Procarbazine Research Articles

Adsorption behavior of temozolomide, carmustine, procarbazine, and lomustine anticancer drugs on zinc oxide nanocage: A DFT study

The adsorption behavior of zinc oxide (Zn12O12) nanocage toward delivering the temozolomide (TMZ), carmustine (CM), procarbazine (PR), and lomustine (LO) anticancer drugs was herein investigated utilizing the density functional theory (DFT) method. The emerging outcomes unveiled the potential efficiency of the Zn12O12 nanocage toward adsorbing the TMZ, CM, PR, and LO drugs and showed prominent negative values of binding energies (ΔEbind) up to −14.69 kcal.mol−1. Among the studied complexes, the Zn12O12-TMZ complex showed the most preferential ΔEbind values in the gas and water phases compared to other studied complexes with values up to −14.69 and −12.88 kcal.mol−1, respectively. The quantum theory of atoms in molecules announced the occurrence of the adsorption process between the Zn12O12 nanocage and anticancer drugs via polar covalent interactions and electrostatic interactions. Based on frontier molecular orbital theory affirmations, the electronic parameters of Zn12O12 nanocage changed preferentially upon adsorption of the studied drug within the most stable configurations. Moreover, the Zn12O12-drug complexes exhibited short recovery times for drug desorption from the nanocage. The results clearly confirmed that the Zn12O12 nanocage is an ideal candidate for the highly efficient development of anticancer TMZ, CM, PR, and LO drug carriers.

Interaction of procarbazine drug and solvent effects on pristine and embedded-zinc oxide nanotube as a drug delivery vehicle: A DFT investigation

Numerous research studies have been carried out on nano-structures regarding their potential applications in drug delivery for treating cancers. Within the current work, the procarbazine (PB) drug delivery ability of a pure ZnO nanotube (PZnO-NT) and X-doped (X = Al, Ge, and In) ZnO-NT is inspected through DFT computations. The results demonstrates that PZnO-NT isn't suitable for the PB drug delivery. We showed that doping the Al, Ge, and In atoms into the ZnO-NT structure changes the adsorption energy (AdE) of PB from −6.9 to −26.4, −28.7, and −31.5 kcal/mol, respectively. Moreover, there is a substantial amount of charge transfer from PB to the doped ZnO-NT based on the natural bond orbital analysis. Using water solvent changes the AdE of the drug on the In-doped ZnO-NT from −31.5 to −29.8 kcal/mol. Hence, based on the computations undertaken within this work, the X-doped ZnO-NT can be utilized as a suitable PB carrier.

Duplex sequencing provides detailed characterization of mutation frequencies and spectra in the bone marrow of MutaMouse males exposed to procarbazine hydrochloride

Mutagenicity testing is an essential component of health safety assessment. Duplex Sequencing (DS), an emerging high-accuracy DNA sequencing technology, may provide substantial advantages over conventional mutagenicity assays. DS could be used to eliminate reliance on standalone reporter assays and provide mechanistic information alongside mutation frequency (MF) data. However, the performance of DS must be thoroughly assessed before it can be routinely implemented for standard testing. We used DS to study spontaneous and procarbazine (PRC)-induced mutations in the bone marrow (BM) of MutaMouse males across a panel of 20 diverse genomic targets. Mice were exposed to 0, 6.25, 12.5, or 25 mg/kg-bw/day for 28 days by oral gavage and BM sampled 42 days post-exposure. Results were compared with those obtained using the conventional lacZ viral plaque assay on the same samples. DS detected significant increases in mutation frequencies and changes to mutation spectra at all PRC doses. Low intra-group variability within DS samples allowed for detection of increases at lower doses than the lacZ assay. While the lacZ assay initially yielded a higher fold-change in mutant frequency than DS, inclusion of clonal mutations in DS mutation frequencies reduced this discrepancy. Power analyses suggested that three animals per dose group and 500 million duplex base pairs per sample is sufficient to detect a 1.5-fold increase in mutations with > 80% power. Overall, we demonstrate several advantages of DS over classical mutagenicity assays and provide data to support efforts to identify optimal study designs for the application of DS as a regulatory test.

MicroOrganoSpheres as a clinically applicable precision oncology platform for the discovery of novel therapies in colorectal cancer.

