Sodium p-hydroxybenzoate alleviates osteoporosis through inhibiting bone metabolism and oxidative stress via activating ERα.

As the population ages, the incidence of osteoporosis (OP) gradually increases and is becoming a growing public health problem. Meanwhile, although traditional pharmacological therapy is extremely efficient in the treatment of OP, its application is constrained because of irreversible adverse drug reactions. Therefore, scientists should actively develop safer drugs while ensuring the therapeutic effect of OP. Previous studies have shown that p-hydroxybenzoic acid (HA) can upregulate the expression of estrogen receptor (ER). Sodium p-hydroxybenzoate (DSN160) is a sodium salt of HA with a lethal dose greater than 5g/kg. However, whether DSN160 has demonstrable anti-osteoporotic activities remains unclear. In this study, DSN160 increased the organ index, length and diameter of the bone and bone mineral density and improved bone microstructure in retinoic acid-induced OP rats. Furthermore, DSN160 reduced bone metabolism-related indicators. In addition, fulvestrant (a specific antagonist of ER) blocked the anti-OP effect of DSN160. In conclusion, our findings showed that DSN160 exerts anti-OP effect through inhibiting bone metabolism and oxidative stress via activating ERα.

Relative safety and efficacy of topical and oral NSAIDs in the treatment of osteoarthritis: A systematic review and meta-analysis.

BACKGROUND: Osteoarthritis (OA) often affects the hands, knees, and hip joints, causing considerable pain and disability, and often affecting the patient's quality of life. Non-steroidal anti-inflammatory drugs (NSAIDs) are common pain relievers often applied as first line therapies for OA. However, prolonged NSAIDs application can have unwanted side effects. Given this, this study was designed to systematically evaluate the efficacy and safety of topical and oral NSAIDs for the treatment of OA. METHODS: We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for relevant papers from their inception dates to May 2021. Our study only included randomized controlled trials comparing topical and oral NSAIDs and all data were analyzed using Review Manager version 5.3 (RevMan version 5.3). RESULTS: We identified 8 RCTs (2096 patients with OA), for evaluation and revealed that, in general, topical and oral NSAIDs presented with similar efficacies for the treatment of OA. The Western Ontario and McMaster Osteoarthritis Index for assessing pain relief in OA patients was (standardized mean difference [SMD] 0.07; 95%CI -0.02, 0.17) and visual analog scale was (SMD -0.01; 95%CI -0.02, 0.18), and improved stiffness in OA patients (SMD 0.09; 95%Cl 0.03, 0.20). CONCLUSIONS: Topical NSAIDs are as effective as oral NSAIDs for the treatment of OA and both topical and oral NSAIDs are equally effective in reducing pain and improving physical function in OA patients. In terms of safety, a larger number of samples are still needed to determine if there are any differences in the safety profile of topical or oral NSAIDs. REGISTRATION NUMBER: INPLASY 2021110009.

[Effects of different long-term fertilization on the activities of enzymes related to carbon, nitrogen, and phosphorus cycles in a red soil].

Using a microplate fluorimetric assay method, five fertilization treatments, i.e. no-fertilizer control (CK) , sole application of nitrogen (N), balanced application of nitrogen, phosphorus, and potassium fertilizer (NPK), application of pig manure (M), and combination of pig manure with balanced chemical fertilizer (MNPK) were selected to investigate the effects of different long-term fertilization regimes on the activity of five enzymes (ß-1, 4-glucosidase, ßG; cellobiohydrolase, CBH; ß-1, 4-xylosidase, ßX; ß-1, 4-N-acetylglucosaminidase, NAG; acid phosphatase, AP) in a red soil sampled from Qiyang, Hunnan Province. The results showed that compared with CK treatment, N treatment had no impact on ßG, ßX, CBH, and NAG activities but reduced AP activity, while NPK, M and MNPK treatments increased the activities of all the five enzymes. Correlation analysis indicated that all the five enzyme activities were positively correlated with the content of nitrate (r=0.465-0.733) , the content of available phosphorus (r=0.612-0.947) , soil respiration (r=0.781-0.949) and crop yield (r=0.735-0.960), while ßG, CBH and AP were positively correlated with pH (r= 0.707-0.809), only AP was significantly correlated with dissolvable organic carbon (r = -0.480). These results suggested that the activities of the measured enzymes could be used as indicators of red soil fertility under different fertilization regimes, but the five enzymes tested provided limited information on the degree of acidification induced by application of mineral nitrogen.