Toxicological aspects of the use of phenolic compounds in disease prevention

The consumption of a diet low in fat and enhanced by fruits and vegetables, especially rich in phenolic compounds, may reduce risks of many civilization diseases. The use of traditional medicines, mainly derived from plant sources, has become an attractive segment in the management of many lifestyle diseases. Concerning the application of dietary supplements (based on phenolic compounds) in common practice, the ongoing debate over possible adverse effects of certain nutrients and dosage levels is of great importance. Since dietary supplements are not classified as drugs, their potential toxicities and interactions have not been thoroughly evaluated. First, this review will introduce phenolic compounds as natural substances beneficial for human health. Second, the potential dual mode of action of flavonoids will be outlined. Third, potential deleterious impacts of phenolic compounds utilization will be discussed: pro-oxidant and estrogenic activities, cancerogenic potential, cytotoxic effects, apoptosis induction and flavonoid-drug interaction. Finally, future trends within the research field will be indicated

Dietary anthocyanins: are they micronutrients?

Dietary anthocyanins might be seen as micronutrients. Even though they are abundant in fruits and vegetables, and thus also in our diet, they occur in plasma and tissues only in trace amounts. However, they profoundly af ect cellular metabolism, organ functioning, and have strong clinical-epidemiological evidence supporting their health-promoting ef ects

Bioavailability of flavonoids: The role of cell membrane transporters

Dietary flavonoids play an important role in the prevention of diseases related to oxidative stress in living systems. Although much attention has been focused on studying the protective functions of flavonoids, so far only limited biochemical research was done to tackle the fundamental issue of how flavonoids enter cells. Flavonoids have limited bioavailability, and consequently low plasma concentrations. Thus, in order to enter the intracellular compartment of cells in target tissues, flavonoids must exploit specific cell membrane transporter systems. This interaction between flavonoids and the proteins that mediate their transmembrane transport is of critical importance since it affects both the pharmacokinetic and pharmacodynamic properties of the flavonoids. Extensive knowledge of cell membrane transporters is therefore essential to fully understand the mechanisms of flavonoid-mediated protective activity in the cardiovascular, renal, hepatic, and central nervous systems, and also to elucidate flavonoid-drug interactions

Oxidative stress-based cytotoxicity of delphinidin and cyanidin in colon cancer cells.

Colorectal cancer is the second most frequent cause of cancer death in the western world. Although the prognosis has improved after the introduction of newer anticancer drugs, the treatment of metastatic colorectal cancer still remains a challenge due to a high percentage of drug-resistant tumor forms. We aimed at testing whether anthocyanidins exerted cytotoxicity in primary (Caco-2) and metastatic (LoVo and LoVo/ADR) colorectal cancer cell lines. Both cyanidin and delphinidin, though neither pelargonidin nor malvidin, were cytotoxic in metastatic cells only. The cell line most sensitive to anthocyanidins was the drug-resistant LoVo/ADR. There, cellular ROS accumulation, inhibition of glutathione reductase, and depletion of glutathione could be observed. This suggests that anthocyanidins may be used as sensitizing agents in metastatic colorectal cancer therapy

Effects of a physical training programme on anthropometric and fitness measures in obese and overweight police trainees and officers

This study investigated the impact of a 10-week training programme on the anthropometric characteristics and physical abilities of obese and overweight police trainees and officers. The anthropometric characteristics measured were Body mass (BM), body height (BH), body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR), while the physical ability variables included Change of direction speed ([CODS] t-test), upper-body muscular endurance (1-minute push-up) (PU), trunk muscular endurance (1-minute sit-up) (SU), and aerobic endurance (2.4km run) (RUN). A sample of 46 (n=36 obese; n=10 overweight) male police trainees (age=29.2±5.2yrs; BH=174.09±5.21cm; BM=100.55±11.99kg) were involved in a ten-week physical activity intervention study. A paired sample t-test and Cohen’s d effect size (ES) found significant changes (p<0.001) in tested anthropometric (BM, BMI, WC and WHtR) and physical ability variables (T-test, PU, SU and RUN). Findings can be used as a guideline for implementing training procedures among overweight and obese police trainees and officers in order to prevent cardiovascular issues and improve their physical fitness

Cellular antioxidant activities and cytotoxic properties of ethanolic extracts of four tropical green leafy vegetables

The present investigation sought to evaluate cellular antioxidant activities of some green leafy vegetables: Vernonia amygdalina, Asteraceae (Va,); Manihot utilissima Pohl., Euphoriaceae (Mu);Corchorous olitorius L., Malvaceae (Co) and Occimum gratissimum L., Lamiaceae (Og) against peroxyl radical-induced oxidation in HepG2 cells and also evaluate their cytotoxic properties against drug sensitive and drug resistant Lovo and Lovo/Adr cancer cell lines respectively. HPLC/DAD/MS investigation of the ethanolic extract of the vegetal matter revealed the presence of 4, 5, 6, and 7 phenolic compounds in Mu, Co, Og and Va respectively. The cellular antioxidant activity was tested with different concentrations (0.1, 0.25, 0.5 and 1.00 mg/ml dried weight) of the extracts. At a concentration of 1.00 mg/ml, the quenching of peroxyl radical in HepG2 cells as shown by the fluorescence units revealed that Og has the best inhibition capacity, followed by Co, Va respectively and with the least inhibition capacity recorded for Mu. However, pro-oxidant activities were observed at lower concentrations of Va (0.1 mg/ml) and Mu (0.1, 0.25 and 0.5 mg/ml). Cytotoxic investigation revealed that the extracts were active against both cell lines with EC50 (\ub5g/ml) ranging from 1.3 to 2.6 for Lovo and 1.5 to 2.7 for Lovo/Adr respectively, and that Va was the most active, while the least activity was recorded for Mu and Co for Lovo and Lovo Adr respectively. The observed cytotoxic properties and the elicited antioxidant activities would be due to the phytochemical constituents among which could be the rich content of flavonoids and cynammoyl derivatives as revealed by the chromatographic investigations