PARP ( IC50 = 50 nM )

3-Aminobenzamide reduces diabetes-induced podocyte depletion and improves diabetes-induced albumin excretion and mesangial expansion in a db/db (Leprdb/db) mouse model[3]. 3-After controlled cortical impact (CCI) in mice, 3-aminobenzamide (1.6 mg/kg intracerebrally injected) prevents NAD+ depletion and enhances water maze performance[4].

Using a PARP Activity Assay Kit, PARP activity is determined. In the presence of sheared genomic DNA, which activates PARP, the amount of ³H-NAD incorporated into trichloroacetic acid (TCA) precipitable material is measured using this method to determine relative PARP activity. After the reaction is allowed to run for 60 minutes at 37°C, the reaction mixture is directly added to washed cultures in 12-well culture plates. The cells are then mechanically removed, moved to a microcentrifuge tube, and precipitated with ice-cold 5% TCA.

3-Aminobenzamide (PARP-IN-1) is a potent inhibitor of PARP that acts as a mediator of oxidant-induced myocyte dysfunction during reperfusion. Its IC50 in CHO cells is approximately 50 nM.

Metabolism / Metabolites
3-Aminobenzamide (3-ABA) is a potent radiosensitizer that inhibits the repair of DNA strand breaks. The aim of this study was to monitor the biodistribution and pharmacokinetics of a fluorinated 3-ABA derivative in tumor-bearing rats by magnetic resonance imaging (MRI). To this end, 3-ABA was labeled with fluorine-19 by trifluoroethylation [3-amino-N-2,2,2-trifluoroethylbenzamide (3-ABA-TFE)], which only slightly increased the cytotoxicity of the compound as demonstrated by colony-forming assays. After intraperitoneal injection of 400 mg/kg BW 3-ABA-TFE to nine Copenhagen rats with Dunning prostate adenocarcinoma, (19)F MR images were acquired at a whole-body MR system with a spatial sampling of 10 x 10 x 15 mm(3). While 3-ABA-TFE was observed in all major organs and the muscular system, only a small and heterogeneous signal could be detected in the adenocarcinoma. Serial MR measurements yielded maximum tissue signals about 2 days after 3-ABA-TFE administration. At this time point, the mean muscle-to-liver and tumor-to-liver signal ratio was 0.31+/-0.07 and 0.11+/-0.04, respectively. Application of the (19)F MRI strategy makes it possible to measure the biodistribution and pharmacokinetics of 3-ABA-TFE in individual animals in a longitudinal manner. The results obtained for the prostate adenocarcinoma indicate that delivery of 3-ABA-TFE to solid tumors may be seriously hampered by tumor-specific factors and that the intratumoral uptake of the substance may be lower than in normal tissues. Therefore, the development of effective carrier systems is mandatory to improve tumor-selective delivery.

