Dermal Toxicity Research Articles

In silico and in vivo study of adulticidal activity from Ayapana triplinervis essential oils nano-emulsion against Aedes aegypti

Nanoinsecticides of plant origin have advantages in the resistance of Aedes aegypti , vectors of infectious diseases. The objective of this study was to evaluate the insecticidal potential of Ayapana triplinervis essential oil nano-emulsions using in silico and in vivo assays in an Aedes aegypti model. Molecular docking showed that minority compounds present in the morphotype A essential oil have a more significant binding affinity to inhibit acetylcholinesterase and juvenile hormone receptors. Aedes aegypti adults were susceptible to A. triplinervis at 150 µg.mL-1 in a diagnostic time of 15 min for morphotype A essential oil nano-emulsion and 45 min for morphotype B essential oil nano-emulsion. The evaluation of toxicity in Swiss albino mice indicated that the nano-emulsions had low acute dermal toxicity and presented LD 50 greater than 2000 mg.Kg −1 . Thus, it is possible to conclude that nano-emulsions have the potential to be used in the chemical control of A. aegypti .

Fabrication, characterization and efficacy evaluation of natural gum-based bioactive haemostatic gauzes with antibacterial properties.

Management of uncontrolled bleeding due to traumatic injuries occurring in battlefields and road traffic accidents is a major healthcare concern, especially in developing countries like India. Since natural coagulation mechanism alone is insufficient to achieve haemostasis quickly in such cases, application of an external haemostatic product is generally required to accelerate the coagulation process. We had recently reported preliminary comparison of four natural absorbent gums, which indicated towards haemostatic potential of gum tragacanth (GT) and xanthan gum (XG). Present study involves fabrication of haemostatic dressings incorporated with different concentrations of GT or XG, along with ciprofloxacin (a broad-spectrum antibiotic) and other excipients over woven cotton gauze. Prepared gauzes were investigated for physico-chemical characteristics, in-vitro blood interaction studies, antibacterial effect and in-vivo haemostatic efficacy in Sprague Dawley rats using two bleeding models. Acute dermal toxicity studies were also carried out as per OECD guidelines. SEM studies showed that gauzes coated with XG had thin, uniform layer of coating, while in case of GT; coating was comparatively rough with insoluble particles of GT adhering over gauze surface, forming voids on the fibers. Coated gauzes exhibited optimum mechanical properties in terms of tensile strength and percent extension at break. GT coated dressings showed good fluid uptake and retention ability in-vitro. Test gauzes were non-hemolytic in nature, did not elicit any dermal toxicity on animals' skin and had the ability to protect against E. coli infection. In-vivo efficacy studies in rat femoral artery and liver laceration bleeding models indicated that gauzes coated with 4% GT were able to clot blood in least time (36.67 ± 3.33s and 40 ± 2.58s respectively) as compared to other gum combinations and commercially available dressing 'Surgispon® (103.3 ± 4.22s and 85 ± 5.62s respectively). Results of this study validate our initial findings of the potential of gum tragacanth to be developed into a suitable haemostatic product.

Study of the dermal anti-inflammatory, antioxidant, and analgesic activity of pinostrobin

Pinostrobin is a flavanone isolated from Renealmia alpinia (Rottb.) Maas, which is used to treat painful diseases and ailments; indigenous peoples use it as plasters. Different plant species have been reported as a source of this flavonoid, among which are: Boesenbergia rotunda, Cajanus cajan, Piper ecuadorense, Piper hispidum, Teloxys graveolens, Kaempferia pandurata, among others.Pinostrobin expresses potentially useful biological activities such as antioxidant, analgesic, and dermal anti-inflammatory, at low levels nonetheless due to its low solubility. The formation of inclusion complexes deems a good strategy to improve the pharmacologic effects of many substances.In the present work, we evaluated the dermal toxicity, analgesic and dermal anti-inflammatory activity of pinostrobin included in cyclodextrins, to improve those effects on experimental animals. To include pinostrobin, we used two of beta cyclodextrin (βCD) and hydroxypropil beta cyclodextrin (HPβCD) complexes using two methods developed by Benesi-Hildebrand and Higuchi-Connors. Dermal anti-inflammatory activity was evaluated in experimental mice by inhibiting the edema generated by 12-O-tetradecanoylforbol-13-acetate (TPA). Analgesic activity was evaluated by inducing chemical pain by means of a Siegmund test. Antioxidant activities were measured with two in vitro tests.Analgesic and dermal anti-inflammatory activities of pinostrobin, as included in control and experimental complexes, showed comparatively better effects than pinostrobin without inclusion complexes. Our results indicate that both beta cyclodextrin (βCD) and hydroxypropyl beta cyclodextrin (HPβCD) enhance the different effects of pinostrobin, which may indicate greater bioavailability.

