Anti-inflammatory, analgesic and anti-tumor properties of gold nanoparticles.

BACKGROUND: Gold nanoparticles (GNPs) are regarded as potential platforms for drug delivery. However, their interaction with live organisms must be understood prior to their utilization as drug carriers. The present study reports the anti-inflammatory, analgesic and anti-tumor effects of GNPs. The biodistribution of GNPs and their effect on various tissues have also been studied. METHODS: GNPs were synthesized through an environmentally friendly route and characterized with TEM and UV-vis. After HT-29 cells had been exposed to GNPs, apoptosis was assessed with Annexin V and propidium iodide staining and caspase-3 activity determined with a confocal laser scanning microscope. GNPs were administrated to male and female Swiss mice for posterior assessment of their anti-inflammatory and analgesic properties. The biodistribution of GNPs and their impact on tissues were studied with UV-vis and histopathological analysis, respectively. RESULTS: Cell apoptosis was observed in a dose-dependent manner for GNPs concentrations ranging from 40µg/mL to 80µg/mL (p<0.05). The best anti-inflammatory activity was observed at the dose of 1500µg/kg, which caused a reduction of 49.3% in leukocyte migration. GNPs showed peripheral analgesia at the dose of 1500µg/kg and have been found in liver, spleen, kidney and lungs. Histopathological examination revealed extravasation of red blood cells in lungs. CONCLUSION: The study draws attention to gold nanoparticles as a resource for technological innovation in the anti-inflammatory, analgesic and anti-tumor fields. GNPs have biological effects that deserve investigation to assess their full interaction with organic systems.

Telmisartan induces apoptosis and regulates Bcl-2 in human renal cancer cells.

It has been well-characterized that the renin-angiotensin system (RAS) physiologically regulates systemic arterial pressure. However, RAS signaling has also been shown to increase cell proliferation during malignancy, and angiotensin receptor blockers (ARBs) are able to decrease pro-survival signaling by inhibiting anti-apoptotic molecules and suppressing caspase activity. In this study, the apoptotic effects of telmisartan, a type of ARB, was evaluated using a non-cancerous human renal cell line (HEK) and a human renal cell carcinoma (RCC) cell line (786). Both types of cells were treated with telmisartan for 4 h, 24 h, and 48 h, and then were assayed for levels of apoptosis, caspase-3, and Bcl-2 using MTT assays, flow cytometry, and immunostaining studies. Analysis of variance was used to identify significant differences between these data (P < 0.05). Following the treatment of 786 cells with 100 µM and 200 µM telmisartan, a marked inhibition of cell proliferation was observed. 50 µM cisplatin also caused high inhibition of these cells. Moreover, these inhibitions were both concentration- and time-dependent (P < 0.05). Various apoptotic effects were also observed compared with control cells at the 24 h and 48 h timepoints assayed (P < 0.001). Furthermore, positive caspase-3 staining and down-regulation of Bcl-2 were detected, consistent with induction of cell death. In contrast, treatment of HEK cells with telmisartan did not produce an apoptotic effect compared with control cells at the 24 h timepoint (P > 0.05). Treatment with cisplatin promoted in HEK cells high index of apoptosis (P < 0.001). Taken together, these results suggest that telmisartan induces apoptosis via down-regulation of Bcl-2 and involvement of caspase-3 in human RCC cells.