Optimizing the Metal Bioreduction Process in Recombinant Shewanella azerbaijanica Bacteria: A Novel Approach via mtrC Gene Cloning and Nitrate-Reducing Pathway Destruction.

Environmental pollution is growing every day in terms of the increase in population, industrialization, and urbanization. Shewanella azerbaijanica is introduced as a highly potent bacterium in metal bioremediation. The mtrC gene was selected as a cloning target to improve electron flux chains in the EET (extracellular electron transfer) pathway. Using the SDM (site-directed mutagenesis) technique, the unique gene assembly featured the mtrC gene sandwiched between two napD/B genes to disrupt the nitrate reduction pathway, which serves as the primary metal reduction competitor. Shew-mtrC gene construction was transferred to expression plasmid pET28a (+) in the expression host bacteria (E. coli BL21 and S. azerbaijanica), in pUC57, cloning plasmid, which was transferred to the cloning host bacteria E. coli Top10 and S. azerbaijanica. All cloning procedures (i.e., synthesis, insertion, transformation, cloning, and protein expression) were verified and confirmed by precise tests. ATR-FTIR analysis, CD, western blotting, affinity chromatography, SDS-PAGE, and other techniques were used to confirm the expression and structure of the MtrC protein. The genome sequence and primers were designed according to the submitted Shewanella oneidensis MR-1 genome, the most similar bacteria to this native species. The performance of recombinant S. azerbaijanica bacterium in metal bioremediation, as sustainable strategy, has to be verified by more research.

The effect of not-anaerobicization and discolored bacteria on uranium reduction by Shewanella sp. RCRI7.

Shewanella sp. RCRI7 is a native strain capable of reducing uranium in anaerobic conditions. In order to employ this bacterium for the bioremediation, the mutual effects of uranium and the bacteria are studied in two different approaches. The optimal settings for the bacterial proliferation capacity and uranium reduction without anaerobicization of the environment, as well as the related effects of bioremediation and bacterial color under uranium-reducing conditions, have been investigated in this study. Uranium reduction procedure was analyzed using XRD, spectrophotometry and ICP-AES. In addition, the uranium's effect on the population of the first-generation of the bacteria as well as the color and growth of the second-generation were investigated using neobar lam and CFU (Colony Forming Unit), respectively. Uranium toxicity reduced the population of non-anaerobicized bacteria more than the anaerobicized bacteria after one day of incubation, while the amount of uranium extracted by the bacteria was almost the same. In both situations, the bacteria were able to reduce uranium after two weeks of incubation. In addition to the cell counts, uranium toxicity disrupts the growth and development of healthy second-generation anaerobicized bacteria, as created creamy-colored colonies grow slower than red-colored colonies. Furthermore, due to malfunctioning cytochromes, unlike red bacteria, creamy-colored bacteria were unable to extract the optimum amount of uranium. This study reveals that reduced uranium can be produced in a deprived environment without anaerobicization. Creamy-colored Shewanella can remove soluble uranium, however the most effective bacteria have red cytochromes. These findings represent a big step forward in the industrialization of uranium bioremediation.

Phytochemical and biological activities of some Iranian medicinal plants.

CONTEXT: Due to adverse effects of synthetic compounds, there is a growing interest in utilization of plant-derived natural products in the pharmaceutical and food industries. Iranian endemic medicinal plants widely used in traditional practice have attracted much attention as antibacterial and antioxidant agents. OBJECTIVE: This review attempts to compile the accessible scientific research pertained to phytochemical compounds, antibacterial and antioxidant effects of essential oils obtained from some of the most widely used and distributed medicinal plants in Iran. METHODS: This review has been compiled using references via reliable databases (Google Scholar, SID and Science Direct) from 2010 to 2020. This literature review was limited to references published in English and Persian languages. RESULTS: Based on studies heretofore carried out, essential oils isolated from mentioned medicinal plants exhibited strong antioxidant activity which is attributed to their main phytochemical compounds; thymol, carvacrol, p-cymene and γ-terpinene. In addition, the antibacterial activities of essential oils of most plant species from Apiaceae and Asteraceae families were more susceptible against Gram-positive bacteria; Staphylococcus aureus and Bacillus cereus than Gram-negative bacteria; however, essential oils of other studied plant species manifested similar behaviours against both Gram-positive and -negative bacteria. CONCLUSIONS: As there is rich ethnobotanical knowledge behind Iranian endemic medicinal plants, further scientific research is required to prove their safety and efficacy. This review revealed that there are numerous valuable medicinal plants adoptable in food and pharmaceutical industries in the near future.

