurrence and metastasis potentials, lower renal toxicity and better anti-inflammation function. Immunohistochemistry stain showed the reduced expression of PTEN, MMP-9, Ki-67 and Annexin A2, but slightly increased expression of DNMT1 and BMP-2. Compared the methylation status of PTEN gene in each group, it was confirming that SeHA nanoparticles hardly possessed the de-methylation effect, but the pure HA strikingly increased the methylation level of such gene. It seemed the dopant selenite ions possessed de-methylation effect onto PTEN gene. Therefore, from the viewpoint of inhibiting metastatic potentials, the SeHA-0.01 might be a feasible biomaterial to inhibit the relapse of the tumor post-surgery.

Asperosaponin VI stimulates osteogenic differentiation of rat adipose-derived stem cells.

In the aging population, the decrease on osteogenic differentiation resulted into a significant reduction in bone formation. Bone tissue engineering has been a successful technique for treatment of bone defects. It is reported that adipose-derived stem cells (ADSCs) have pluripotency to differentiate into adipocytes and osteoblasts. However little is revealed about the effect of the herbal medicine Asperosaponin VI (ASA VI) on ADSCs differentiation. In our study, we isolated and identified ADSCs from rats. We examined the effect of different concentrations of ASA VI in ADSCs on alkaline phosphatase (ALP) activity, calcium deposition, the expression of bone-related proteins and the release of inflammatory cytokines. Flowcytometry assay showed ADSCs were highly expressed CD44 and CD105, but hardly expressed CD34 and CD45, suggesting ADSCs were successfully isolated for follow-up experiments. ALP activity examination and Alizarin red (AR) stain showed that ASA VI enhanced the ALP activity and promoted matrix mineralization in ADSCs. In addition, bone-related protein OCN and RUNX2, and Smad2/3 phosphorylation was upregulated after ASA VI treatment in ADSCs. ELISA results showed that ASA VI blocked the release of TNF-α, IL-6 and IL-1ß in ADSCs. Considering this results, we concluded that ASA VI promotes osteogenic differentiation of ADSCs through inducing the expression of bone-related proteins. These findings enriched the function of ASA VI as a regenerative medicine and shed new light for the treatment of bone defects in clinical research.

[Total ginsenosides fought against right ventricular hypertrophy through inhibiting calcineurin signal pathway].

OBJECTIVE: To observe the effect of total ginsenosides (TG) on monocrotaline (MCT) induced right ventricular hypertrophy rats, and to explore its correlation with calcineurin (CaN) pathway. METHODS: Fifty male Sprague Dawley rats were randomly divided into the normal control group, the MCT model group, and the low, middle, high dose TG treatment groups, 10 in each group. All medication was performed by peritoneal injection for 18 days. Right ventricular peak systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), and right ventricular weight/body weight (RVW/BW) were measured. Intracellular free calcium concentrations were measured by Ca2+ fluorescence indicator Fura2/AM. The atrial natriuretic factor (ANF) and CaN mRNA expression of the myocardial tissue were quantitatively analyzed by Real-time PCR. The protein expression of CaN was detected by Western blot. RESULTS: Compared with the MCT model group, preventive treatment of TG at the 3 doses could significantly reduce RVSP, RVHI, RVW/BW, and ANF mRNA expression, and decrease Ca2+ concentration in myocardial cells, CaN mRNA and protein expression in the myocardial tissue. CONCLUSION: TG could obviously improve MCT-induced right ventricular hypertrophy, which was possibly achieved through suppressing MCT-activated CaN signal transduction.

[Effect of xuebijing injection on perioperative coagulation function and inflammatory reaction in senile patients receiving total hip arthroplasty].

