A novel facile method has been established for rapid on-site detection of antidiabetes chemicals used to adulterate botanical dietary supplements (BDS) for diabetes. Analytes and components of pharmaceutical matrices were separated by thin-layer chromatography (TLC) then surface-enhanced Raman spectroscopy (SERS) was used for qualitative identification of trace substances on the HPTLC plate. Optimization and standardization of the experimental conditions, for example the method used for preparation of silver colloids, the mobile phase, and the concentration of colloidal silver, resulted in a very robust and highly sensitive method which enabled successful detection when the amount of adulteration was as low as 0.001 % (w/w). The method was also highly selective, enabling successful identification of some chemicals in extremely complex herbal matrices. The established TLC-SERS method was used for analysis of real BDS used to treat diabetes, and the results obtained were verified by liquid chromatography-triple quadrupole mass spectrometry (LC-MS-MS). The study showed that TLC-SERS could be used for effective separation and detection of four chemicals used to adulterate BDS, and would have good prospects for on-site qualitative screening of BDS for adulterants.

Ephedrine and its analogues are in the list of prohibited substance in adulteration to botanical dietary supplements (BDS) for their uncontrollable stimulating side effects. However, they were always adulterated illegally in BDS to promote losing weight. In order to avoid detection, various kinds of ephedrine analogues were added rather than ephedrine itself. This has brought about great difficulties in authentication of BDS. In this study, we put forward for the first time a method which combined thin-layer chromatography (TLC) and surface-enhanced Raman scattering (SERS) to directly identify trace adulterant. Ephedrine, pseudoephedrine, methylephedrine, and norephedrine were mixed and used in this method to develop an analytical model. As a result, the four analogues were separated efficiently in TLC analysis, and trace-components and low-background SERS detection was realized. The limit of detection (LOD) of the four analogues was 0.01 mg/mL. Eight common Raman peaks (△υ = 620, 1003, 1030, 1159, 1181, 1205, 1454, 1603 cm(-1)) were extracted experimentally and statistically to characterize the common feature of ephedrine analogues. A TLC-SERS method coupled with common-peak model was adopted to examine nine practical samples, two of which were found to be adulterated with ephedrine analogues. Identification results were then confirmed by UPLC-QTOF/MS analysis. The proposed method was simple, rapid, and accurate and can also be employed to trace adulterant identification even when there are no available reference derivatives on-site or unknown types of ephedrine analogues are adulterated.

Celastrol is well known for its anti-inflammatory and anti-cancer effects. In this study, the efficacy of celastrol against dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD) in mice was established and the mechanism was investigated using lipidomics. Celastrol treatment significantly alleviated DSS-induced colitis in mice, as revealed by the body weight, colon length, scores of rectal bleeding and diarrhea, serum TNF-α level, and histological analysis results. Lipidomics analysis based on UPLC/MS revealed characteristic changes in the metabolic profiles of the colitis mice, with altered levels of lipid markers associated with IBD, including LPC18 : 0, LPC18 : 1, LPC18 : 2, sphingomyelin (SM), and increased LPC18 : 0/LPC18 : 1 and LPC18 : 0/LPC18 : 2 ratios. For the celastrol-treated colitis mice, however, levels of the above lipid markers were restored, together with recovered saturated LPC/unsaturated LPC ratios. Accordingly, using GC-MS analysis, increased stearic acid (C18 : 0)/oleic acid (C18 : 1) and stearic acid (C18 : 0)/linoleic acid (C18 : 2) ratios were observed in colitis mice, which were later recovered after celastrol treatment. Quantitative real-time PCR analysis revealed that the liver expression of stearoyl-coenzyme A desaturase 1 (SCD1), the key enzyme controlling the desaturation of saturated fatty acid, was dramatically inhibited in IBD mice, and was obviously recovered after celastrol treatment. These results suggest that the increased saturated LPC/unsaturated LPC (and saturated fatty acid/unsaturated fatty acid) ratios associated with SCD1 down-regulation could be regarded as biomarkers of colitis, and celastrol alleviates DSS-induced colitis partially via up-regulation of SCD1, restoring the altered balance between stearic acid- and oleic acid-derived lipid species, which plays an important role in alleviating colitis. In all, this study provided the scientific basis for further development of celastrol in treating IBD.

Adulteration of botanical dietary supplements with prohibited synthetic drugs has become a serious problem. In this paper, a method for testing synthetic drugs used to adulterate botanical dietary supplements was developed using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) coupled with a linearity ion-trap system in the multiple reaction monitoring (MRM) plus enhanced product ion (EPI) mode. Twenty-three drugs exhibiting various pharmacological effects, comprising blood pressure and lipid-lowering agents, sedative drugs, anti-diabetic drugs, weight-reducing agents and aphrodisiac compounds, were studied. For all drugs, a single transition was monitored using protonated molecules as precursor ions. EPI spectra were stored in a library and recognized by library searching. Several undeclared drugs were identified in herbal remedies, e.g., glibenclamide, sibutramine hydrochloride and sildenafil. Overall, 35 positive samples were found out of a total of 105 botanical dietary supplements tested. The method was selective, sensitive, rapid, high-throughput and reliable.