Evaluation of antitumor efficacy and toxicity of novel 6-nitro-2-(3-chloropropyl)-1H-benz[de]isoquinoline-1,3-dione in vivo in mouse.

AIM: This study was aimed to assess the in vivo anti-tumoral potency of the novel 6-nitro-2-(3-chloropropyl)-1H-benz[de]isoquinoline-1,3-dione [Compound 1] that has earlier demonstrated excellent cytotoxicity in 15 out of 17 human tumor cell lines tested. MATERIALS AND METHODS: Two murine tumors namely Sarcoma-180 (S-180) and Ehrlich ascites carcinoma (EAC) were used to measure its in vivo anti-tumor activity through the increase in median survival times (MST) of drug treated (T) over untreated control (C) mice. Drug-induced toxicity in respect of hematological parameters, femoral bone marrow and splenic cellularity as well as biochemical parameters and histopathology of liver and kidney were assessed in vivo in normal and S-180 bearing mice sequentially on days 9, 14 and 19 following drug treatment at the optimum dose of 60 mg/kg administered from day 1 to 7. RESULTS: Results revealed significant tumor regression effects in S-180 and EAC as T/Cmax values of 138 and 189 were obtained at its optimum dose of 60 mg/kg for QD1-7 . Toxicity assay indicated no significant cardiotoxicity, hepatotoxicity or nephrotoxicity of the compound in normal and S-180 bearing mice. An initial hyposplenic cellularity and the femoral bone marrow suppression effect observed on day 9 reached normalcy by day 19. HPLC analysis revealed that it has appreciable stability (half-life ~ 3 h) in murine blood plasma in vitro. CONCLUSION: Above results justify potential candidature of the compound for further drug development.

Antitumor efficacy and apoptotic activity of substituted chloroalkyl 1H-benz[de]isoquinoline-1,3-diones: a new class of potential antineoplastic agents.

A series of ten chloroalkyl 1H-benz[de]isoquinoline-1,3-diones (naphthalimides) were synthesized and evaluated for antitumor activity. Amongst them, new compounds 2d and 2i carrying a 6-NO(2) substituent in the aromatic portion of the molecule possessed significant antineoplastic activity. The most active compound 2i had elicited significant cytotoxicity in 15 human tumor cell lines namely Leukemia: MOLT-4, HL-60; Lymphoma: U-937; Colon: 502713, HT-29, SW-620, HCT-15, COLO-205; Liver: Hep-2; Prostate DU-145, PC-3; Breast: MCF-7; Neuroblastoma: IMR-32, SK-N-SH and Ovary: OVCAR-5 out of the 17 cell lines screened. Flow cytometric analysis performed to study the effect of compound 2i on the progression of cell cycle of MOLT-4 cells, revealed rise in sub-G(1) fraction and concomitant accumulation of cells in S and G(2)/M phases, indicating apoptosis, mitotic arrest and/or delay in exit of daughter cells from mitotic cycle respectively. It also induced caspase-mediated apoptosis of MOLT-4 cells in a dose dependant manner. Light and electron microscopic studies revealed characteristic morphology of apoptotic MOLT-4 cells after in vitro treatment with 10 µM concentration of the compound. Apoptosis induction was also observed in HL-60 cells by compounds 2d and 2i to an extent much greater than camptothecin and cis-platin at 10 µM concentration. Both the compounds have shown minimal suppressive effect on human PBMC having high IC(50) values of 3,582 and 1,536 µM respectively. These compounds inhibited DNA and RNA synthesis in murine ascites Sarcoma-180 tumor cells in vitro at 8 µM concentration. Above results indicate promising chemotherapeutic potential of the key compound 2i.

6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione, a potent antitumor agent, induces cell cycle arrest and apoptosis.

