Naringin inhibits tumor growth and reduces interleukin-6 and tumor necrosis factor α levels in rats with Walker 256 carcinosarcoma

The flavonoid naringin is a polyphenolic compound that naturally occurs in citrus. Patients with cancer generally present features of malnutrition and cachexia. Levels of the proinflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) are raised in patients with cancer. This study was designed to analyze the in vivo effect of naringin in the therapeutic treatment of rats bearing Walker 256 carcinosarcoma (W256). Rats were treated intraperitoneally with different doses of naringin (10, 25 and 35 mg/kg), for 50 days. At 25 mg/kg, naringin inhibited tumor growth by ~75%. With this treatment, TNF-α and IL-6 levels decreased (p<0.05) in comparison with the control. In addition, two rats presented complete tumor regression. Inhibition of tumor growth, survival increase and the reduction of TNF-α and IL-6 levels in rats bearing W256 treated with naringin strongly suggest that this compound has potential as an anticarcinogenic drug.

β-Hydoxy-β-methylbutyrate supplementation affects Walker 256 tumor-bearing rats in a time-dependent manner

BACKGROUND & AIMS

Cancer cachexia affects intermediary metabolism with intense and general catabolism. Walker 256 tumor is a model injected either subcutaneously (Sc) or intraperitoneally (Ip), with different metabolic features. Beta-hydroxy beta-methylbutyrate (HMbeta) is a leucine metabolite with anti-catabolic properties, the aim of this study being to investigate its effects on metabolic parameters in both tumor models.

METHODS

Controls (subcutaneous control group (ScC) and intraperitoneal control group (IpC)) and supplemented animals (subcutaneous supplemented group (ScS) and intraperitoneal supplemented group (IpS)) showed these results.

RESULTS

Protein Sc values were (47.8%) lower than Ip groups. Sc group fat content was (65.16%) higher than Ip groups. Liver glycogen value for Sc groups was (38.4%) higher than Ip groups. Muscle glycogen value for Sc groups were (2.75 times) higher than Ip groups. Corticosterone and insulin values were lower (44.53%) and higher (45.94%), respectively, in Sc when compared with Ip groups. Glucose and lactate values for ScS were the lowest (61.7% and 41.53%) compared to other groups. ScC glutamine value was the highest (40.8%) of all groups. Glutamate Sc values were (42.65%) lower than Ip groups. Sc groups showed greater survival time compared with Ip groups. ScS group showed 100% increase in survival time when compared with ScC.

CONCLUSIONS

HMbeta supplementation can increase survival time and promotes metabolic changes in cancer-bearing animals, but it seems to work in a time-dependent manner.

Enhanced antitumor efficacy on hepatoma-bearing rats with adriamycin-loaded nanoparticles administered into hepatic artery

AIM: To investigate the antitumor activity of adriamycin (ADR) encapsulated in nanoparticles (NADR) and injected into the hepatic artery of hepatoma-bearing rats.

METHODS: NADR was prepared by the interfacial polymerization method. Walker-256 carcinosarcomas were surgically implanted into the left liver lobes of 60 male Wistar rats, which were divided into 4 groups at random (15 rats per group). On the 7th day after implantation, normal saline (NS), free ADR (FADR), NADR, or ADR mixed with unloaded nanoparticles (ADR + NP) was respectively injected via the hepatic artery (i.a.) of rats in different groups. The dose of ADR in each formulation was 2.0 mg/kg body weight and the concentration was 1.0 mg/mL. Survival time, tumor enlargement ratio, and tumor necrosis degree were compared between each group.

RESULTS: Compared with the rats that received NS i.a., the rats that received FADR or ADR + NP acquired apparent inhibition on tumor growth, as well as prolonged their life span. Further significant anticancer efficacy was observed in rats that received i.a. administration of NADR. Statistics indicated that NADR brought on a more significant tumor inhibition and more extensive tumor necrosis, as compared to FADR or ADR + NP. The mean tumor enlargement ratio on the 7th day after NADR i.a. was 1.106. The mean tumor-bearing survival time was 39.50 days. Prolonged life span ratio was 109.22% as compared with rats that accepted NS.

