Effect of ethyl acetate extract of usnea longissima on esophagogastric adenocarcinoma in rats

Abstract Purpose: To investigate the effects of the EtOAc extract of U. longissima which is uninvestigated previously on esophagogastric cancer induced in rats with N-methyl-N-nitro-N-nitrosoguanidin (MNNG). Methods: The anticancer activity of EtOAc extract of U. longissima was examined in the esophagogastric adenocarcinoma models induced in rats with MNNG. EtOAc extract of U. longissima, 50 and 100 mg/kg oral doses were administered once daily for six months. MNNG induced differentiated and undifferentiated type adenocarcinomas in the esophageal and gastric tissues of rats. Results: EtOAc extract of U. longissima obtained from U. longissima prevented gastric and esophageal cancerogenesis induced in rats with MNNG. EtOAc extract of U. longissima did not have a lethal effect at doses of 500, 1000 and 2000 mg/kg. The prominent anticarcinogenic activity of EtOAc extract of U. longissima 50 and 100 mg/kg suggests that it is not toxic and it is selective to the cancer tissue. Conclusion: This information may shed light on clinical implementation of EtOAc extract of U. longissima in future.

Effect of thiamine pyrophosphate on retinopathy induced by hyperglycemia in rats: A biochemical and pathological evaluation.

Purpose: Information is lacking on the protective effects of thiamine pyrophosphate (TPP) against hyperglycemia‑induced retinopathy in rats. This study investigated the biochemical and histopathological aspects of the effect of TPP on hyperglycemia‑induced retinopathy induced by alloxan in rats. Materials and Methods: The rats were separated into a diabetic TPP‑administered group (DTPG), a diabetes control group (DCG) and a healthy group (HG). While the DTPG was given TPP, the DCG and HG were administered distilled water as a solvent at the same concentrations. This procedure was repeated daily for 3 months. At the end of this period, all of the rats were euthanized under thiopental sodium anesthesia, and biochemical and histopathological analyses of the ocular retinal tissues were performed. The results of the DTPG were compared with those of the DCG and HG. Results: TPP prevented hyperglycemia by increasing the amount of malondialdehyde and decreasing endogen antioxidants, including total glutathione, glutathione reductase, glutathione S‑transferase and superoxide dismutase. In addition, the amounts of the DNA oxidation product 8‑hydroxyguanine were significantly lower in the retinas of the DTPG compared to the DCG. In the retinas of the DCG, there was a marked increase in vascular structures and congestion, in addition to edema. In contrast, little vascularization and edema were observed in the DTPG, and there was no congestion. The results suggest that TPP significantly reduced the degree of hyperglycemia‑induced retinopathy. Conclusions: The results of this study indicate that TPP may be useful for prophylaxis against diabetic retinopathy.