Lack of mechanism-based inactivation of rat hepatic microsomal cytochromes P450 by doxorubicin

1999 ◽  
Vol 77 (8) ◽  
pp. 589-597 ◽  
Author(s):  
Johnny Di Re ◽  
Chunja Lee ◽  
David S Riddick
Keyword(s):  
Lipid Peroxidation ◽  
Cytochrome P450 ◽  
Reductase Activity ◽  
Cytochromes P450 ◽  
Microsomal Protein ◽  
Positive Control ◽  
Male Rats ◽  
Protein Levels

Administration of the antineoplastic doxorubicin to rodents causes depression of hepatic cytochrome P450 (CYP) dependent biotransformation, an effect that has been partially attributed to the ability of doxorubicin to stimulate microsomal lipid peroxidation. Since doxorubicin can be bioactivated by the CYP/NADPH-CYP reductase system to products that bind covalently to microsomal protein, we hypothesized that doxorubicin functions as a mechanism-based inactivator of hepatic microsomal CYPs and (or) NADPH-CYP reductase under conditions in which doxorubicin-stimulated NADPH-dependent lipid peroxidation is minimized. In vitro studies were conducted with hepatic microsomes isolated from untreated and phenobarbital-treated male rats. Unlike the positive control carbon tetrachloride, doxorubicin (10 µM) did not stimulate NADPH-dependent lipid peroxidation in microsomal incubations containing EDTA (1.5 mM). Doxorubicin did not cause NADPH-dependent loss of microsomal CYP, heme, or steroid hydroxylation activities selective for CYP2A, CYP2B, CYP2C11, and CYP3A. The positive control 1-aminobenzotriazole caused marked NADPH-dependent decreases in all of these parameters. Neither doxorubicin nor 1-aminobenzotriazole caused NADPH-dependent loss of NADPH-CYP reductase activity, and neither compound altered the immunoreactive protein levels of CYP2B, CYP2C11, CYP3A, and NADPH-CYP reductase. These results indicate that a pharmacologically relevant concentration of doxorubicin does not cause direct mechanism-based inactivation of hepatic microsomal CYPs or NADPH-CYP reductase, suggesting that the ability of doxorubicin to depress hepatic CYP-mediated biotransformation in vivo is due to lipid peroxidation mediated heme destruction, altered heme metabolism, and (or) decreased expression of selected CYP enzymes.Key words: doxorubicin, cytochrome P450, mechanism-based inactivation, lipid peroxidation.

scholarly journals Biochemical effects of the porphyrinogenic drug allylisopropylacetamide. A comparative study with phenobarbital

1973 ◽  
Vol 134 (4) ◽  
pp. 859-868 ◽  
Author(s):  
Manchanahalli R. Satyanarayana Rao ◽  
Govindarajan Padmanaban
Keyword(s):  
Reductase Activity ◽  
Time Lag ◽  
Liver Weight ◽  
Microsomal Protein ◽  
Female Rats ◽  
Biochemical Effects ◽  
Increase Liver Weight ◽  
Cytochrome P 450

Successive administrations of allylisopropylacetamide, a potent porphyrinogenic drug, increase liver weight, microsomal protein and phospholipid contents. There is an increase in the rate of microsomal protein synthesis in vivo and in vitro. The drug decreases microsomal ribonuclease activity and increases NADPH–cytochrome c reductase activity. Phenobarbital, which has been reported to exhibit all these changes mentioned, is a weaker inducer of δ-aminolaevulinate synthetase and increases the rate of haem synthesis only after a considerable time-lag in fed female rats, when compared with the effects observed with allylisopropylacetamide. Again, phenobarbital does not share the property of allylisopropylacetamide in causing an initial decrease in cytochrome P-450 content. Haematin does not counteract most of the biochemical effects caused by allylisopropylacetamide, although it is quite effective in the case of phenobarbital. Haematin does not inhibit the uptake of [2-14C]allylisopropylacetamide by any of the liver subcellular fractions.

Testosterone augments endotoxin-mediated cerebrovascular inflammation in male rats

2005 ◽  
Vol 289 (5) ◽  
pp. H1843-H1850 ◽  
Author(s):  
Ali Razmara ◽  
Diana N. Krause ◽  
Sue P. Duckles
Keyword(s):  
Blood Vessels ◽  
In Vitro Models ◽  
Male Rats ◽  
Cerebral Blood Vessels ◽  
Treatment Groups ◽  
Protein Levels ◽  
Cox 2 ◽  
The Impact