3592 Background: Patient-derived models of cancer, such as cell lines, patient-derived organoids, and patient-derived xenografts, are useful models of patient response in the clinic. However, these models are often not clinically applicable within the time periods necessary to inform clinical decision making, as they can take weeks to months to develop. An ideal platform using patient-derived models would be generated from a core biopsy with a subsequent drug screen within 10-14 days to minimize delay in therapy. We recently reported the development of MicroOrganoSpheres (MOS) that can be used in drug screens within 14 days of obtaining a biopsy. In the current study, we use this MOS system as precision oncology platform in colorectal cancer (CRC) to identify new therapies and predict response to therapy. Methods: CRC patient tissue samples were collected under a Duke Institutional Review Board approved protocol (Pro00089222). Resections or biopsies were mechanically and enzymatically digested to obtain a single cell suspension. Cells were then plated in Matrigel at a ratio of 20,000 cells:5 µL Matrigel to establish “mini-bulk” organoid cultures. After establishment for 5-7 days, cultures were harvested with subsequent generation of MOS at a ratio of 50 cells per MOS. After growing for 3-4 days, MOS were used for dose-response curves using oxaliplatin, SN38, and 5-Fluorouracil (5-FU) as well as high-throughput drug screens with the NCI Approved Oncology Drugs Set VI library. Results: We developed and optimized a MOS pipeline on over 50 CRC specimens, including 9 primary rectal, 35 primary CRC, 12 CRC liver metastasis, and 1 CRC lung metastasis lines with a success rate of 80% and an average of 10-21days from biopsy to MOS generation. The high success of generating CRC MOS in a clinically applicable time frame led to the next phase of the project where a total of 10 CRC MOS were tested against standard of care chemotherapy agents used in CRC (oxaliplatin, irinotecan and 5-FU) as well as the NCI Approved Oncology Drugs Set VI within 14-21days of establishment. We noted a range of sensitivity of approximately 100-fold for standard of care agents. The most sensitive drugs found in the high-throughput screen were Bortezomib, Carfilzomib, and Panobinostat and the most resistant were Gefitinib, Chlorambucil, and Procarbazine hydrochloride. Conclusions: These results demonstrate that our MOS pipeline can be used as a precision oncology platform within a clinically applicable time frame to potentially guide therapy. We are now in the process of correlating drug response in MOS to patient outcome data and these findings will be presented at the annual meeting.

The potential of pure and atom-decorated AlP nano-sheet as a drug delivery system for procarbazine: A DFT approach

The impact of decorating the Y (Y = Ti or Sc) atom on the procarbazine (PA) drug delivery performance of an AlP nano-sheet (AlP-NS) was investigated by performing DFT calculations. It was found that the pristine AlP-NS was not a good choice for the drug delivery of PA. Decorating Ti and Sc into the AlP-NS surface increased the adsorption energy of PA from −6.2 to −29.7 and −31.9 kcal/mol, respectively. The Y atom considerably contributed to the generation of virtual orbitals of Y-decorated AlP-NS, which showed that these atoms were more suitable for a nucleophilic attack compared to Al. Finally, the adsorption performance and capacity of PA increased after the decoration of the Y atom, which made the nano-sheet more suitable for the drug delivery of PA. In cancerous cells with a low pH, PA was significantly protonated, which led to the separation of PA from the Y-decorated AlP-NS surface.

Mutational signatures in T-lymphocytes of rats treated with N-propyl-N-nitrosourea and procarbazine.

We have used whole genome sequencing (WGS) to determine mutational signatures induced in the T-cells of rats treated in vivo with N-propyl-N-nitrosourea (PNU) or procarbazine (PCZ). The signatures from the treated rats were different from the signature of background mutations. The main component of the spontaneous T-cell mutational signature was C➔T transition with all other single base substitutions evenly distributed. The PNU-induced mutational signature showed relatively equal contributions from C➔T and T➔C transitions, and T➔A transversions. The PCZ-induced signature was characterized by T➔C transitions, T➔A and, to a smaller extent, T➔G transversions. C➔G transversions were infrequent in either the PNU or PCZ signatures. WGS not only allowed mutational signature detection, but also measured quantitative responses to mutagen treatment: 10-40× increases in the number of mutations per clone were detected in T-cell clones from treated rats. The overall strand specificity of induced mutations for annotated rat genes was comparable to the strand specificity of mutations determined previously for the endogenous X-linked Pig-a gene. Our results provide valuable reference data for future applications of WGS in safety research and risk assessment.

