Cisplatin is a chemotherapeutic drug but induces acute kidney injury (AKI). Cisplatin-induced AKI depends on several signaling pathways leading to apoptosis in tubular epithelial cells. Glutamine is a substrate for the synthesis of glutathione, the most abundant intracellular thiol and antioxidant, and plays an important role in protecting cells from apoptosis induced by different stimuli. In the present study, we investigated the protective effect of glutamine on cisplatin-induced AKI. Rats were divided into control, glutamine, cisplatin, and cisplatin plus glutamine groups. Glutamine ameliorated renal dysfunction, tissue injury, and cisplatin-induced apoptosis. Cisplatin increased cell death, caspase-3 cleavage, activation of MAPKs and p53, oxidative stress, and mRNA expression of TNF-α and TNFR1 in HK-2 cells. Glutamine treatment reduced cisplatin-induced these changes in HK-2 cells. Notably, glutamine reduced the cisplatin-induced expression of organic cation transporter 2 (OCT2) and cisplatin accumulation. Our results suggest that the protective effect of glutamine on cisplatin is specific for proximal tubular cells and the initial effects may be related to attenuation of cisplatin uptake. Thus, glutamine administration might represent a new strategy for the treatment of cisplatin-induced AKI.

Curcumin, the active ingredient of turmeric (Curcuma longa), has a wide range of beneficial effects including anti-inflammation and analgesia. However, poor bioavailability of curcumin hinders its clinical application. To overcome this limitation, we modified the structure of curcumin and synthesized new derivatives with favourable pharmacokinetic profiles. Recently, curcumin has been shown to have an antagonizing effect on transient receptor potential vanilloid type 1 (TRPV1) ion channels. We investigated the antinociceptive activity of KMS4034 which had the most favourable pharmacokinetics among the tested curcumin derivatives. To evaluate the mechanism of the antinociceptive effects of KMS4034, capsaicin (I(CAP))- and heat (I(heat))-induced currents in TRPV1 expressing HEK293 cells were observed after the application of KMS4034. Nociceptive behavioural measurement using the hot-plate test, formalin test, and chronic constriction injury (CCI) model were evaluated in mice. Also, calcitonin gene-related peptide (CGRP) was stained immunohistochemically in the L4/5 dorsal horns in mice with neuropathic pain. I(CAP) (P<0.01) and I(heat) (P<0.05) of TRPV1 were significantly blocked by 10 μM KMS4034. Behaviourally, noticeable antinociceptive effects after 10 mg kg(-1) of KMS4034 treatment were observed in the first (P<0.05) and second phases (P<0.05) of the formalin and hot-plate tests. The mechanical threshold of CCI mice treated with 10 mg kg(-1) KMS4034 was significantly increased compared with control. Immunohistochemical CGRP expression was decreased in the lamina I-II of the lumbar dorsal horns in KMS4034-treated CCI mice compared with the control (P<0.05). KMS4034 may be an effective analgesic for various pain conditions.

Bis(2-ethylhexyl) phthalate (DEHP) is the most used member of the phthalate class of compounds. Extensive use of this plasticizer allows daily exposure to humans via various routes. A positive relationship between DEHP exposure and neurobehavioral disorders is suspected. But, there are insufficient data on the harmfulness of neurobehavioral disorders caused by DEHP exposure, particularly at daily exposure levels. In this study, we assessed the consequences of daily DEHP ingestion (2 and 20 mg/kg diets) in male mice for at least 100 days and examined its effects on neuronal functions associated with neurobehavioral disorders, such as depression and cognitive decline. We found the marked depressive behaviors and reduced learning and memory function in the DEHP-ingestion groups, and that biomarkers related to chronic stress were increased in plasma and brain tissues. Long-term DEHP ingestion induced collapse of glutamate (Glu) and glutamine (Gln) homeostasis as a result of disruption of the Glu-Gln cycle in the medial prefrontal cortex and hippocampus. The reduced glutamatergic neurotransmission activity caused by DEHP ingestion was demonstrated using an electrophysiological method. This study revealed that long-term exposure to DEHP is hazardous and can cause neurobehavioral disorders, even at daily exposure levels.