7 research outputs found
Research of the Influences of Input Parameters on the Result of Vehicles Collision Simulation
Vehicle collisions are complex processes which are determined by a large number of different parameters. The development of computer programs for simulation has made the collision analysis and reconstruction procedure easier, as well as the possibility to realise the influences of different parameters on collision processes, which was not possible while using classical methods. The quality of results of vehicle collision simulation and reconstruction is expressed by an error which is determined on the basis of the difference between vehicles stopping positions, which was obtained by the simulation of established vehicles stopping positions in real collisions. Being acquainted with the influence of collision parameters on the simulation error enables the development of more reliable models for automatic optimisation of the collision process and reduction of the number of iterations in the procedure of a collision reconstruction. Within the scope of this paper, the analysis and classification of different collision parameters have been carried out. It has been done by the degree of the influence on the error in the simulation process in the software package Virtual CRASH. Varying twenty different collision parameters on the sample of seven crash tests, their influence on the distance, trajectory and angular error has been analysed, and ten parameters with the highest level of influence (centre of gravity position from front axle of vehicle 1, restitution coefficient, collision place in longitudinal direction, collision place in transverse direction, centre of gravity height-vehicle2, centre of gravity height-vehicle1, collision angle, contact plane angle, slowing down the vehicle and vehicle movement direction) have been distinguished
The Molecular Mechanisms of Apoptosis Induced by Allium flavumL. and Synergistic Effects with New-Synthesized Pd(II) Complex on Colon Cancer Cells
Considering that induction of apoptosis is one of the main strategies in cancer therapy, the molecular mechanisms of cytotoxic effects of Allium flavumL. on colon cancer cell lines were investigated and applied in single and co-treatments with new-synthesized Pd(II) complex. The analysis of chemical composition identified caffeic acid glycosides as the most dominant phenolics in A.flavum extract. In all investigated extracts, A.flavum showed cytotoxic effects on colon cancer cells (IC50=1.64-84g/mL) but not on healthy cells. Combinations of plant extracts with Pd(II) complex caused lower IC50 values and better proapoptotic activity. Pd(II) complex induced high percentage of necrosis in a single treatment, but in the combination with plant extracts it had better proapoptotic and lower necrotic activity. Treatments and co-treatments induced higher O-2(-) production and influenced apoptosis biomarkers, leading to Fas protein overexpression and activation of caspases 8 and 9. Practical ApplicationsIn view of the achieved anticancer properties, insufficiently investigated Allium flavum L. is a promising candidate for developing new anticancer compounds and deserves further research and scientific validation. This study has great impact on investigation of new anticancer substances from natural source, focuses on the importance of using plants as the source of medicinal drugs, contributes to the development of the appropriate therapy and gives contribution in both scientific and practical means. Because of its synergistic actions with the newly synthesized chemical anticancer agent and ability to reduce side effects (thus reducing necrotic activity of Pd[II] complex), A.flavum can be used as a dietary food supplement or supplement to chemotherapy perhaps in combination with currently used chemotherapeutics or in some strategies in cancer therapy. This finding is also important from a nutritional point of view because this extracts contain significant amounts of bioactive constituents, which provide health benefits
Antioxidant and antimicrobial activity of two Asplenium species
Extracts of the aerial (fronds) and underground parts (rhizome and roots) of Asplenium adiantum-nigrum L. and Asplenium ruta-muraria L. were analyzed for their phenolic composition and antioxidant properties (scavenging capacities against DPPH center dot and ABTS(center dot+)), and were comparatively assayed for antimicrobial and antibiofilm activity. Total of the 17 phenolic compounds, belonging to the classes of phenolic acids (hydroxybenzoic and hydroxycinnamic acids), flavonoids (flavan-3-ols, flavonols), and xanthones were identified and quantified using UHPLC/DAD/(-)HESI-MS/MS analysis. The present study shows that two analyzed ferns are significantly diverse in terms of their phenolic profile. Flavonoids considerably contribute to the total phenolic content of A. ruta-muraria, ranging from 47% in roots to around 75% in rhizome and fronds, while A. adiantum-nigrum preferably accumulates xanthones. Antioxidant activity of fern methanol extracts was ascribed to their phenolics content. Extracts of rhizomes of both Asplenium ferns exhibited the highest antimicrobial activity, while frond extracts were more efficient in inhibition of Candida albicans biofilm formation. The present study provides experimental evidence that methanol extracts from two analyzed Asplenium fern species exhibit strong antibacterial effect against Gram-negative bacteria which candidate them as a potentially useful natural antimicrobial agents
Nepetalactone-rich essential oil mitigates phosphinothricin-induced ammonium toxicity in Arabidopsis thaliana (L.) Heynh.