BACKGROUND: Anticancer activities of several substituted naphthalimides (1H-benz[de]isoquinoline-1,3-diones) are well documented. Some of them have undergone Phase I-II clinical trials. Presently a series of ten N-(hydroxyalkyl) naphthalimides (compounds 1a-j) were evaluated as antitumor agents. METHODS: Compounds 1a-j were initially screened in MOLT-4, HL-60 and U-937 human tumor cell lines and results were compared with established clinical drugs. Cytotoxicities of compounds 1d and 1i were further evaluated in a battery of human tumor cell lines and in normal human peripheral blood mononuclear cells. Cell cycle analysis of compound 1i treated MOLT-4 cells was studied by flow cytometry. Its apoptosis inducing effect was carried out in MOLT-4 and HL-60 cells by flow cytometry using annexin V-FITC/PI double staining method. The activities of caspase-3 and caspase-6 in MOLT-4 cells following incubation with compound 1i were measured at different time intervals. Morphology of the MOLT-4 cells after treatment with 1i was examined under light microscope and transmission electron microscope. 3H-Thymidine and 3H-uridine incorporation in S-180 cells in vitro following treatment with 8 µM concentration of compounds 1d and 1i were studied. RESULTS: 6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione (compound 1i), has exhibited maximum activity as it induced significant cytotoxicity in 8 out of 13 cell lines employed. Interestingly it did not show any cytotoxicity against human PBMC (IC50 value 273 µM). Cell cycle analysis of compound 1i treated MOLT-4 cells demonstrated rise in sub-G1 fraction and concomitant accumulation of cells in S and G2/M phases, indicating up-regulation of apoptosis along with mitotic arrest and/or delay in exit of daughter cells from mitotic cycle respectively. Its apoptosis inducing effect was confirmed in flow cytometric study in MOLT-4 and the action was mediated by activation of both caspase 3 and 6. Light and transmission electron microscopic studies corroborated its apoptosis inducing efficacy at a concentration of 10 µM in MOLT-4 cells. Its apoptosis induction was also observed in HL-60 cells to an extent much greater than well known apoptosis inducing agents as camptothecin and cis-platin at 10 µM concentration each. It significantly inhibited DNA and RNA synthesis in S-180. CONCLUSIONS: In essence, compound 1i showed potential as an antitumor agent.

Neem leaf glycoprotein matures myeloid derived dendritic cells and optimizes anti-tumor T cell functions.

In an objective to find out an effective, nontoxic dendritic cell (DC) maturating agent for human use, CD14(+) monocytes were differentiated with GMCSF/IL-4 and matured with neem leaf glycoprotein (NLGP). NLGP matured DCs (NLGP-DCs) show upregulated expression of CD83, CD80, CD86, CD40 and MHCs, in a comparable extent of control, LPS. NLGP-DCs secrete high amount of IL-12p70 with low IL-10. NLGP upregulates the expression of crucial transcription factor, ikaros, indicating maturation towards DC1 phenotype. Increased expression of CD28 and CD40L on T cells following co-culture with NLGP-DCs was noticed to promote DC-T interactions. As a result, T cells secrete high amount of IFN gamma with low IL-4 and generates anti-tumor type 1 immune microenvironment. Such NLGP-DCs present carcinoembryonic antigen (CEA) effectively to T cells to increase T cell mediated cytotoxicity of CEA(+) tumor cells in vitro and in vivo. With emergence of the NLGP as a promising DC maturating agent, NLGP-DCs can be used as a candidate vaccine tool for antigen specific cancer immunotherapy.

Evaluation of fluoren-NU as a novel antitumor agent.

