Uromastyx acanthinura as a natural treatment in a mouse model of type 2 diabetes

Abstract

Aims: Oral testimonies from North Africa attribute anti-diabetic effects to medicinal preparations of the lizard Uromastyx acanthinura (UA). No scientific evidence of such effects is currently available. The acute effects of oral administration of UA to C57Bl/6J mice with diet-induced diabetes were tested and, if effectiveness was shown, the effect of subchronic UA administration was assessed in the same model.

Methods: Mice were fed a diet containing 60% fat for at least 12 weeks. To assess acute effects, different doses of UA or saline were orally administered with 2g of glucose/kg during an oral glucose tolerance test (OGTT) on different days in a randomised crossover design. The most effective dose was then fed together with the high-fat diet for 90 days and compared to high-fat diet alone in a parallel design. Body weight (BW), food consumption, welfare, and external appearance were assessed weekly. HbA1c, OGTT, and intraperitoneal insulin tolerance tests (IPITT) were performed at baseline and after treatment. Severity of neuropathy was evaluated by cold allodynia response in the acetone test.

Results: UA significantly decreased glucose levels as compared to saline 15min after administration. After 90 days of treatment, no differences were seen in OGTT or HbA1c between the groups, while IPITT showed higher glucose levels in UA-treated animals. Although weight increase was similar in both groups, weight tended to be higher in the treated group, which had a significantly higher daily food consumption. Cold allodynia response improved in frequency and intensity in the UA group.

Conclusions: Orally administered UA acutely decreased blood glucose in diabetic mice. Paradoxically, long-term administration of UA increased food consumption, weight, and insulin resistance. Improved nociceptive response suggested an effect on pain and/or neuropathy. Although additional studies are needed to elucidate the properties and potential applications of UA, our results highlight the value of ethnomedical approaches to African traditional medicine as starting point to evaluate new bioactive components.

Keywords: African traditional medicine; Animal reduction; Cross-over design; Diabetes; Diseño cruzado; Medicina tradicional africana; Neuropathy; Neuropatía; Reducción animal; Uromastyx.