Evaluation of Cyc1 protein stability in Acidithiobacillus ferrooxidans bacterium after E121D mutation by molecular dynamics simulation to improve electron transfer.

Cyc1 (Cytochrome c552) is a protein in the electron transport chain of the Acidithiobacillus ferrooxidans (Af) bacteria which obtain their energy from oxidation Fe2+ to Fe3+. The electrons are directed through Cyc2, RCY (rusticyanin), Cyc1 and Cox aa3 proteins to O2. Cyc1 protein consists of two chains, A and B. In the present study, a novel mutation (E121D) in the A chain of Cyc1 protein was selected due to electron receiving from Histidine 143 of RCY. Then, the changes performed in the E121D mutant were evaluated by MD simulations analyzes. Cyc1 and RCY proteins were docked by a Patchdock server. By E121D mutation, the connection between Zn 1388 of chain B and aspartate 121 of chain A weaken. Asp 121 gets farther from Zn 1388. Therefore, the aspartate gets closer to Cu 1156 of the RCY leading to the higher stability of the RCY/Cyc1 complex. Further, an acidic residue (Glu121) becomes a more acidic residue (Asp121) and improves the electron transfer to Cyc1 protein. The results of RMSF analysis showed further ligand flexibility in mutation. This leads to fluctuation of the active site and increases redox potential at the mutation point and the speed of electron transfer. This study also predicts that in all respiratory chain proteins, electrons probably enter the first active site via glutamate and exit histidine in the second active site of each respiratory chain protein.

U (VI) tolerance affects Shewanella sp. RCRI7 biological responses: growth, morphology and bioreduction ability.

Native Shewanella sp. RCRI7 is recently counted as an operative bacterium in the uranium bio-reduction. The aim of this study was to investigate the effects of uranium tolerance on the morphology and population of RCRI7, following its potential removal capacity in different time intervals. In this research, the bacterial growth and uranium removal kinetic were evaluated in aerobic TSB medium, uranium-reducing condition (URC), aerobic uranium-containing (AUC) and anaerobic uranium-free (AUF) solution, following evaluations of omcAB gene expressions. In addition, spectrophotometry analyses were performed in URC confirming the bio-reduction mechanism. It was found that the bacteria can grow efficiently in the presence of 0.5 mM uranium anaerobically, unlike AUC and AUF solutions. Since the bacterium's adsorption capacity is quickly saturated, it can be deduced that uranium reduction should be dominant as incubation times proceed up to 84 h in URC. In 92 h incubation, the adsorbed uranium containing unreduced and reduced (U (IV) monomeric), was released to the solution due to either increased pH or bacterial death. In AUC and AUF, improper conditions lead to the reduced bacterial size (coccus-shape formation) and increased bacterial aggregations; however, membrane vesicles produced by the bacteria avoid the uranium incrustation in AUC. In overall, this study implies that Shewanella sp. RCRI7 are well tolerated by uranium under anaerobic conditions and the amount of regenerated uranium increases over time in the reduced form.

Investigating the rus and petI operon expression patterns in exposed Acidithiobacillus ferrooxidans sp. FJ2 to different doses of gamma irradiation.

