By Timothy J. King, Ph.D., Vice President, Research
Studies utilizing rodent models of diabetes, diabetic nephropathy and metabolic dysfunction have shown astaxanthin (ASTX) administration to significantly and positively alter diabetes-associated pathology including dysregulation of glucose levels and insulin sensitivity [1-5].
Recently, Sila et al. extended these observations by evaluating the effects of 20mg/kg/day of ASTX purified from shrimp shell waste in a rat model of diabetes (alloxan-induced). Groups of six mice each were untreated, alloxan-treated, alloxan+ASTX treated, or alloxan+olive oil delivery vehicle for 21 days. Alloxan is a glucose analogue that in rodents targets pancreatic beta cells for destruction via generation of reactive oxygen species ultimately resulting in a loss of insulin production similar to Type I diabetes and kidney dysfunction similar to diabetic nephropathy. The induced disease manifests as; increased plasma glucose levels, decreased insulin levels, elevated creatine, urea and uric acid. Histological alterations in the kidney include severe injury of tubular and glomeruli architecture. Additionally, increased measures of oxidative stress are observed including; plasma and kidney malondialdehyde (MDA) levels and kidney protein carbonyl levels as well as decreases in protective antioxidant functions including; glutathione, superoxide dismutase, catalase and glutathione peroxidase.
Importantly, administration of ASTX in this model resulted in significant reductions in plasma glucose levels and increased insulin levels. Additionally, histological manifestation of kidney pathology was ameliorated by ASTX treatment. Significant reductions in all markers of oxidative stress as well as significant increases in antioxidant protection markers were also observed in plasma and kidney tissue. In total, these results support the role of ASTX in reducing oxidative stress and increasing antioxidant protection important in prevention of diabetes-associated kidney nephropathy and joins several published studies in underscoring the potential for ASTX to ameliorate diabetes-associated insulin/glucose dysregulation and resulting pathomechanisms of diabetes-associated disease.
References:
Uchiyama K, Naito Y, Hasegawa G, Nakamura N, Takahashi J, Yoshikawa T, 2002.
Astaxanthin protects beta-cells against glucose toxicity in diabetic db/db mice.
Redox Report, 7(5): 290-293.
Bhuvaneswari S, Anuradha CV, 2012.
Astaxanthin prevents loss of insulin signaling and improves glucose metabolism in liver of insulin resistant mice.
Canadian Journal of Physiology and Pharmacology, 90(11): 1544-1552.
Bhuvaneswari S, Arunkumar E, Viswanathan P, Anuradha CV, 2010.
Astaxanthin restricts weight gain, promotes insulin sensitivity and curtails fatty liver disease in mice fed a obesity-promoting diet.
Process Biochemistry, 45(8): 1406-1414.
Arunkumar E, Bhuvaneswari S, Anuradha CV, 2012.
An intervention study in obese mice with astaxanthin, a marine carotenoid–effects on insulin signaling and pro-inflammatory cytokines.
Food & Function, 3(2): 120-126.
Naito Y, Uchiyama K, Aoi W, Hasegawa G, Nakamura N, Yoshida N, Maoka T, Takahashi J, Yoshikawa T, 2004.
Prevention of diabetic nephropathy by treatment with astaxanthin in diabetic db/db mice.
Biofactors, 20(1): 49-59.
Sila A, Ghlissi Z, Kamoun Z, Makni M, Nasri M, Bougatef A, Sahnoun Z, 2014.
Astaxanthin from shrimp by-products ameliorates nephropathy in diabetic rats.
European Journal of Nutrition, Epub ahead of print.