CONCLUSION: Therapeutic effect of ADR on liver malignancy can be significantly enhanced by its nanopaticle formulation and administration via hepatic artery.

Cancer cachexia and tumor growth reduction in Walker 256 tumor-bearing rats supplemented with N-3 polyunsaturated fatty acids for one generation

In this study we investigated the effect of lifelong supplementation of the diet with coconut oil (CO, rich in saturated fatty acids) or fish oil (FO, rich in n-3 polyunsaturated fatty acids, PUFAs) on tumor growth, animal survival, and metabolic indicators of cachexia in adult rats. Female Wistar rats were supplemented with CO or FO prior to mating and then throughout pregnancy and gestation, and then the male offspring were supplemented from weaning until 90 days of age. Then they were inoculated subcutaneously with Walker 256 tumor cells. Tumor weight at 14 days in control rats (those fed standard chow) was approximately 20 g. These animals displayed cancer cachexia, which was characterized by loss of weight, hypoglycemia, hyperlacticidemia, hypertriacylglycerolemia, and depletion of glycogen stores. Supplementation of the diet with CO did not change these parameters, except that there was a smaller decrease in serum triacylglycerol concentration. Supplementation of the diet with FO significantly decreased tumor growth (by approximately 60%), increased survival (50% at 30 days postinoculation vs. 30% in the controls and 13.5% in the CO group), and prevented the fall in body weight. Furthermore, FO supplementation partly abolished the fall in serum glucose, totally prevented the elevation in serum lactate concentrations, partly prevented the hypertriacylgylcerolemia, and preserved tissue glycogen stores. Lifelong consumption of FO, rich in n-3 PUFAs, protects against tumor growth and cancer cachexia and improves survival.

Effect of a moderate intensity exercise training protocol on the metabolism of macrophages and lymphocytes of tumour-bearing rats

It is commonly accepted that moderate intensity exercise is beneficial to the immune system. We tested the influence of a moderate intensity training protocol (8 weeks) upon immune system function in Wistar tumour-bearing (TB) rats. The metabolism of glucose and glutamine in lymphocytes and macrophages was assessed, together with some functional parameters (hydrogen peroxide production and lymphocyte proliferative response). These substrates were chosen since they represent the most important energetic and synthetic metabolites for these cellular types. The training protocol caused a decrease of 17.4 per cent in the production of H(2)O(2) by macrophages, as well as a decrease in glucose consumption (25 per cent) and lactate production (47.1 per cent), and an increase in the production of labelled CO(2) from the oxidation of [U-(14)C]-glucose, in TB rats. The training protocol was also able to induce changes in the maximal activity of some key enzymes in the metabolism of glucose and glutamine, a reduction of hexokinase (68.8 per cent) activity and an increase in the activity of citrate synthase (10.1 per cent) in TB rats. The training protocol increased the proliferative response of lymphocytes cultivated in the absence of mitogens (75 per cent), of those cultivated in the presence of ConA (38.2 per cent) and in the presence of LPS (45.0 per cent). These cells also showed an increase in the maximal activity of some key enzymes of the glycolytic and glutaminolytic pathways. Our data demonstrated that the training protocol was able to induce an increase in aerobic utilisation of both substrates in lymphocytes and macrophages. The training protocol was also able to prevent several changes in glucose and glutamine metabolism that are normally present in sedentary TB rats. These changes in immune cell metabolism induced by the training protocol were able to increase TB rat survival.

