Curcumin Acts as a Chemosensitizer for Leiomyosarcoma Cells In Vitro But Fails to Mediate Antioxidant Enzyme Activity in Cisplatin-Induced Experimental Nephrotoxicity in Rats

Background. Cisplatin (cis-diamminedichloroplatinum) is a widely used chemotherapeutic agent for the treatment of various cancers. Although it represents an effective regimen, its application is accompanied by side effects to normal tissues, especially to the kidneys. Cisplatin generates free radicals and impairs the function of antioxidant enzymes. Modulation of cisplatin-induced oxidative stress by specific antioxidant molecules represents an attractive approach to minimize side effects. Methods. We studied the ability of curcumin to sensitize leiomyosarcoma (LMS) cells to cisplatin. Assays for cell proliferation, mitochondrial function, induction of apoptosis, and cell cycle arrest were performed using various concentrations of cisplatin and a concentration of curcumin that caused a nonsignificant reduction in cell viability. Moreover, the effect of curcumin was examined against cisplatin-induced experimental nephrotoxicity. Renal injury was assessed by measuring serum creatinine, blood urea nitrogen (BUN), and the kidney's relative weight. Oxidative stress was measured by means of enzymatic activities of superoxide dismutase and glutathione peroxidase in the rats' blood and malondialdehyde levels in rats' urine. Results. In our study, we found that curcumin sensitizes LMS cells to cisplatin by enhancing apoptosis and impairing mitochondrial function. In an in vivo model of cisplatin-induced experimental nephrotoxicity, intraperitoneal administration of curcumin failed to preserve blood's antioxidant enzyme activity and decrease lipid peroxidation. Nevertheless, curcumin was able to protect nephrons' histology from cisplatin's toxic effect. Conclusion. Our results showed that curcumin can act as chemosensitizer, but its role as an adjunctive cisplatin-induced oxidative stress inhibitor requires further dose-finding studies to maximize the effectiveness of chemotherapy.

Effects of α-Lipoic Acid, Carnosine, and Thiamine Supplementation in Obese Patients with Type 2 Diabetes Mellitus: A Randomized, Double-Blind Study

Type 2 diabetes mellitus (T2DM) is evolving to an epidemic of the modern world. T2DM is associated with a number of pathological complications, including cardiovascular disease that is mostly promoted by the increased oxidative stress in type 2 diabetic patients. We performed a randomized double-blind placebo-controlled trial to investigate the effectiveness of an individualized oral supplementation with α-lipoic acid (ALA), carnosine, and thiamine. For that purpose, 82 obese type 2 diabetic patients were randomly assigned to 2 groups, and were either supplemented daily with 7 mg ALA/kg body weight, 6 mg carnosine/kg body weight, and 1 mg thiamine/kg body weight or placebo for 8 weeks. An array of biochemical tests including the estimation of oxidative stress and platelet aggregation were performed at baseline and at follow-up. Moreover, the antiplatelet activity of each of the supplement's components was determined ex vivo at human and washed rabbit platelets. Glucose and HbA_1c levels were significantly reduced after supplementation (135.7 ± 19.5 mg/dL vs. 126.5 ± 16.8 mg/dL and 8.3% ± 0.3% vs. 6.03% ± 0.58%, respectively, P < .05); however, insulin was significantly increased (3.6 ± 0.7 μIU/mL vs. 6.8 ± 0.2 μIU/mL, P < .05). The patients treated with the supplement recorded higher follow-up values for HOMA-IR and HOMA-β, and a significant drop in serum hydroperoxide level. Only ALA inhibited platelets aggregation ex vivo through ADP, platelet activating factor, arachidonic acid, epinephrine, collagen, and thrombin pathways. Daily supplementation with an individualized ALA, carnosine, and thiamine supplement effectively reduced glucose concentration in type 2 diabetic patients, probably by increasing insulin production from the pancreas. In addition to that, the reduction of oxidative stress and inhibition of platelet aggregation could potentially provide greater cardiovascular protection. Further studies are needed to fine-tune the supplementation dose-response effects in T2DM patients.