Novel topical esmolol hydrochloride improves wound healing in diabetes by inhibiting aldose reductase, generation of advanced glycation end products, and facilitating the migration of fibroblasts.

Aims/ObjectivesWound healing in people with diabetes is delayed secondary to impaired nitric oxide generation, advanced glycation end products (AGE), and poor migration of epithelial cells. We developed a novel topical esmolol hydrochloride (Galnobax) and assessed its efficacy for wound healing in streptozocin-induced diabetic hairless rat.MethodsAll experiments were performed at an animal laboratory and tertiary-care research facility. Ex vivo aldose reductase inhibition was assessed from enzymes obtained from a bacterial culture (spectrophotometer), sorbitol content in homogenized red blood cells, and AGE in glucose and bovine serum by fluorometry following the addition of esmolol in varying concentrations. A scratch assay of human fibroblasts, endothelial cells, and keratinocytes was assessed under a high-glucose environment and after esmolol by phase-contrast microscopy. The efficacy evaluation of the topical application of Galnobax (14 and 20%) or vehicle was conducted in streptozotocin-induced diabetic hairless rats, and endogenous nitrite and hydroxyproline from homogenized wound tissue were measured along with pharmacokinetic and dermal toxicity in Hanford miniature swine.ResultsEsmolol inhibited the formation of sorbitol by 59% in erythrocytes in comparison to glucose-induced sorbitol levels. AGE generation in bovine serum albumin was reduced at 1 mM esmolol concentrations (2.6 ± 1.7) compared with control (p < 0.05) and similar to that of diclofenac (2.5 ± 1.3). Esmolol at 1 and 10 µM enhanced the migration of fibroblasts, epithelial cells, and keratinocytes compared with control. The nitric oxide levels (day 7) were 44 and 112% higher with Galnobax (14%) than those of the diabetic group (p < 0.05) and the vehicle control group (p < 0.05), respectively. The days 7 and 14 hydroxyproline in the wound was higher by 22 and 44% following Galnobax (14%) compared with the diabetic and vehicle control groups. The wound area exhibited better reduction with Galnobax at 14% up to day 10 follow-up compared with the controls. The pharmacokinetic and dermal toxicity in miniature swine suggested no significant adverse event with Galnobax.ConclusionsTopical esmolol hydrochloride is a novel, safe, and effective treatment modality that acts through pleotropic mechanisms to hasten wound healing in diabetes.

Evaluation of the Cutaneous Toxicity of the Aqueous Extract of the Aerial Parts of Mitracarpus scaber (Rubiaceae) in Rats (Rattus norvegicus Strain Wistar)

Mitracarpus scaber is a known plant in the Ivorian pharmacopoeia where it is used in various ways for the treatment of different diseases and ailments, including skin problems. The present study aims at evaluating the cutaneous toxicity of the aqueous extract of the aerial parts of M. scaber in the Wistar rat following exposure to a single dose or repeated doses. In the acute dermal toxicity experiment, a total of six (6) female rats were divided into two (2) groups, with three (3) rats per group. While a total of 32 male and female rats were divided into four (4) groups, each group consisted of eight (8) rats, four (4) males and four (4) females in the subacute dermal toxicity experiment. For the acute dermal toxicity study, rats in one group received a single application of the extract at the concentration of 2000 mg/ml on the first day of the experimental period. While the rats in the subacute study received topical application of the extract at the concentrations of 200, 400 and 800 mg/ml once a day for 28 days. The various applications were made to the dorsal shaved area of the skin. Throughout the respective fourteen (14) and twenty-eight (28) day study periods, all rats were monitored for any changes in physical appearance and behavior that might occur due to the toxic effects of the plant. No mortality or abnormal physical appearance was observed, and physiological and behavioral changes were not observed in all rats in either study. Body weight, kidney and liver weights, and hematology and biochemistry results did not show significant differences (p &gt; 0.05) between all groups in the subacute study. Similarly, histopathological examinations of the liver, kidney and skin revealed no structural alterations. This study suggests that topical application of the aqueous extract of the aerial parts of M. scaber does not induce acute and subacute adverse effects on the skin or systemic toxicity in Wistar rats.