The bioleaching process is developing as an economic and successful biotechnology method in the metallurgy industry. Acidithiobacillus ferrooxidans is one of the most important bacteria involved in uranium bioleaching which converts insoluble U4+ to soluble U6+ by oxidation of Fe2+ to Fe3+ using several periplasmic proteins encoded by the genes in rus and petI operons in its electron transport pathway. Accordingly, the purpose of this study was to consider the expression of these genes through exposed A. ferrooxidans sp. FJ2 to γ-ray in 17 different doses targeting uranium extraction yield. Acidithiobacillus ferrooxidans sp. FJ2 was irradiated by gamma rays at 25, 50, 75, 100, 150, 300, 450, 600, 750 Gy and 1, 2, 5, 10, 15, 20, 25 and 30 kGy doses. Moreover, the Eh value of 9k culture media was measured as special screening criteria to select the four treatments. The selected bacteria were cultured in 9k media, containing 50% uranium ore powder in the bioleaching process. Then, the value of pH & Eh of culture media, Fe2+ and uranium concentrations in 4, 8 and 13 day's period of incubation were measured. In followings, the expression levels of cyc1, cyc2, rus, coxB, petA, petB, petC and cycA genes at the end of each period were investigated by real-time PCR. Overall, all samples demonstrated a decrease in pH value and Fe2+ concentration and an increase in Eh value and U concentration in time intervals. The gamma irradiation in given doses raised the expression levels of all genes encoded in rus and petI operons, except petB gene during the bioleaching process, although, it had no effect either on the pH, Eh values or on Fe2+ and uranium concentrations. This result implies that during the oxidation of ferrous iron and formation of Jarosite sediment, the decreasing trend of pH and the increasing trend of Eh occurred in all samples. However, the differences in expression of the genes of rus and petI operons in the samples did not have an effect on uranium extraction.

Investigation of Cyc1 protein structure stability after H53I mutation using computational approaches to improve redox potential.

Acidithiobacillus ferrooxidans (Af) is an acidophilic bacterium that grows in rigid surroundings and gets its own energy from the oxidation of Fe2+ to Fe3+. These bacteria are involved in the bioleaching process. Cyc1 is a periplasmic protein with a crucial role in electron transportation in the respiratory chain. His53 of the Cyc1 protein, involved in electron transfer to CoxB, was selected for mutation and bioinformatics studies. His53 was substituted by Ile using PyMol software. Molecular dynamics simulations were performed for wild and mutant types of Cyc1 protein. The conformational changes of mutated protein were studied by analyzing RMSD, RMSF, SASA, Rg, H Bond, and DSSP. The results of the RMSF analysis indicated an increase in the flexibility of the ligand in the mutant. Finally, active site instability leads to an increase in the value of E0 at the mutation point and improving electron transfer. On the other, His53 in Cyc1 is interconnected to Glu126 in CoxB through the water molecule (W76) and hydrogen bonding. In the H53I mutation, there was a decrease in the distance between H2O 2030, 2033, and isoleucine 53, and subsequently, the distance to the water molecule 76 between the two proteins was reduced and strengthens the hydrogen bond between Cyc1 and CoxB, finally improves electron transfer and the bioleaching process.

Effect of the Met148Leu mutation on the structure and dynamics of the rusticyanin protein from Acidithiobacillus sp. FJ2.

The rusticyanin protein, a blue monomeric copper protein type-1, is one of the main components in the iron-electron transfer chain of the Acidithiobacillus ferrooxidans, and is the product of the rus gene expression. Herein, first the bacterial DNA of Acidithiobacillus sp. FJ2 was extracted. Then, the rus gene sequence and the sequence amino acid rusticyanin protein were determined. The Met148Leu mutation increased the oxidase activity of the rusticyanin protein, thereby enhancing the efficiency of the bioleaching process by bacteria Acidithiobacillus ferroxidans. Met148Leu mutation was created in the rusticyanin protein, then molecular dynamics (MD) simulations and structural analysis were performed. The MD analysis of the wild-type and mutant protein demonstrated a slight instability in the mutant protein and significant instability in the active site of the mutant protein. The usefulness of this study is the genetic manipulation of the native Acidithiobacillus sp. FJ2 bacterium, which can boost the bioleaching efficiency of the bacterium to some extent, and investigating its effects on the structure of a mutant protein using computational methods.

Evaluation of mtr cluster expression in Shewanella RCRI7 during uranium removal.

