High-density lipoproteins (HDL) comprise a heterogeneous family of lipoprotein particles divided into subclasses that are determined by density, size and surface charge as well as protein composition. Epidemiological studies have suggested an inverse correlation between High-density lipoprotein-cholesterol (HDL-C) levels and the risk of cardiovascular diseases and atherosclerosis. HDLs promote reverse cholesterol transport (RCT) and have several atheroprotective functions such as anti-inflammation, anti-thrombosis, and anti-oxidation. HDLs are considered to be atheroprotective because they are associated in serum with paraoxonases (PONs) which protect HDL from oxidation. Polyphenol consumption reduces the risk of chronic diseases in humans. Polyphenols increase the binding of HDL to PON1, increasing the catalytic activity of PON1. This review summarizes the evidence currently available regarding pharmacological and alternative treatments aimed at improving the functionality of HDL-C. Information on the effectiveness of the treatments has contributed to the understanding of the molecular mechanisms that regulate plasma levels of HDL-C, thereby promoting the development of more effective treatment of cardiovascular diseases. For that purpose, Scopus and Medline databases were searched to identify the publications investigating the impact of current therapies focused on high-density lipoproteins.

Pomegranate is a polyphenol-rich fruit. Studies have shown that extracts prepared from its juice or from different parts of the pomegranate plant have various biological activities including antioxidant, antimicrobial, anti-inflammatory, anticarcinogenic, cardioprotective, and antidiabetic. The therapeutic potential has been attributed to various phytochemicals, including ellagic acid, punicic acid, flavonoids, anthocyanidins, anthocyanins, flavonols, and flavones. This review focuses on the scientific evidence of pomegranate juice as hypoglycemic, emphasizing the chemical composition and the possible mechanisms of action associated with this effect. Studies were identified using the PubMed, Scopus, and ISI Web of Science databases to identify relevant articles focused on the hypoglycemic effect of pomegranate juice. The physiological responses to pomegranate juice are reported here, including a decrease of oxidative stress damage, an increase of insulin-dependent glucose uptake, maintenance of β-cell integrity, inhibition of nonenzymatic protein glycation, an increase of insulin sensitivity, modulation of peroxisome proliferator-activated receptor-gamma, inhibition of α-amylase, inhibition of α-glucosidase and dipeptidyl peptidase-4, and decreases in inflammation. Overall, we found a significant hypoglycemic effect of pomegranate in in vitro and in vivo studies and we summarize the potential mechanisms of action.

A resistant barley (Hordeum vulgare L., PI 366450) was used to compare physiological responses of a susceptible barley (‘Morex’) to the recently introduced pest, Russian wheat aphid, Diuraphis noxia (Mordvilko). As measured by chlorosis, leaf rolling, and streaking, damage by Russian wheat aphid was greater in ‘Morex’ than in PI 366450. The inhibition of growth, as measured by plant height, shoot dry weight, and number of leaves, also was greater in ‘Morex’ than in PI 366450. Relative water contents of leaves or stems showed no differences between ‘Morex’ and PI 366450 as a result of infestation. Well-watered PI 366450 showed greater stomatal closure in response to aphid infestation than ‘Morex’. However, the stomatal resistance responses of water-deprived PI 366450 and ‘Morex’ to Russian wheat aphids could not be distinguished. The two-dimensional SDS-PAGE protein profiles of uninfested ‘Morex’ and PI 366450 leaves were virtually identical. Upon infestation, a complex of proteins (≈23 kD) was altered in the PI 366450 profile and had decreased levels in ‘Morex’. Chlorophyll measurements indicated a greater relative loss of chlorophyll during infestation in ‘Morex’ than in PI 366450 when deprived of water; no differences could be distinguished when well watered. Measurements of the effectiveness of photosystem II to transfer electrons also showed no differences between well-watered resistant and susceptible barleys as a result of aphid infestation. However, the ability of the quinone pool in ‘Morex’ to recover after illumination was reduced greatly relative to that of PI 366450.

During early stages of infestation by Russian wheat aphids (Diuraphis noxia [Mordvilko]; RWAs), barley (Hordeum vulgare L.) leaf cells collapsed and showed autofluorescence in the mesophyll and bundle sheath adjacent to the RWA stylet sheath. The response was visually similar to the hypersensitive cell death response, typical of resistance to microbial pathogens. Resistant barley produced significantly more collapsed, autofluorescent cells (CAC) than did susceptible barley. RWA stylet entry sites and sheath paths also fluoresced, making them easy to observe in whole leaf sections. The number of CAC increased with the number of RWAs and with the number of days of feeding in resistant plants. The CAC could be observed 1 d following infestation, making this the most rapid plant response toward the RWAs known to date. The response may be useful in screening for resistant plants and may provide insight into resistance mechanisms in barley.