Increased Variation in Body Weight and Food Intake Is Related to Increased Dietary Fat but Not Increased Carbohydrate or Protein in Mice

Acute and Repeated Dose 28-Day Oral Toxicity Study of the Aqueous Extracts from the Leafy Stem and Fruit of Pedalium murex D.Royen EX.L in Wistar Rats

Background

Pedalium murex (P. murex) is used in folk medicine for treatment of male infertility. However, scientific data on its safety are limited.

Objective

This study was carried out to assess the acute and repeated dose 28-day oral toxicity of the aqueous extracts from P. murex leafy stem and fruit in Wistar rats.

Methods

The acute toxicity test was performed according to the line 423 of the Organization for Economic Cooperation and Development (OECD) guidelines. The rats were randomly divided into three groups (n = 3). The control group received distilled water, while the experimental groups were given at a single dose, 5000 mg/kg of each extract. The repeated dose 28-day oral toxicity was performed according to the line 407 of the OECD guidelines. 35 rats divided into 7 groups of 5 male rats each were daily treated for 28 days with each extract at 200 mg/kg, 400 mg/kg, and 800 mg/kg, respectively. The in-life parameters were recorded during the follow-up. At the end of this study, organ weights, hematology, biochemistry, and histology parameters were analyzed.

Results

In the acute oral toxicity test, there was no morbidity or mortality related to the treatments. Both extracts belong therefore to category 5 of the globally harmonized system (GHS) of classification. In the repeated dose 28-day oral toxicity test, both extracts did not alter animal's behavior. However, both extract administration led to proteinuria and renal damages.

Conclusion

P. murex leafy stem and fruit aqueous extracts exhibited potential nephrotoxicity. Therefore, care should be taken when they are used over an extended period.

Chowing down: diet considerations in rodent models of metabolic disease

Diet plays a substantial role in the etiology, progression, and treatment of chronic disease and is best considered as a multifaceted set of modifiable input variables with pleiotropic effects on a variety of biological pathways spanning multiple organ systems. This brief review discusses key issues related to the design and conduct of diet interventions in rodent models of metabolic disease and their implications for interpreting experiments. We also make specific recommendations to improve rodent diet studies to help better understand the role of diet on metabolic physiology and thereby improve our understanding of metabolic disease.

Competing paradigms of obesity pathogenesis: energy balance versus carbohydrate-insulin models

The obesity pandemic continues unabated despite a persistent public health campaign to decrease energy intake (“eat less”) and increase energy expenditure (“move more”). One explanation for this failure is that the current approach, based on the notion of energy balance, has not been adequately embraced by the public. Another possibility is that this approach rests on an erroneous paradigm. A new formulation of the energy balance model (EBM), like prior versions, considers overeating (energy intake > expenditure) the primary cause of obesity, incorporating an emphasis on “complex endocrine, metabolic, and nervous system signals” that control food intake below conscious level. This model attributes rising obesity prevalence to inexpensive, convenient, energy-dense, “ultra-processed” foods high in fat and sugar. An alternative view, the carbohydrate-insulin model (CIM), proposes that hormonal responses to highly processed carbohydrates shift energy partitioning toward deposition in adipose tissue, leaving fewer calories available for the body’s metabolic needs. Thus, increasing adiposity causes overeating to compensate for the sequestered calories. Here, we highlight robust contrasts in how the EBM and CIM view obesity pathophysiology and consider deficiencies in the EBM that impede paradigm testing and refinement. Rectifying these deficiencies should assume priority, as a constructive paradigm clash is needed to resolve long-standing scientific controversies and inform the design of new models to guide prevention and treatment. Nevertheless, public health action need not await resolution of this debate, as both models target processed carbohydrates as major drivers of obesity.