In recent years, bioremediation is considered as an efficient method to remove the pollutants from the industrial wastewater. In this study, quantitative gene expressions (Real-time RT-PCR) of mtr gene cluster (mtrA, mtrB, mtrC, mtrD, mtrE, mtrF and omcA) in five different uranium concentrations (0.1, 0.25, 0.5, 1 and 2 mM) were performed with ICP and microscopic live cell counting analysis under anaerobic condition, by Shewanella RCRI7 as a native bacterium. The results indicated that the amount of uranium removal and live-cell counting were decreased in the higher uranium concentrations (1 and 2 mM), due to the uranium toxicity, suggesting 0.5 mM as the optimum uranium concentration for Shewanella RCRI7 resistance. The expression of mtrCED and omcA genes presented increasing trend in the lower uranium concentrations (0.1, 0.25 and 0.5 mM) and a decreasing trend in 1 and 2 mM, while mtrABF, presented an inverse pattern, proving the alternative role of mtrF for mtrC and omcA, as the substantial multiheme cytochromes in Extracellular Electron Transfer (EET) pathway. These data are a proof of these gene vital roles in the EET pathway, proposing them for genetic engineering toward EET optimization, as the certain pathway in heavy metal bioremediation process.

Anti-inflammatory Effects of Deuterium-Depleted Water Plus Rosa Damascena Mill. Essential Oil Via Cyclooxygenase-2 Pathway in Rats.

OBJECTIVES: Natural medicine has been proposed for treating sepsis worldwide. Therefore, in this study, the effect of deuterium-depleted water (DDW) alone and adjuvant with Rosa damascena Mill. (RD) essential oils was considered through the evaluation of oxidative stress-antioxidant parameters and the expression of cyclooxygenase-2 (COX-2) inflammatory gene in liver damage caused by sepsis. MATERIALS AND METHODS: The rats were randomly divided into 5 groups: 1) laparotomy group; 2) cecal ligation and puncture (CLP) group; 3) DDW (15 ppm and 30 ppm doses) group; 4) DDW (15 ppm and 30 ppm doses) plus RD essential oil (100 mg/kg.bw); 5) indomethacin (2 mg/kg.bw) as a positive control. The treatments were daily administrated for 2 weeks and the CLP model was created on the day 15. Then, the animals were killed and their liver tissue was separated for histopathologic and biochemical assessment. RESULTS: Our results demonstrated that the treatment of animals with DDW and DDW plus RD essential oil was effective due to the regulation of the oxidative stress-antioxidant parameters including lipid peroxidation, glutathione (GSH), GSH s-transferases, myeloperoxidase, ferric reducing ability of plasma and inflammatory parameters such as prostaglandin E2 and COX-2. Pathological studies also showed that sepsis led to the liver tissue injuries, which can be reduced by treatments. CONCLUSION: Sepsis caused oxidative stress in the liver tissue, but the administration of DDW and DDW plus RD essential oil can be useful to prevent and heal these injuries.

Synergistic effects of deuterium depleted water and Mentha longifolia L. essential oils on sepsis-induced liver injuries through regulation of cyclooxygenase-2.

CONTEXT: Mentha longifolia L. (Lamiaceae), a traditional medicinal herb, has been highly valued for exhibiting antimicrobial, antioxidant and antispasmodic properties. OBJECTIVE: For the first time, the synergetic anti-inflammatory effects of deuterium depleted water (DDW) and M. longifolia essential oils (ML) were investigated in experimental sepsis. MATERIALS AND METHODS: Fifty Wistar rats were divided into 5 groups (n = 10): negative control (laparotomy), CLP, treatment groups including the combination of DDWs (15 and 30 ppm) and ML (100 mg/kg b.w) and indomethacin. At 24 h after CLP induction, lipid peroxidation (LP), glutathione (GSH), glutathione in S-transferases (GST), ferric reducing ability of plasma (FRAP), myeloperoxidase (MPO), prostaglandin E2 (PGE2), and COX-2 expression were determined in the plasma and liver tissues. RESULTS: Compared with the CLP group, the administration of DDWs and ML significantly (p < 0.05) prevented the increase of LP, COX-2 and PGE2 levels and liver enzymes. Additionally, the decreased levels of FRAP and GSH induced by sepsis were remarkably (p < 0.05) risen by the administration of DDWs and ML in comparison to the CLP group. However, no significant (p > 0.05) differences were observed regarding GST, ALP and bilirubin levels. Our results also proved the synergistic anti-inflammatory activities of the DDWs and ML. The anti-inflammatory effects of the DDWs and ML were confirmed by histopathological studies. DISCUSSION AND CONCLUSIONS: The combination of DDWs and ML exerted synergistic anti-inflammatory activity against CLP-induced sepsis possibly through modulating oxidative stress/antioxidant parameters.

