Evaluation of toxicity of beta-tethymustine, a new anticancer compound, in mice

Sensitization of cisplatin therapy by a naphthalimide based organoselenium compound through modulation of antioxidant enzymes and p53 mediated apoptosis

The widely used anti-cancer drug cisplatin imparts various toxic manifestations in the host, with nephrotoxicity being the most severe one. The trace element selenium shows antioxidant activity in both human and animals. The present study was designed to assess the chemoprotecting and chemoenhancing efficacy of a naphthalimide based organoselenium compound 2-(5-selenocyanato-pentyl)-benzo[de]isoquinoline 1,3-dione during cisplatin chemotherapy in mice bearing Ehrlich ascites carcinoma cells. Cisplatin (5 mg/kg b.w.) was administered intraperitoneally and the organoselenium compound (3 mg/kg b.w.) was given by oral gavage in concomitant and pretreatment schedule. The effects of the test compound was evaluated by assaying biochemical, hematological, histological, genotoxicity parameters and by investigating induction of apoptosis in tumor cells, and calculating tumor growth response in the host. The organoselenium compound significantly prevented cisplatin induced generation of reactive oxygen species (ROS), reactive nitrogen species, and onset of lipid peroxidation in the kidney tissue of the experimental mice. In addition, the test compound was also substantially restored cisplatin induced depleted activities of the renal antioxidant enzymes and reduced glutathione level; prevented the serum blood urea nitrogen level, creatinine level, chromosomal aberration, DNA damage, histological alterations of kidney, and normalized the hematological profile of the tumor bearing mice. Furthermore, the organoselenium compound alone or during combination therapy induced apoptosis in tumor cells through mitochondria mediated and DNA damage mediated pathway and ultimately increased the life span of the tumor bearing host. Hence, the results showed that the test compound not only reduced the toxicity of cisplatin but also enhanced its anti-tumor efficacy.

Efeito do miriadenolídeo isolado de Alomia myriadenia (Asteraceae) sobre o tumor de Erlich ascítico no camundongo

Estudou-se atividade antineoplásica de um produto natural isolado de Alomia myriadenia (miriadenolídeo) no modelo do tumor de Ehrlich em camundongos. Dezoito fêmeas de camundongo Swiss foram inoculadas com 2x10(7) células viáveis de tumor de Ehrlich via intraperitoneal (0,3ml) e posteriormente distribuídas aleatoriamente em três grupos que receberam: grupo I (controle) - 0,3ml de solução de Hanks; grupo II - 31µg/kg de miriadenolídeo; e grupo III - 139µg/kg de miriadenolídeo. No oitavo dia de experimento, foram realizados exames hematológicos e perfil protéico sérico eletroforético. Coletou-se todo o líquido ascítico para avaliação do volume, aparência, pH, contagem de células viáveis e inviáveis, realização de esfregaços para contagem de células claras e escuras, leucócitos e avaliação das regiões organizadoras de nucléolos argentafins (AgNORs). Foram realizados exames macro e microscópicos do baço, fígado e rins e aspirado o conteúdo da medula óssea dos fêmures direito e esquerdo de cada animal para avaliação da relação mielóide:eritróide. Não houve diferença significativa no volume, pH, contagem de células viáveis e inviáveis entre os três grupos estudados, observando-se valores de 17,6 x 10(4) células tumorais viáveis no grupo III, 27,7 x 10(4) no grupo II e 21,1 x 10(4) no grupo I. As AgNORs apresentaram-se pequenas, com distribuição difusa e incontáveis no grupo I, e em menor quantidade no grupo III. Os animais do grupo III apresentaram a menor concentração protéica total sérica (4,7g/dl) (P<0,05) quando comparados com os do grupo II (5,3g/dl) e do grupo I (5,1g/dl). Os valores de albumina foram semelhantes nos três grupos (2,6g/dl), e as globulinas totais foram maiores (P<0,05) no grupo II (2,71g/dl) quando comparadas com os valores médios do grupo III (2,11g/dl) e semelhantes ao grupo I (2,43g/dl). Não houve diferença entre alfa e beta globulinas entre os três grupos estudados, porém as gamaglobulinas foram maiores (P<0,05) no grupo II (1,72g/dl) quando comparadas com as do grupo III (1,13g/dl). Com relação ao eritrograma e leucograma, não houve diferença significativa entre os grupos tratados. A relação mielóide:eritróide foi maior (P<0,05) no grupo III (1,40) quando comparada com a relação nos grupos I (0,92) e II (0,61). A contagem de reticulócitos também foi maior (P<0,05) (11,2) no grupo III, quando comparada com as dos grupos I (4,3) e II (3,6). Em todos os grupos, observou-se degeneração hepática.

