Kubra Koc

Biomonitoring of the genotoxic effects and oxidative potentials of commercial edible dung beetles (Onitis sp.), grasshopper (Caelifera sp.) and mole crickets (Gryllotalpa sp.) in vitro

In this investigation, the genotoxic and oxidative effects of water soluble extracts of dung beetles, flying grasshopper and mole crickets have been assessed on cultured human blood cells. The extracts were added to the culture tubes at 12 different concentrations (0–2000 ppm). Micronucleus test was used to monitor the DNA and the chromosomal damage produced by aqueous extracts in vitro. In addition, to assess the oxidative effects, total antioxidant capacity (TAC) and total oxidant status (TOS) levels were also measured. Our results indicated that these extracts did not show genotoxic effects at the tested concentrations. However, the extracts caused dose-dependent alterations in both TAC and TOS levels. Based on the findings, it was concluded that the studied insects can be consumed safely, but it is necessary to consider the cellular damages which are likely to appear depending on oxidative stress at higher concentrations. It has also been suggested that this in vitro approach for oxidative and genotoxicity assessments may be useful to evaluate the potential health risks of edible insects.

The efficacy of oleuropein against non-steroidal anti-inflammatory drug induced toxicity in rat kidney

Indomethacin is generally used in clinical therapeutics as a non‐steroidal anti‐inflammatory drug. However, its use has been limited due to the gastrointestinal and renal toxic effects of this drug. These toxic effects were associated with not only the inhibition of prostaglandin synthesis but also drug‐elevated oxidative stress. To ameliorate these toxicities, natural antioxidants can be used as an alternative and/or combination therapies. Therefore, the current study was conducted to assess the renoprotective effects of oleuropein against indomethacin‐induced renal damages. Male Sprague‐Dawley rats were pretreated with oleuropein (75, 150, and 300 mg/kg), and then treated with indomethacin (25 mg/kg). To evaluate kidney function, serum blood urea nitrogen, uric acid, and creatinine were measured. In addition, prostaglandin E2, tumor necrosis factor‐alpha, endothelial nitric oxide synthase, caspase‐3, oxidant/antioxidant status, and 8‐Oxo‐2′‐deoxyguanosine levels were determined for the antioxidative and anti‐inflammatory effects of oleuropein. Tissue sections were also histopathologically assessed. The biochemical and histopathological analysis proved the toxic effects of indomethacin on kidney. However, the pretreatment with oleuropein (300 mg/kg) protects kidney from indomethacin‐induced damages. Our study proved that prior administration of oleuropein has renoprotective activity against indomethacin‐associated toxicities.

Impact of high-dose oleuropein on cisplatin-induced oxidative stress, genotoxicity and pathological changes in rat stomach and lung

Abstract The current systemic treatments of the various solid tumors involve Cisplatin (CIS)-based chemotherapy. Due to its cytotoxicity, this approach is limited. Moreover, the safety of CIS is only discussed especially in breast and stomach cancers. Therefore, we, for the first time, explored the restorative efficacy of oleuropein (OLE), in stomach and lung injuries induced by CIS. Sprague-Dawley rats were divided into eight groups: control CIS, OLE and CIS + OLE. Single dose of (7 mg/kg) CIS was administered intraperitoneally to CIS and CIS + OLE groups. After 24 h, 50, 100 and 200 mg/kg OLE was given for three consecutive days to OLE and CIS + OLE groups. The 8-OH-dG, total oxidative/antioxidant status (TOS/TAS) and malondialdehyde (MDA) levels were evaluated and histopathological analyses were performed on the studied tissues. The results indicated that CIS significantly increased 8-OH-dG, MDA and TOS levels and caused severe tissue damages. However, high dose of OLE induced a significant decrease in the 8-OH-dG, MDA levels, an increase in TAS levels and it restores CIS-induced tissue damages. We hope that the results of this study will provide an impetus for future studies on novel therapeutic strategies including the protective use of oleuropein in gastric and lung cancers due to chemotherapy.