Considering the Effect of Rosa damascena Mill. Essential Oil on Oxidative Stress and COX-2 Gene Expression in the Liver of Septic Rats.

OBJECTIVES: Sepsis is a clinical illness with a high rate of mortality all over the world. Oxidative stress is considered the main phenomenon that occurs in sepsis. Rosa damascena Mill. is an ancient herbal plant with high pharmacological activities. MATERIALS AND METHODS: Cecal ligation and puncture (CLP) as a standard model was used to induce sepsis in rats. Male adult rats were randomly divided into 5 groups. Different doses of R. damascena essential oil (50 and 100 mg/kg.bw) were gavaged orally for 14 days and on day 15 CLP was performed. After 24 h, blood samples and liver tissues were removed in order to measure oxidative stress [myeloperoxidase (MPO), malondialdehyde (MDA), glutathione (GSH), glutathione-S-transferase, and ferric reducing ability of plasma (FRAP)] and biochemical parameters [alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT), and bilirubin] together with plasma prostaglandin E2 (PGE2) and COX-2 expression. RESULTS: The essential oil was capable of modulating all of the oxidative stress, antioxidant, and anti-inflammatory parameters induced by CLP as characterized by elevations in MPO and MDA levels as well as increases in AST and ALT concentrations concomitant with PGE2 and COX-2 increments. The antioxidant defense system such as GSH and FRAP was also increased in the essential oil treated groups. CONCLUSION: Our results showed that the essential oil has antioxidative and hepatoprotective activities through reducing the oxidative injury in sepsis caused by CLP.

Assessing the effect of Mentha longifolia essential oils on COX-2 expression in animal model of sepsis induced by caecal ligation and puncture.

CONTEXT: Mentha longifolia L. (Lamiaceae), a traditional Iranian plant, possesses antimicrobial and antioxidant activities. OBJECTIVE: We investigated the potential protective effects of M. longifolia essential oils (E.Os) on caecal ligation and puncture (CLP) induced liver injury. MATERIALS AND METHODS: Wistar Albino rats (n = 50) were grouped as follows: (1) a laparotomy group (LAP); (2) a CLP group (CLP); (3) the treatment groups received orally the E.Os (50 and 100 mg/kg b.w) and indomethacin (2 mg/kg b.w) for 2 weeks. The oxidative stress parameters, liver enzymes and prostaglandin E2 (PGE2) level were measured in liver and plasma tissues. The liver was also harvested for the real time PCR of cyclooxygenase (COX-2) expression following histopathological examinations. RESULTS: The results indicated that the CLP operation significantly increased lipid peroxidation (LP) [1.79-fold], myeloperoxidase (MPO) [2.76-fold], PGE2 [1.56-fold] besides plasma aspartate aminotransferase (AST) [2.4-fold] and alanine aminotransferase (ALT) activities [2.22-fold], while, markedly reduced glutathione (GSH) [0.63-fold] and ferric reducing ability of plasma (FRAP) levels [0.63-fold]. Even COX2 expression significantly increased in the CLP group as compared to the LAP group. Treatments of rats with the E.Os could return all the hepatic and plasma biomarkers to the normal levels. These results were further confirmed by pathological examination on liver indicating that E.Os could successfully improve the CLP-induced liver injuries. DISCUSSION AND CONCLUSIONS: Our findings suggest that E.Os is able to protect liver injuries against sepsis via modulating the oxidative stress parameters concomitant with the suppression of inflammatory reactions such as PGE2 and COX-2.