Pig-a gene mutations in bone marrow granulocytes of procarbazine-treated F344 rats.

It was previously demonstrated that procarbazine (PCZ) is positive in the rat erythrocyte Pig-a gene mutation assay. However, since mammalian erythrocytes lack genomic DNA, it was necessary to analyze nucleated bone-marrow erythroid precursor cells to confirm that PCZ induces mutations in the Pig-a gene (Revollo et al., Environ Mol Mutagen, 2020). In this study, the association between Pig-a mutation and loss of GPI anchors was further strengthened and the genesis of Pig-a mutation in PCZ-dosed rats was evaluated by analyzing bone-marrow granulocytes. Erythrocytes and granulocytes both originate from myeloid progenitor cells, but granulocytes contain DNA throughout their developmental stages. F344 rats were treated with three doses of 150 mg/kg PCZ; 2 weeks later, CD48-deficient mutant phenotype bone-marrow granulocytes (BMGs [CD11b+ ]) were isolated by flow-cytometric sorting. Sequencing data showed that the CD48-deficient mutant phenotype BMGs contained mutations in the Pig-a gene while wild-type BMGs did not. PCZ-induced mutations included missense, nonsense and splice site variants; the majority of mutations were A > T, A > C, and A > G, with the mutated A on the nontranscribed DNA strand. The PCZ-induced mutational analysis in BMGs supports the association between the phenotype measured in the Pig-a assay and mutation in the Pig-a gene. Also, PCZ mutation spectra were similar in bone-marrow erythroids and BMGs, but none of the mutations detected in BMGs were the same as the erythroid precursor cell mutations from the same rats. Thus, mutations induced in the Pig-a assay appear to be induced after commitment of myeloid progenitor cells to either the granulocyte or erythroid pathway.

The 28\u2009+\u200928\xa0day design is an effective sampling time for analyzing mutant frequencies in rapidly proliferating tissues of MutaMouse animals

The Organisation for Economic Co-Operation and Development Test Guideline 488 (TG 488) uses transgenic rodent models to generate in vivo mutagenesis data for regulatory submission. The recommended design in TG 488, 28 consecutive daily exposures with tissue sampling three days later (28 + 3d), is optimized for rapidly proliferating tissues such as bone marrow (BM). A sampling time of 28 days (28 + 28d) is considered more appropriate for slowly proliferating tissues (e.g., liver) and male germ cells. We evaluated the impact of the sampling time on mutant frequencies (MF) in the BM of MutaMouse males exposed for 28 days to benzo[a]pyrene (BaP), procarbazine (PRC), isopropyl methanesulfonate (iPMS), or triethylenemelamine (TEM) in dose–response studies. BM samples were collected + 3d, + 28d, + 42d or + 70d post exposure and MF quantified using the lacZ assay. All chemicals significantly increased MF with maximum fold increases at 28 + 3d of 162.9, 6.6, 4.7 and 2.8 for BaP, PRC, iPMS and TEM, respectively. MF were relatively stable over the time period investigated, although they were significantly increased only at 28 + 3d and 28 + 28d for TEM. Benchmark dose (BMD) modelling generated overlapping BMD confidence intervals among the four sampling times for each chemical. These results demonstrate that the sampling time does not affect the detection of mutations for strong mutagens. However, for mutagens that produce small increases in MF, sampling times greater than 28 days may produce false-negative results. Thus, the 28 + 28d protocol represents a unifying protocol for simultaneously assessing mutations in rapidly and slowly proliferating somatic tissues and male germ cells.

