Diterpene glycosides from Fructus Rubi ameliorates benign prostatic hyperplasia in rats through the androgen and TGF-ß/Smad signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Fructus Rubi (FR), a food material with medicinal value, is used in traditional Chinese medicine (TCM) for treatment of various kidney-related problems, such as impotence, spermatorrhea, and frequent urination. It is also frequently used to produce diverse functional foods in China. AIM OF STUDY: The purpose of this research was to assess the therapeutic effects of FR diterpene glycosides on RWPE-1 epithelial cell (RWPE-1), a human normal prostatic epithelial cell, and benign prostate hyperplasia (BPH) rats, both of which had been exposed to dihydrotestosterone (DHT) and testosterone propionate (TP), respectively, and to investigate the mechanism of action. METHODS: Target proteins that could stably bind to certain diterpene glycosides were screened through drug affinity responsive target stability combined with mass spectrometry (DARTS/MS). DHT-induced RWPE-1 cells were used to detect drug activity. TP was subcutaneously injected to induce BPH in rats. The extract of diterpene glycosides from FR (FDS) was orally administered for 28 days. The DHT levels in the serum and prostate tissue of the rats were measured through enzyme-linked immunosorbent assay (ELISA), and to analyze cell proliferation and epithelial-mesenchymal transition (EMT), the protein expression of prostate-specific antigen (PSA), androgen receptor (AR), steroid 5α-reductase type 2 (SRD5A2), proliferating cell nuclear antigen (PCNA), S100 calcium-binding protein A2 (S100A2), transforming growth factor-ß1 (TGF-ß1), E-cadherin, vimentin, and Smad4 was determined through western blotting (WB), immunohistochemistry (IHC), or immunofluorescence (IF). RESULTS: FDS reduced the proliferation of DHT-induced RWPE-1 cells. It also significantly inhibited rat prostate enlargement; decreased DHT levels in the serum and prostate tissue; inhibited the protein expression of AR, PSA, PCNA, S100A2, TGF-ß1, E-cadherin, and Smad4; and increased the protein expression of E-cadherin. CONCLUSION: The present study is the first to report that diterpene glycosides isolated from FR inhibited BPH at the cellular level, regulated the proliferation of prostate cells through the androgen signaling pathway, and prevented EMT in the prostate through the S100A2-mediated TGF-ß/Smad signaling pathway. These results indicate that FDS is a promising multitarget therapy for BPH.

Constituents of the fruits of Rubus chingii Hu and their neuroprotective effects on human neuroblastoma SH-SY5Y cells.

Rubi fructus (Rubus chingii Hu) is a fruit of Rubus genus and is used in medicine and food applications. In this study, eight new phenylpropanoids (1-8) and seven known compounds (9-15) were isolated from the dried fruits of Rubus chingii Hu, and their structures were characterized through high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. Electronic circular dichroism (ECD) experiments were performed, and the results were compared with ECD spectra. Compound 3 was characterized through extensive single crystal X-ray diffraction. Evaluation of the neuroprotective pharmacological activities revealed that compounds 6, 7, 9, and 14 exerted protective effects against H2O2-induced neurotoxicity by reducing the reactive oxygen species levels at concentrations of 50 and 100 µM. Moreover, the three compounds 6, 9, and 14 significantly inhibited the expression of the Casp3 gene at a concentration of 50 µM. Compounds 7 and 9 effectively repressed the expression of the MYC gene. Compounds 6 and 9 obviously upregulated the ratio of Bcl2/Bax in SH-SY5Y cells and inhibited cell apoptosis. The study results can be used as a reference for the development of R. chingii products to realize their neuroprotective functions in the future.

Retraction Note to: Analysis of loxoprofen in tablets, patches, and equine urine as tert-butyldimethylsilyl derivative by gas chromatography-mass spectrometry.

The authors have retracted this article [1] because after publication they became aware that the equine urine samples analysed for loxoprofen in this study were in fact equine plasma samples. Therefore the results and conclusions of this article cannot be relied upon. All authors agree to this retraction.

Analysis of loxoprofen in tablets, patches, and equine urine as tert-butyldimethylsilyl derivative by gas chromatography-mass spectrometry.

Loxoprofen is a non-steroidal anti-inflammatory drug of the 2-arylpropionic acid type, which has used to treat musculoskeletal disorders in the horse racing industry. However, it has also used illicitly to mask clinical signs of inflammation and pain in racehorses. Thus, its accurate analysis has become an important issue in horse doping laboratories. In this study, an analytical method of loxoprofen was developed as tert-butyldimethylsilyl (TBDMS) derivative by gas chromatography-mass spectrometry (GC-MS). Characteristic fragment ions of [M-15], [M-57], and [M-139] permitted the accurate and selective detection of loxoprofen. Under optimal conditions, this method showed good linearity (r ≥ 0.999) in the range of 10-500 ng/mL, repeatability (% relative standard deviation = 5.6-8.5), and accuracy (% relative error = - 0.3-0.9) with a detection limit of 1.0 ng. When applied to the analysis of loxoprofen in tablet and patch products, loxoprofen was positively identified as TBDMS derivative by GC-MS. The present method provided rapid and accurate determination of loxoprofen in patch and tablet products. Levels of loxoprofen were highest in equine urine at 0.5 and 1 h after oral administration with single dose (3 mg/kg) to three horses, and then rapidly reduced to below the lower limit of quantification at 24 h. Therefore, the present method will be useful for the pharmacokinetic study and doping tests for loxoprofen and other similar acidic drugs in horses.

Gas chromatographic-mass spectrometric analyses of cholesterol and its precursors in rat plasma as tert-butyldimethylsilyl derivatives.

BACKGROUND: Cholesterol and its metabolic precursors occurring in metabolic pathways are important biochemical indicators in pathological conditions. METHODS: A method for the simultaneous determination of cholesterol and its metabolic precursors, such as lanosterol and 7-dehydrocholesterol, in rat plasma is demonstrated. It involves their extraction after saponification, followed by conversion to tert-butyldimethylsilyl (TBDMS) derivatives for analysis by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode (GC-SIM-MS). RESULTS: The characteristic fragment ions of [M-57], m/z 443, 483, and 441 permitted the accurate and selective detection of cholesterol and its precursors in rat plasma. The whole procedure of TBDMS derivatization, with subsequent GC-SIM-MS analysis, was linear (r>or=0.9994), reproducible (% relative standard deviation=2.2 to 7.5), and accurate (% relative error=-5.6 to 7.7), with detection limits of 0.02 to 0.07 ng/ml. Recoveries were measured to be ranged from 89.5 to 95.4%. CONCLUSION: The present method was useful for the quantification of cholesterol and its precursors in rat plasma samples of 1 microl.