Toxicological Evaluation of Silver Nanoparticles Synthesized with Peel Extract of Stenocereus queretaroensis.

Silver nanoparticles (AgNPs) synthesized with plants are widely used in different industries, such as the medical, industrial, and food industries; however, their hazards and risks remain unclear. Here, we aimed to evaluate the toxicological effects of AgNPs in both in vitro and in vivo models. Previously, we developed and characterized green synthesized AgNPs based on Stenocereus queretaroensis (S. queretaroensis). The present study evaluates the toxicity of these AgNPs through cytotoxicity and mutagenicity tests in vitro, as well as genotoxicity tests, including the evaluation of acute oral, dermal, and inhalation toxicity, along with dermal and ocular irritation, in vivo, according to guidelines of The Organization for Economic Co-operation and Development (OECD). We evaluated cell cytotoxicity in L929 cells, and the half-maximal inhibitory concentration was 134.76 µg/mL. AgNPs did not cause genotoxic or mutagenic effects. Furthermore, in vivo oral, dermal, and acute inhalation toxicity results did not show any adverse effects or mortality in the test animals, and after the dermal and ocular irritation assessments, the in vivo models did not exhibit irritation or corrosion. Therefore, the results show that these previously synthesized S. queretaroensis AgNPs do not represent a risk at the tested concentrations; however, little is known about the effects that AgNPs induce on physiological systems or the possible risk following long-term exposure.

Antagonistic Skin Toxicity of Co-Exposure to Physical Sunscreen Ingredients Zinc Oxide and Titanium Dioxide Nanoparticles.

Being the main components of physical sunscreens, zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO2 NPs) are often used together in different brands of sunscreen products with different proportions. With the broad use of cosmetics containing these nanoparticles (NPs), concerns regarding their joint skin toxicity are becoming more and more prominent. In this study, the co-exposure of these two NPs in human-derived keratinocytes (HaCaT) and the in vitro reconstructed human epidermis (RHE) model EpiSkin was performed to verify their joint skin effect. The results showed that ZnO NPs significantly inhibited cell proliferation and caused deoxyribonucleic acid (DNA) damage in a dose-dependent manner to HaCaT cells, which could be rescued with co-exposure to TiO2 NPs. Further mechanism studies revealed that TiO2 NPs restricted the cellular uptake of both aggregated ZnO NPs and non-aggregated ZnO NPs and meanwhile decreased the dissociation of Zn2+ from ZnO NPs. The reduced intracellular Zn2+ ultimately made TiO2 NPs perform an antagonistic effect on the cytotoxicity caused by ZnO NPs. Furthermore, these joint skin effects induced by NP mixtures were validated on the epidermal model EpiSkin. Taken together, the results of the current research contribute new insights for understanding the dermal toxicity produced by co-exposure of different NPs and provide a valuable reference for the development of formulas for the secure application of ZnO NPs and TiO2 NPs in sunscreen products.

A combination of linalool and linalyl acetate synergistically alleviates imiquimod-induced psoriasis-like skin inflammation in BALB/c mice.

Introduction: Psoriasis is a chronic inflammatory skin disorder characterized by keratinocyte hyperproliferation and differentiation with increased immune cell infiltration. The anti-psoriatic effect of lavender oil has been reported. However, its phytoconstituents, linalool (L) and linalyl acetate (LA), showed a distinctive affinity with psoriasis targets. Objectives: This investigation was aimed to determine the combined effect of L and LA in ameliorating psoriasis-like skin inflammation and its safety in long-term topical uses. Methods: The combined effect of L and LA was compared with their individual effects. The anti-psoriatic activity was performed using imiquimod (IMQ)-induced psoriasis in BALB/c mice and evaluated to reduce PASI and CosCam scores and Th-1 and Th-17 cell-specific cytokine levels. The acute and repeated dose dermal toxicities were investigated as per the OECD guidelines. Results: L and LA combination (LLA) in the 1:1 w/w ratio at 2% concentration showed a synergistic effect. The combination showed 76.31% and 71.29% recovery in PASI and CosCam Scores; however, L2% and LA2% showed 64.28% and 47.61% recovery in PASI and 64.75 and 56.76% recovery in CosCam scores, respectively. It showed >90% and >100% recovery in Th-17 and Th-1 cell-specific cytokines, respectively, and restored epidermal hyperplasia and parakeratosis toward normal compared with psoriatic mice. A marked reduction in NF-κB, cck6, and the IL-17 expression was also observed in the LLA-treated group. This combination was safe in a therapeutically effective dose for 28 days as no significant changes were observed in organ and body weights, liver and kidney parameters, and differential leukocyte counts. Conclusion: This study proves the synergy between L and LA in a 1:1 w/w ratio at 2% in the treatment of psoriasis-like skin inflammation and provides strong scientific evidence for its safe topical use.