OBJECTIVE: To observe the effect of xuebijing Injection (XI) on perioperative coagulation and inflammatory reaction in senile patients receiving total hip arthroplasty (THA). METHODS: Totally eighty patients receiving THA at Luoyang Orthopedics Hospital, 65 to 85 years old, were randomly assigned to the control group (40 cases) and the treatment group (40 cases). All patients received routine perioperative therapies. Those in the treatment group received XI (adding 50 mL XI in 100 mL normal saline, 30 min each time). XI was continually injected after THA, twice daily for 3 successive days. Blood samples were harvested on the morning of the 2nd admission day (TO), immediately after operation (T1), on the morning of the 3rd day after operation (T3), and on the morning of the 5th day after operation (T4) to detect prothrombin time (PT), thrombin time (TT), activated partial thromboplastin time (APTT), levels of FIB and D-dimer (D-D), changes of white blood cell (WBC), neutrophils (N), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and IL-6. Complications of surgery were compared between the two groups. RESULTS: There was no statistical difference in operation time, intraoperative blood loss, and blood transfusion between the two groups (P >0.05). Compared with TO in the same group, WBC, N, CRP, ESR, IL-6, PT, TT, and D-D all increased in the control group at T1-T4 (P < 0.05); APTT increased at T1-T2 (P <0.05); FIB increased at T1-T3 (P <0.05). WBC, N, IL-6, PT, and D-D all increased in the treatment group at T1-T3 (P <0.05); CRP and ESR increased at T1-T4 (P < 0.05); TT increased at T1-T2 (P <0.05); APTT and FIB increased at T1 (P <0.05). Compared with the control group at the same time period, WBC, N, CRP, and IL-6 all decreased in the treatment group at T1-T4 (P <0.05), ESR decreased at T3-T4 (P <0.05); PT and TT decreased at T1-T3 (P <0.05); FIB and D-D decreased at T2-T4 (P<0.05). The occurrence of each complication was significantly lower in the treatment groups than in the control group. CONCLUSION: XI could improve the perioperative high coagulation state of senile THA patients, inhibit inflammatory reactions, and reduce complications.

[Inhibitory effect of nitric oxide-induced total ginsenosides on right ventricular hypertrophy in rats].

OBJECTIVE: To observe the effect of total ginsenosides (TG) on right ventricular hypertrophy induced by monocrotaline (MCT) in rats, and study its relationship with the nitric oxide pathway. METHOD: Male Sprague Dawley rats were randomly divided into the control group, the MCT model group, TG-treated (20, 40, 60 mg kg-1 d-1) groups, and the L-arginine (L-arg) th NO release, T + L-N and L-a + L-N groups were wi th NOS into study TG's effect 200 mg kg-1 d-1 group. Besides, and its relationship wi also set, intraperitoneally injected with TG 40 mg kg-1 d -1 and L-arg 200 mg kg-1 - d-1, and orally administered hibitor L-NAME 20 mg kg-1 d-1. After all of the groups were given drugs for 18 d, their right ventricular peak systolic pressure (RVSP) ventricular hypertrophy index (RVHI) and RVW/BW were determined. Ultra-structure of myocardial cells was observed with transmission electron microscope. The NO2 -/NO3 - content in myocardial tissues were detected with the nitrate reduction method. ANF and eNOS mRNA expressions in right ventricle tissues were detected by using real-time RT-PCR. RESULT: Low, middle and high doses of TG and L-arg preventive administration could significantly reduce RVSP, RVHI, RVW/BW and ANF mRNA expressions (P < 0. 05) , and ameliorate cellular mitochondrial swelling and degeneration. L-NAME could prevent the effect of L-arg on above indexes, whereas L-NAME of the same dose could not impact the reducing effect of TG 40 mg kg -1 on above indexes. TG 60 mg kg -1 could raise eNOS mRNA expression, but TG 20 mg kg-1 and 40 mg kg-1 showed no effect. CONCLUSION: TG can significantly attenuate MCT-induced right cardiac hypertrophy in rats. Its anti-hypertrophic effect is partially realized through NO.

Total ginsenosides inhibit the right ventricular hypertrophy induced by monocrotaline in rats.

Ginsenosides have been reported to release nitric oxide (NO) and decrease intracellular free Ca(2+) in cardiovascular system, which play important roles in antihypertrophic effect. This study investigated the potential inhibitory effect of total ginsenosides (TG) on right ventricular hypertrophy induced by monocrotaline (MCT, 60 mg/kg/d) and examined the possible antihypertrophic mechanism in male Sprague Dawley rats. MCT-intoxicated animals were treated with TG (20, 40, 60 mg/kg/d) for 18 d. TG treatment ameliorated MCT-induced elevations in right ventricular peak systolic pressure, right ventricular hypertrophy and the expression of atrial natriuretic peptide; N(G)-nitro-L-arginine-methyl ester (L-NAME), an NO synthase (NOS) inhibitor, had no influence on these inhibitory effects of TG 40 mg/kg/d, and TG at this dose had no any effect on the eNOS mRNA expression, suggesting the limited rule of NO in TG's effects. To further examine the mechanisms of the protection, the expression of calcineurin and its catalytic subunit CnA, as well as extracellular signal-regulated kinase-1 (ERK-1) and mitogen-activated protein kinase (MAPK) Phosphatase-1 (MKP-1) was examined. TG treatment significantly suppressed MCT-induced elevations of these signaling pathways in a dose-dependent manner. In summary, TG is effective in protecting against MCT-induced right ventricle hypertrophy, possibly through lowering pulmonary hypertension. Multiple molecular mechanisms appeared to be involved in this protection, such as the suppression of MCT-activated calcineurin and ERK signaling pathways.