TAMI-20. POLY(ADP-RIBOSE) GLYCOHYDROLASE INHIBITION SEQUESTERS NAD+ TO POTENTIATE THE METABOLIC LETHALITY OF ALKYLATING CHEMOTHERAPY IN IDH MUTANT TUMOR CELLS

Abstract Mutations in IDH1 or IDH2 characterize the majority of diffuse infiltrative gliomas of younger adulthood. DNA alkylator chemotherapy has proven to be an effective treatment for IDH mutant glioma, yet recurrences remain frequent and improved treatments are needed. Upon exposure of cancer cells to DNA alkylating agents, poly(ADP-ribose) polymerases (PARPs) catalyze the transient oligomerization of nicotinamide adenine dinucleotide (NAD+) into poly-ADP-ribose (PAR) chain-assemblies, which stimulate the DNA damage response. Here, we find that, in IDH mutant glioma cells, alkylator-induced cytotoxicity is dramatically augmented by pharmacologic inhibition or genetic knockout of the PAR breakdown enzyme poly(ADP-ribose) glycohydrolase (PARG). Mechanistically, we show this augmentation is driven by a metabolic state pairing amplified alkylator-induced DNA damage with catastrophic depletion of NAD+. IDH mutant cancer cells have low basal levels of NAD+, rendering them vulnerable to prolonged NAD+ depletion. Either of two clinically-utilized monofunctional alkylators, procarbazine (PCZ) or temozolomide (TMZ), when exposed to multiple IDH mutant lines, activated PARP conversion of cellular NAD+ monomers into polymerized PAR. Subsequent PAR breakdown and recycling of NAD+ monomers was then halted by concomitant PARG inactivation, amplifying PARylation-mediated DNA damage signaling and critically depleting free NAD+, resulting in profound cytotoxicity. This effect was partially reversed by NAD+ rescue supplementation, confirming the key contribution of metabolic stress. Combined alkylator treatment and PARG inhibition in vivo maximized both NAD+ depletion and cytotoxicity in an endogenous IDH mutant cancer model. Thus, alkyating DNA damaging agents expose a metabolic liability in IDH mutant cancers, and subsequent targeted blockade of PAR breakdown and NAD+ metabolite recovery can exploit this vulnerability to provide genotype-specific therapeutic benefit.

Procarbazine adsorption on the surface of single walled carbon nanotube: DFT studies

In this research, the performance of single-walled carbon nanotube (SWCN) as a sensor and nanocarrier for procarbazine (PC) was investigated by infra-red (IR), natural bond orbital (NBO), frontier molecular orbital (FMO) computations. All of the computations were done using the density functional theory method in the B3LYP/6-31G (d) level of theory The calculated negative values of adsorption energy, enthalpy changes, Gibbs free energy changes showed the PC interaction with SWCN is exothermic, spontaneous and experimentally possible. The increasing of specific heat capacity (CV) of SWCN after adsorption of PC showed the thermal conductivity improved during the interaction process and this nanostructure is an excellent sensing material for the detection of PC. The NBO results demonstrate in all of the evaluated conformers a chemical bond with SP3 hybridization is formed between the medicine and SWCN. The great values of thermodynamic constants showed the adsorption process is irreversible and SWCN is not a suitable nanocarrier for delivery of PC. The density of states (DOS) spectrums showed the bandgap of SWCN decreased sharply after the adsorption of PC and this nanomaterial can be used as a sensor for electrochemical detection of PC.

CD59-deficient bone marrow erythroid cells from rats treated with procarbazine and propyl-nitrosourea have mutations in the Pig-a gene.

Procarbazine (PCZ) and N-propyl-N-nitrosourea (PNU) are rodent mutagens and carcinogens. Both induce GPI-anchored marker-deficient mutant-phenotype red blood cells (RBCs) in the flow cytometry-based rat RBC Pig-a assay. In the present study, we traced the origin of the RBC mutant phenotype by analyzing Pig-a mutations in the precursors of RBCs, bone marrow erythroid cells (BMEs). Rats were exposed to a total of 450 mg/kg PCZ hydrochloride or 300 mg/kg PNU, and bone marrow was collected 2, 7, and 10 weeks later. Using a flow cell sorter, we isolated CD59-deficient mutant-phenotype BMEs from PCZ- and PNU-treated rats and examined their endogenous X-linked Pig-a gene by next generation sequencing. Pig-a mutations consistent with the properties of PCZ and PNU were found in sorted mutant-phenotype BMEs. PCZ induced mainly A > T transversions with the mutated A on the nontranscribed strand of the Pig-a gene, while PNU induced mainly T > A transversions with the mutated T on the nontranscribed strand. The treatment-induced mutations were distributed across the protein coding sequence of the Pig-a gene. The causal relationship between BMEs and RBCs and the agent-specific mutational spectra in CD59-deicient BMEs indicate that the rat RBC Pig-a assay, scoring CD59-deficient mutant-phenotype RBCs in peripheral blood, detects Pig-a gene mutation.

