The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been widely used in agriculture and forestry since the 1940s. 2,4-D has been shown to produce a wide range of adverse effects-from embryotoxicity and teratogenicity to neurotoxicity-on animal and human health. The purpose of this study was to determine the possible effects of pre- and postnatal exposure to 2,4-D on oxidative stress in ventral prostate, ovary and breast. Pregnant rats were daily exposed to oral doses of 70 mg/kg/day of 2,4-D from 16 days of gestation up to 23 days after delivery. Then, the pups were sacrificed by decapitation at postnatal day (PND) 45, 60, or 90. Antioxidant enzyme activities and some parameters of the oxidative stress were assessed in ventral prostate, breast, and ovary. Results show that 2,4-D produced three different effects. First, it increased the concentration of some radical oxygen species and the rates of lipid peroxidation and protein oxidation in ventral prostate, thereby causing oxidative stress at all ages studied. Although an increase in the activity of some antioxidant enzymes was detected, this seemed to have been not enough to counteract the oxidative stress. Second, 2,4-D promoted the oxidative stress in the breasts, mainly during puberty and adulthood, probably because the developing gland is more sensitive to xenobiotics than the adult organ. Third, 2,4-D altered the activity of some antioxidant enzymes and increased lipid peroxide concentration in the ovary. This effect could reflect the variety of ovarian cell types and their different responses to endocrine changes during development.

properties-synthesis-and-control-ofweeds/oxidative-stress-as-a-possible-mechanism-of-toxicity-of-the-herbicide-2-4-dichlorophenoxyacetic-acid

This study assessed the acute toxicity and repellence as well as feeding deterrence effect of volcanic ash (VA) on Sitophilus oryzae adults under laboratory conditions. VA resulted in significant adult mortality of S. oryzae. Acute toxicity of the VA was similar to that of commercially available diatomaceous earth DiatomiD ® demonstrating its insecticidal potential. Median lethal concentration values (LC 50 ) obtained were 1610 [1449, 1778] mg/kg for VA and 1046 [916, 1168] mg/kg for DiatomiD ® .Similarly to other inert dusts, VA particle size shows a bi-modal distribution and porosity which increases its surface area. Among the smallest particles, the highest volumetric loading was close to 5 µm with a distribution of smaller particles peaking at 0.5µm. Results indicate that VA is not repellent to S. oryzae. An "engagement" response or increased interaction of the insects with the VA treated surface was observed. However, feeding deterrence indices showed that both VA and diatomaceous earth had strong feeding deterrent action. Contact of insects with VA may lead to mortality by adherence of the VA particles to the insect cuticle. However, insects prefer feeding on sites without VA covered substrates and this could have a positive impact on its use for pest management.

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is used on a wide variety of terrestrial and aquatic broadleaf weeds. 2,4-D has been shown to produce a wide range of adverse effects on animal and human health. The aim of the current study was to evaluate the effects of pre- and postnatal exposure to 2,4-D on rat ventral prostate (VP). Pregnant rats were exposed daily to oral doses of 70 mg/kg/day of 2,4-D from 16 days of gestation up to 23 days after delivery. Then, the treated groups (n = 8) were fed with a 2,4-D added diet until sacrificed by decapitation on postnatal day (PND) 45, 60, or 90. Morphometric studies were performed and androgen receptor (AR) protein levels in the VP were determined. AR, insulin-like growth factor-I (IGF-1) and insulin-like growth factor-I receptor (IGF-1R) mRNA expression in the VP along with testosterone (T), dihydroxytestosterone (DHT), growth hormone (GH) and IGF-1 serum levels were also determined to ascertain whether these parameters were differentially affected. Results of this study showed that 2,4-D exposure during gestation and until adulthood altered development of the prostate gland in male rats, delaying it at early ages while increasing its size in adults, indicate that 2,4-D could behave as endocrine disruptors (EDs).