Activation of inflammatory mechanisms contributes to cerebrovascular pathophysiology. Male gender is associated with increased stroke risk, yet little is known about the effects of testosterone in the cerebral circulation. Therefore, we explored the impact of testosterone treatment on cerebrovascular inflammation with both in vivo and in vitro models of inflammation. We hypothesized that testosterone would augment the expression of two vascular markers of cellular inflammation, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Using four groups of male rats [intact, orchiectomized (ORX), and ORX treated with either testosterone (ORXT) or the testosterone metabolite 17β-estradiol (ORXE)], we determined effects of the sex hormones on cerebrovascular inflammation after intraperitoneal LPS injection. Western blot analysis showed that induction of inflammatory markers was increased in cerebral blood vessels from ORXT rats compared with intact or ORX rats. In contrast, in cerebral blood vessels from ORXE rats, there was a significant decrease in endotoxin-induced COX-2 and iNOS protein levels. Confocal microscopy of cerebral blood vessels from ORXT rats showed increased COX-2 and iNOS immunoreactivity in both endothelial and smooth muscle cells after LPS treatment. In vitro incubation with LPS also induced COX-2 in pial vessels isolated from the four animal treatment groups, with the greatest induction observed in ORXT vessels compared with the ORX and ORXE groups. Production of PGE2, a principal COX-2-derived prostaglandin end product, was also greatest in cerebral vessels isolated from ORXT rats. In conclusion, testosterone increases cerebrovascular inflammation; this effect may contribute to stroke differences between men and women.

Mechanism-based inactivation of hepatic cytochrome P450 2C6 and P450 3A1 following in vivo administration of 3,5-diethoxycarbonyl-1,4-dihydro-2,6-dimethyl-4-ethylpyridine to rats: differences from previously observed in vitro results

1994 ◽  
Vol 72 (4) ◽  
pp. 397-401 ◽  
Author(s):  
S. M. Kimmett ◽  
J. P. McNamee ◽  
G. S. Marks
Keyword(s):  
Cytochrome P450 ◽  
Competitive Inhibition ◽  
Female Rats ◽  
Male Rats ◽  
Hepatic Microsomes ◽  
In Vitro Effects ◽  
P450 Isozymes ◽  
In Vivo Administration

Using progesterone 21-hydroxylase as a selective substrate for P450 2C6 in phenobarbital-treated male rats, and androstenedione and progesterone 6β-hydroxylases as well as erythromycin N-demethylase as selective markers for P450 3A1 in dexamethasone-treated female rats, we have shown that these P450 isozymes undergo mechanism-based inactivation after in vivo administration of 3,5-diethoxycarbonyl-1,4-dihydro-2,6-dimethyl-4-ethylpyridine (4-ethyl DDC). These results differ from our previous studies where no inactivation was observed after in vitro administration of 4-ethyl DDC to rat hepatic microsomes. We show that the differences between the in vivo and in vitro effects of 3,5-diethoxycarbonyl-1,4-dihydro-2,4,6-trimethylpyridine (DDC) analogues are due to the presence of residual 4-ethyl DDC in the in vitro experiments causing time-independent competitive inhibition and obscuring observation of mechanism-based inactivation.Key words: 3,5-diethoxycarbonyl-1,4-dihydro-2,6-dimethyl-4-ethylpyridine, cytochrome P450, steroid hydroxylation, rat hepatic microsomes.

Chemosensitizing Activity of Histone Deacetylases Inhibitory Cyclic Hydroxamic Acids for Combination Chemotherapy of Lymphatic Leukemia

2018 ◽  
Vol 18 (4) ◽  
pp. 365-371 ◽  
Author(s):  
Denis V. Mishchenko ◽  
Margarita E. Neganova ◽  
Elena N. Klimanova ◽  
Tatyana E. Sashenkova ◽  
Sergey G. Klochkov ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Acute Toxicity ◽  
Histone Deacetylases ◽  
Hydroxamic Acids ◽  
Water Soluble ◽  
Male Rat ◽  
Hybrid Male ◽  
Cyclic Hydroxamic Acids

