Evaluation of two contrasted activated carbon-based sequestration strategies to reduce soil-bound chlordecone bioavailability in piglets

Chlordecone (Kepone) (CLD) is a highly persistent pesticide formerly used in the French West Indies. High levels of this pesticide are still found in soils and represent a subsequent source of contamination for outdoor-reared animals which may ingest involuntary non negligible amounts of soil. In that context, sequestering matrices like activated carbons (ACs) may be used to efficiently decrease the bioavailability of such organic pollutants. The present study intends to assess the respective efficiency of two sequestering strategies where two different ACs were provided either via feed incorporation or via soil amendment. This study involved 20 piglets randomly distributed into 5 experimental groups (4 replicates). All groups were exposed to 10 μg of CLD per kg of BW per day during 10 days via a contaminated soil. In both "Soil-ACs" treatment groups, the contaminated soil was amended by 2% (mass basis) of one of the two ACs. The two "Feed-ACs" groups received the contaminated soil and one dough ball containing 0.5% (mass basis) of one of the ACs. The piglets were then euthanized before collection of pericaudal adipose tissue and the whole liver and CLD analysis. A significant decrease of CLD concentrations in liver and adipose tissue was observed only in the "Soil-ACs" groups in comparison with the control group (P < 0.001). This decrease was particularly important for the coconut shell activated carbon where relative bioavailability was found lower than 1.8% for both tissues.

Evaluation of Antidepressant Potential of Hydrastis canadensis in Mice

BACKGROUND: Depression is one of the most common chronic psychological disorders around the world presenting with many interpersonal and social problems. Common antidepressants have various adverse effects and are not safe for long-term therapy. Alternative safer remedies are under investigation with a focus on herbal therapies. Hydrastis canadensis is a perennial herb, rich in many phytoconstituents ranging from amino acids to alkaloids, flavonoids, and steroids. It is also widely used in Chinese folklore tradition for mood elevating effects; however, this has not been scientifically proven. AIM: This study is thus aimed at evaluating antidepressant potential of this plant. MATERIALS AND METHODS: Ethanolic extract of dried root of plant was prepared by maceration technique and was subjected to phytochemical screening. Mice were divided into four groups (n = 5). Tween 80, 2 ml (negative control), fluoxetine 10 mg/kg (positive control), and extracts at 150 mg/kg and 250 mg/kg were administered by intraperitoneal route to mice in their respective groups. The locomotor activity was assessed for 5 min using actimeter at 0, 30, and 60 min for each animal. Increase in locomotion was an index of antidepressant effect. The mean value of each group was calculated and results were compared by one-way ANOVA. p < 0.05 was considered statistically significant. RESULTS: Phytochemical screening yielded positive results for alkaloids and saponins. Locomotion was increased in groups treated with fluoxetine and extract at 150 mg and 250 mg/kg dose when compared to negative control (1% – Tween 80). This was an index of antidepressant effect. However, the results were statistically significant (p < 0.05) for fluoxetine and extract treated groups at 250 mg/kg. Fluoxetine demonstrated the highest antidepressant effect. CONCLUSION: This study has demonstrated the antidepressant potential of Hydrastis canadensis ethanolic extract. Further studies are required to validate these findings on other experimental models. The specific active constituent and effects at cellular level need to be evaluated.

Amendment of soil by biochars and activated carbons to reduce chlordecone bioavailability in piglets

Chlordecone (Kepone or CLD) is a highly persistent pesticide formerly used in French West Indies. Nowadays high levels of this pesticide are still found in soils which represent a subsequent source of contamination for outdoor-reared animals. In that context, sequestering matrices like biochars or activated carbons (ACs) are believed to efficiently decrease the bioavailability of such compounds when added to contaminated soils. The present study intends to test the respective efficiency of soil amendment strategies using commercial ACs or biochars (obtained by a 500 °C or 700 °C pyrolysis of 4 distinct type of wood). This study involved three experimental steps. The first one characterized specific surface areas of biochars and ACs. The second one assessed CLD-availability of contaminated artificial soils (50 μg g^-1 of Dry Matter) amended with 5% of biochar or AC (mass basis). The third one assessed CLD bioavailability of those artificial soils through an in vivo assay. To limit ethically the number of animals, selections of the most promising media were performed between each experimental steps. Forty four castrated male 40-day-old piglets were exposed during 10 day by amended artificial soils according to their group (n = 4). Only treatment groups exposed through amended soil with AC presented a significant decrease of concentrations of CLD in liver and adipose tissue in comparison with the control group (p < 0.001). A non-significant decrease was obtained by amending artificial soil with biochars. This decrease was particularly high for a coconut shell activated carbon were relative bioavailability was found lower than 3.2% for both tissues. This study leads to conclude that AC introduced in CLD contaminated soil should strongly reduce CLD bioavailability.

Activated carbon, a useful medium to bind chlordecone in soil and limit its transfer to growing goat kids

Chlordecone (Kepone) (CLD) is a highly persistent pesticide which was extensively used in the French West Indies; high levels of CLD can still currently be found in large agricultural areas. As CLD transfers from soil to animals mainly via involuntary ingestion, the consumption of foodstuffs derived from animals raised in contaminated areas may significantly contribute to exposure of humans to CLD. The present study was designed to test the efficacy of two different activated carbons (ACs) sources in limiting CLD transfer from soil to animal. Three soils (ASs) were prepared according to the OECD guideline 207. One standard soil (SS) lacking AC, and two modified preparations of SS supplemented with 2% coconut-based activated carbon (ORBO), SSO or with 2% lignite-based one (DARCO), SSD. All three soils were spiked with 10 μg of kepone per g of dry matter and aged for three weeks. This study involved 15 goat kids randomly assigned to the 3 experimental groups (n = 5/group), which were fed the experimental matrices at an exposure dose of 10 μg CLD per kg of body weight per day. After 21 d of oral exposure, CLD in adipose tissue and liver were analysed by LC-MS-MS. A significant decrease of 63.7% and 74.7% of CLD concentrations in adipose tissue and liver, respectively, were obtained from animals exposed using SS containing DARCO as compared to those receiving only SS. Decreases in CLD levels of 98.2% (adipose tissue) and 98.7% (liver) were obtained for animals exposed using SS containing ORBO. This study leads us to conclude that (i) the presence of AC in CLD-contaminated soil strongly reduces CLD bioavailability, and (ii) the efficacy depends on the nature and characteristics of the AC used.