Evaluation of Wound Healing Activity of 80% Methanol Root Crude Extract and Solvent Fractions of Stephania abyssinica (Dill. & A. Rich.) Walp. (Menispermaceae) in Mice.

BackgroundThe root of Stephania abyssinica (Dill. and A. Rich.) Walp. (Menispermaceae) is traditionally used to treat wounds. Despite the fact that there have been in vitro studies and claims supporting wound healing, there has been no scientific data on the in vivo wound healing activities of the root of S. Abyssinica.ObjectiveThe aim of the study was to evaluate the wound healing activity of 80% methanol root extract and solvent fractions of S. Abyssinica in mice.MethodsThe roots of S. Abyssinica were air dried, ground and macerated by 80% methanol three times successively. The crude extract was fractionated by water, hexane and ethyl acetate separately. The acute dermal toxicity test was done by applying 2000 mg/kg of the 10% w/w crude extract. Wound healing activity of crude extract was evaluated on excision, incision and burn wound models, while the fractions were evaluated on excision wound model only.ResultsIn mice, an acute dermal toxicity test of 2000 mg/kg of the 10% w/w crude extract was found to be safe. The 10% w/w crude extract ointment (CEO) produced significant (p < 0.001) wound contraction from 4th to 16th post wounding days, and the 5% w/w CEO were significant (p < 0.01) wound contraction on 10th post wounding day as compared to simple ointment (SO) treated group on excision wound. On burn wound models, the CEO showed highly significant (p < 0.001) from the 6th post wounding days onwards. The tensile strength was increased significantly (p < 0.001) by the CEO treated mice as compared to the untreated group and SO group.ConclusionThe data obtained from this study showed 80% methanol crude extract, the aqueous and the 10% w/w ethyl acetate fraction possessed better wound healing activities, and decreased period of epithelialization.

Engineering Antimicrobial Polymer Nanocomposites: In Situ Synthesis, Disruption of Polymicrobial Biofilms, and In Vivo Activity.

The increasing incidence of microbial infections and a limited arsenal of effective antibacterial and antifungal agents have entailed the need for new broad-spectrum therapeutics. Polymer-inorganic nanocomposites have emerged as an integral choice of antimicrobials but are limited by complicated synthesis, narrow-spectrum activity, and poor in vivo efficacy. Herein, chloride counterions of a nontoxic, moderately antibacterial polymer have been explored for in situ nanoprecipitation-based synthesis of water-soluble polymer-silver chloride nanocomposites. With the controlled release of silver ions, the nanocomposites were highly active against multidrug-resistant bacteria as well as fluconazole-resistant fungi. Alongside the elimination of metabolically inactive bacterial cells, the nanocomposites disrupted polymicrobial biofilms, unlike antibiotics and only silver-based ointments. This underlined the role of the engineered composite design, where the polymer interacted with the biofilm matrix, facilitating the penetration of nanoparticles to kill microbes. Further, the nanocomposite diminished Pseudomonas aeruginosa burden in mice skin infection (>99.9%) with no dermal toxicity proving its potential for clinical translation.

Wound healing efficacy of novel ayurveda formulation- Pentabark Kashaya: In wistar rats using excision wound model- an in vivo study