Background: Anti-tumor effect of hydroxamic acid derivatives is largely connected with its properties as efficient inhibitors of histone deacetylases, and other metalloenzymes involved in carcinogenesis. Objective: The work was aimed to (i) determine the anti-tumor and chemosensitizing activity of the novel racemic spirocyclic hydroxamic acids using experimental drug sensitive leukemia P388 of mice, and (ii) determine the structure-activity relationships as metal chelating and HDAC inhibitory agents. Method: Outbreed male rat of 200-220 g weights were used in biochemical experiments. In vivo experiments were performed using the BDF1 hybrid male mice of 22-24 g weight. Lipid peroxidation, Fe (II) -chelating activity, HDAC fluorescent activity, anti-tumor and anti-metastatic activity, acute toxicity techniques were used in this study. Results: Chemosensitizing properties of water soluble cyclic hydroxamic acids (CHA) are evaluated using in vitro activities and in vivo methods and found significant results. These compounds possess iron (II) chelating properties, and slightly inhibit lipid peroxidation. CHA prepared from triacetonamine (1a-e) are more effective Fe (II) ions cheaters, as compared to CHA prepared from 1- methylpiperidone (2a-e). The histone deacetylase (HDAC) inhibitory activity, lipophilicity and acute toxicity were influenced by the length amino acids (size) (Glycine < Alanine < Valine < Leucine < Phenylalanine). All compounds bearing spiro-N-methylpiperidine ring (2a-e) are non-toxic up to 1250 mg/kg dose, while compounds bearing spiro-tetramethylpiperidine ring (1a-e) exhibit moderate toxicity which increases with increasing lipophility, but not excite at 400 mg/kg. Conclusion: It was shown that the use of combination of non-toxic doses of cisplatin (cPt) or cyclophosphamide with CHA in most cases result in the appearance of a considerable anti-tumor effect of cytostatics. The highest chemosensitizing activity with respect to leukemia Р388 is demonstrated by the CHA derivatives of Valine 1c or 2c.

In Vitro and In Vivo Neutralizing Activity of Uvaria chamae Leaves Fractions on the Venom of Naja nigricollis in Albino Rat and Bovine Blood

2020 ◽  
Vol 14 (4) ◽  
pp. 295-311
Author(s):  
Ada Gabriel ◽  
Mamman Mohammed ◽  
Mohammed G. Magaji ◽  
Yusuf P. Ofemile ◽  
Ameh P. Matthew ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Neglected Tropical Diseases ◽  
Lethal Dose ◽  
Positive Control ◽  
Haemolytic Activity ◽  
Cytotoxic Activities ◽  
Albino Rat ◽  
Aqueous Residue

Background: Snakebite envenomation is a global priority ranked top among other neglected tropical diseases. There is a folkloric claim that Uvaria chamae is beneficial for the management of snakebite and wounds in African ethnobotanical surveys. Besides, there are many registered patents asserting the health benefits of U. chamae. Objective: This study aimed to investigate U. chamae’s potentials and identify candidates for the development of tools for the treatment and management of N. nigricollis envenomation. Methods: Freshly collected U. chamae leaves were air-dried, powdered, and extracted in methanol. The median lethal dose of the extract was determined and further fractionated with n-hexane, n-butanol and ethyl acetate. Each fraction was tested for neutralizing effect against venom-induced haemolytic, fibrinolytic, hemorrhagic, and cytotoxic activities. Results: U. chamae fractions significantly (p<0.05) neutralized the haemolytic activity of N. nigricollis venom in n-butanol; 31.40%, n-hexane; 33%, aqueous residue; 39.60% and ethyl acetate; 40.70% at the concentration of 100mg/ml of each fraction against 10mg/ml of the snake venom when compared to the positive control. The fibrinolytic activity of N. nigricollis venom was significantly (p<0.05) neutralized in n-hexane at 73.88%, n-butanol; 72.22% and aqueous residue; 72.22% by the fractions of U. chamae. In addition, haemorrhagic activity of N. nigricollis venom was significantly (p<0.05) neutralized by U. chamae fractions at the concentrations of 100mg/ml, 200mg/ml and 400mg/ml except for n-butanol and aqueous residues at 400 mg/ml. Conclusion: U. chamae leaves fractions possess a high level of protection against N. nigricollis venoms-induced lethality and thus validate the pharmacological rationale for its usage in the management of N. nigricollis envenomation.

scholarly journals Amelioration of lipid peroxidation in vivo and in vitro by Satureja khozestanica essential oil in alloxan-induced diabetic rats

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Hassan Ahmadvand ◽  
Majid Tavafi ◽  
Ali Khosrowbeygi ◽  
Gholamreza Shahsavari ◽  
Maryam Hormozi ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Essential Oil ◽  
Diabetic Rats

scholarly journals All-Trans Retinoic Acid Increases DRP1 Levels and Promotes Mitochondrial Fission

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1202
Author(s):  
Bojjibabu Chidipi ◽  
Syed Islamuddin Shah ◽  
Michelle Reiser ◽  
Manasa Kanithi ◽  
Amanda Garces ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Mitochondrial Fission ◽  
Normal Function ◽  
Mitochondrial Network ◽  
Protein Levels ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Area And Perimeter

