Obesity, classified as an epidemic by the WHO, is a disease that continues to grow worldwide. Obesity results from abnormal or excessive accumulation of fat and usually leads to the development of other associated diseases, such as type 2 diabetes, hypertension, cancer, cardiovascular diseases, among others. In vitro and in vivo models have been crucial for studying the underlying mechanisms of obesity, discovering new therapeutic targets, and developing and validating new pharmacological therapies against obesity. Preclinical animal models of obesity comprise a variety of species: invertebrates, fishes, and mammals. However, small rodents are the most widely used due to their cost-effectiveness, physiology, and easy genetic manipulation. The induction of obesity in rats or mice can be achieved by the occurrence of spontaneous single-gene mutations or polygenic mutations, by genetic modifications, by surgical or chemical induction, and by ingestion of hypercaloric diets. In this review, we describe some of the most commonly used murine models in obesity research.

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Gastric bypass in obese patients is associated with a high remission rate of diabetes and improvement of the metabolic control. Although confirmation with randomized controlled studies is needed, these results suggest that this type of surgery might be particularly indicated for obese diabetic patients with good pancreatic reserve.

Some diet profiles are associated with the risk of developing cancer; however, some nutrients show protective effects. Porphyra umbilicalis is widely consumed, having a balanced nutritional profile; however, its potential for cancer chemoprevention still needs comprehensive studies. In this study, we incorporated P. umbilicalis into the diet of mice transgenic for the human papillomavirus type 16 (HPV16), which spontaneously develop pre-malignant and malignant lesions, and determined whether this seaweed was able to block lesion development. Forty-four 20-week-old HPV+/− and HPV−/− mice were fed either a base diet or a diet supplemented with 10% seaweed. At the end of the study, skin samples were examined to classify HPV16-induced lesions. The liver was also screened for potential toxic effects of the seaweed. Blood was used to study toxicological parameters and to perform comet and micronucleus genotoxicity tests. P. umbilicalis significantly reduced the incidence of pre-malignant dysplastic lesions, completely abrogating them in the chest skin. These results suggest that P. umbilicalis dietary supplementation has the potential to block the development of pre-malignant skin lesions and indicate its antigenotoxic activity against HPV-induced DNA damage. Further studies are needed to establish the seaweed as a functional food and clarify the mechanisms whereby this seaweed blocks multistep carcinogenesis induced by HPV.

The production of chestnut (Castanea sativa Miller) is mostly concentrated in Europe. Chestnut is recognized by its high content of antioxidants and phytosterols. This work aimed to evaluate the effects of dietary chestnut consumption over physiological variables of FVB/n mice. Eighteen FVB/n male 7-month-old mice were randomly divided into three experimental groups (n = 6): 1 (control group) fed a standard diet; 2 fed a diet supplemented with 0.55% (w/w) chestnut; and 3 supplemented with 1.1% (w/w) chestnut. Body weight, water, and food intake were recorded weekly. Following 35 days of supplementation, the mice were sacrificed for the collection of biological samples. Chestnut supplementation at 1.1% reduced abdominal adipose tissue. Lower serum cholesterol was also observed in animals supplemented with chestnut. There were no significant differences concerning the incidence of histological lesions nor in biochemical markers of hepatic damage and oxidative stress. These results suggest that chestnut supplementation may contribute to regulate adipose tissue deposition.