BackgroundWound healing plays a major concern in the field of surgery as it requires uneventful healing. Management aims towards prevention of infection and to accelerate healing. Acharya Sushruta has given more emphasis on Vrana (wound) and its chikitsa (treatment). Many antiseptic agents which prevent infection are widely used but have no role in accelerating the healing process and are cytotoxic, deleterious to wound healing. In this regard an innovative polyherbomineral formulation Pentabark Kashaya (PK)was formulated to assess acute dermal toxicity and woundhealing activity. ObjectiveTo explore the wound healing efficacy of novel Ayurveda Formulation i.e Pentabark Kashaya in Wistar rats using the excision wound model. Materials and methodAcute dermal toxicity study was carried out on five female Wistar rats by following the OECD guideline 434 and signs of toxicity were assessed for the period of 14 days. Wound healing activitywas assessed on the excision wound model. 18 male Wistar rats were procured for the study and divided into three groups (n = 6 in each group). The test group was treated with application of PK, standard group with Povidone iodine solution 5% and control group with distilled water. The parameters assessed were epithelialization period, wound contraction rate, wound closure day and swab test for microbial load for the period of 21 days. Statistical analysis was done by using one way ANOVA and Tukeys HSD to assess changes in between three groups at each time point. ResultsNo signs of acute dermal toxicity were seen, which proved that PK is safe for application. Significant results were seen in the parameters of wound healing like period of epithelialization and wound closure day. Percentage of wound contraction rate was increased in test group when compared to other groups. Histopathology of skin showed marked changes in re-epithelialization, dermal fibroblast, dermal fibrocytes in test group when compared to control group. ConclusionPK is safe for application and it is effective in wound healing.Clinical Trial Registration No.: Not applicable.

Preclinical safety of tetrahydrocurcumin loaded lipidic nanoparticles incorporated into tacrolimus ointment: In vitro and in vivo evaluation

Preclinical safety and proof of concept studies for a topical ointment comprising of concentrated tetrahydrocurcumin loaded lipidic nanoparticles (THC-LNs) and tacrolimus ointment (TTO) is proposed in the present investigation. The skin irritation potential and acute dermal toxicity were performed in rats in compliance with the Organization for Economic Cooperation and Development (OECD) guidelines (402, 404 and 410) while the cytotoxic potential was performed in HaCaT cells. Finally, in vivo evaluation was performed in Imiquimod mice model of psoriasis. In primary skin irritation assessment, TTO formulation, marketed formulation (Tacroz® Forte), THC-LNs, and blank LNs were topically applied on intact skin sites in rats while another group served as a negative control group for 72 h. TTO did not induce any adverse reactions. Repeated 28 days dermal toxicity followed by biochemical and histopathological assessment showed negligible alternations and skin lesions. THC-LNs revealed negligible cytotoxic potential in HaCaT cells. TTO showed significantly high anti-psoriatic activity in comparison to marketed ointment. This was also confirmed via histopathological evaluation. Based on these findings, it can be ascertained that TTO showed minimal toxicity and has ample potential for further clinical analysis. The above studies affirm the potential of TTO as an alternative for psoriasis.

Acute and subchronic toxicity of multicomponent antiparasitic drugs Insaсar Total C Plus, Insaсar Total K Plus

The purpose of the research is to study acute oral toxicity in mice, and acute dermal and subchronic toxicity in rats of multicomponent antiparasitic Insacar Total C Plus (for dogs) and Insacar Total K Plus (for cats).Materials and methods. The toxicity of the drugs was studied in September-April 2020–2021 at the premises of the VNIIP – FSC VIEV Vivarium. To determine acute oral toxicity, 80 outbred mice weighing 20 g were used, of which 7 test and one control group were formed. The drugs were administered once in a 1 : 3 dilution with polyethylene glycol as a solution through an intragastric tube and an automatic controller. The control animals were intact. After a single administration, the physical condition of the test mice was monitored within 14 days; weight gain, expected clinical toxicity symptoms and possible death were assessed. Before and on days 1, 3, 7, 11 and 14 of the experiment, the test and control mice’s weight gain were evaluated. The toxicity parameters were calculated by the methods of Pershin, Miller and Taintner. In a subchronic experiment, the study drugs were tested on 80 outbred white rats divided into 6 test and 2 control groups. The rats’ coat was also shaved on the back. The solution was applied to the shaved skin area once a day for 7 days at doses of 1,000 mg/kg (0.1 mL/100 g), 500 mg/kg (0.05 mL/100 g) and 200 mg/kg (0.02 mL/100 g) of the animal weight. On day 8 of the experiment, 5 rats from each group were euthanized; their blood samples were taken, and the internal organs were examined. On day 21 of the experiment, the second part of the animals was euthanized to analyze the reversibility of potential pathoanatomical changes after prolonged repeated application of the drug. The results were processed statistically.Results and discussion.The half-lethal dose (LD 50) after oral administration of the drug for dogs to the mice was 2,475 by the Pershin method, and 2,500±388 mg/kg by the Miller and Taintner method. LD50 of the drug for cats when administered into the mice’s stomach was 2,713 by the Pershin method, and 2,650±403 mg/kg by the Miller and Taintner method (hazard class 3). LD 50 when applied to the rats’ skin was more than 10,000 mg/kg (hazard class 4). When applied once to the rats’ skin, the drugs had a slightly irritating effect. In subchronic experiment on the rats with daily drug application on their skin at doses of 1,000 mg/kg, 500 and 200 mg/kg, no negative effects on the general condition or death of the animals were observed during the entire study. Hematological and biochemical parameters of the test rats that were treated with the drug for dogs at a dose of 200 mg/kg, an increased content of lymphocytes up to 83.40% was observed on day 8 of the experiment, and up to 74.20 % in the control; and an increased glucose level up to 6.08±1.23 mmol/L, and up to 4.82±0.70 mmol/L in the control; LDH was up to 766.00±264.19 U/L, and up to 434.80±525.89 U/L in the control.

