Inhibition of Tumor Growth and Modulation of Antioxidant Activity of Rhodoxanthin Isolated from Taxus baccata Aril against B16F10 Murine Malignant Melanoma.

Malignant melanoma is the most aggressive type of skin cancer, and due to the numerous limitations of current treatment methods, there is an urgent need to develop novel approaches for both the prevention and treatment of malignant melanoma, with research-oriented bioactive substances representing a notable first step. The current study decided to expand on previous rhodoxanthin research by investigating the possible anti-tumor effect as well as the effect on the antioxidant status in the case of murine melanoma in an experimental model. The 21-day study was carried out on female C57BL/6J mice. On the first day of the experiment, they were subcutaneously inoculated with 106 B16F10 cells and were given rhodoxanthin orally until the end of the study. Rhodoxanthin supplementation significantly reduced tumor growth (42.18%) and weight (15.74%). Furthermore, the epidermal growth factor (EGF) activity was reduced and the concentration of 8-OHdG dropped in the treated melanoma-bearing mice compared to the untreated ones, demonstrating the role of rhodoxanthin in slowing tumor growth, one of the mechanisms being the reduction of EGF level and the decrease of DNA oxidation. The administration of rhodoxanthin determined variations in antioxidant enzymes, both at the plasma level and at the tissue level.

Phytochemical Characterization of Taxus baccata L. Aril with Emphasis on Evaluation of the Antiproliferative and Pro-Apoptotic Activity of Rhodoxanthin.

Taxus baccata L., an evergreen tree, was known until recently due to its high concentration of toxic compounds. The purpose of the present study was to focus on the only non-poisonous part, the red arils, which have recently been described as an important source of various bioactive constituents. To establish total phenolic, flavonoid, and carotenoid content, antioxidant capacity, and cytotoxic properties, two types of extracts were obtained. The chemical profile of the ethanolic extract was evaluated using chromatographic (HPLC-DAD-ESI+) and spectral (UV-Vis) methods, and the antioxidant activity of the ethanolic extract was assessed using DPPH and FRAP assays, yielding moderate results. In the second type of extract (methanol: ethyl acetate: petroleum ether (1:1:1, v/v/v)) we identified three carotenoids using open column chromatography and RP-PAD-HPLC, with rhodoxanthin being the most abundant. Considering the above and mainly because of the lack of information in the literature about this pigment and its biological effects, we decided to further investigate the cytotoxic activity of rhodoxanthin, the main carotenoid presented in aril, and its protective effect against H2O2-induced oxidative stress using two cell lines: human HaCaT keratinocytes and B16F10 murine malignant melanoma. The MTT and Annexin-V Apoptosis assays showed a substantial cytotoxic potential expressed in a dose-dependent manner towards the melanoma cell line, however, no obvious cytotoxic effects on human keratinocytes were noticed.

Natural Endotoxemia in Dogs-A Hidden Condition That Can Be Treated with a Potential Probiotic Containing Bacillus subtilis, Bacillus licheniformis and Pediococcus acidilactici: A Study Model.

Spore-based Bacillus spp. products are considered to have a higher probiotic potential compared to products containing only lactic acid bacteria because their viability in the gastrointestinal (GI) tract is higher, even when GI environmental conditions are unfavorable. The aim of this study was to assess the effect of a Bacillus subtilis, Bacillus licheniformis and Pediococcus acidilactici spore-based potential probiotic on the natural levels of postprandial endotoxemia. A total of 11 dogs completed the study: group 1-healthy dogs: n = 5; group 2-dogs with apparent dysbiosis: n = 6. For 30 days, the dogs were fed the probiotic product; clinical examinations and blood sampling were done before and after completion of the probiotic treatment. Endotoxin levels were assessed pre-meal, 6 h and 12 h post-meal, before initiation and after completion of the treatment. The results showed a decrease in endotoxin levels after treatment, especially 12 h post-meal (group 1: 20.60%; group 2: 44.93%). This study reports new information with regard to natural endotoxemia levels in dogs and suggests that a multi-strain formula (spore-based) consisting of B. subtilis, B. licheniformis and P. acidilactici is able to diminish endotoxin values.