Chemical reactivity and adsorption properties of pro-carbazine anti-cancer drug on gallium-doped nanotubes: a quantum chemical study.

In this study, we propose new armchair single-walled nanotubes (SWNTs) for stable adsorption, increasing drug delivery performance and decreasing side effects of pro-carbazine (Pro-CB) anti-cancer in the framework of B3LYP/6-31g*/Lanl2DZ level of theory. Indeed, doping gallium (Ga) metal in SWNTs is naturally followed by changing of geometry, increasing dipole moment, and creating one site with high reactivity in order to better adsorption of the drug molecule. Chemical reactivity descriptors show that SWNTs and Pro-CB have electrophile and nucleophile roles in interaction, respectively. More importantly, high local and dual softness in Ga-doped SWNTs indicate improvement of drug adsorption. Parallel and perpendicular complexes result from their interaction in the N and the O sites. Negative values of binding energy (Ebind) show that composed complexes are energetically stable especially in the O site in comparison with the N site. On the other hand, more negative value of the Ebind in SWCNTs shows that these nanotubes are more effective for drug adsorption than their boron nitride counterparts. Graphical abstract The Ga dopping results in reducing of HOMO-LUMO gap and increasing charge transfer between SWNTs and Pro-CB, and formation better complex, especially SWCNT.

Integrated In Vivo Genotoxicity Assessment of Procarbazine Hydrochloride Demonstrates Induction of Pig-a and LacZ Mutations, and Micronuclei, in MutaMouse Hematopoietic Cells.

Procarbazine hydrochloride (PCH) is a DNA‐reactive hematopoietic carcinogen with potent and well‐characterized clastogenic activity. However, there is a paucity of in vivo mutagenesis data for PCH, and in vitro assays often fail to detect the genotoxic effects of PCH due to the complexity of its metabolic activation. We comprehensively evaluated the in vivo genotoxicity of PCH on hematopoietic cells of male MutaMouse transgenic rodents using a study design that facilitated assessments of micronuclei and Pig‐a mutation in circulating erythrocytes, and lacZ mutant frequencies in bone marrow. Mice were orally exposed to PCH (0, 6.25, 12.5, and 25 mg/kg/day) for 28 consecutive days. Blood samples collected 2 days after cessation of treatment exhibited significant dose‐related induction of micronuclei in both immature and mature erythrocytes. Bone marrow and blood collected 3 and 70 days after cessation of treatment also showed significantly elevated mutant frequencies in both the lacZ and Pig‐a assays even at the lowest dose tested. PCH‐induced lacZ and Pig‐a (immature and mature erythrocytes) mutant frequencies were highly correlated, with R2 values ≥0.956, with the exception of lacZ vs. Pig‐a mutants in mature erythrocytes at the 70‐day time point (R2 = 0.902). These results show that PCH is genotoxic in vivo and demonstrate that the complex metabolism and resulting genotoxicity of PCH is best evaluated in intact animal models. Our results further support the concept that multiple biomarkers of genotoxicity, especially hematopoietic cell genotoxicity, can be readily combined into one study provided that adequate attention is given to manifestation times. Environ. Mol. Mutagen. 60:505–512, 2019. © 2018 Her Majesty the Queen in Right of Canada

Assessment of the Pig-a, micronucleus, and comet assay endpoints in rats treated by acute or repeated dosing protocols with procarbazine hydrochloride and ethyl carbamate.