Integrative analysis to explore the biological association between environmental skin diseases and ambient particulate matter

Although numerous experimental studies have suggested a significant association between ambient particulate matter (PM) and respiratory damage, the etiological relationship between ambient PM and environmental skin diseases is not clearly understood. Here, we aimed to explore the association between PM and skin diseases through biological big data analysis. Differential gene expression profiles associated with PM and environmental skin diseases were retrieved from public genome databases. The co-expression among them was analyzed using a text-mining-based network analysis software. Activation/inhibition patterns from RNA-sequencing data performed with PM2.5-treated normal human epidermal keratinocytes (NHEK) were overlapped to select key regulators of the analyzed pathways. We explored the adverse effects of PM on the skin and attempted to elucidate their relationships using public genome data. We found that changes in upstream regulators and inflammatory signaling networks mediated by MMP-1, MMP-9, PLAU, S100A9, IL-6, and S100A8 were predicted as the key pathways underlying PM-induced skin diseases. Our integrative approach using a literature-based co-expression analysis and experimental validation not only improves the reliability of prediction but also provides assistance to clarify underlying mechanisms of ambient PM-induced dermal toxicity that can be applied to screen the relationship between other chemicals and adverse effects.

Efficiency of hypericum perforatum, povidone iodine, tincture benzoin and tretinoin on wound healing

Different topical agents have been used to accelerate wound healing. The purpose of this study is to compare the safety and efficacy of topical application of the extract of Hypericum perforatum (HPE), povidone iodine (PI), tincture benzoin (TB) and tretinoin (T) on surgical wound healing. Ten adult female, Wistar albino rats were included in the study. HPE, PI, TB and T solutions were applied on the wounds. After seven days, tissue samples were collected and inflammatory cells, re-epithelialization, granulation tissue, angiogenesis, collagen accumulation, hemorrhage and lysis of cells were investigated histopathologically. No dermal toxicity was noted. HPE, TB, PI have all showed good epithelialization and granulation, but HPE showed the most advanced stage of healing within a short period of time. HPE had significantly higher values of re-epithelialization and collagen accumulation, but lower inflammatory cell count and granulation tissue. TB had the second best in re-epithelialization, collagen accumulation and the highest granulation tissue. PI induced better reepithelialization and granulation than the control group with remarkable cell lysis. As a result, HPE can be a safe, effective, and cheap agent that can be used for surgical wounds.

Risk Assessment of the Pesticide Coragen 20 SC with the Active Substance Chlorantraniliprole