Correlation of bioelectrical impedance analysis phase angle with changes in oxidative stress on end-stage renal disease patients, before, during, and after dialysis

Chronic kidney disease is a condition that promotes oxidative stress. There are conflicting evidence about the role of hemodialysis on oxidative stress, that are mostly related with the various types of membrane materials used, the quality and type of dialysate, the method used, etc. The phase angle (PhA), which is determined with bioelectrical impedance analysis (BIA), measures the functionality of cell membranes. In this study, the correlation of the PhA with parameters of oxidative stress is attempted for the first time. We evaluated parameters of oxidative status as total antioxidant capacity (TAC) in erythrocytes (RBCs) and plasma of patients with ESRD undergoing hemodialysis with low flux synthetic polysulfone membranes. Measurements were recorded from 30 patients (16 men and 14 women) aged 64 ± 14 years before, during, and after dialysis, and in 15 healthy volunteers aged 56 ± 12 years The PhA was obtained by BIA. The plasma TAC increased significantly (41%, p < 0.05). Intracellular TAC noted a non-significant increase. Total antioxidant capacity of the patients before and after hemodialysis was significantly lower from the healthy volunteers (p < 0.05) showing that ESRD patients are at the state of increased oxidative stress. The PhA increased in significantly positive correlation with plasma TAC at the end of hemodialysis. The process of hemodialysis with biocompatible synthetic membranes and bicarbonate dialysate improved plasma TAC. The positive correlation of PhA with extracellular TAC could evolve to a method of oxidative stress estimation by BIA but further research is needed.

A simple procedure for estimation of total body surface area and determination of a new value of Meeh's constant in rats

Precise calculation of total body surface area (TBSA) or premarked surface areas (P-MSAs) is of great importance in many biomedical applications. The aim of the paper was to present a simple procedure of measurement of P-MSAs in small animals and to determine a more accurate Meeh's constant (k), for a commonly used weight range of laboratory rats. A series of 30 Wistar rats, weighing 195-240 g, were anaesthetized and weighted. The TBSA of each animal was measured using a clear pocket and a planimeter. The data obtained were entered into the Meeh's formula (TBSA = kW(2/3)), the most commonly used for small experimental animals, so that a k value for each animal as well as a mean k value (9.83) were obtained. The TBSA of the animals was also calculated using the aforementioned mean k value and compared with that obtained using k values reported in previous studies. According to our findings, the new mean k value, determined with the use of our procedure of surface area measurement, ensured greater accuracy in the determination of the TBSA of experimental rats of a specific weight range. We also suggest a new procedure of surface area measurement which is easy, accurate and does not require animal sacrifice.

Intra-peritoneal application of catechins and EGCG as in vivo inhibitors of ozone-induced oxidative stress

Oxidative stress is considered as a prominent feature of many acute and chronic diseases as well as of the normal aging process. We examined the effects of intra-peritoneal administration of catechins and EGCG as in vivo inhibitors of oxidative stress induced by ozone administration in two groups of Wistar rats. The first group was treated by intra-peritoneal administration of catechins and EGCG after the administration of ozone and the second group was pretreated by intra-peritoneal administration of catechins and EGCG prior to ozone administration. We determined in blood the activity of the enzymes superoxide dismutase and glutathione peroxidase, total antioxidant capacity, levels of copper and zinc and in urine malonaldehyde contents. Ozone administration resulted in significant reduction of glutathione peroxidase activity, plasma zinc levels and plasma and Red Blood Cells antioxidant capacity. Catechins and EGCG upregulate superoxide dismutase activity and maintain plasma and Red Blood Cells antioxidant capacity. Malonaldehyde levels at the end of the study were significantly increased only in the first group. Our data demonstrate that treatment with catechins and EGCG cannot reverse or prevent the effects of oxidative stress although some modulation occurs.