Interactions
Chronic irradiation (three times a week) with ultraviolet B light of the skin of hairless mouse Uscd (Hr) strains resulted in the induction of skin tumors after 25 to 41 weeks. Topical applications of 3-aminobenzamide (3AB; 0.1 or 1 M) after each irradiation significantly shortened the earliest time of onset of tumors to 13 to 25 weeks and increased the number of animals that developed tumors over 41 weeks from 67% without 3AB to 73% and 81% with 0.1 and 1 M 3AB, respectively. ...
The poly(ADP-ribosyl)transferase inhibitor, 3-aminobenzamide (3-ABA), reduced morphological evidence of 1,2-dibromo-3-chloropropane (DBCP)-induced DNA damage determined by alkaline elution. The DBCP plasma, kidney, and testis tissue doses determined between 1 and 8 hr after a single intraperitoneal injection were somewhat higher with than without 3-ABA pretreatment. Furthermore, the amount of DBCP metabolites covalently bound to macromolecules was reduced to about 20-30 percent of control, indicating that 3-ABA may have an effect on the formation/detoxication of reactive DBCP metabolites. ...
... 3-aminobenzamide (3AB) combined with X-rays was used to evaluate the micronucleus dose-response relationship in /in vitro-irradiated lymphocytes/ blood from 14 individuals. While it is known that 3AB inhibits poly(ADP-ribose) polymerase activity in vitro, ... it also increases the X-ray-induced micronucleus yields. The resulting dose-response relationship varies from subject to subject. ...
Gene expression of human immunodeficiency virus type 1 (HIV-1) is induced not only by trans activation mediated through a gene product (tat) encoded by the virus but also by treatment of virus-carrying cells with DNA-damaging agents such as UV light. Employing an artificially constructed DNA in which the chloramphenicol acetyltransferase gene was placed under the control of the HIV-1 long terminal repeat, ... the induction process in HeLa cells /was analyzed/ and ... inhibitors of poly(ADP-ribose) polymerase /including 3-aminobenzamide/ suppressed UV-induced HIV-1 gene expression but not tat-mediated expression. ... Suppression occurs at the posttranscriptional level. These results indicate that HIV-1 gene expression is activated by at least two different mechanisms, one of which involves poly-ADP ribosylation. ...
Synergistically enhanced sister chromatid exchange (SCE) frequency by cyclophosphamide (CP) was observed when L1210 lymphoid tumor cells were exposed in vivo to a non-toxic concentration of 3-aminobenzamide (3-AB). Additive effects in SCE induction in vivo were observed when either Ehrlich ascites tumor (EAT) cells or P388 lymphocytic leukemia cells treated with CP were exposed to 3-AB in vivo. 3-AB enhanced the survival time of L1210 tumor bearing BDF1 mice treated with CP. However, the combined CP plus 3-AB treatment did not increase the survival of either EAT BALB/c- or P388 BDF1-tumor bearing mice compared with the effect on survival by CP alone. Therefore the in vivo differential antitumor effect, by CP in conjunction with 3-AB, appears to correlate well with the in vivo differential effect on cytogenetic damage caused by the combined CP plus 3-AB treatment. In the Salmonella typhimurium/mammalian microsome test CP appears to have a dose dependent ability to induce base-pair substitutions in strains TA 100 and TA 1535 and frameshift mutations in strains TA 98 and TA 1537. Both types of mutation were synergistically increased in the presence of 3-AB.

[1]. Radiosensitization of human and rodent cell lines by INO-1001, a novel inhibitor of poly(ADP-ribose) polymerase. Cancer Lett. 2004 Mar 18;205(2):155-60.

[2]. Poly(ADP-ribose) polymerase inhibition improves endothelial dysfunction induced by reactive oxidant hydrogen peroxide in vitro. Eur J Pharmacol. 2007 Jun 14;564(1-3):158-66.

[3]. Poly(ADP-ribose) polymerase inhibitors ameliorate nephropathy of type 2 diabetic Leprdb/db mice. Diabetes. 2006 Nov;55(11):3004-12.

[4]. Local administration of the poly(ADP-ribose) polymerase inhibitor INO-1001 prevents NAD+ depletion and improves water maze performance after traumatic brain injury in mice. J Neurotrauma. 2007 Aug;24(8):1399-405.

3-aminobenzamide is a substituted aniline that is benzamide in which one of the meta- hydrogens is replaced by an amino group. It has a role as an EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor. It is a member of benzamides and a substituted aniline.

