Influence of different wild-garlic (Allium ursinum) extracts on the gastrointestinal system: spasmolytic, antimicrobial and antioxidant properties.

OBJECTIVES: As there are no previous studies of the European wild-garlic (Allium ursinum) effects on the gastrointestinal system, despite its traditional applications in gastrointestinal disorders' treatment and regular use in the human diet, we have quantified and compared spasmolytic, antimicrobial and antioxidant activities of its different leaf extracts. METHODS: Wild-garlic extracts were tested for spasmolytic activity on isolated rat ileum, antimicrobial activity on selected Gram-positive and Gram-negative bacteria and fungi by microdilution method and antioxidant capacity by DPPH radical-scavenging assay. KEY FINDINGS: Wild-garlic extracts were found to decrease ileal basal tone. As the relaxation of K+ -induced contractions was similar to one caused by papaverin, the observed spasmolytic effect was most likely mediated through Ca2+ -channel inhibition. Ethanolic extract (with the highest phenolic and high alk(en)yl cysteine sulphoxides' levels) produced the strongest spasmolytic activity. In case of acetylcholine-induced contractions, only hydromethanolic extract showed no statistical difference in comparison with positive control. All samples exhibited certain antioxidant potential and strong antimicrobial activity against tested enteropathogenic strains (Salmonella enteritidis was the most sensitive, followed by Escherichia coli, Proteus mirabilis and Enterococcus faecalis). CONCLUSION: Besides other already established health-promoting effects, wild garlic could be useful in treatment of mild gastrointestinal disturbances.

Hypotensive, cardiodepressant, and vasorelaxant activities of black currant (Ribes nigrum 'Ben Sarek') juice.

The aim of this study was to evaluate the effects of black currant (Ribes nigrum L. 'Ben Sarek') juice on the blood pressure and frequency of cardiac contractions, as well as vasomotor responses of rat aortic rings. Arterial blood pressure was measured directly from the carotid artery in the anaesthetized rabbits. The aortic rings were pre-contracted with KCl (80 mmol·L-1), after which black currant juice was added. An intravenous injection of black currant juice (0.33-166.5 mg·kg-1) induced a significant and dose-dependent decrease of rabbit arterial blood pressure and heart rate. The black currant juice decreased arterial blood pressure of rabbit by 22.33% ± 3.76% (p < 0.05) and heart rate by 17.18% ± 2.93% (p < 0.05). Cumulative addition of the black currant juice (0.01-3 mg·mL-1) inhibited concentration-dependent KCl induced contractions of the isolated rat aorta. The black currant juice, at the concentration of 3 mg·mL-1, caused a maximum relaxation of 21.75% ± 3.15% (p < 0.05). These results demonstrate that black currant juice can induce hypotension. The hypotensive effect of the black currant may occur as the consequence of its inhibitory activity on the rate of heart contraction and vasorelaxant effects.

Beneficial effects of calcium oral coadministration in gentamicin-induced nephrotoxicity in rats.

Frequent therapeutical use of an aminoglycoside antibiotic gentamicin (GM) is limited by its nephrotoxic effects often characterized by both morphological and functional alterations of kidney leading to acute renal failure. The aim of this study was to examine the effect of dietary calcium supplementation on GM-induced nephrotoxicity in rats. Experiments were performed on 30 adult male Wistar rats divided into three groups of 10 animals each. G-group received GM intraperitoneally at a dose of 100 mg/kg; GCa-group received the same dose of GM concomitantly with 1 g/kg calcium carbonate given orally; and C-group, serving as control, received 1 mL/day of normal saline. All groups were treated during 8 consecutive days. Quantitative evaluation of GM-induced structural and functional changes of kidney was performed by histopathological, morphometrical, and biochemical analyses. Compared with control, G-group of rats were found to have diffusely and unequally thickened glomerular basement membrane with neutrophil cells infiltration. In addition, vacuolization of cytoplasm of proximal tubule cells with coagulation-type necrosis was observed. These GM-induced pathological lesions were significantly reduced in the rats of GCa-group. Morphometric analysis revealed statistically significant differences in the size of glomeruli (area, major and minor axes, perimeter), optical density, and roundness of glomeruli (p < 0.05) between G and GCa groups. Biochemical analysis showed significant elevation in blood urea and serum creatinine concentrations, whereas potassium concentration was lowered in G-group compared with the other groups (p < 0.01). It is concluded that oral supplementation of calcium during treatment with GM resulted in significant reduction of morphological and functional kidney alterations.