Active ingredient of the commercial herbicide BASTA (B), phosphinothricin, acts as an inhibitor of glutamine synthetase (GS), a key enzyme in ammonium assimilation. The treatment with BASTA leads to an elevation of ammonium levels in plants and further to various physiological alterations, ammonium toxicity and lethality. Results of the present study emphasize the complexity underlying control mechanisms that determine BASTA interaction with essential oil (EO) from Nepeta rtanjensis (NrEO), bioherbicide inducing oxidative stress in target plants. Simultaneous application of NrEO and BASTA, two agents showing differential mode of action, suspends BASTA-induced ammonium toxicity in Arabidopsis thaliana plants. This is achieved through maintaining GS activity, which sustains a sub-toxic and/or sub-lethal ammonium concentration in tissues. As revealed by the present study, regulation of GS activity, as influenced by BASTA and NrEO, occurs at transcriptional, posttranscriptional, and/or posttranslational levels. Two genes encoding cytosolic GS, GLN1;1 and GLN1;3, are highlighted as the main isozymes in Arabidopsis shoots contributing to NrEO-induced overcoming of BASTA-generated ammonium toxicity. The effects of NrEO might be ascribed to its major component nepetalactone, but the contribution of minor EO components should not be neglected. Although of fundamental significance, the results of the present study suggest possible low efficiency of BASTA in plantations of medicinal/aromatic plants such as Nepeta species. Furthermore, these results highlight the possibility of using NrEO as a bioherbicide in BASTA-treated crop fields to mitigate the effect of BASTA residues in contaminated soils
Antagonistic Interaction between Phosphinothricin and Nepeta rtanjensis Essential Oil Affected Ammonium Metabolism and Antioxidant Defense of Arabidopsis Grown In Vitro
Phosphinothricin (PPT) is one of the most widely used herbicides. PTT targets glutamine synthetase (GS) activity in plants, and its phytotoxicity is ascribed to ammonium accumulation and reactive oxygen species bursts, which drives rapid lipid peroxidation of cell membranes. In agricultural fields, PPT is extensively sprayed on plant foliage; however, a portion of the herbicide reaches the soil. According to the present study, PPT absorbed via roots can be phytotoxic to Arabidopsis, inducing more adverse effects in roots than in shoots. Alterations in plant physiology caused by 10 days exposure to herbicide via roots are reflected through growth suppression, reduced chlorophyll content, perturbations in the sugar and organic acid metabolism, modifications in the activities and abundances of GS, catalase, peroxidase, and superoxide dismutase. Antagonistic interaction of Nepeta rtanjensis essential oil (NrEO) and PPT, emphasizes the existence of complex control mechanisms at the transcriptional and posttranslational level, which result in the mitigation of PPT-induced ammonium toxicity and in providing more efficient antioxidant defense of plants. Simultaneous application of the two agents in the field cannot be recommended; however, NrEO might be considered as the PPT post-treatment for reducing harmful effects of herbicide residues in the soil on non-target plants
Potential of Teucrium chamaedrys L. to modulate apoptosis and biotransformation in colorectal carcinoma cells.
ETHNOPHARMACOLOGICAL RELEVANCE Teucrum chamaedrys L. is one of the known medicinal plants, useful for treatment of various health problems, especially digestive. In this study, we investigated methanol, ethyl-acetate and acetone extracts of T. chamaedrys in respect to their anticancer properties in SW480 colorectal cancer cells. MATERIALS AND METHODS Cytotoxicity and proapoptotic potential were assessed by MTT cell viability assay and AO/EB double staining. Molecular mechanisms of induced apoptosis were determined by monitoring Fas receptor protein expression through immunofluorescence, Caspase 8 and 9 activity, as well as concentrations of O2.- spectrophotometrically. Additionally, mRNA expression of biotransformation enzymes (CYP1A1, CYP1B1, GSTP1) and membrane transporters (MRP1 and MRP2) involved in drug resistance were investigated by qPCR method. Qualitative analysis of individual phenolic compounds was performed by reversed phase HPLC-MS analysis. RESULTS Methanol extract shows the best cytotoxicity and selectivity compared to ethyl-acetate and acetone extracts, mainly causing apoptosis of SW480 cells, without affecting normal HaCaT keratinocytes. The increased expression of Fas receptor protein and caspase 8 activity indicate that the death receptor-mediated pathway plays a crucial role in the observed apoptosis. The increased caspase 9 activity and O2.- concentration suggest that mitochondria are also involved in the apoptosis. T. chamaedrys methanol extract inhibits mRNA expression of CYP1A1, CYP1B1, GSTP1, MRP1 and MRP2 in SW480 cells. CONCLUSIONS Induction of apoptosis and inhibition of CYP1A1, CYP1B1, GSTP1, MRP1 and MRP2 mRNA expression implies that T. chamaedrys can serve as a valuable source of bioactive compounds as dietary supplements or selective anticancer agents, with the ability to induce apoptosis and modulate drug resistance in colorectal cancer cells