Stress-induced reproductive arrest in Drosophila occurs through ETH deficiency-mediated suppression of oogenesis and ovulation.

BACKGROUND: Environmental stressors induce changes in endocrine state, leading to energy re-allocation from reproduction to survival. Female Drosophila melanogaster respond to thermal and nutrient stressors by arresting egg production through elevation of the steroid hormone ecdysone. However, the mechanisms through which this reproductive arrest occurs are not well understood. RESULTS: Here we report that stress-induced elevation of ecdysone is accompanied by decreased levels of ecdysis triggering hormone (ETH). Depressed levels of circulating ETH lead to attenuated activity of its targets, including juvenile hormone-producing corpus allatum and, as we describe here for the first time, octopaminergic neurons of the oviduct. Elevation of steroid thereby results in arrested oogenesis, reduced octopaminergic input to the reproductive tract, and consequent suppression of ovulation. ETH mitigates heat or nutritional stress-induced attenuation of fecundity, which suggests that its deficiency is critical to reproductive adaptability. CONCLUSIONS: Our findings indicate that, as a dual regulator of octopamine and juvenile hormone release, ETH provides a link between stress-induced elevation of ecdysone levels and consequent reduction in fecundity.

Acute and sub-chronic toxicity of Liberin, an anti-diabetic polyherbal formulation in rats.

BACKGROUND: The polyherbal formulation (PHF) liberin, is known to exert anti-hyperglycemic effects in type 2 diabetes mellitus. Hence, it is important to study the safety profile of PHF in the current study through acute and chronic toxicity evaluation. OBJECTIVES: This research aims to assess the acute and sub-chronic toxicity of PHF in rats. MATERIALS AND METHODS: PHF was administered once orally (1000 mg/kg body weight), and the rats (male and female) were monitored for toxicity signs for a 14-day period. For a 28-day chronic toxicity study, rats were daily administered with PHF dose of 500 mg/kg and 1000 mg/kg body weight. Rats were followed up for mortality, weight changes, and other morbidities. Further haematological, biochemical, and histopathological changes were assessed. RESULTS: No death related to treatment or toxicity signs were recorded in the acute single-dose administration group. The results showed that the PHF was tolerated well up to a dose of 1000 mg/kg body weight. Even at the high dose of 1000 mg/kg body weight, sub-chronic tests did not show any significant difference between the dosed and normal groups. No significant changes were seen in the histopathological analysis of the liver, spleen, and kidney as well as haematological and biochemical parameters in acute, sub-chronic and satellite groups following the administration of PHF. CONCLUSION: The results confirmed that there was no adverse effect of this PHF at the maximum dose of 1000 mg/kg body weight in Wistar rats. Further, no adverse delayed effects related to PHF were observed in the satellite group. Therefore, this PHF appears safe for therapeutic purposes in the Ayurvedic medicinal system.