Ultrastructural changes induced in Walker carcinosarcoma by treatment with dihematoporphyrin ester and light in animals with diabetes mellitus

The purpose of this study was to evaluate by electron microscopy the tumoral fine structure changes induced by photodynamic therapy (PDT) in diabetic animals. Walker -256 carcinosarcoma harvested from animals with/without diabetes mellitus exposed to PDT (Photofrin II/5 mg/kg and 24 hrs later He-Ne laser irradiation/632.8 nm; 10 mW) and examined by electron microscopy showed different degrees of lesions in the nucleus and cytoplasmic fine structure. The ultrastructural changes induced by PDT in animals with diabetes mellitus bearing carcinosarcoma are characterized by: lysis of chromatin situated on the central zone of nucleus; swelling and vacuolization of mitochondria; formation of phagosome--like structures; myelin figures; degenerescence and disappearance of cytoplasmic organelles. Summing up, the data presented in this work demonstrate that the exposure to three doses of PDT produces changes in tumoral fine structure, increases survival rate and reduces incidence of carcinosarcoma in rats with diabetes mellitus.

Tumor growth promoting activity of an immunosuppressive substance and its modulation by protein-bound polysaccharide PSK

The role of an immunosuppressive substance (IS), which is increased in the serum of tumor-bearing animals, was examined in rats. IS isolated from cancerous ascites fluid of rats was administered to Walker 256 tumor-bearing rats to examine changes in the serum level of IS, tumor growth and survival rate. PSK, an immunomodulator, was also administered. Serum IS increased with tumor growth. The administration of IS to tumor-transplanted rats caused the tumor to grow and shortened the animals' survival time. The administration of PSK, however, inhibited the increase in serum level of IS, resulting in the suppression of tumor growth and a prolongation of survival time. The findings suggested that IS is a useful parameter for predicting not only tumor growth but also the therapeutic effect of immunomodulators such as PSK.

Effect of a protein bound polysaccharide (PS-K) on tumor development and infections in splenectomized rats and mice

Daily oral administration of PS-K, an immunomodulating agent, was found to improve survival rate in tumor bearing mice and rats and to decrease susceptibility to infection in mice. Surprisingly, splenectomized tumor bearing rats and mice responded better to PS-K treatment as measured by survival rate, tumor size and immunosuppressive properties of serum. The mechanism of PS-K antitumor activity in both experimental systems might be due to the alteration of splenic immune suppressive mechanisms during tumor growth in the host. On the other hand, host resistance to acute infection was found to be less dependent upon the presence or absence of spleen suggesting a different mechanism of PS-K activity in acute infectious disease.

Studies of amygdalin (laetrile) toxicity in rodents

Amygdalin (laetrile), given to Fischer 344 rats in doses of 250, 500, and 750 mg/kg intraperitoneally daily for five days, caused mortalities of 30.8% 44.1%, and 56.8%, respectively. The mode of death and the elevated serum cyanide levels in the dying animals strongly suggested cyanide poisoning as the cause of death. These findings seriously question the use of amygdalin in clinical medicine under any circumstances.

Brain changes and survival of animals with tumors implanted in the brain

The effects of tumor cells implanted into the brain of animals on survival rates and gross and microscopic brain changes have been ascertained. Walker carcinosarcoma 256 cell suspensions were injected at several brain sites in rats and leukemia L1210 and P388 and Ehrlich ascites tumor cells, intracerebrally into BDF1 mice. Such neoplasms provided for rapid and rather predictable growth increments. The survival rates were dependent on the number of cells introduced, those receiving the higher counts succumbing first. The brains of the animals revealed fairly discrete space-occupying lesions and neurological symptoms became apparent only hours before death due to intracranial pressure.

Influence of stress of lesion growth and on survival of animals bearing parenteral and intracerebral leukemia L1210 and Walker tumors

Rats with Walker tumor injected intramuscularly in both hind legs and subjected to forced swimming for 15 min daily for 10 days displayed a trend toward decreased lesion size, especially in older intact animals as compared to unexercised intact or bilaterally adrenalectomized controls. Secondary tumor nodules occurred at the lower abdominal or inguinal areas and appeared to be more extensive in the older exercised rats. The survival rates of forced exercised rats bearing Walker tumor cortically did not differ significantly from the respective controls as was also the case with adult BDF1 mice withintraperitoneal or cortical l1210 tumor and subjected daily to electroshock at 0.25mA for 15 min.