MATERIALS AND METHODS: In silico Molecular Dynamics (MD) was used to determine the interactions of K21 inside the pocket of the targeted protein (crystal structure of fibroblast collagenase-1 complexed to a diphenyl-ether sulphone based hydroxamic acid; PDB ID: 966C; Crystal structure of MMP-2 active site mutant in complex with APP-derived decapeptide inhibitor. MD simulations were accomplished with the Desmond package in Schrödinger Drug Discovery Suite. Blood samples (~ 0.5 mL) collected into K2EDTA were immediately transferred for further processing using the Litron MicroFlow® PLUS micronucleus analysis kit for mouse blood according to the manufacturer's instructions. Bacterial Reverse Mutation Test of K21 Molecule was performed to evaluate K21 and any possible metabolites for their potential to induce point mutations in amino acid-requiring strains of Escherichia coli (E. coli) (WP2 uvrA (tryptophan-deficient)).
RESULTS: Molecular Simulation depicted that K21 has a specific pocket binding on various MMPs and SrtA surfaces producing a classical clouting effect. K21 did not induce micronuclei, which are the result of chromosomal damage or damage to the mitotic apparatus, in the peripheral blood reticulocytes of male and female CD-1 mice when administered by oral gavage up to the maximum recommended dose of 2000 mg/kg. The test item, K21, was not mutagenic to Salmonella typhimurium (S. typhimurium) strains TA98, TA100, TA1535 and TA1537 and E. coli strain WP2 uvrA in the absence and presence of metabolic activation when tested up to the limit of cytotoxicity or solubility under the conditions of the test.
CONCLUSION: K21 could serve as a potent protease inhibitor maintaining the physical and biochemical properties of dental structures.
OBJECTIVE: To evaluate the adverse effects of aqueous extract of CN leaves (AECNL).
MATERIALS AND METHODS: The oral toxicity of the AECNL was tested following Organisation for Economic Co-operation and Development (OECD) guidelines. Mutagenicity (Ames test) of AECNL was evaluated using TA98 and TA100 Salmonella typhimurium strains.
RESULTS: No mortality or morbidity was found in the animals upon single and repeated dose administration. However, significant body weight loss was observed at 2000 mg/kg during sub-chronic (90 d) exposure. In addition, increased eosinophil at 500 mg/kg and decreased serum alkaline phosphatase levels at 2000 mg/kg were observed in male rats. Variations in glucose and lipid profiles in treated groups were also observed compared to control. Ames test revealed no evidence of mutagenic or carcinogenic effects at 500 μg/well of AECNL.
CONCLUSION: The median lethal dose (LD50) of the AECNL is >5000 mg/kg and the no-observed-adverse-effect level is identified to be greater than 2000 mg/kg/day in 90-d study.
AIM OF THE STUDY: To assess the in vitro mutagenicity and in vivo genotoxicity of aqueous extract of V. officinalis leaves using a modified Ames test and rat bone marrow micronucleus assay according to OECD guidelines.
MATERIALS AND METHODS: In vitro Ames test was carried out using different strains of Salmonella (TA97a, TA98, TA100, and TA1535) and Escherichia coli WP2 uvrA (pKM101) in the presence or absence of metabolic activation (S9 mixture). For micronucleus experiment, male and female Sprague-Dawley rats (n = 6/group) were received a single oral daily dose of 500, 1000, and 2000 mg/kg of V. officinalis extract for three days. Negative and positive control rats were received distilled water or a single intraperitoneal injection of 50 mg/kg of cyclophosphamide, respectively. Following dissection, femurs were collected and bone marrow cells were stained with May-Grünwald-Giemsa solution for micronucleus assessment.
RESULTS: Ames test results demonstrated that 5, 2.5, 1.25 and 0.625 mg/ml of V. officinalis extract induced a significant mutagenic effect against TA100 and TA98 strains (with and without metabolic activation). Findings of the animal study showed there were no significant increase in the micronucleated polychromatic erythrocytes (MNPE) and no significant alterations in the polychromatic erythrocytes (PCE) to normochromatic erythrocytes (NCE) ratio of treated rats as compared with their negative control. Meanwhile, significantly increased in the MNPEs was seen in the cyclophosphamide-treated group only.
CONCLUSION: Aqueous extract of V. officinalis has mutagenic effect against TA98 and TA100 strains as demonstrated by Ames test, however, there is no in vivo clastogenic and myelotoxic effect on bone marrow micronucleus of rats indicating that the benefits of using V. officinalis in traditional practice should outweigh risks.