---

Mechanism of Action
Poly(ADP-ribosyl)transferase inhibitor
A 3 hr exposure to 1 mM H2O2 followed by 6 hr post-challenge growth in peroxide-free medium induces necrosis in U937 cells. Addition of the poly(ADP-ribose)polymerase inhibitor 3-aminobenzamide during recovery prevents necrosis and triggers apoptosis, as shown by the appearance of apoptotic bodies, extensive blebbing and formation of multimeric DNA fragments as well as 50 kb double stranded DNA fragments. Thus, the same initial damage can be a triggering event for both apoptotic and necrotic cell death. Furthermore, necrosis does not appear to be a passive response to overwhelming damage.
Treatment with 3-aminobenzamide, known as an inhibitor of poly(ADP-ribose)polymerease, decreased the toxicity and covalent binding of the herbicide dichlobenil (2,6-dichlorobenzonitrile; 12 mg/kg; i.p.) in the mouse olfactory mucosa. In vitro studies showed that 3-aminobenzamide markedly reduced the NADPH-dependent covalent binding of [14C]dichlobenil and the hydroxylation of p-nitrophenol which have previously been suggested to be mediated by a common form of cytochrome P450 (P450) in rat olfactory microsomes ... . Furthermore, 3-aminobenzamide markedly reduced the P450-dependent metabolic activation of [3H]NNK (4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone) in rat olfactory microsomes and slightly decreased the P450 2B1-dependent pentoxyresorufindealkylase activity in liver microsomes of phenobarbital-treated rats. The present results suggest that 3-aminobenzamide is also an inhibitor of P450 and that the lack of toxicity of dichlobenil in the olfactory mucosa of 3-aminobenzamide-treated mice is related to a decreased metabolic activation of dichlobenil at this site... .
... Cll lines deficient in poly(ADP-ribose) synthesis due to deficiency in the enzyme poly(ADP-ribose) polymerase (PADPRP) or depletion of its substrate NAD+ overexpress GRP78. Furthermore, this overexpression of GRP78 is associated with the acquisition of resistance to topoisomerase II-directed drugs such as etoposide (VP-16) ... Thus, /the/ studies suggest that interference with NAD+-PADPRP metabolism could provide an important approach to (a) define pathways of GRP78 induction, (b) study the effect of GRP78 on other cellular processes, (c) elucidate the mechanism of GRP78-dependent resistance to topoisomerase II targeted drugs, and (d) modulate responses to chemotherapy in normal and tumor tissues. However, in the in vivo situation, it is impractical to interfere with NAD+-PADPRP metabolism by mutational inactivation of PADPRP or by depletion of its substrate NAD+. Therefore, ... several inhibitors of NAD+-PADPRP metabolism including 3-aminobenzamide, PD128763, and 6-aminonicotinamide /were examined/ for their ability to reproduce the results obtained with cell lines deficient in NAD+-PADPRP metabolism relative to the induction of GRP78 and subsequent development of resistance to VP-16. ... 6-aminoicotinamide treatment is highly effective in the induction of GRP78 and subsequent development of resistance to VP-16, whereas treatment with 3-aminobenzamide or PD128763 does not induce GRP78 and thus does not result in VP-16 resistance.
For more Mechanism of Action (Complete) data for 3-AMINOBENZAMIDE (7 total), please visit the HSDB record page.

