Gram-negative and gram-positive antibacterial properties of the whole plant extract of willow herb (Epilobium angustifolium).

The emergence of new pathogens and the increase in the number of multidrug-resistant strains in well-established pathogens during the past decade represent a growing public health concern globally. With the current lack of research and development of new antibiotics by large pharmaceutical companies due to poor financial returns, new alternatives need to be explored including natural herbal or plant-based extracts with reported antibacterial properties. Willow herb (Epilobium angustifolium) preparations have been used in traditional aboriginal and folk medicine preparations externally as an antiphlogistic to treat prostate and gastrointestinal disorders and as an antiseptic to treat infected wounds. The authors hypothesized that a whole plant extract of willow herb would exhibit antimicrobial properties on a variety of both Gram-positive and gram-negative bacteria in culture. The authors found that, in comparison to growth controls, willow herb extract significantly inhibited the growth of Micrococcus luteus (p < .01), Staphylococcus aureus (p < .05), Escherichia coli (p < .001), and Pseudomonas aeruginosa (p < .001). They also found that willow herb extract inhibited the growth of bacteria in culture more effectively than vancomycin (p < .05) or tetracycline (p < .004). These results provide preliminary support for the traditional folkloric claim that the plant willow herb possesses antibacterial properties against a variety of gram-positive and gram-negative bacteria. Given that whole plant extract was utilized for this study, further investigations are warranted to determine which specific part of the plant (i.e., leaves, stem, roots, and flowers) possess the antibacterial properties.

Ebselen decreases oxygen free radical production and iron concentrations in the hearts of chronically iron-overloaded mice.

Chronic iron overload is a major cause of cardiac failure throughout the world, but its pathogenesis remains to be clarified. It is conjectured that the toxicity of iron is due to its ability to catalyze the formation of oxygen free radicals (OFR), which can damage cellular membranes, proteins, and DNA. The authors report on the cardioprotective effects of the glutathione peroxidase (GPx) mimic ebselen on iron concentrations in the heart and GPx activity, and on the production of the cytotoxic aldehydes hexanal, 4-hydroxyl-2-nonenal (HNE), and malondialdehyde (MDA). Fifteen B6D2F1 mice were randomized to 1 of 3 treatment groups for a total of 20 treatments: 1) control (0.1 mL normal saline i.p. per mouse, per day); 2) iron-only (10 mg iron dextran i.p. per mouse, per day); 3) iron plus ebselen (25 mg/kg p.o. per mouse, per day). In comparison to iron-only treated mice, the authors' findings show that supplementation with ebselen can decrease both cytotoxic aldehyde and iron concentrations in heart tissue. Additionally, mice supplemented with ebselen had an increase in GPx activity level in comparison to iron-only treated mice. To the authors' knowledge, this is the first study to examine the cardioprotective effects of ebselen against OFR damage in a model of chronic iron overload. These findings suggest that ebselen may have significance in the management of disorders of iron overload.

Milk whey protein decreases oxygen free radical production in a murine model of chronic iron-overload cardiomyopathy.

BACKGROUND: Chronic iron overload is a major cause of organ failure worldwide, but its pathogenesis remains to be elucidated. OBJECTIVES: To examine in an experimental murine model of iron-overload cardiomyopathy the relation between milk whey protein and, first, the production of reactive oxygen free radical species and, second, antioxidant reserve status. METHODS: B6D2F1 mice were randomly assigned to four treatment groups (n=8 per treatment group): placebo control; iron only; whey only; and iron with whey. Reactive oxygen free radical species in the heart were quantified by the cytotoxic aldehydes malondialdehyde (MDA), 4-hydroxy-nonenal (HNE) and hexanal, while antioxidant reserve status was quantified by glutathione (GSH) and glutathione peroxidase (GPx) activity in the heart tissue. RESULTS: Significantly decreased concentrations (pmol/100 mg wet weight tissue) of MDA (2468+/-261), HNE (912+/-38) and hexanal (5385+/-927) were observed in the heart tissue of the group receiving iron with whey, in comparison with the iron-only treatment group (MDA 9307+/-387, HNE 1416+/-157, hexanal 14,874+/-2955; P<0.001). Significantly increased GPx (141+/-38 IU/L) and GSH (521+/-136 IU/L) activity were observed in mice receiving iron with whey, in comparison with mice receiving iron only (GPx 100+/-10 IU/L, GSH 446+/-33 IU/L; P<0.001). CONCLUSION: Mice receiving iron treatments with whey supplementation had significantly lower concentrations of cytotoxic aldehydes and significantly higher cardiac levels of GPx and GSH activity than did iron-only treated mice. Additional basic research is warranted to examine the exact mechanisms by which milk whey protein protects the heart.

Decreasing effects of iron toxicosis on selenium and glutathione peroxidase activity.

Heart failure due to chronic iron overload is a leading cause of cardiovascular mortality in the second and third decades of life worldwide, but its mechanism is not known. Deficiencies of selenium have been shown to result in damage to the myocardium and to the development of various cardiomyopathies. In the current investigation, the dose-dependent effects of chronic iron toxicosis on heart tissue concentrations of selenium and the protective antioxidant enzyme glutathione peroxidase (GPx) were investigated in a murine model of iron-overload cardiomyopathy (n = 20). Significant dose-dependent decreases in heart tissue selenium concentrations (r = -0.95, p < 0.001) and selenium-dependent GPx activity (r = -0.93, p < 0.001) were observed in chronically iron-loaded mice in comparison with placebo controls. These results suggest that dietary supplementation with selenium may be beneficial in the clinical management of disorders of iron metabolism.