The utility and sensitivity of the newly developed flow cytometric Pig-a gene mutation assay have become a great concern recently. In this study, we have examined the feasibility of integrating the Pig-a assay as well as micronucleus and Comet endpoints into acute and subchronic general toxicology studies. Male Sprague-Dawley rats were treated for 3 or 28 consecutive days by oral gavage with procarbazine hydrochloride (PCZ) or ethyl carbamate (EC) up to the maximum tolerated dose. The induction of CD59-negative reticulocytes and erythrocytes, micronucleated reticulocytes in peripheral blood, micronucleated polychromatic erythrocytes in bone marrow, and Comet responses in peripheral blood, liver, kidney, and lung were evaluated at one, two, or more timepoints. Both PCZ and EC produced positive responses at most analyzed timepoints in all tissue types, both with the 3-day and 28-day treatment regimens. Furthermore, comparison of the magnitude of the genotoxicity responses indicated that the micronucleus and Comet endpoints generally produced greater responses with the higher dose, short-term treatments in the 3-day study, while the Pig-a assay responded better to the cumulative effects of the lower dose, but repeated subchronic dosing in the 28-day study. Collectively, these results indicate that integration of several in vivo genotoxicity endpoints into a single routine toxicology study is feasible and that the Pig-a assay may be particularly suitable for integration into subchronic dose studies based on its ability to accumulate the mutations that result from repeated treatments. This characteristic may be especially important for assaying lower doses of relatively weak genotoxicants. Environ. Mol. Mutagen. 60:56-71, 2019. © 2018 Wiley Periodicals, Inc.

The role of flavonoid antioxidant, morin in improving procarbazine-induced oxidative stress on testicular function in rat.

Background:Procarbazine (PCZ) is an effective chemotherapeutic drug used in the treatment of lymphoma; however, oxidative stress–mediated testicular toxicity is a major side effect. Recently, therapeutic intervention using flavonoids against oxidative stress–related pathologies is gaining more attention. Morin (MOR) is a natural flavonoid with proven antioxidant activity. This study was designed therefore to evaluate the potential role of MOR in ameliorating PCZ-induced testicular oxidative stress and altered sperm quality in rat model.Methods:A total of 24 male Wistar rats (170–180 g) were randomly assigned into 4 treatment groups: I, control; II, PCZ (2 mg/kg b.w.); III, PCZ (2 mg/kg b.w.) + MOR (100 mg/kg b.w.) simultaneously administered and IV, MOR (100 mg/kg b.w.), and all treatments lasted 14 days.Results:PCZ treatment displayed significant reduction in sperm number, sperm motility, percentage normal sperm cells, and daily sperm production rate. Meanwhile the activities of testicular enzymes: gamma-glutamyl transferase, acid phosphatase, and lactate dehydrogenase were significantly altered in the PCZ group compared to control. Furthermore, PCZ caused a significant reduction in levels of glutathione and ascorbic acid as well as activities superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase in the testes of PCZ-treated rats. A significant increase in testicular malondialdehyde level was also observed in the PCZ group. MOR treatment, however, significantly restored the altered sperm parameters and biochemical markers in the testis.Conclusions:Our data suggest that MOR administration protected against PCZ-induced testicular and spermatotoxicity in rat, by improving testicular antioxidant system.

Adverse effects of paternal chemotherapy exposure on the progeny brain: intergenerational chemobrain.

Recent advances in cancer treatments have led to significant increases in cure rates. Most cancer patients are treated with various cytotoxic chemotherapy regimens. These treatment modalities are mutagenic and genotoxic and cause a wide array of late-occurring health problems, and even exert a deleterious influence on future offspring. The adverse effects from exposed parents on offspring are referred to as transgenerational effects, and currently little is known about chemotherapy-induced transgenerational effects. Furthermore, transgenerational effects have not been studied in the brains of progeny of exposed parents. In this study, we analyzed the existence and molecular nature of transgenerational effects in the brains of progeny of animals exposed to three common chemotherapy agents: cyclophosphamide (CPP), procarbazine (PCB) and mitomycin C (MMC). For the first time, our results show that paternal exposure to chemotherapy drugs causes transgenerational changes in the brain of unexposed progeny. Although no DNA damage was observed in terms of γH2AX levels, some alterations were found in levels of PCNA, protein involved in DNA repair, replication and profileration. Furthermore, there were changes in proliferation and apoptosis proteins BCL2 and AKT1, the proteins associated with DNA methylation, DNMT1 and MeCP2. Some altered expression trends were noted in proteins involved in myelin biogenesis, MBP and MYT1L. Moreover, global transcriptome profiling revealed changes in over 200 genes in the whole brains of progeny of animals exposed to CPP, and the changes in the levels of FOXP2 and ELK1proteins were confirmed by western blot analysis. These findings suggest that paternal chemotherapy significantly affects offspring brain development and may affect brain functioning. This research provides a key roadmap for future investigations of the novel phenomenon of transgenerational effects of chemotherapy in the brain of progeny of exposed parents.