Enhancement of the tumour inhibitory activity, in vivo, of diospyrin, a plant-derived quinonoid, through liposomal encapsulation

Diospyrin, a bisnaphthoquinonoid plant product, shows inhibitory activity against murine tumour in vivo and human cancer cell lines in vitro. Efforts have further been made to obtain synthetic derivatives of diospyrin with the objective of improved therapeutic effects. With the goal to reduce the toxicity towards normal cells and enhance the efficacy to tumour cells, diospyrin was encapsulated in liposomal vesicle and its antitumour potential was observed on the growth of Ehrlich ascites tumour in Swiss mice. It was found that the longevity of the tumour-bearing mice was significantly enhanced by treatment with liposomal diospyrin as compared with the free drug. Biochemical assay of liver function enzymes, viz. LDH, AP, GOT and GPT in blood serum of the tumour-bearing mice showed substantial alterations in the activity of these enzymes. These parameters were, however, restored to near normal level when the drug treatment was given encapsulated in a liposome. Histopathological studies on the liver tissues indicated a near normal pathological status in the treated animals despite being challenged by tumour cells. This study on diospyrin has shown, for the first time, an enhancement of its antitumour effect in vivo through liposomal encapsulation.

Black tea protects immunocytes from tumor-induced apoptosis by changing Bcl-2/Bax ratio

It is known that cancer is associated with altered immune function. We demonstrated earlier that black tea inhibits tumor growth in a dose-dependent manner. Here, we report that apoptosis was the cause of immunocyte death in Ehrlich's ascites carcinoma (EAC)-bearing mice and anti-tumor dose of black tea restored EAC-induced immunosuppression by inhibiting apoptosis. A search for the molecular mechanism revealed that EAC burden increased the expression of the pro-apoptotic proteins p53 and Bax in splenic lymphocytes although did not change the level of pro-proliferative protein Bcl-2. Interestingly, anti-tumor dose of black tea down-regulated p53, decreased Bax while augmenting Bcl-2 in these cells. As a result, Bcl-2/Bax ratio was increased and the immunocytes were protected from tumor-induced apoptosis. Thus, unlike many other anti-cancer agents, black tea is not only devoid of immunosuppressive effect but also acts as immuno-restorer in tumor-bearing host. These results, thus, raise the possibility of inclusion of black tea in successful therapeutic regimen against cancer.

Evaluation of dimethylaminosulfonates of alkane diols as a novel group of anticancer agents

A series of title compounds has been synthesized and evaluated by the cytotoxicity assays conducted in vitro in seven human tumor cell lines, initially in MT-4 and H-9, followed by U-937, PM-1, MCF-7, Hep-3B, and K-562. These compounds were simultaneously compared with the existing clinical drug, busulfan and also with an experimental drug, hepsulfam. IC(50) values of these agents in T-cell lymphoma and leukemic cell lines indicate that two of these agents hexsulfamyl and octsulfamyl (compounds 3 and 4) were significantly more potent than busulfan and were comparable in antileukemic activity with hepsulfam. In order to determine the effect of these agents on normal proliferating cells, the toxicity of 3 and 4 was also determined in vitro against human peripheral blood mononuclear cells (PBMC) and against murine bone marrow progenitor cells. PBMC assay data indicate that these agents were generally less toxic than hepsulfam. The results of the colony forming unit-erythroid (CFU-E) and granulocyte-macrophage colony forming unit (CFU-GM) assays, however, indicate that these agents were more toxic than hepsulfam to erythroid progenitor cells than to granulocyte-macrophage progenitors. The toxicity of octsulfamyl was further assessed in vivo in normal Swiss mice by measuring drug-induced changes in hematological parameters, femoral bone marrow cellularity and splenic cellularity as well as hepatotoxicity and nephrotoxicity on day 7 and 14 following drug treatment at the dose of 1.0 mg/kg body weight from days 1 to 5. The results indicate that the compound did not adversely affect hematopoiesis. Marginal bone marrow suppression was observed on day 7, which gradually tends to reach normalcy on day 14. The other parameters were within normal limit.