Anticancer and cytotoxic effects of a triorganotin compound with 2-mercapto-nicotinic acid in malignant cell lines and tumor bearing Wistar rats

Nowadays, investigation for possible therapeutic applications of various metal-based drugs attracts the scientific interest worldwide. The triorganotin compound bis[triphenyltin(IV)](3-carboxy-pyridine-2-thionato) (SnMNA), was tested for its anti-proliferative and antitumor activities. Cytotoxic activity was assessed by Trypan blue and 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide assay (MTT). SnMNA exhibited potent cytotoxic effects against leiomyosarcoma cells (LMS) and human breast adenocarcinoma cells (MCF-7), which is 200 times stronger than that of cisplatin. Moreover, SnMNA induced significant apoptosis in LMS and MCF-7 cells characterized by flow cytometry analysis and DNA fragmentation. Acute and chronic toxicity studies on Wistar rats caused kidney and lung toxicity at a single dose of 80mg/kgBody Weight (BW) or four repeated doses of 8mg/kgBW once per week. Furthermore, antitumor activity studies on sarcoma bearing Wistar rats revealed that SnMNA complex at four repeated doses of 5.4mg/kgBW every three days prolonged mean survival time of the animal at 200% and decreased mean tumor growth rate (MTGR) compared to the control group (p<0.05). It is noteworthy to mention that the 30% (3 out of 10) of the bearing animals were totally cured. These findings indicate that SnMNA might be a promising new antitumor agent.

Changes in copper and zinc plasma concentrations during the normal menstrual cycle in women

OBJECTIVE

To investigate whether there is a fluctuation of the copper and zinc plasma levels during the menstrual cycle and if this correlates to the physiological fluctuations of estradiol and progesterone plasma concentrations in eumenorrhoic women.

METHODS

We studied 14 eumenorrhoic women. Copper (Cu), zinc (Zn), estradiol (E2) and progesterone (Prg) plasma concentrations, during time of menstruation (time 1), midfollicular phase (time 2), time of ovulation (time 3) and midluteal phase (time 4) were determined.

RESULTS

We observed significant changes in both copper plasma concentrations and zinc plasma concentrations during the four times studied (p < 0.05). The changes of Cu during the various phases correlated negatively with the changes in E2 (r > 0.5, p < 0.05), whereas the changes of Zn correlated positively with those of E2 (r > 0.8, p < 0.05). We were unable to demonstrate any statistically significant correlation between Cu and Prg or Zn and Prg.

CONCLUSIONS

This study indicates that there is a cyclic fluctuation of Cu and Zn concentrations in plasma during the menstrual cycle, in healthy eumenorrhoic women. This cyclic fluctuation might be due to the cyclic fluctuation of plasma levels of E2.

Anticancer effects on leiomyosarcoma-bearing Wistar rats after electromagnetic radiation of resonant radiofrequencies

