Backgroundβ-Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anti-cancer effects against a broad spectrum of tumors. The mechanism by which β-elemene kills cells remains unclear. The aim of the present study is to investigate the anti-tumor effect of β-elemene on human gastric cancer cells and the molecular mechanism involved.Resultsβ-Elemene inhibited the viability of human gastric cancer MGC803 and SGC7901 cells in a dose-dependent manner. The suppression of cell viability was due to the induction of apoptosis. A robust autophagy was observed in the cells treated with β-elemene; it was characterized by the increase of punctate LC3 dots, the cellular morphology, and the increased levels of LC3-II protein. Further study showed that β-elemene treatment up-regulated Atg5-Atg12 conjugated protein but had little effect on other autophagy-related proteins. PI3K/Akt/mTOR/p70S6K1 activity was inhibited by β-elemene. Knockdown of Beclin 1 with small interfering RNA, or co-treatment with the autophagy inhibitor, 3-methyladenine or chlorochine enhanced significantly the antitumor effects of β-elemene.ConclusionsOur data provides the first evidence that β-elemene induces protective autophagy and prevents human gastric cancer cells from undergoing apoptosis. A combination of β-elemene with autophagy inhibitor might thus be a useful therapeutic option for advanced gastric cancer.

A portable kit was demonstrated for rapid and reliable surface-enhanced Raman scattering (SERS) detection of drugs in human urine. This kit contains two sealed reagent tubes, a packet of standardized SERS substrates, and a mini Raman device. A 3 min pretreatment for separating amphetamines from human urine was developed with an extraction rate of >80% examined by ultraperformance liquid chromatography (UPLC). Simultaneously, highly reproducible two-dimensional (2D) gold nanorod (GNR) arrays were assembled by the use of methoxymercaptopoly(ethylene glycol) (mPEG-SH) capping. Thirty batches of GNR arrays produced the 1001 cm(-1) intensity of methamphetamine (MA) molecules with a relative standard deviation (RSD) of 7.9%, and a 21 × 21 μm(2) area mapping on a 2D GNR array produced a statistical RSD of <10%, implying an excellent reproducibility and uniformity. The detection limit of amphetamines in human urine was at least 0.1 ppm. Moreover, the portable kit was successfully used for detecting MA, 3,4-methylenedioxymethamphetamine (MDMA), and methcathinone (MC) in 30 volunteers' urine samples with various clinical natures, and the dual-analyte detection of MA and MDMA implied a good capability of multiplex analysis. UPLC examination and the SERS recovery test clearly indicated that our pretreatment procedure was sufficient to lower the high background signals caused by complex components in urine and demonstrated the practicability and the resistance to false positives, which is a vital problem for law enforcement applications. The excellent performance of our portable kit promises a great prospective toward a rapid, reliable, and on-spot analyzer, especially for public safety and healthcare.