ABSTRACT
Nitric oxide synthase- (NOS-) dependent endothelial dysfunction induced by oxidative stress (OS) is assumed to play a pivotal role in the pathogenesis and progression of diabetes mellitus-related erectile dysfunction (DMED). Cysteine-rich whey protein isolate (CR-WPI) is a widely used protein supplement and has been confirmed to reduce reactive oxygen species (ROS) by increasing cellular antioxidant glutathione (GSH). However, it is currently unknown whether CR-WPI elicits therapeutic effects in DMED. Here, we provide diabetic rats with CR-WPI to determine its effect on DMED and the underlying mechanisms. The results suggest that CR-WPI supplementation increased GSH biosynthesis and reduced ROS content and simultaneously upregulated the dimethylarginine dimethylaminohydrolase (DDAH)/asymmetrical dimethylarginine (ADMA)/nitric oxide synthase (NOS) metabolic pathway. Evaluation of intracavernous pressure (ICP) also showed an improvement of penile erectile function in CR-WPI-treated rats. The results of the vitro cell culture showed that glutathione pretreatment protected corpus cavernosum smooth muscle cells (CCSMC) from H2O2-induced apoptosis by decreasing Caspase 9 and Caspase 3 expressions. These results augur well for the potential therapeutic application of dietary CR-WPI supplementation for treating diabetic erectile dysfunction.
Subject(s)
Diabetes Mellitus, Experimental , Erectile Dysfunction , Amidohydrolases , Animals , Arginine/metabolism , Cysteine/metabolism , Cysteine/pharmacology , Cysteine/therapeutic use , Erectile Dysfunction/drug therapy , Humans , Hydrogen Peroxide , Male , Nitric Oxide Synthase/metabolism , Oxidative Stress , Rats , Rats, Sprague-Dawley , Whey Proteins/pharmacology , Whey Proteins/therapeutic useABSTRACT
OBJECTIVE: The prevalence and costs associated with treating pressure ulcers (PU) are at high levels. Frequently, PUs heal slowly or not at all, which may be due to the patient's catabolic state which may include protein energy malnutrition. The objective of this open label clinical trial was to improve healing rates by providing patients with a patented, high-quality protein containing all essential amino acids to ensure positive nitrogen balance. An additional benefit of this protein is the delivery of bioavailable cysteine (cystine) to promote glutathione (GSH) synthesis which supports immune function and heightens antioxidant defences. METHODS: Patients with category II, III and IV PUs were fed 20g BID whey protein dietary supplement for 16-120 days, without change in ongoing 'best practice' PU management and their progress recorded. RESULTS: A total of 10 patients were recruited, with an average age of 77 years. Most had shown no improvement in healing for ≥2 months before treatment and usually had other complications including chronic obstructive pulmonary disease (COPD), diabetes and various cardiovascular diseases. There were a total of 23 PUs, with some patients having more than one. Of these, 44% (n=10) showed complete resolution 83% (n=19) had better than 75% resolution over the observation period. Healing rates ranged from 16.9-0.2cm2/month (healed PUs) and 60.0-1.6cm2/month for resolving PUs. CONCLUSION: By providing the necessary amino acids to rebuild tissues and bioactive cysteine (cystine) to promote synthesis of intracellular GSH and positive nitrogen balance, improvement in PUs healing was achieved.
Subject(s)
Dietary Supplements , Pressure Ulcer/diagnosis , Pressure Ulcer/therapy , Proteins/administration & dosage , Wound Healing/physiology , Aged , Aged, 80 and over , Cohort Studies , Cysteine/pharmacology , Cystine/pharmacology , Female , Humans , Male , Middle Aged , Pilot Projects , Prognosis , Prospective Studies , Severity of Illness IndexABSTRACT
BACKGROUND: Psoriasis is a common autoimmune disease with enhanced systemic inflammation and heightened levels of oxidative stress. Glutathione is the major antioxidant in human cells. OBJECTIVES: To determine if a nondenatured bioactive whey protein isolate previously demonstrated to increase glutathione levels can clinically improve patients with psoriasis vulgaris. METHODS: A single site, prospective, non-blinded trial. Seven patients with psoriasis were recruited to take a nondenatured bioactive whey protein isolate, 20g orally per day, in addition to their current treatments, if any. Psoriasis Area and Severity Index scores and photographs were taken at baseline and monthly for three months. RESULTS: Patients with psoriasis were found to have a beneficial clinical improvement, whether they were on existing topical therapy, narrowband ultraviolet B, or no other treatment. CONCLUSION: The positive preliminary outcomes from this pilot study suggest a randomized, double-blind, clinical trial would be worthwhile in evaluating whether this protein isolate would result in statistically significant improvement for patients with psoriasis.
