Volume 3 Number 4 November 2005

 

Review Articles
209

Diabetic Retinopathy, Oxidative Stress and Antioxidants
RENU A. KOWLURU

219

Nutritional Supplementation, Cataracts and Age-Related Macular Degeneration
ELIZABETH J. JOHNSON[ABSTRACT]

231

Nutrition and Age-related Ocular Disease
HANNAH BARTLETT AND FRANK EPERJESI

243

Flavonoids in Skin Cancer Chemoprevention
A. SAIJA AND FRANCESCO CIMINO

259

Mormordica cochinchinensis, Rosa roxburghii, Wolfberry, and Sea Buckthord-Highly Nutritional Fruits Supported by Tradition and Science
D.S. BURKE, C.R. SMIDT AND L.T. VUONG[ABSTRACT]

267

Book Review
[ABSTRACT]

270

ICMAN 2006 Meeting
[ABSTRACT]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current Topics in Nutraceutical Research, Volume 3, Number 4, pp. 209-218 (2005)

Diabetic Retinopathy, Oxidative Stress and Antioxidants
RENU A. KOWLURU

ABSTRACT: Diabetic retinopathy is the leading cause of blindness in young adults. The mechanisms that lead to its development are poorly understood. Studies have shown that the maintenance of good metabolic control is the best treatment to prevent/inhibit the development of diabetic retinopathy, but such control is often difficult to maintain for long duration. Oxidative stress and nitrosylation of retinal proteins are increased in diabetes, and the retinal mitochondria become dysfunctional. Dietary supplementation with antioxidants in animal models of diabetic retinopathy is beneficial in inhibiting the accelerated retinal capillary cell apoptosis, development of retinopathy and the metabolic abnormalities that are postulated to be involved in the pathogenesis of diabetic retinopathy. However, clinical data with antioxidants in diabetic patients is somewhat ambiguous. Since diabetic retinopathy is a multifactorial disease, a single antioxidant or a group of drugs may not entirely prevent or inhibit diabetic retinopathy. However, it is likely that supplementation with multi-antioxidants with different mechanisms of actions could provide an inexpensive adjunct therapy to help preserve vision in diabetic patients. This could offer patients an opportunity to supplement their best possible sensible glycemic control with additional therapies.

 

 

 

Current Topics in Nutraceutical Research, Volume 3, Number 4, pp. 219-230 (2005)

Nutritional Supplementation, Cataracts and Age-Related Macular Degeneration
ELIZABETH J. JOHNSON

ABSTRACT: Age-related cataract and age-related macular degeneration (AMD) are the major causes of visual impairment and blindness in the aging population. Specific nutrients in the diet are thought to be important in the prevention of these diseases are vitamins C and E, the carotenoids, lutein and zeaxanthin, zinc, and omega-3 long chain polyunsaturated fatty acids, e.g. docosahexaenoic acid (DHA). Given that the lens and retina suffer oxidative damage, these nutrients are thought to be protective through their role as antioxidants. Additionally, lutein and zeaxanthin may provide protection as filters against light damage, i.e. absorbers of blue light. DHA may affect membrane composition of the lens and retina, which could alter membrane structure and function. The focus of this review is to evaluate the evidence for nutritional supplementation in cataract and AMD prevention.

 

 

Current Topics in Nutraceutical Research, Volume 3, Number 4, pp. 231-242 (2005)

Nutrition and Age-related Ocular Disease
HANNAH BARTLETT AND FRANK EPERJESI

ABSTRACT: Use of ocular nutritional supplementation has been investigated with regard to prevention of onset or progression of age-related ocular disease. There is particular interest in the use of nutritional supplementation as a prevention and treatment strategy for age-related macular degeneration, as it is the leading cause of visual disability in the developed World. Pertinent articles on nutrition and age-related ocular disease published in peer-reviewed journals were identified, using a multi-staged, systematic approach. Reports from epidemiological studies provide conflicting evidence for the role of beta-carotene, vitamin A, vitamin C, and vitamin E in prevention of age-related cataract. However, several studies support an inverse relationship between lutein/zeaxanthin and this condition. There is also epidemiological and clinical support for use of lutein/zeaxanthin in prevention of onset and progression of age-related macular disease. The Age-Related Eye Disease Study reported a beneficial effect of high-dose nutritional supplementation for late stages of this condition. There is some clinical evidence for a therapeutic effect of Ginkgo biloba extract in glaucoma. Review of the literature supports an association between lutein/zeaxanthin and reduced risk of age-related macular disease and age-related cataract. Further work is needed to clarify the role of GBE in glaucoma, and future work may involve investigating its use for treatment or prevention of ARMD.

 

 

 

Current Topics in Nutraceutical Research, Volume 3, Number 4, pp. 243-258 (2005)

Flavonoids in Skin Cancer Chemoprevention
A. SAIJA AND FRANCESCO CIMINO

ABSTRACT: UV radiation is a very potent initiator of photochemical reactions. In biological systems, the absorbed light can interact with endogenous molecules (lipids, proteins and DNA) so producing, directly or indirectly, deleterious cytotoxic and genotoxic effects. Chronic exposure of mammalian skin to UV radiation induces a number of biological responses (including edema, hyperplasia, immune suppression, DNA damage, photoaging, etc.), which may be involved in the development of skin cancer. Thus, it is imperative to protect the skin from UV lightinduced damage. Recent researches have been carried out to investigate the scientific basis for photoprotection by naturally occurring antioxidants to be topically or systemically employed for minimizing the harmful effect of sun exposure. Several plant compounds have gained considerable attention as chemopreventers effective against skin cancer. In particular, flavonoids represent an interesting class of active compounds in the protection of UV light-induced skin damage due to their wide spectrum of activities including anti-inflammatory, antioxidant, antimutagenic, anti-carcinogenic and capability to modulate enzyme activities involved in cell response. Herein the state of art of flavonoids in the protection against UVinduced skin cancer will be reviewed, with particular regard for issues relating to their topical application or oral administration.

 

 

 

 

Current Topics in Nutraceutical Research, Volume 3, Number 4, pp. 259-266 (2005)

Momordica cochinchinensis, Rosa roxburghii, Wolfberry, and Sea Buckthorn-Highly Nutritional Fruits Supported by Tradition and Science
D. S. BURKE, C.R. SMIDT AND L.T. VUONG

ABSTRACT: Most diets in developed nations fall far short of recommended fruit and vegetable, and thus key nutrient, intake. Momordica cochinchinensis (gac), indigenous to Southeast Asia, contains high concentrations of lycopene and beta-carotene. In Vietnam, gac is prized by natives for promoting longevity and vitality. In a supplementation trial among Vietnamese children, gac increased serum vitamin A levels more than synthetic beta-carotene. Rosa roxburghii (cili), native to southwest China and traditionally used to combat stress and aging, is very rich in vitamin C and other phytonutrients. In humans, cili enhanced immunity and raised erythrocyte superoxide dismutase (SOD). Lycium chinense (wolfberry), also of Chinese origin, and traditionally used for longevity, wellness, and vision, is very rich in highly utilizable zeaxanthin. In animals, wolfberry showed immune modulating and antioxidant actions, and in humans, significantly increased blood SOD. Hippophae rhamnoides (sea buckthorn), native to Siberia and the Himalayas and traditionally used to expel phlegm and promote digestion, was shown in animals to have liver-protective and antioxidant activity. In humans, sea buckthorn greatly increased the dietary intake of flavonoids and vitamin C, and showed cardiovascular benefits. Thus, due to their nutritional value, intake of these fruits may greatly enhance the diet.s healthfulness.