No abstract

Cellular imaging after transplantation may provide important information to determine the efficacy of stem cell therapy. We have reported that graphene quantum dots (GQDs) are a type of robust biological labeling agent for stem cells that demonstrate little cytotoxicity. In this study, we examined the interactions of GQDs on human neural stem cells (hNSCs) with the aim to investigate the uptake and biocompatibility of GQDs. We examined the mechanism of GQD uptake by hNSCs and investigated the effects of GQDs on the proliferation, metabolic activity, and differentiation potential of hNSCs. This information is critical to assess the suitability of GQDs for stem cell tracking. Our results indicated that GQDs were taken up into hNSCs in a concentration- and time-dependent manner via the endocytosis mechanism. Furthermore, no significant change was found in the viability, proliferation, metabolic activity, and differentiation potential of hNSCs after treatment with GQDs. Thus, these data open a promising avenue for labeling stem cells with GQDs and also offer a potential opportunity to develop GQDs for biomedical applications.

No abstract

An increasing number of cancer patients are using herbs in combination with conventional chemotherapeutic treatment. It is therefore important to study the potential consequences of the interactions between herbs and anticancer drugs. The effects of extracts from Panax ginseng (PGS) and Salvia miltiorrhiza Bunge (SMB) on the pharmacokinetics of 5-fluorouracil (5-FU) were performed in vivo and detected by high performance liquid chromatography (HPLC), while, an ATP assay was used to study the pharmacodynamic interactions in vitro. The results of the pharmacokinetic experiments showed a significant increase in the elimination half-life (t1/2(k e )) of 5-FU in the PGS-pretreated group and in the area under the curve (AUC) in the SMB-pretreated group compared with the control group. However, after SMB pretreatment, weight loss was observed in rats. The results of pharmacodynamic experiments showed that neither PGS nor SMB, when used alone, directly inhibited cancer cell growth at 0.1-100 μg/ml. Moreover, PGS had a synergistic cytotoxic effect with 5-FU on human gastric cancer cells but not on normal gastric cells. The results imply that when combined with 5-FU, PGS may be a better candidate for further study. This study might provide insights for the selection of herbal-chemotherapy agent interactions.

Jitai tablet (JTT) is a traditional Chinese medicine used to treat neuropsychiatric disorders. We previously demonstrated that JTT treatment led to increased level of dopamine transporter (DAT) in the striatum, thus indicating that JTT might have therapeutic potential for Parkinson's disease (PD), which is characterized by dysregulated dopamine (DA) transmission and decreased striatal DAT expression. The aim of this study was to investigate the neuroprotective effect of JTT on MPTP-induced PD mice. Using locomotor activity test and rotarod test, we evaluated the effects of JTT (0.50, 0.15, or 0.05 g/kg) on MPTP-induced behavioral impairments. Tyrosine hydroxylase TH-positive neurons in the substantia nigra and DAT and dopamine D2 receptor (D2R) levels in the striatum were detected by immunohistochemical staining and/or autoradiography. Levels of DA and its metabolites were determined by HPLC. In MPTP-treated mice, behavioral impairments were alleviated by JTT treatment. Moreover, JTT protected against impairment of TH-positive neurons and attenuated the MPTP-induced decreases in DAT and D2R. Finally, high dose of JTT (0.50 g/kg) inhibited the MPTP-induced increase in DA metabolism rate. Taken together, results from our present study provide evidence that JTT offers neuroprotective effects against the neurotoxicity of MPTP and thus might be a potential treatment for PD.