Coragen 20 SC is a new product in Norway containing the active substance chlorantraniliprole. It is applied for use in apples against codling moth (Cydia pomonella), apple fruit moth (Argyresthia conjugella) and free leaf living larvae. The Norwegian Scientific Committee for Food Safety (VKM) was asked by the Norwegian Food Safety Authority to perform a risk assessment on human health, environmental fate and ecotoxicological of the active substance and the product. The risk assessment of the product was approved at a meeting 11th of May 2010 by VKMs Scientific Panel on Pesticides (Panel 2). VKMs Panel 2 concludes as following: The product and the active substance have low acute oral, dermal and inhalation toxicities. Both are non-irritating to the skin, and no allergenic potential by skin contact were shown. Coragen was non-irritating to the eyes, while chlorantraniliprole showed a weak irritating potential. Chlorantraniliprole is not shown to have any genotoxic or carcinogenic potential, or to be teratogenic or toxic to the reproduction of female animals. The potential for testicular toxicity of chlorantraniliprole is unclear because the study design and the limited number of young dogs (2/sex/group) do not provide basis for a firm conclusion. No particular target organ for toxicity in any species in the sub-chronic and chronic toxicity studies was seen. The observed dose- and time dependent increased degree of microvesiculation in the zona fasiculata of the adrenal cortex in male rats, is however of uncertain biological significance. All test species (rat, mice, dog) showed physiological adaption to chlorantraniliprole administration (increased liver metabolism with induction of cytochrome P450 enzymes) which was manifested as increased liver weight and hepatocellular hypertrophy. In the chronic toxicity study in mice, the increased liver weight and hepatocellular hypertophy was accompanied with eosinofilic foci, which was assessed as an adverse effect. The no observed effect level (NOAEL) derived from this study serves as basis for calculations of values for acceptable daily intake (ADI) and acceptable operator exposure level (AOEL). &#x0D; In Panel 2‘s opinion a sub-chronic study (90 days) with the technical material (E2Y45-282) including relevant concentration of the impurity IN-G2S78 should be performed. This would bring information on possible influence of the impurity on the toxicological profile of the technical material, and consequently on the assessment of the NOAELs in the various toxic studies. &#x0D; The estimated risk for operator and for bystanders or for workers re-entering treated crops is assessed as minimal. &#x0D; Chlorantraniliprole is persistent in soil with half live of about 1 year. The long half life indicates high potential for accumulation in soil after repeated use, which is confirmed by both model simulations and field studies. The Panel considers field data from the south of Europe not to be relevant for the Nordic conditions based on different climate conditions and soil properties contributing in different directions.&#x0D; The Panel considers that the existing documentation is not sufficient for a firm conclusion on the use of normalised field data for modelling purposes. However, the substance is persistent and expected to accumulate in soil. The Panel concludes that there is minimal risk for toxic effects on mammals, birds, bees, and microorganisms in soil due to chlorantraniliprole exposure with the proposed exposure regime. Panel concludes that there is “very high risk” for effects on in-field non target arthropods from chlorantraniliprole exposure. &#x0D; For soil living invertebrates, earthworms seem rather insensitive to chlorantraniliprole and the Panel considers the toxic effects to be minimal. Panel considers the risk for toxic effects on soil living arthropods to be high. Crustaceans and insects larvae are the aquatic organisms most sensitive to chlorantraniliprole. The Panel concludes that there is a minimal risk of toxic effects on aquatic organisms due to exposure to chlorantraniliprole with the proposed application regime provided that a buffer zone of 30 m to surface water is applied.

Risk Assessment of the Pesticide Centium with the Active Substance Clomazone

Centium is a new product in Norway containing the active substance clomazone. The product is applied for use as a herbicide in potato, carrot, cabbage, brussel sprout, swedes, oil seed rape, pea and bean. The Norwegian Institute for Agricultural and Environmental Research recommend approval in potato, carrot, swedes and pea. They do not recommend approval in oil seed rape, cabbage and bean because of lacking documentation on efficacy. The Norwegian Scientific Committee for Food Safety (VKM) was asked by the Norwegian Food Safety Authority to perform a risk assessment on human health and environmental fate of the active substance and the product. The risk assessment of the product was finalized at a meeting May 18, 2011, by VKM’s Scientific Panel on plant protection products (Panel 2). VKM Panel 2’s conclusion is as follows: &#x0D; &#x0D; The active ingredient clomazone is of moderate acute toxicity after oral and inhalation exposure and of low dermal toxicity. The product Centium is of low acute toxicity after oral exposure, by skin contact or by inhalation; however the product may contain a co-formulant, monomeric isocyanate, with sensitizing properties. Due to the lack of documentation on the monomer content, the Panel cannot evaluate the risk of sensitization. UK Poem model estimation of exposure show that exposure to operator is below AOEL and the health risk is therefore minimal. &#x0D; The effects observed in the dog study were considered due to the exposure of clomazone and should therefore be used to determine the NOAEL value. &#x0D; The fertility index used in the two-generation study in rats is not considered relevant as a measure of critical effect. The Panel suggests to use 4000 ppm (354 mg/kg bw/day) which is the highest dose tested in the study. &#x0D; Dose dependent responses were not always evident in the rat teratology study, but significant effects were found at the two highest dose levels (300 and 600 mg/kg bw/day). The observed effects were considered adverse. The proposed NOAEL of 100 mg/kg bw/day was therefore supported. &#x0D; The teratology study with rats is considered relevant for determination of acute reference dose (ARfD) since skeletal malformations can be induced after short exposure periods if the exposure is taking place during a sensitive period of foetal development. &#x0D; The Panel also concludes that based on the results from modeling with MACRO (4.4.2) using the Nordic groundwater scenarios and the input parameters agreed upon in the EU there is a potential for contamination of groundwater exceeding the trigger value of 0.1µg/L for the active ingredient following prescribed usage.