---

Therapeutic Uses
/EXPL THER/: Poly (ADP-ribose) polymerase (PARP), a nuclear enzyme activated by strand breaks in DNA, plays an important role in the colon injury associated with experimental colitis. The aim of the present study was to examine the effects of 3-aminobenzamide (3-AB), an inhibitor of PARP activity, in the development of acute pancreatitis caused by cerulein in mice. Intraperitoneal injection of cerulein in mice resulted in severe, acute pancreatitis characterized by edema, neutrophil infiltration and necrosis and elevated serum levels of amylase and lipase. Infiltration of pancreatic and lung tissue with neutrophils (measured as increase in myeloperoxidase activity) was associated with enhanced expression of the intercellular adhesion molecule-1 (ICAM-1) and P-selectin. Immunohistochemical examination demonstrated a marked increase in the staining (immunoreactivity) for transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF) in the pancreas of cerulein-treated mice in comparison to sham-treated mice. Acute pancreatitis in vehicle-treated mice was also associated with a significant mortality (40% survival at 5 days after cerulein administration). In contrast, (1) the degree of pancreatic inflammation and tissue injury (histological score), (2) upregulation/formation of ICAM-1 and P-selectin, (4) neutrophils infiltration and (5) the expression of TGF-beta and VEGF was markedly reduced in pancreatic tissue obtained from cerulein-treated mice which have been treated with 3-AB. These findings provide the evidence that PARP inhibition reduces the degree of pancreas injury caused by acute pancreatitis induced by cerulein administration.
/EXPL THER/: Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme which plays an important role in regulating cell death and cellular responses to DNA repair. Pharmacological inhibitors of PARP are being considered as treatment for cancer both in monotherapy as well as in combination with chemotherapeutic agents and radiation, and were also reported to be protective against untoward effects exerted by certain anticancer drugs. ... pharmacological inhibition of PARP with 3-aminobenzamide or PJ-34 dose-dependently reduces VEGF-induced proliferation, migration, and tube formation of human umbilical vein endothelial cells in vitro. These results suggest that treatment with PARP inhibitors may exert additional benefits in various cancers and retinopathies by decreasing angiogenesis.
/EXPL THER/: The activation of poly (ADP-ribose) polymerase (PARP) plays a pivotal role in mediating N-methyl-N-nitrosourea (MNU)-induced photoreceptor cell apoptosis. ... the retinoprotective effects of the PARP inhibitor 3-aminobenzamide (3-AB) against MNU-induced retinal damage in relation to dose and timing of prescription, and the involvement of the transcription factor nuclear factor (NF)-kappaB /were examined/. Female Sprague-Dawley rats were intraperitoneally injected with 60 mg/kg MNU at 50 days of age, and were then immediately given a subcutaneous injection of 0, 1, 5, 10, 30 or 50 mg/kg of 3-AB, or were injected with 50 mg/kg 3-AB 12h before, concurrently, or 4, 6 or 12h after MNU. Rats were killed 3 and 7 days after MNU, and MNU-treated and 3-AB-injected retinas were compared with MNU-untreated control retinas or MNU-treated/3-AB-uninjected retinas. Apoptosis in photoreceptor cells was detected by performing formamide-induced DNA denaturation and staining with anti-single-stranded DNA antibody. Retinal morphologies were compared and evaluated morphometrically using the photoreceptor cell ratio and retinal damage ratio as indices to evaluate the efficacy of 3-AB. ... expression of the phosphorylated form of NF-kappaB and IkappaBalpha (p-NF-kappaB and p-IkappaBalpha, respectively) in retinas of MNU-treated rats concurrently treated with or without 50mg/kg 3-AB, compared with MNU-untreated control retinas /was examined/. 3-AB dose-dependently suppressed photoreceptor cell apoptosis: 50mg/kg 3-AB injected concurrently with MNU completely rescued photoreceptor cell damage; 30 mg/kg 3-AB significantly reduced photoreceptor cell damage; 10 mg/kg 3-AB tended to suppress photoreceptor cell damage; or=4hr after MNU, it did not exert a retinoprotective effect. p-NF-kappaB levels of MNU-treated rat retinas were significantly lower than those of MNU-untreated control retinas, while 50 mg/kg 3-AB injected concurrently with MNU preserved the p-NF-kappaB levels; p-IkappaBalpha levels tended to decrease after MNU injection, compared with untreated control retinas, but the difference was not significant. Thus, 3-AB dose-dependently suppressed MNU-induced retinal damage, and 50mg/kg 3-AB injected concurrently with MNU completely rescued photoreceptor cell apoptosis via preservation of NF-kappaB activity.
/EXPL THER/: Poly(ADP-ribose) polymerases (PARPs) are defined as a family of cell signaling enzymes present in eukaryotes, which are involved in poly(ADP-ribosylation) of DNA-binding proteins. The best studied of these enzymes (PARP-1) is involved in the cellular response to DNA damage so that in the event of irreparable DNA damage overactivation of PARP-1 leads to necrotic cell death. Inhibitors of PARP-1 activity in combination with DNA-binding antitumor drugs may constitute a suitable strategy in cancer chemotherapy. When DNA is moderately damaged, PARP-1 participates in the DNA repair process and the cell survives. However, in the case of extensive DNA damage PARP-1 overactivation induces a decrease of NAD+ and ATP levels leading to cell dysfunction or even to necrotic cell death. So, due to PARP-1 involvement in cell death, pharmacological inhibition of PARP-1 activity by PARP-1 inhibitors may constitute a suitable target to enhance the activity of antitumor drugs through inhibition of necrosis and activation of apoptosis. PARP-1 inhibitors such as 3-aminobenzamide, 1,5-dihydroxyisoquinolinone and the recently patented tryciclic benzimidazoles have shown potent inhibitory effects of PARP-1 activity in tumor cells.
For more Therapeutic Uses (Complete) data for 3-AMINOBENZAMIDE (7 total), please visit the HSDB record page.

C₇H₈N₂O

136.15

136.063

3544-24-9

1645

Off-white to light brown solid powder

1.2±0.1 g/cm3

329.6±25.0 °C at 760 mmHg

115-116 °C(lit.)

153.2±23.2 °C

0.0±0.7 mmHg at 25°C

1.633

0.33

2

2

1

10

136

0

GSCPDZHWVNUUFI-UHFFFAOYSA-N

InChI=1S/C7H8N2O/c8-6-3-1-2-5(4-6)7(9)10/h1-4H,8H2,(H2,9,10)

3-aminobenzamide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: 25 mg/mL (183.62 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

---

Solubility in Formulation 2: 30% propylene glycol+ 5% Tween 80+ 65% D5W: 30 mg/mL (220.35mM)

---

 (Please use freshly prepared in vivo formulations for optimal results.)