Evaluation of Gamma Irradiation Effect on the Oxidative Stress Factors in Septic Rats Treated With Iranian Plant Essential Oils

ABSTRACT Cuminum cyminum L. (CM), Zataria multiflora Boiss. (ZM) and Mentha piperita L. (MP) are traditional medicinal plants with various pharmacological properties. This study was designed to assess the role of gamma irradiation -a modern decontamination method- in hepatoprotective effects of their essential oil (E.Os) in septic rats induced by experimental cecal ligation and puncture (CLP) model. The rats were divided into 20 groups; sham-operated (SOP); CLP; CLP + CM, ZM and MP (E.Os) (100 & 200 mg/kg b.w) and CLP + gamma irradiated (10 and 25 kGy) E.Os (100 & 200 mg/kg b.w) as treatment groups. All E.Os were injected i.p immediately after sepsis induction. 24 hour after CLP, the rats were sacrificed and the liver tissue was examined considering lipid peroxiation (LP), glutathione (GSH) and myeloperoxidase (MPO) activity. The results indicated that CLP operation caused significant (P<0.05) increase in the LP and MPO levels concomitant with decreased GSH level. Administration of the E.Os (100 and 200 mg/kg b.w) extracted from non irradiated plants as well as the irradiated (10 and 25 kGy) plant E.Os could significantly (P<0.05) modulate the levels of LP, MPO and GSH. It can be concluded that all E.Os even after irradiation exposure could modulate the oxidative injury parameters related to liver damages in CLP rat model. In conclusion, the plant irradiation didn't have any adverse effects on the hepatoprotective activities of the extracted oils.

Effect of metal sulfide pulp density on gene expression of electron transporters in Acidithiobacillus sp. FJ2.

In Acidithiobacillus ferrooxidans, one of the most important bioleaching bacterial species, the proteins encoded by the rus operon are involved in the electron transfer from Fe2+ to O2. To obtain further knowledge about the mechanism(s) involved in the adaptive responses of the bacteria to growth on the different uranium ore pulp densities, we analyzed the expression of the four genes from the rus operon by real-time PCR, when Acidithiobacillus sp. FJ2 was grown in the presence of different uranium concentrations. The uranium bioleaching results showed the inhibitory effects of the metal pulp densities on the oxidation activity of the bacteria which can affect Eh, pH, Fe oxidation and uranium extractions. Gene expression analysis indicated that Acidithiobacillus sp. FJ2 tries to survive in the stress with increasing in the expression levels of cyc2, cyc1, rus and coxB, but the metal toxicity has a negative effect on the gene expression in different pulp densities. These results indicated that Acidithiobacillus sp. FJ2 could leach the uranium even in high pulp density (50%) by modulation in rus operon gene responses.

U(VI) biosorption by bi-functionalized Pseudomonas putida @ chitosan bead: Modeling and optimization using RSM.

In this work, Pseudomonas putida cells immobilized into chitosan beads (PICB) were synthesized to investigate the impact of microorganism entrapment on biosorption capacity of prepared biosorbent for U(VI) biosorption from aqueous solutions. Response Surface Methodology (RSM) based on Central Composite Design (CCD) was utilized to evaluate the performance of the PICB in comparison with chitosan beads (CB) under batch mode. Performing experiments under optimal condition sets viz. pH 5, initial U(VI) concentration 500mg/L, biosorbent dosage 0.4g/L and 20wt.% bacterial cells showed that the observed biosorption capacity enhanced by 1.27 times from 398mg/g (CB) to 504mg/g (PICB) that confirmed the effectiveness of cells immobilization process. FTIR and potentiometric titration were then utilized to characterize the prepared biosorbents. While the dominant functional group in the binding process was NH3(+) (4.78meq/g) in the CB, the functional groups of NH3(+), NH2, OH, COOH (6.00meq/g) were responsible for the PICB. The equilibrium and kinetic studies revealed that the Langmuir isotherm model and the pseudo-second-order kinetic model were in better fitness with the CB and PICB experimental data. In conclusion, the present study indicated that the PICB could be a suitable biosorbent for uranium (VI) biosorption from aqueous solutions.

Chemotherapeutic effect of Berberis integerrima hydroalcoholic extract on colon cancer development in the 1,2-dimethyl hydrazine rat model.

