Protein-caloric-restriction diet during lactation programs lean phenotype and improves the antioxidative system in adult female rat offspring.

Nutritional insults early in life, such as during the suckling phase, are associated with phenotypic alterations and promote adverse permanent effects that impair the capacity to maintain energy balance in adulthood. This study aimed to evaluate the long-term effects of a low-protein (LP) diet during lactation on the metabolism and antioxidant systems of adult female rat offspring. Dams were fed a low-protein diet (4% protein) during the first two weeks of lactation or a normal-protein (NP) diet (20% protein) during the entire lactation period. The female offspring received a standard diet throughout the experiment. At 90 days of age, female LP offspring exhibited decreased body weight, feeding efficiency, and fat pad stores. The adult LP female offspring displayed brown adipose tissue hyperplasia without alterations in glucose homeostasis. The LP diet decreased liver triglyceride content and improved the antioxidant system compared to the NP group. The LP diet during the suckling phase promotes a lean phenotype and improves the hepatocyte antioxidant system in adult female offspring. Thus, the LP diet may play an important role in homeostasis and the prevention of metabolic damage.

Metformin's performance in in vitro and in vivo genetic toxicology studies.

Metformin is a hypoglycemiant drug prescribed for the treatment and control of the type 2 diabetes mellitus. Recently, the potential efficacy of this antidiabetic drug as an anticancer agent has been demonstrated in various mammalian cancer cells. This report evaluates the mutagenic as well as the recombinogenic potentials of the metformin drug in therapeutically relevant plasma concentrations (12.5 µM, 25.0 µM or 50.0 µM). Since the loss of heterozygosity is a process associated with carcinogenesis, the recombinogenic potential of such a drug was evaluated by the homozygotization assay using a heterozygous diploid strain of Aspergillus nidulans. The homozigotization indices (HI) for the genetic markers from the metformin-treated diploids were not statistically different from the negative control (non-treated diploids). For the first time, this indicated a lack of recombinogenic activity of the antidiabetic drug. The mutagenic potential of the metformin drug was evaluated by the chromosome aberrations and the micronuclei tests in human lymphocytes cultures. The metformin drug did not show any significant increase either in the numerical or in the structural chromosome aberrations and did not affect significantly the mitotic index when compared to the negative control. In the in vitro micronucleus test, the drug did not increase the number of micronuclei or nuclear buds when compared with the negative control. The data in this study suggest that the metformin drug is not a secondary cancer inducer, since it has neither showed recombinogenic nor mutagenic activities when used in pharmacological concentrations.