A new nitrososourea derivative, namely fluoren-NU, 3-[2-(3-(2-chloroethyl)-3-nitrosouriedo}ethyl]-spiro[5,9'-fluorenyl]imidazolidine-2,4-dione (compound 2e), was synthesized from 3-(2-bromoethyl)-spiro [5,9'-fluorenyl]imidazolidine-2,4-dione via a four-step synthetic procedure. Its chemical alkylating activity was assessed by coupling with 4-(4-nitrobenzyl)pyridine. In vitro screening in six human tumor cell lines, namely SK-N-SH CNS, IMR-32 neuroblastoma, A549 lung, DU-145 prostate, HL-60 leukemia, and U-937 lymphoma, revealed its significant cytotoxicity in SK-N-SH. Its in vivo antitumoral potency was assessed in murine ascites tumors Ehrlich ascites carcinoma (EAC) and Sarcoma-180 (S-180) by measuring the increase in median survival times (MST) of drug-treated (T) over untreated control (C) mice. Results revealed significant tumor regression effects in both of these tumors. Life span of mice bearing advanced tumor for 5 days before the drug challenge was also considerably increased. In vivo toxicological assay at its optimum dose of 40 mg/kg for days 1-7 treatment schedule was conducted sequentially on day 9, 14, and 19 in normal and EAC-bearing mice. Results revealed that it did not adversely affect hematopoiesis or exhibit drug-induced hepatotoxicity and nephrotoxicity. It has shown minimal cytotoxic effect on human peripheral blood mononuclear cells (PBMC) having a high IC50 value of 792 microM. Compared to Mitonafide and CCNU used as standards it also significantly inhibited DNA and RNA synthesis in EAC tumor cells in vitro at 8 microM concentration.

Synthesis and evaluation of ethylnitrosoureas of substituted naphthalimides as anticancer compounds.

Four new ethylnitrosourea derivatives of substituted naphthalimides 3a-d have been synthesized from the respective N-(2-ethylamino) naphthalimides. Their chemical alkylating activity compared with the clinical drug CCNU and an experimental compound Mitonafide indicated that they possess lower alkylating activity than CCNU and comparable activity with the latter. Their anti-tumor efficacies were assessed in vivo in two murine ascites tumors namely Sarcoma-180 (S-180) and Ehrlich ascites carcinoma (EAC) by measuring the increase in median survival times (MST) of drug treated (T) over untreated control (C) mice. CCNU and Mitonafide were used as positive controls for comparison. The representative compound 3a has displayed marginal anti-tumoral activity in these tumors. Three compounds were further screened in vitro in 4 different human tumor cell lines but no significant activity was observed in those lines. These compounds moderately inhibit the synthesis of DNA and RNA in S-180 tumor cells.

Antitumor activity of Nitronaphthal-NU, a novel mixed-function agent.

Nitronaphthal-NU (Compound 1) was synthesized as a mixed-function antitumor agent based on the structures of the clinical drug CCNU and experimental compound Mitonafide. In vitro screening in four human tumor cell lines namely SNB-78 CNS, HOP-62 Lung, T47D Breast and SiHa - cervix revealed significant cytotoxicity in the former two cell lines much greater than CCNU and comparable to Mitonafide used as standards. In vivo antitumoral potency assessed in the murine ascites tumors Sarcoma-180 (S-180) and Ehrlich ascites carcinoma (EAC) by measuring the increase in median survival times of drug treated (T) over untreated control (C) mice, revealed highly significant (p<0.001) tumor regression effects greater than standards. Life span of mice bearing advanced tumor for 10 days before the drug challenge was also considerably increased. Its toxicity was assessed in vivo in normal and S-180 bearing mice by measuring drug-induced changes in haematological parameters, femoral bone marrow and splenic cellularities as well as hepatotoxicity and nephrotoxicity sequentially on days 9, 15 and 21 following drug treatment at the optimum dose of 50 mg/kg from day 1 to 7. Results indicate that it did not adversely affect haematopoiesis. The other parameters were within normal limit. The compound comparable to standards inhibited the synthesis of DNA and RNA in S-1 80 tumor cells.

Response of Cervical Intra-epithelial Lesions to Vitamin E Supplementation - A Preliminary Report.

Carcinoma of the uterine cervix is preceded by well characterized pre-cancerous lesions which if left untreated may progress to invasive carcinoma. In the present study women in the age group of 35-55 years with cervical intraepithelial lesions (CIN I & II) were treated with vitamin E and advised to come for follow up after every three months for one year. This preliminary report shows vitamin E can restrict and regress CIN I & II lesions with elevation in circulating vitamin E levels. Improvement in immune status as reflected in mitogenic responses of peripheral blood lymphocytes was also noted.