Interaction of procarbazine with calf thymus DNA-a biophysical and molecular docking study.

Interaction of procarbazine (PCZ) with calf thymus DNA was studied using biophysical and molecular docking studies. Procarbazine was to interact with DNA with a binding constant of 6.52×103 M-1 as calculated using ultraviolet-visible spectroscopy. To find out the binding mode, molecular docking was performed that predicted PCZ to interact with DNA through groove binding mode with binding affinity of -6.7kcal/mole. To confirm the groove binding nature, different experiments were performed. Dye displacement assays confirmed the non-intercalative binding mode. Procarbazine displaced Hoechst dye from the minor groove of DNA while it was unable to displace intercalating dyes. There was no increase in the viscosity of DNA solution in presence of PCZ. Also, negligible change in the secondary structure of DNA was observed in presence of PCZ as evident by circular dichroism spectra. Procarbazine caused decrease in the melting temperature of DNA possibly because of decrease in the stability of DNA caused by groove binding interaction of PCZ with DNA.

The <i>in vivo</i> Pig-a gene mutation assay is applied to study the genotoxicity of procarbazine hydrochloride in Sprague-Dawley rats

The <i>in vivo</i> Pig-a gene mutation assay is applied to study the genotoxicity of procarbazine hydrochloride in Sprague-Dawley rats

Antigenotoxic effects of resveratrol: assessment of in vitro and in vivo response.

Experiments were performed to evaluate the in vitro and in vivo dose response for antigenotoxic effects of resveratrol (RES). For the in vitro study, HL-60 cells were co-treated with the test genotoxin and three concentrations of RES. Thereafter, genotoxic effects were assessed in the cytokinesis-block micronucleus test. Results of the in vitro experiments using genotoxins nitroquinoline-1-oxide (NQO) and mitomycin C (MMC) showed maximum inhibition of genotoxicity with the lowest test concentration of RES. The mouse bone marrow micronucleus assay was used for evaluating the in vivo antigenotoxic effects of RES against genotoxins diepoxybutane (DEB), MMC, methyl methanesulfonate and procarbazine (PCB). The experimental animals received RES pre-treatment by gavage 30min, 24 and 48h before injecting the genotoxin intraperitoneally. The in vivo studies demonstrated efficacy of the lowest test dose of RES for exerting maximum protection against chromosomal damage induced by all four genotoxins. The antigenotoxic effect observed with 6.25mg/kg RES was significantly higher than that of 100mg/kg RES against PCB and DEB. In conclusion, the findings from the present study indicate that lower test concentrations/doses of RES are more effective in exerting antigenotoxic effects.

Quercetin, a Flavonoid Antioxidant, Ameliorated Procarbazine-Induced Oxidative Damage to Murine Tissues.

Procarbazine (PCZ) (indicated in Hodgkin’s disease), is an alkylating agent known to generate free radicals in vivo, while Quercetin (QCT) is a flavonoid antioxidant with proven free radical scavenging capacity. This study investigated the protective effects of QCT on PCZ-induced oxidative damage in the rat. Male Wistar rats (160–180 g) were randomized into five groups (n = 5/group): I (control), II PCZ-treated (2 mg/kg body weight (bw) for seven days); III pre-treated with QCT (20 mg/kg bw) for seven days, followed by PCZ for seven days; IV co-treated with PCZ and QCT for seven days and V administered QCT alone for seven days. PCZ caused a significant increase in plasma total bilirubin, urea, and creatinine when compared with control (P < 0.05). Similarly, plasma activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transferase (γ-GT) were significantly increased in the PCZ-treated group relative to control. Furthermore, PCZ caused a significant decrease in the activities of hepatic superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) as well as levels of ascorbic acid (AA) and glutathione (GSH). This was followed by a significant increase in hepatic malondialdehyde (MDA) content. However, QCT pre-treatment and co-treatment ameliorated the PCZ-induced changes in plasma levels of urea, creatinine, and bilirubin as well as the activities of ALP, AST, ALT, and GGT. QCT also ameliorated hepatic AA and GSH levels and the activities of SOD, CAT, and GST. This all suggests that QCT protected against PCZ-induced oxidative damage in rats.