Analysis and interpretation of pharmacokinetic studies following DEET administration to rats, dogs, and humans

Pharmacokinetic studies on the undiluted insect repellent active ingredient, DEET, were assessed for relevance to exposure assessment for humans. Five studies designed to define the DEET plasma concentration profiles of systemic exposure occurring at the respective NOAELs for two laboratory species using dermal and/or oral exposure scenarios and human volunteers at the 95th percentile of consumer use were undertaken to support EPA re-registration. The studies reported herein demonstrate that the DEET plasma concentration for Sprague-Dawley rats and Beagle dogs at the respective NOAELs following oral bolus dosing is much greater in terms of Cmax and AUC than that achieved following human dermal administration at the 95th percentile of consumer use. In addition, these plasma level data confirm that a high-dose rat subchronic dermal toxicity study with DEET is the most relevant model for human safety assessment of this topically applied insect repellent active ingredient. Therefore, utilization of pharmacokinetic plasma level data is important to exposure assessment of DEET and significantly reduces uncertainty in human health safety assessment.

Assessment of Toxicity and Wound Healing Activity of Selaginella Bryopteris Extract

Aim The aim of the study was to assess the toxicity profile of Selaginella bryopteris extract and evaluate its wound healing activity. Methods In vitro wound healing activity of S. bryopteris extract (5% and 10%) was performed using Clonogenic and Scratch assays. The toxicity profile of S. bryopteris extract ointment was evaluated on animals using acute toxicity and dermal toxicity tests. In vivo wound healing activity of S. bryopteris extract ointment (5% and 10%) was used to determine tensile strength in the incision wound healing model. Results Results exhibited that the extract was safe up to 2000 mg/kg per oral dose and non-reactive while applied topically. In vitro results showed that S. bryopteris extract closed the wound gap created by 97.13% in 48 h. The clonogenic assay revealed that the surviving factor for HaCaT cells and MEF cells was 0.78 and 0.85 after treated with 10% concentrations of S. bryopteris. The tensile strength exhibited by S. bryopteris 5% and 10% groups was 395.4 g and 558.5 g in comparison to the control group. Conclusion Thus, S. bryopteris extract can be used as an alternative safe drug therapy against topical wounds.

Dermal Toxicity Influence of Gold Nanomaterials after Embedment in Cosmetics.

Gold nanomaterials (Au NMs) have been widely used in cosmetic products for improving the brightening, and reducing the wrinkling of, skin, etc.; however, the dermal safety of Au NMs is rarely concerned. A previous study found that cosmetics could enhance the toxicity of Au nanosheets, but different physicochemical properties of Au NMs will induce different interaction modes with ingredients of cosmetics, potentially leading to different toxicity profiles. In the present study, spherical and rodlike Au NMs were first found in commercial cosmetics, and then Au nanospheres (NSs) with different sizes and Au nanorods (NRs) with different aspect ratios were prepared to simulate these Au NMs in cosmetics and further investigate their toxicity before and after embedment in cosmetics. It was found that the primary sizes, morphologies, and optical absorptions of these Au NSs and NRs before and after embedment were similar; however, their hydrodynamic sizes and zeta potentials were noticeably different. Then, these Au NSs and NRs presented weak or no cytotoxicity against HaCaT keratinocytes, while cosmetic cream could alleviate their cytotoxicity. Moreover, the cream could enhance the accumulation of Au NSs and NRs in the skin of hairless mice, but it also alleviated the toxicological responses of Au NSs and NRs in terms of superoxide dismutase (SOD) elevation and malondialdehyde (MDA) reduction. Therefore, the embedment of Au NSs and NRs into cosmetics can alleviate the in vitro and in vivo dermal toxicities of Au NSs and NRs.