Dietary plant microRNAs as potential regulators of cellular cholesterol efflux

AIM

Epidemiological evidence suggests adherence to vegetable-rich diets is associated to atheroprotective effects and bioactive components are most likely to play a relevant role. The notion of inter-kingdom regulation has opened a new research paradigm and perhaps microRNAs (miRNAs) from edible vegetables could influence consumer gene expression and lead to biological effects. We aimed to investigate the potential impact of broccoli-derived miRNAs on cellular cholesterol efflux in vitro.

METHODS

Four miRNAs (miR159a, miR159b, miR166a and miR403) from Brassica oleracea var. italica (broccoli), a widely consumed cruciferous vegetable, were selected for further investigation, based on their high abundancy in this vegetable and their presence in other plants. Selected miRNAs were synthesized with a 3'-terminal 2'-O-methylation and their cellular toxicity, in vitro gastrointestinal resistance and cellular uptake were evaluated. Potential target genes within the mammalian transcriptome were assessed in silico following pathway analysis. In vitro cholesterol efflux was assessed in human THP-1-derived macrophages.

RESULTS

miRNAs survival to in vitro GI digestion was around 1%, although some variation was seen between the four candidates. Cellular uptake by mammalian cells was confirmed, and an increase in cholesterol efflux was observed. Pathway analysis suggested these miRNAs are involved in biological processes related to phosphorylation, phosphatidylinositol and Wnt signaling, and to the insulin/IGF pathway.

CONCLUSIONS

Health-promoting properties attributed to cruciferous vegetables, might be mediated (at least in part) through miRNA-related mechanisms.

In vitro effects of two bioactive compounds, gallic acid and methyl gallate, on urolithiasis

INTRODUCTION AND OBJECTIVES

This study aimed to evaluate the role of two widely distributed natural phenolic compounds, gallic acid (GA) and methyl gallate (MG), in an in vitro model of urolithiasis, by using the methodology of calcium oxalate (CaOx) crystals formation, which is the most common type of urinary or kidney stones.

MATERIAL AND METHODS

The compounds GA and MG were subjected to anti-crystallization activities in different concentrations (0.003-0.03 mg/mL), and the quantity and morphology of crystals were determined by microscopy after 60 min.

RESULTS

GA inhibited about 44-57% of the total CaOx crystals formation, while MG inhibited about 48.35%, when compared to vehicle-exposed samples (distilled water; negative control group). GA and MG exposure inhibited monohydrate type calculi formation, which is considered the most common and harmful crystal category. The compounds also decreased absorbance, which in turn is related to reduced CaOx aggregation and precipitation.

CONCLUSIONS

Altogether, this study shows, for the first time, that GA and MG are promising compounds with antiurolithiatic properties, opening new perspectives for future in vivo evaluations of the potential of these compounds in the treatment and/or prevention of urinary or kidney stones.

In vitro effects of 2 bioactive compounds, gallic acid and methyl gallate, on urolithiasis

INTRODUCTION AND OBJECTIVES

This study aimed to evaluate the role of 2 widely distributed natural phenolic compounds, gallic acid (GA) and methyl gallate (MG), in an in vitro model of urolithiasis, by using the methodology of calcium oxalate crystals formation, which is the most common type of urinary or kidney stones.

MATERIAL AND METHODS

The compounds GA and MG were subjected to anti-crystallization activities in different concentrations (0.003-0.03mg/mL), and the quantity and morphology of crystals were determined by microscopy after 60min.

RESULTS

GA inhibited about 44-57% of the total calcium oxalate crystals formation, while MG inhibited about 48.35%, when compared to vehicle-exposed samples (distilled water; negative control group). GA and MG exposure inhibited monohydrate type calculi formation, which is considered the most common and harmful crystal category. The compounds also decreased absorbance, which in turn is related to reduced calcium oxalate crystals aggregation and precipitation.

CONCLUSIONS

Altogether, this study shows, for the first time, that GA and MG are promising compounds with antiurolithiatic properties, opening new perspectives for future in vivo evaluations of the potential of these compounds in the treatment and/or prevention of urinary or kidney stones.

[Antifungal effect of phenolic and carotenoids extracts from chiltepin (Capsicum annum var. glabriusculum) on Alternaria alternata and Fusarium oxysporum]

The effect of phenolic and carotenoid extracts from chiltepin fruits on mycelial growth and the inhibition of conidial germination of Alternaria alternata and Fusarium oxysporum were investigated in the present work. Phenolic extracts inhibited mycelial growth of A.alternata by 38.46%, and significantly reduced conidial germination on the fifth day after treatment to 92% in relation to control. No significant changes were observed in the inhibition of mycelial growth in Fusarium oxysporum; however, the number of germinated conidia was reduced, showing 85% inhibition five days after treatment in relation to control. Moreover, carotenoid extracts showed 38.5% inhibition of mycelial growth and 85.3% inhibition of conidial germination of A.alternata, five days after treatment. Carotenoid extracts showed less inhibition of mycelial growth (20.3%) in F.oxysporum, with respect to A.alternata; while there was greater inhibition of conidial germination (96%) on the fifth day after treatment. Phenolic and carotenoid extracts from chiltepin may be a promising alternative as a natural fungicide against fungi of agricultural importance.