The sub-chronic oral toxicity of 1,3,5-trimethylbenzene in Sprague–Dawley rats

Commelina benghalensis (Wandering Jew) Linn exhibits abortifacient potentials and hepatotoxicity in pregnant Wistar rats via elevating indicators of oxidative stress and activating proinflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Commelina benghalensis Linn is a perennial plant with upright stems reaching a height of 1 m. Its stem is commonly used to induce abortion in traditional medicine. However, there are insignificant scientific data to evaluate such a claim.

AIM OF THE STUDY

The study was conducted to determine the abortifacient and toxicological potential of ethanol extract of Commelina benghalensis Linn stem (EECBS) via selected proinflammatory and oxidative stress biomarkers in pregnant Wistar rats.

MATERIALS AND METHODS

To determine the phytochemicals responsible for EECBS's toxicity and abortifacient effects, high-performance liquid chromatography-photodiode array detection (HPLC-PDA) and gas chromatography-mass spectrometry (GC-MS) was used. The abortion rate was determined by monitoring the markers of reproductive system failure in the experimental model. To assess rat hepatotoxicity, biochemical markers and immunohistopathological parameters were used.

RESULTS

Results demonstrated the presence of isomeric benzene-mesitylene compounds in EECBS. Also, EECBS significantly altered the markers of liver function and oxidative damage while eliciting a significantly reduced (P < 0.05) number of live fetuses, number of corpora lutea, progesterone, estradiol, and luteinizing hormone, whereas the number of dead fetuses percentage vaginal opening, and post-implantation loss increased significantly (P < 0.05). Estrogenicity studies indicated a significant (P < 0.05) increase in uterine weight, uterine glucose, and ALP dose-dependently. Moreover, EECBS also caused a vaginal hemorrhage preceding the parturition. Also, EECBS treatment significantly increased levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and significantly elevated the expression of COX-2 protein in the liver.

CONCLUSION

The current investigation established Commelina benghalensis Linn stem's abortifacient activity. Continuous use, on the other hand, may cause liver damage in pregnant rats by disrupting antioxidant defense mechanisms, promoting the production of pro-inflammatory cytokines, and increasing COX-2 expression. Hence, caution should be excised while consuming this plant's stem for medication purposes, especially during the gestational period.

Environmental fate and aquatic effects of propylbenzenes and trimethylbenzenes: A review

Propylbenzenes (PBZs) and trimethylbenzenes (TMBs) are aromatic hydrocarbon compounds widely used in many industries with potential release to different environments. The fate and aquatic effects of these compounds in the environment were evaluated. Evidence suggests that PBZs and TMBs will rapidly volatilise from water and bioaccumulate in aquatic organisms. Under both aerobic and anaerobic conditions, these compounds are readily biodegradable, whereby 1,2,3-TMB is more stable than the others. In air, all five compounds have atmospheric photo-oxidation half-lives ranging from 0.31 to 1.55 d. The toxicity data collectively show that PBZs, 1,2,4- and 1,3,5-TMB pose high acute toxicity effects on aquatic organisms. Furthermore, freshwater species are more sensitive to these compounds than marine species. There is not much data on the occurrence of PZBs and TMBs in the aquatic environment. This review presents the current state of knowledge on the fate of PBZs and TMBs. Moreover, the acute and joint toxicity of these compounds to different aquatic organisms, especially in marine organisms, warrants further investigation.

Toxicological responses of BEAS-2B cells to repeated exposures to benzene, toluene, m-xylene, and mesitylene using air-liquid interface method

In order to reduce exposure to toxic chemicals, the European REACH regulation (1907/2006) recommends substituting toxic molecules with compounds that are less harmful to human health and the environment. Toluene is one of the most frequently used solvents in industries despite its toxicity. The objective of this study is to better understand and compare the toxicity of toluene and its homologues in a bronchial cell model. Thus, human bronchial BEAS-2B cells were exposed to steams of toluene, m-xylene, mesitylene (1,3,5-trimethylbenzene), and benzene (20 and 100 ppm). Exposure was carried out using an air-liquid interface (ALI) system (Vitrocell) during 1 h/day for 1, 3, or 5 days. Cytotoxicity, xenobiotic metabolism enzyme gene expression, and inflammatory response were evaluated following cell exposures. BEAS-2B cell exposure to toluene and its homologues revealed the involvement of major (CYP2E1) and minor metabolic pathways (CYP1A1). A late induction of genes (EPHX1, DHDH, ALDH2, and ALDH3B1) was measured from Day 3 and can be linked to the formation of metabolites. An increase in the secretion level of inflammatory markers (TNF-α, IL-6, IL-8, MCP-1, and GM-CSF) was also observed. In parallel, regulation between inflammatory mediators and the expression of transmembrane glycoprotein mucin MUC1 was also studied. This in vitro approach with ALI system points out the relevance of conducting repeated exposures to detect potential late effects. The difference recorded after cell exposure to toluene and its homologues highlights the importance of substitution principle.

Safety assessment of the ethanolic extract of Gongronema latifolium Benth. leaves: a 90-day oral toxicity study in Sprague Dawley rats

Background

The leaves of Gongronema latifolium Benth. have long been recognized traditionally as a remedy for a variety of ailments in Africa. This study was conducted to evaluate the safety profile of the ethanolic extract of G. latifolium (GLES) leaves through a repeated dose 90-day oral toxicity study in male and female of Sprague Dawley rats.

Methods

GLES was orally administered at doses of 250, 500 and 1000 mg/kg/day consecutively for 90 days.

Results

No behavioral or physiological changes and mortality were observed. GLES did not have a marked impact on general hematological parameters and did not precipitate nephrotoxicity. However, compared to the control, serum triglycerides, total cholesterol and low-density lipoprotein levels were lower and white adipose tissue paired retroperitoneal fat depots were depleted in male rats treated with GLES3 by the end of the experiment. The liver was significantly enlarged in GLES-treated rats of both sexes. Negative gender-specific alterations were observed with the highest dose. Adverse risk was evident in the female rats mainly due to marked body weight gain and cerebrum weight reduction.

Conclusion

Further research is needed to reach more specific conclusions about to the safety of ingesting high doses of GLES for long periods of time.

Gasoline toxicology: overview of regulatory and product stewardship programs

Significant efforts have been made to characterize the toxicological properties of gasoline. There have been both mandatory and voluntary toxicology testing programs to generate hazard characterization data for gasoline, the refinery process streams used to blend gasoline, and individual chemical constituents found in gasoline. The Clean Air Act (CAA) (Clean Air Act, 2012: § 7401, et seq.) is the primary tool for the U.S. Environmental Protection Agency (EPA) to regulate gasoline and this supplement presents the results of the Section 211(b) Alternative Tier 2 studies required for CAA Fuel and Fuel Additive registration. Gasoline blending streams have also been evaluated by EPA under the voluntary High Production Volume (HPV) Challenge Program through which the petroleum industry provide data on over 80 refinery streams used in gasoline. Product stewardship efforts by companies and associations such as the American Petroleum Institute (API), Conservation of Clean Air and Water Europe (CONCAWE), and the Petroleum Product Stewardship Council (PPSC) have contributed a significant amount of hazard characterization data on gasoline and related substances. The hazard of gasoline and anticipated exposure to gasoline vapor has been well characterized for risk assessment purposes.