The aim of this study was to investigate the efficacy of a Berberis integerrima hydroalcoholic extract as a chemotherapeutic agent in colon carcinogenesis in the rat induced by 1,2-dimethyl hydrazine (DMH). Male Wistar rats were divided into five groups: a negative control group without DMH treatment; a control group injected DMH (20 mg/kg b.w); two groups receiving B. integerrima extract (50 and 100 mg/kg b.w), concomitant with injected DMH, as chemotherapeutic groups; a positive control group receiving 5-fluorouracil (5-FU) along with DMH. The effects of the extracts were determined by assessment of hepatic malondialdehyde (MDA), glutathione (GSH), ferric reducing ability of plasma (FRAP), and the activities of hepatic glutathione S-transferase and cytochrome P450 (GST and CYP450). Additionally, colon tissues were assessed for colonic ß-catenin and histopathological analysis. In DMH-treated rats, the extracts partially normalized the levels of FRAP, CYP450, ß-catenin, and GST. Likewise, formation of aberrant crypt foci (ACF) in colon tissue of DMH-treated was reduced by the extracts. Thus, the extracts possess chemotherapeutic activity against colon carcinogenesis.

Hepatoprotective effects of Iranian Hypericum scabrum essential oils against oxidative stress induced by acetaminophen in rats

This studied examined the protective role of Hypericum scabrum oils (100 and 200 mg/kg b.w, i.p) on acetaminophen-induced liver damages in the rat. The hepatic oxidative/antioxidant parameters such as lipid peroxidation (LP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and ferric reducing ability of plasma (FRAP) were measured 2, 4, 8, 16 and 24h after the treatments confirmed by histopathological consideration. The results indicated that increased levels of hepatic LP and FRAP and SOD activity were reversed in the rats treated with oils. In addition, the depleted GSH were compensated with the oil treatments. The protective effect of the oils was further confirmed by the histophatological examination carried out on liver biopsies. The data pointed out that H. scabrum oil could modulate the hepatic toxicity induced by the APAP through adjusting the oxidative stress/antioxidant parameters and could be of potential candidate for the treatment of acetaminophen induced oxidative stress liver damages.

Potential preventive role of Iranian Achillea wilhelmsii C. Koch essential oils in acetaminophen-induced hepatotoxicity.

BACKGROUND: The essential oil of Achillea wilhelmsii C. Koch (100 & 200 mg/kg b.w, i.p) was evaluated against acetaminophen induced hepatic injuries in rats. For this purpose, the activities of cytochrome P450 (CYP450), glutathione s-transferase (GST) and markers of liver injuries (ALT, AST, ALP) together with level of GSH measured analytically in time intervals (2, 4, 8, 16 & 24 h) after treatments confirmed by histophatological consideration in rat livers. RESULTS: Administration of acetaminophen (500 mg/kg bw, i.p) significantly increased the activity of CYP450 concomitant with increasing the release of ALT and AST. Whereas, GSH level and GST activity were decreased significantly after acetaminophen treatment. Treatment of rats with Achillea wilhelmsii essential oils significantly modulate these parameters to normal values. Also, histophatological analysis of liver biopsies was consistent with the biochemical findings. CONCLUSION: The data led us to conclude the curative potential of Achillea wilhelmsii essential oils against APAP induced hepatic injuries.

Effect of dietary caraway essential oils on expression of ß-catenin during 1,2-dimethylhydrazine-induced colonic carcinogenesis.

We have recently reported that the inhibition of colonic premalignant lesions induced by 1,2-dimethylhydrazine (DMH) is mediated by the interference of caraway oil components in the activities of the main hepatic xenobiotic metabolizing enzymes. The present study was carried out to examine the effect of dietary caraway oils on the progression of cancer, with emphasis on ß-catenin expression in the colon during DMH-induced colonic carcinogenesis. For this purpose, colon cancer was induced by DMH in rats (20 mg/kg body weight for 5 weeks) and groups of animals were given dietary caraway essential oils at two levels (0.01 and 0.1%) for 16 weeks. After 16 weeks and at the end of the experimental period the colon tissue biopsies were processed for histopathological examination and the expression of ß-catenin at mRNA and protein levels was estimated by polymerase chain reaction and enzyme-linked immunosorbent assay. The formation of premalignant lesions based on aberrant crypt foci (ACF) in DMH-treated rats was greatly inhibited (72-87%) in rats given dietary essential oils when compared to respective controls. There was a correlation between the number of colonic ACF formation and the expression levels of ß-catenin measured at protein and mRNA levels. These results indicate that the Wnt/ß-catenin signaling pathway is activated during colon cancer promotion and that the expression of colonic ß-catenin is altered in long-term caraway oil feeding, leading to suppression of DMH-induced premalignant lesions in rat colon.