Acute Toxicity Assessment of Reactive Red 120 to Certain Aquatic Organisms.

Laboratory experiments were conducted to evaluate the acute toxicity of a widely used textile dye namely Reactive Red 120 (RR 120) on certain aquatic species such as Pseudokirchneriella subcapitata (green alga), Lemna gibba (duck weed), Daphnia magna (water flea) and Oncorhynchus mykiss (Rainbow trout). All experiments were performed as per the OECD Guidelines for Testing of Chemicals. The toxicity end points of EC50, LC50, NOEC and LOEC for RR 120 were determined with 95% confidence limits using TOX STAT version 3.5. The EC50 of RR 120 for green alga, duck weed and water flea are >100.00, 64.34, 10.40 mg L(-1), respectively and LC50 for Rainbow trout is 78.84 mg L(-1). Based on the results, the test item RR 120 could be classified as non-toxic to green alga, harmful to duck weed and Rainbow trout, toxic to water flea.

Oxidative stress and inflammatory responses of rat following acute inhalation exposure to iron oxide nanoparticles.

In this research, we investigated the toxicity responses of rat following a continuous 4 h inhalation exposure of only the head and nose to iron oxide nanoparticles (Fe(3)O(4) NPs, size = 15-20 nm). The rats for the investigation were exposed to a concentration of 640 mg/m(3) Fe(3)O(4) NPs. Markers of lung injury and proinflammatory cytokines (interleukin-1ß, tumor necrosis factor-α, and interleukin-6) in bronchoalveolar lavage fluid (BALF) and blood, oxidative stress in lungs, and histopathology were assessed on 24 h, 48 h, and 14 days of postexposure periods. Our results showed a significant decrease in the cell viability, with the increase in the levels of lactate dehydrogenase, total protein, and alkaline phosphatase in the BALF. Total leukocyte count and the percentage of neutrophils in BALF increased within 24 h of postexposure. Immediately following acute exposure, rats showed increased inflammation with significantly higher levels of lavage and blood proinflammatory cytokines and were consistent throughout the observation period. Fe(3)O(4) NPs exposure markedly increased malondialdehyde concentration, while intracellular reduced glutathione and antioxidant enzyme activities were significantly decreased in lung tissue within 24-h postexposure period. On histological observation, the lung showed an early activation of pulmonary clearance and a size-dependant biphasic nature of the Fe(3)O(4) NPs in causing the structural alteration. Collectively, our data illustrate that Fe(3)O(4) NPs inhalation exposure may induce cytotoxicity via oxidative stress and lead to biphasic inflammatory responses in Wistar rat.

Repeated dose dermal toxicity study of nano zinc oxide with Sprague-Dawley rats.

CONTEXT: In light of the increased use of zinc oxide nanoparticles in cosumer products such as sunscreens, there is a need for screening the potential dermal toxicity of these nanoparticles. OBJECTIVE: The aim of this study is to identify the risk associated with the nano zinc oxide at realistic exposure levels through dermal route. This study is to understand the toxic potential of nano zinc oxide through repeated dermal exposure for a period of 28 days. MATERIALS AND METHODS: Six- to 8-week-old Sprague-Dawley rats were applied with three different doses (75, 180, and 360 mg/kg body weight) of nano zinc oxide (20 nm) at 5 days/week basis for a period of 28 days. The dose levels were calculated taking into consideration the percentage of nanomaterial in the sunscreen, number of application times, and average weight of the consumer in order to assess the realistic risk related to it. Control group animals were applied with distilled water alone. The collagen content was estimated in skin and tail of all the treated and control animals. RESULTS: The content was significantly decreased in all the nano zinc oxide-treated groups with an inverse dose relationship. DISCUSSION AND CONCLUSION: The percentage collagen loss was high in skin when compared with tail. This may be due to the site of application where in the nano zinc oxide may be passed through skin due to their small size and may induce oxidative stress. Hence, we suggest that regulators and industry need to address the toxicity of nanomaterials with a realistic exposure assessment rather following conventional dose measurements following existing protocols.

Nanoemulsified ethanolic extract of Pyllanthus amarus Schum & Thonn ameliorates CCl4 induced hepatotoxicity in Wistar rats.

Phyllanthus amarus (PA) is commonly used in traditional medicine for hepatoprotectivity. The major limitation is that, treatment requires a large quantity of herbal extract for a longer duration. Aim of the present study was to encapsulate ethanolic plant extract for sustained release of constituents in intestine and facilitate maximum absorption. The efficacy was compared for the hepatoprotective activity of nanoencapsulated ethanolic extract of P. amarus (NPA) and PA in carbon tetrachloride (CCl4) induced hepatotoxic male rats. Based on total phenol content (TPC), the loading efficiency of nanocapsules was 89% (pH 7.0) and optimum concentration was 2:18 (mg/mL) for plant extract: olive oil. Scanning electron microscopy (SEM) showed a spherical morphology, photon correlation spectroscopy (PCS) identified mean particle diameter as 213 nm and Fourier transform infrared spectroscopy (FT-IR) revealed that the phytoconstituents were stable. An oral dose of NPA (20 mg/kg body wt.) showed a better hepatoprotective activity than PA (100 mg/kg body wt.) and also repeated dose oral toxicity proved to be safe. These biochemical assessments were supported by rat biopsy examinations. In conclusion, the nanoemulsification method may be applied for poor water-soluble ethanolic herbal extracts to reduce the dosage and time.

Toxicity Assessment of Expired Pesticides to Green Algae Pseudokirchneriella subcapitata.

In order to investigate the effect of expired pesticides on the yield and growth rate of green algae Pseudokirchneriella subcapitata, a study was conducted as per the Organisation for Economic Cooperation and Development (OECD) guideline number 201. Fifteen expired pesticide formulations, most commonly used in Indian agriculture, were tested in comparison with their unexpired counterparts. The expired pesticide formulations studied belonged to various class and functional groups: organophosphate, pyrethroid-based insecticides; azole-based fungicides; acetamide, propionate, acetic acid-based herbicides; fungicides mixtures containing two actives-azole and dithiocarbamate. The toxicity endpoints of yield (EyC50: 0-72 h) and growth rate (ErC50: 0-72 h) of Pseudokirchneriella subcapitata for each pesticide formulation (both expired and unexpired pesticides) were determined statistically using TOXSTAT 3.5 version software. The results pointed out that some expired pesticide formulations exhibited higher toxicity to tested algal species, as compared to the corresponding unexpired pesticides. These data thus stress the need for greater care to dispose expired pesticides to water bodies, to avoid the effects on aquatic ecospecies tested.