In the heart, mitochondrial homeostasis is critical for sustaining normal function and optimal responses to metabolic and environmental stressors. Mitochondrial fusion and fission are thought to be necessary for maintaining a robust population of mitochondria, and disruptions in mitochondrial fission and/or fusion can lead to cellular dysfunction. The dynamin-related protein (DRP1) is an important mediator of mitochondrial fission. In this study, we investigated the direct effects of the micronutrient retinoid all-trans retinoic acid (ATRA) on the mitochondrial structure in vivo and in vitro using Western blot, confocal, and transmission electron microscopy, as well as mitochondrial network quantification using stochastic modeling. Our results showed that ATRA increases DRP1 protein levels, increases the localization of DRP1 to mitochondria in isolated mitochondrial preparations. Our results also suggested that ATRA remodels the mitochondrial ultrastructure where the mitochondrial area and perimeter were decreased and the circularity was increased. Microscopically, mitochondrial network remodeling is driven by an increased rate of fission over fusion events in ATRA, as suggested by our numerical modeling. In conclusion, ATRA results in a pharmacologically mediated increase in the DRP1 protein. It also results in the modulation of cardiac mitochondria by promoting fission events, altering the mitochondrial network, and modifying the ultrastructure of mitochondria in the heart.

scholarly journals TRIM27 interacts with Iκbα to promote the growth of human renal cancer cells through regulating the NF-κB pathway

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chengwu Xiao ◽  
Wei Zhang ◽  
Meimian Hua ◽  
Huan Chen ◽  
Bin Yang ◽  
...  
Keyword(s):  
Cell Lines ◽  
Prognostic Indicator ◽  
The Cancer Genome Atlas ◽  
Mrna Levels ◽  
Loss Of Function ◽  
Protein Levels ◽  
Kaplan Meier ◽  
Cancer Genome Atlas

Abstract Background The tripartite motif (TRIM) family proteins exhibit oncogenic roles in various cancers. The roles of TRIM27, a member of the TRIM super family, in renal cell carcinoma (RCC) remained unexplored. In the current study, we aimed to investigate the clinical impact and roles of TRIM27 in the development of RCC. Methods The mRNA levels of TRIM27 and Kaplan–Meier survival of RCC were analyzed from The Cancer Genome Atlas database. Real-time PCR and Western blotting were used to measure the mRNA and protein levels of TRIM27 both in vivo and in vitro. siRNA and TRIM27 were exogenously overexpressed in RCC cell lines to manipulate TRIM27 expression. Results We discovered that TRIM27 was elevated in RCC patients, and the expression of TRIM27 was closely correlated with poor prognosis. The loss of function and gain of function results illustrated that TRIM27 promotes cell proliferation and inhibits apoptosis in RCC cell lines. Furthermore, TRIM27 expression was positively associated with NF-κB expression in patients with RCC. Blocking the activity of NF-κB attenuated the TRIM27-mediated enhancement of proliferation and inhibition of apoptosis. TRIM27 directly interacted with Iκbα, an inhibitor of NF-κB, to promote its ubiquitination, and the inhibitory effects of TRIM27 on Iκbα led to NF-κB activation. Conclusions Our results suggest that TRIM27 exhibits an oncogenic role in RCC by regulating NF-κB signaling. TRIM27 serves as a specific prognostic indicator for RCC, and strategies targeting the suppression of TRIM27 function may shed light on future therapeutic approaches.

scholarly journals Therapeutic effects of sesamolin on leukemia induced by WEHI-3B in model mice

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Senthil Nagarajan ◽  
Jae Kwon Lee
Keyword(s):  
Nk Cell ◽  
Neoplastic Cell ◽  
Positive Control ◽  
Cytolytic Activity ◽  
Leukemic Cells ◽  
Therapeutic Effects ◽  
Control Drug ◽  
Lysis Activity

AbstractSesamolin is one of the lignans derived from sesame oil. It has demonstrated significant antioxidant, anti-aging, and anti-mutagenic properties. It also reportedly augments natural killer (NK) cell lysis activity. We previously reported that sesamolin also exerts anticancer effects in vitro and induces enhanced NK cell cytolytic activity against tumor cells. Herein, we aimed to determine the mechanism by which sesamolin prevents and retards tumorigenesis in BALB/c mouse models of leukemia induced by murine (BALB/c) myelomonocytic leukemia WEHI-3B cells. Banded neutrophils, myeloblasts, and monocytic leukemic cells were more abundant in the leukemia model than in normal mice. Sesamolin decreased the number of leukemic cells by almost 60% in the leukemia model mice in vivo; additionally, sesamolin and the positive control drug, vinblastine, similarly hindered neoplastic cell proliferation. Spleen samples were ~ 4.5-fold heavier in leukemic mice than those obtained from normal mice, whereas spleen samples obtained from leukemic mice treated with sesamolin had a similar weight to those of normal mice. Moreover, sesamolin induced a twofold increase in the cytotoxic activity of leukemic mouse NK cells against WEHI-3B cells. These results indicated that sesamolin exerts anti-leukemic effects in vivo.

Sign in / Sign up

Export Citation Format

Share Document