Natural antioxidants in diabetes treatment and management: prospects of astaxanthin.

Diabetes remains a major health emergency in our entire world, affecting hundreds of millions of people worldwide. In conjunction with its much-dreaded complications (e.g., nephropathy, neuropathy, retinopathy, cardiovascular diseases, etc.) it substantially reduces the quality of life, increases mortality as well as economic burden among patients. Over the years, oxidative stress and inflammation have been highlighted as key players in the development and progression of diabetes and its associated complications. Much research has been devoted, as such, to the role of antioxidants in diabetes. Astaxanthin is a powerful antioxidant found mostly in marine organisms. Over the past years, several studies have demonstrated that astaxanthin could be useful in the treatment and management of diabetes. It has been shown to protect ß-cells, neurons as well as several organs including the eyes, kidney, liver, etc. against oxidative injuries experienced during diabetes. Furthermore, it improves glucose and lipid metabolism along with cardiovascular health. Its beneficial effects are exerted through multiple actions on cellular functions. Considering these and the fact that foods and natural products with biological and pharmacological activities are of much interest in the 21st-century food and drug industry, astaxanthin has a bright prospect in the management of diabetes and its complications.

Therapeutic attributes and applied aspects of biological macromolecules (polypeptides, fucoxanthin, sterols, fatty acids, polysaccharides, and polyphenols) from diatoms - A review.

Diatoms are ubiquitous, biologically widespread, and have global significance due to their unique silica cell wall composition and noteworthy applied aspects. Diatoms are being extensively exploited for environmental monitoring, reconstruction, and stratigraphic correlation. However, considering all the rich elements of diatoms biology, the current literature lacks sufficient information on the therapeutic attributes and applied aspects of biological macromolecules from diatoms, hampering added advances in all aspects of diatom biology. Diatoms offer numerous high-value compounds, such as fatty acids, polysaccharides, polypeptides, pigments, and polyphenols. Diatoms with a high content of PUFA's are targets of transformation into high-value products through microalgal technologies due to their wide application and growing market as nutraceuticals and food supplements. Diatoms are renewable biomaterial, which can be used to develop drug delivery systems due to biocompatibility, surface area, cost-effective ratio, and ease in surface modifications. Innovative approaches are needed to envisage cost-effective ways for the isolation of bioactive compounds, enhance productivity, and elucidate the detailed mechanism of action. This review spotlights the notable applications of diatoms and their biologically active constituents, such as fucoxanthin and omega 3 fatty acids, among others with unique structural and functional entities.

Astaxanthin from shrimp by-products ameliorates nephropathy in diabetic rats.

AIM: This study investigated the hypoglycemic and antioxidant effects of shrimp astaxanthin on the kidney of alloxan-induced diabetic rats. METHODS: Animals were distributed into four groups of six rats each: a control group (C), a diabetic group (D), a diabetic group supplemented with Astaxanthin (D+As) dissolved in olive oil and a diabetic group supplemented with olive oil (D+OO). In vitro antidiabetic effect was tested in plasma and kidney tissue. RESULTS: The group D of rats showed significant (P < 0.05) increase of glycemia, creatinine, urea and uric acid levels compared to those of the control group (C). Moreover, plasma and kidney malondialdehyde (MDA) and protein carbonyl (PCO) levels for the rats of the group D were significantly increased compared to the control group. Contrariwise, antioxidant enzyme activities, such as catalase (EC 1.11.1.6), superoxide dismutase (EC 1.15.1.1) and non-enzymatic levels of reduced glutathione, were significantly (P < 0.05) decreased in the plasma and kidney of diabetic rats compared to the control ones. The astaxanthin supplementation in rats diet improved the antioxidant enzyme activities and significantly decreased the MDA and PCO levels compared to diabetic rats. Indeed, no significant (P ≥ 0.05) improvement was observed for the fourth group (D+OO) compared to the control group (C). Histological analysis of kidney showed glomerular hypertrophy and tubular dilatation for the diabetic rats. For D+As rats, these histopathological changes were less prominent. CONCLUSIONS: Our results suggest that shrimp astaxanthin may play an important role in reduction of oxidative damage and could prevent pathological changes in diabetic rats suggesting promising application of shrimp astaxanthin in diabet treatment.

Antiobesity effects of Undaria lipid capsules prepared with scallop phospholipids.

Based on previous research findings, a capsule was developed containing n-3 polyunsaturated fatty acid rich scallop phospholipids (PLs) with an incorporation of brown seaweed (Undaria pinnatifida) lipids (ULs) containing fucoxanthin. The antiobesity effects of the capsules were evaluated with an animal model using 3-wk-old male KK-A(y) mice. Each group received different combinations of lipid (UL, PL, UL + PL, or UL + PL capsule) either incorporated into the diet or into drinking water. Animals were sacrificed after a 4-wk experimental feeding period, and adipose tissues and organs were dissected and weighed. Blood samples were obtained to determine plasma lipid profiles. Uncoupling protein 1 (UCP1) mRNA expression levels were determined by real-time polymerase chain reaction analysis, and UCP1 expression was determined by western blotting analysis. Treatment with either UL alone or UL + PL (capsule) through drinking water resulted in a significant reduction in body weight, compared to the control group. The total white adipose tissue weight of mice fed the UL + PL capsule in drinking water was significantly reduced. Both UCP1 and UCP1 mRNA expression in epididymal fat from mice fed the capsule were significantly higher than in the control group. These results suggest that incorporation of UL into scallop-derived PL by means of capsulation may lead to an additive increase in the antiobesity properties of these bioactive lipids.