Herbicide Paraquat provokes the stress responses of HPA axis of laboratory mouse, Mus musculus

Citrullus colocynthis Seed Ameliorates Layer Performance and Immune Response under Acute Oxidative Stress Induced by Paraquat Injection

Simple Summary

In recent years, natural, plant-based antioxidants have been increasingly popular among poultry producers to boost production and welfare. Colocynth, i.e., Citrullus colocynthis, is an herbaceous plant known to have antioxidant properties. Employing laying hens, this study investigated the potency of dietary colocynth seed supplementation to reduce the deleterious effects of acute oxidative stress induced by paraquat injection. The results demonstrated that supplementing layers’ diets with colocynth seed at 0.1% alleviated oxidative stress responses and significantly improved egg production performance. Furthermore, the immunological responses of the acute-oxidative-stressed layers were enhanced with colocynth seed supplementation. Thus, the inclusion of colocynth seed in layer chickens’ diets can improve egg production performance, restore the redox balance, and enhance immunological responses when they are reared under acute oxidative stress conditions.

Abstract

Oxidative stress is a detrimental physiological state that threatens birds’ productivity and general health. Colocynth is an herbal plant known for its bioactive properties, and it is mainly known for its antioxidant effects. This study’s purpose was to investigate how effective colocynth seed is at lowering the detrimental impact of acute oxidative stress caused by paraquat (PQ) injection in laying hens. A total of 360 Hy-Line Brown chickens, aged 39 weeks, were gathered and divided into four equal groups (10 hens × 9 replicates) in a 2 × 2 factorial design. The experimental groups were given either a basal diet or the basal diet supplemented with colocynth seed (1% of diet). Starting from week 40 of age and for 7 successive days, the experimental groups were either injected daily with paraquat (5 mg/kg body weight) or with saline (0.5 mL, 0.9% NaCl). Egg production performance with selected stress biomarkers and immunological response parameters were investigated at the end of week 40 of age. Our data revealed a significant reduction in egg production with an increase in blood stress biomarkers (i.e., HSP-70, corticosterone, and H/L ratio) in PQ-injected groups compared with non-stressed groups. Furthermore, an unbalanced redox state was detected in acute oxidative stress groups, with a significant rise in lipid peroxidation level, a reduction in total antioxidant capacity (TAC), and a drop in superoxide dismutase (SOD) and catalase enzyme activity. Supplementing PQ-injected hens with colocynth seed reduced the deleterious effects of acute oxidative stress. There was a significant drop in stress biomarkers with a significant rise in antioxidant enzyme activity and TAC observed in the PQ-injected group provided with colocynth seed supplementation. Remarkably, supplementation of colocynth in the non-stressed group resulted in a significant 27% increase in TAC concentration and 17% higher SOD activity when compared with the non-stressed control group. Colocynth supplementation in the PQ-injected group elevated the total white blood cell count by 25% and improved the B-lymphocyte proliferation index (a 1.3-fold increase) compared with the PQ-injected group that did not receive supplementation. Moreover, the non-stressed colocynth-supplemented group had significantly higher cell-mediated and humoral immune responses than the non-stressed control group. This study demonstrated that colocynth seed supplementation in birds exposed to acute oxidative stress may effectively alleviate its negative impacts on production performance, immunological responses, and redox status. We also inferred that, under normal conditions, colocynth seed can be added to laying hens’ diets to stimulate production and ameliorate immune responses.

Agrochemicals and neurogenesis

Agrochemicals or pesticides are compounds widely used to prevent, destroy or mitigate pests such as insects, rodents, herbs and weeds. However, most of them also act as environmental estrogens, anti-estrogens and/or antiandrogenic chemicals. In addition, both herbicides (such as glyphosate and paraquat) and insecticides (such as pyrethroids, organophosphates, neonicotinoids and rotenone) have been shown to exert significant adverse effects on hippocampal neurogenesis. These effects are particularly important because neurogenesis dysregulation could be associated with cognitive decline and neuropathologies such as Alzheimer's disease. This review focuses on the most commonly used agrochemicals in Argentina and their effects on the hippocampal neurogenesis of mammals. It also discusses the disruption of hormone synthesis and action as a possible mechanism through which these chemical compounds could alter the brain functions. Finally, we propose some lines of research to study the potential endocrine mechanisms involved in the effects of agrochemicals on human health and biodiversity.

8-Formylophiopogonanone B Antagonizes Paraquat-Induced Hepatotoxicity by Suppressing Oxidative Stress

Flavonoids are some of the most important natural products with a variety of physiological activities. 8-Formylophiopogonanone B (8-FOB) is a naturally existing homoisoflavonoid in Ophiopogon japonicus. Paraquat (PQ) has been widely used as a potent herbicide and has high toxicity in humans. The goal of the present study was to investigate whether 8-FOB could protect against PQ-induced hepatotoxicity in vitro and in vivo. We first tested the protective effects of 8-FOB on PQ-induced cytotoxicity in L02 cells by determining cell viability, intracellular oxidative stress levels, mitochondrial function, and apoptosis in vitro. To verify the protective effects of 8-FOB, we pretreated mice with 8-FOB and assessed liver function, hepatic oxidative stress, and histopathological changes after PQ administration. Our results revealed that 8-FOB could antagonize PQ-induced hepatotoxicity in vitro and in vivo. The antagonistic effects could be attributed to suppressing oxidative stress, preserving mitochondrial function, and inhibiting apoptosis. The present study is the first to document that 8-FOB, a homoisoflavonoid compound, is an effective antioxidant for antagonizing PQ-induced hepatotoxicity.

Paraquat induced impaired reproductive function and modulation of retinal and extra-retinal photoreceptors in Japanese quail (Coturnix coturnix japonica)

Paraquat (PQ) being a potent herbicide, causes toxic effect on growth, development and reproduction of plant as well as in animals. In this study we have mainly focused on the toxic effect of PQ on photoperception via different photoreceptors present in retina, pineal and hypothalamus and thereby its effect on hypothalamic - pituitary - gonadal (HPG) axis. PQ was administered i.p.10 mg/kg body weight daily for 1 week in poultry birds Japanese quail (Coturnix coturnix japonica). Our findings clearly indicated decrease in immunoreactivity of retinal and extra retinal photoreceptors (Iodopsin, rhodopsin and transducin) following PQ treatment in comparison to control group. Increased immunoreactivity of GnIH was observed in testis and epididymis of PQ treated group. Decreased mRNA expression of photoreceptors (rhodopsin and melanopsin), steroidogenic genes, androgen receptor, GnRH-I were found in PQ treated group while increased mRNA expression of melatonin receptors (Mel 1a R, Mel 1b R, Mel 1c R) and GnIH were found in PQ treated group. Thus, from the present results it may be concluded that PQ treatment alters the photoperception via altering the expression of photoreceptors and also modulates the HPG axis thereby alters the reproductive functions in Japanese quails.