Evaluation of colloidal platinum on cytotoxicity, oxidative stress and barrier permeability across the gut epithelium

Abstract

Colloidal platinum (Pt) is widely consumed due to its health promoting benefits. However, the exact biological effects of these nanoparticles have not been studied in detail, particularly in the gut. In the present study we observed that colloidal Pt was not cytotoxic towards three different epithelial colon cancer cell lines. Co-treatment of the colon cancer cell line Caco-2 with the oxidative stress inducing agent hydrogen peroxide (H2O2) and colloidal Pt resulted in a significant decrease in H2O2 induced oxidative stress. Colloidal Pt by itself did not induce any oxidative stress. Additionally, both overnight pretreatment of Caco-2 cells with colloidal Pt followed by 1 h treatment with H2O2, or co-treatment of cells for 1 h with colloidal Pt and H2O2 resulted in a significant recovery of cell death. Of note, the same protective effects of colloidal Pt were not observed when the oxidative stress was induced in the presence of 2, 2-azobis (2-amidinopropane) dihydrochloride, indicating that the source of free radicals may define the outcome of anti-oxidant activity of colloidal Pt. Colloidal Pt was also able to cross a model intestinal barrier formed in vitro with differentiated Caco-2 cells easily. Overall, our data indicate that colloidal Pt was not toxic towards intestinal epithelial cells, reduced H2O2 induced oxidative stress, protected from oxidative stress related death of intestinal epithelial cells and could pass a model gut barrier easily. Colloidal Pt can therefore be consumed orally for its anti-oxidant and other health promoting benefits.

In vitro impact of platinum nanoparticles on inner ear related cell culture models

“…So far, our results seemed to be in line with in vitro studies exposing numerous animal and human cell lines to Pt-NP with less than 10 nm in particle size and within a certain concentration range: No or moderate cell death induction have been described up to 80 μg/ml [ 31 – 36 , 41 , 49 ], only higher Pt-NP concentrations exposed to both healthy and tumor cells induced stress and DNA damage [ 31 – 33 , 49 , 50 ]. It is well known, that Pt-NP may also display enzymological properties for scavenging H 2 O 2 and superoxide anion radicals [ 37 – 41 , 58 , 59 ], which could be demonstrated in tests with Pt-NP sizes from 1 to 5 nm in several cell lines. Hereby, 1 nm Pt-NP showed the highest ability for scavenging of reactive oxygen species and, thus, no cytotoxicity could be confirmed at Pt-NP concentrations as high as 50 μg/ml [ 30 ].…”

“…Some reports confirmed any cytotoxic effects of Pt-NPs with average size below 10 nm and at concentrations below 100 μg/ml in several human and animal cell lines [ 30 – 36 ]. Furthermore, Pt-NP are very well characterized as reactive oxygen species scavenger [ 30 , 37 – 41 ]. On the other hand, it has also been reported that 1–9 nm sized Pt-NP induced oxidative stress, inflammation, chromosome condensation or other negative biological effects in a concentration depending manner in normal and cancer cells of both human and animals, bacteria and algae [ 31 , 35 , 42 – 49 ].…”

<p>Platinum Nanoparticles As A Therapeutic Agent Against Dextran Sodium Sulfate-Induced Colitis In Mice</p>

“…PtNPs have been reported to be nontoxic to intestinal epithelial cells at a concentration of up to 80 μg/mL, 31 so PtNPs at the gavage concentration of 2.8 μg/mL in our animal experiment were unlikely to irritate intestinal epithelium. By damaging proteins, DNA and lipids, oxidative stress induces the pathogenesis of a myriad of diseases such as diabetes, neurodegeneration, atherosclerosis and cancer, while antioxidant supplementation has been recognized to exert favorable effects on disease control by restoring the redox balance.…”

Lactobacillus frumentiimproves antioxidant capacityvianitric oxide synthase 1 in intestinal epithelial cells

“…Furthermore, we found that the increase in TEER and decrease in P app were both inhibited by NPA, suggesting that L. frumenti-induced intestinal epithelial barrier function enhancement is dependent on the NOS1-mediated NO production. To investigate whether the facilitation of intestinal epithelial barrier function is associated with L. frumenti-induced antioxidant capacity enhancement, we established an oxidative stress model using H 2 O 2 stimulation as previously reported (28,54). Our data showed that the intestinal epithelial barrier function was damaged by H 2 O 2 -induced oxidative stress and the damage can be rescued by L. frumenti pretreatment.…”