Browsing by Author "Evans, Nicholas Paul"
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- Green tea extract and epigallocatechin gallate decrease muscle pathology and NF-κB immunostaining in regenerating muscle fibers of mdx miceEvans, Nicholas Paul (Virginia Tech, 2009-09-25)Duchenne muscular dystrophy is a debilitating genetic disorder characterized by severe muscle wasting and early death in affected boys. The primary cause of this disease is mutations in the dystrophin gene resulting in the loss of the dystrophin protein from the plasma membrane of muscle fibers. In the absence of dystrophin, muscles undergo massive muscle degeneration and inflammation. Inflammation is believed to contribute substantially to dystrophic muscle pathology. The transcription factor NF-κB regulates inflammatory gene expression and provides a logical target for therapeutic treatments. Green tea extract and its primary polyphenol, epigallocatechin gallate, have been shown to have anti-inflammatory properties and to improve dystrophic muscle pathology. The purpose of these studies was to determine if dietary treatment with green tea extract or epigallocatechin gallate administered prior to disease onset could reduce dystrophic muscle pathology during the early disease time course and identify potential mechanisms through which NF-κB may be involved. Green tea extract has been shown to decrease muscle pathology and increase muscle function in mdx mice, a dystrophic mouse model. These changes have been attributed to the antioxidant potential of epigallocatechin gallate; however, other mechanisms such as suppression of the inflammatory response have not been evaluated. In the studies reported herein, both green tea extract and epigallocatechin gallate significantly decreased muscle pathology in mdx mice when provided in their diets prior to disease onset. In green tea extract (0.25% and 0.5%) treated mdx mice, serum creatine kinase, a systemic marker of muscle damage, was decreased by 85% at age 42 days. Normal fiber morphology in the tibialis anterior muscle was increased by 32% at this age (P≤0.05). The primary histopathological change was a 21% decrease in regenerating fibers (P≤0.05). NF-κB staining in central nuclei of regenerating fibers was decreased by 34% (P≤0.05). In epigallocatechin gallate (0.1%) treated mdx mice, serum creatine kinase was unchanged; however, normal fiber morphology in the tibialis anterior was increased by 20% at ages 28 and 42 days (P≤0.05). At age 42 days, the primary histopathological change was a 21% decrease in regenerating fibers (P≤0.05). NF-κB staining in central nuclei of regenerating muscle fibers was decreased by 21% at this age (P≤0.05). Epigallocatechin gallate appears to be the primary polyphenol of green tea extract responsible for many of the beneficial changes in dystrophic muscle. These data suggest that both green tea extract and epigallocatechin gallate decrease NF-κB activity in regenerating fibers resulting in reduced muscle pathology. Complimentary and alternative medicine approaches, including the use of green tea, provide important therapeutic options for ameliorating Duchenne muscular dystrophy. Green tea extract and epigallocatechin gallate are effective at decreasing muscle pathology potentially by reducing NF-κB activity in regenerating fibers in mdx mice. Use of these botanicals appears to elicit a beneficial response in dystrophic muscle that may ultimately lead to effective therapies for patients with this incurable disease.
- Impact of Dietary Beta-glucan Supplementation on Performance and Immune Response of Broiler Chickens During ChallengeOtt, Christopher Philip (Virginia Tech, 2015-09-04)Coccidiosis is a costly parasitic disease to the poultry industry with multiple prevention methods being explored to control its impact. One approach under development is the use of -glucans, which are carbohydrates from cell walls of various plant species. The first study evaluated the feeding effects of algae- derived -glucans on performance and responses of broilers during a coccidiosis challenge. Cobb 500 broilers (n=1280) were fed a control diet, control supplemented with 150 g/MT Algamune (BG), 100 g/MT Algamune ZPC (BGZn), or 0.01% Salinomycin (Sal). On d 15, challenged birds received mixed Eimeria inoculum. Measurements were taken on d 7, 14, 21, and 28, and lesion scores assessed on d 21. The challenge resulted in reduced BW, and higher feed conversion ratio (FCR) was observed in the challenged birds with Sal and BGZn. Escherichia coli (E. coli) is normally commensal to the gastrointestinal tract, but certain serotypes cause disease in domestic poultry. A subsequent study was conducted to evaluate the feeding effects of algae-derived glucan (1,3 -glucan) on performance of broiler chickens during an E. coli challenge. Cobb 500 broilers (n=900) were fed a control diet, control + 25 mg/kg of -glucan, or control + 100 mg/kg of -glucan. On d 0, litter was sprayed with E. coli inoculum. Measurements were taken on d 7, 14, 21, and 28. -glucan supplementation increased BW gain andlowered FCR. The results from these studies offer some insight to the effects of -glucans on poultry and their potential to offset negative effects caused by infectious challenges.