Inflammation and oxidative stress are two major causes of various life-threatening diseases. Hesperidin (Hsd) and its aglycone, hesperetin (Hst), are two flavonoids from citrus species that have numerous biological properties, particularly antioxidant and anti-inflammatory. New findings showed that the antioxidant activity of Hsd/Hst was not only limited to its radical scavenging activity, but it augmented the antioxidant cellular defenses via the ERK/Nrf2 signaling pathway as well. Various in vitro and in vivo studies have been conducted to evaluate Hsd, its metabolites, or its synthetic derivatives at reducing inflammatory targets including NF-κB, iNOS, and COX-2, and the markers of chronic inflammation. In this review, new findings regarding the molecular targets of Hsd and Hst in the reduction of oxidative stress are discussed. Also, in the anti-inflammatory section, we provide a summary of significant investigations concerning the mechanisms of action based on the studied inflammation models.

Based on World Health Organization reports, resistance of bacteria to well-known antibiotics is a major global health challenge now and in the future. Different strategies have been proposed to tackle this problem including inhibition of multidrug resistance pumps and biofilm formation in bacteria and development of new antibiotics with novel mechanism of action. Flavonoids are a large class of natural compounds, have been extensively studied for their antibacterial activity, and more than 150 articles have been published on this topic since 2005. Over the past decade, some promising results were obtained with the antibacterial activity of flavonoids. In some cases, flavonoids (especially chalcones) showed up to sixfold stronger antibacterial activities than standard drugs in the market. Some synthetic derivatives of flavonoids also exhibited remarkable antibacterial activities with 20-to 80-fold more potent activity than the standard drug against multidrug-resistant Gram-negative and Gram-positive bacteria (including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus). This review summarizes the ever changing information on antibacterial activity of flavonoids since 2005, with a special focus on the structure-activity relationship and mechanisms of actions of this broad class of natural compounds.

Natural antioxidants, including polyphenols, flavonoids, anthocyanins and carotenoids, play an important role in the treatment and prevention of a large number of diseases. However, studies indicate that natural antioxidants can act as prooxidants, which produce free radicals and cause DNA damage and mutagenesis. The prooxidant activity is typically catalyzed by metals, particularly transition metals such as Fe and Cu, present in biological systems. In this article, we aim to review new in vitro and in vivo evidence of the prooxidant activity of phenolics, flavonoids, anthocyanins and carotenoids. We highlight the role of catalyzing metals, including transition metals, non-transition metals and metalloids, in the prooxidant activity of natural antioxidants. Prooxidant structure-activity relationships of simple phenolics, flavonoids and anthocyanins and the role of cellular antioxidant defense, including endogenous antioxidant compounds and antioxidant enzymes, are also addressed in this review. In addition, we discuss the question, With respect to in vitro evidence of the prooxidant activity of antioxidants, can we translate this activity into biological systems and the human body? Copyright © 2016 John Wiley & Sons, Ltd.

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Dyslipidemia is a leading risk factor for cardiovascular disease and is also a common feature of obesity. Curcumin is a bioactive phytochemical with well-known antioxidant, anti-inflammatory, and cardioprotective properties. The present study investigated the hypolipidemic activity of curcumin in obese individuals. Participants (n = 30) were treated with curcuminoids (1 g/day), or placebo in a randomized, double-blind, placebo-controlled, crossover trial. Serum concentrations of total cholesterol, triglycerides, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, together with anthropometric parameters and high-sensitivity C-reactive protein were measured before and after each treatment period. Anthropometric parameters including weight, BMI, waist circumference, hip circumference, arm circumference, and body fat remained statistically unchanged by the end of trial (p > 0.05). As for the lipid profile parameters, serum triglycerides were significantly reduced following curcumin supplementation (p = 0.009). However, curcuminoids were not found to affect serum levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and high-sensitivity C-reactive protein (p > 0.05). In summary, the findings of the present study indicated that curcuminoid supplementation (1 g/day for 30 days) leads to a significant reduction in serum triglycerides concentrations but do not have a significant influence on other lipid profile parameters as well as body mass index and body fat.

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Curcumin has a potential anti-anxiety effect in individuals with obesity.