In the present study, the effects of a resonant low intensity static electromagnetic field (EMF), causing no thermal effects, on Wistar rats have been investigated. Sarcoma cell lines were isolated from leiomyosarcoma tumors induced in Wistar rats by the subcutaneous (s.c) injection of 3,4-benzopyrene. Furthermore, smooth muscle cells (SMC) were isolated from the aorta of Wistar rats and cultivated. Either leiomyosarcoma cells (LSC) or SMC were used to record a number of characteristic resonant radiofrequencies, in order to determine the specific electromagnetic fingerprint spectrum for each cell line. These spectra were used to compose an appropriate algorithm, which transforms the recorded radiofrequencies to emitted ones. The isolated LSC were cultured and then exposed to a resonant low intensity radiofrequency EMF (RF-EMF), at frequencies between 10 kHz to 120 kHz of the radiowave spectrum. The exposure lasted 45 consecutive minutes daily, for two consecutive days. Three months old female Wistar rats were inoculated with exposed and non-exposed to EMF LSC (4 x 10(6) LCS for animal). Inoculated with non-exposed to EMF cells animals were then randomly separated into three Groups. The first Group was sham exposed to the resonant EMF (control Group-CG), the second Group after the inoculation of LSC and appearance of a palpable tumor mass, was exposed to a non-resonant EMF radiation pattern, for 5 h per day till death of all animals (experimental control Group-ECG). The third Group of animals after inoculation of LSC and the appearance of a palpable tumor mass, was exposed to the resonant EMF radiation for 5 h per day, for a maximum of 60 days (experimental Group-I, EG-I). A fourth Group of animals was inoculated with LSC exposed to EMF irradiation and were not further exposed to irradiation (experimental Group-II, EG-II). Tumor induction was 100% in all Groups studied and all tumors were histologically identified as leiomyosarcomas. In the case of the EG-I, a number of tumors were completely regretted (final tumor induction: 66%). Both Groups of animals inoculated with exposed or non-exposed to the EMF LSC, (EG-I and EG-II, respectively) demonstrated a significant prolongation of the survival time and a lower tumor growth rate, in comparison to the control Group (CG) and the experimental control Group (ECG). However, the survival time of EG-I animals was found to be significantly longer and tumor growth rate significantly lower compared to EG-II animals. In conclusion, our results indicate a specific anticancer effect of resonant EMF irradiation. These results may possibly be attributed to (a) the duration of exposure of LSC and (b) the exposure of the entire animal to this irradiation.

Effects of low intensity static electromagnetic radiofrequency fields on leiomyosarcoma and smooth muscle cell lines

In this study we investigated the effects of low intensity static radiofrequency electromagnetic field (EMF) causing no thermal effects, on leiomyosarcoma cells (LSC), isolated from tumors of fifteen Wistar rats induced via a 3,4-benzopyrene injection. Electromagnetic resonance frequencies measurements and exposure of cells to static EMF were performed by a device called multi channel dynamic exciter 100 V1 (MCDE). The LSC were exposed to electromagnetic resonance radiofrequencies (ERF) between 10 kHz to 120 kHz, for 45 min. During a 24h period, after the exposure of the LSC to ERF, there was no inhibition of cells proliferation. In contrast, at the end of a 48 h incubation period, LSC proliferation dramatically decreased by more than 98% (P<0.001). At that time, the survived LSC were only 2% of the total cell population exposed to ERF, and under the same culture conditions showed significant decrease of proliferation. These cells were exposed once again to ERF for 45 min (totally 4 sessions of exposure, of 45 min duration each) and tested using a flow cytometer. Experiments as above were repeated five times. It was found that 45% of these double exposed to ERF, LSC (EMF cells) were apoptotic and only a small percentage 2%, underwent mitosis. In order to determinate their metastatic potential, these EMF cells were also counted and tested by an aggregometer for their ability to aggregate platelets and found to maintain this ability., since they showed no difference in platelet aggregation ability compared to the LSC not exposed to ERF (control cells). In conclusion, exposure of LSC to specific ERF, decreases their proliferation rate and induces cell apoptosis. Also, the LSC that survived after exposed to ERF, had a lower proliferation rate compared to the LSC controls (P<0.05) but did not loose their potential for metastases (platelet aggregation ability). The non-malignant SMC were not affected by the EMF exposure (P<0.4). The specific ERF generated from the MCDE electronic device, used in this study, is safe for humans and animals, according to the international safety standards.

Anticarcinogenic and antiplatelet effects of carvacrol

AIM

To investigate the effect of carvacrol on chemical carcinogenesis, cancer cell proliferation and platelet aggregation, and to find possible correlation between all these processes and the antioxidant properties of carvacrol.

MATERIALS AND METHODS

3,4-benzopyrene-induced carcinogenesis model using Wistar rats was used. Leiomyosarcoma cells from Wistar rats were used to study carvacrol antiproliferative activity in vitro. The carvacrol antiplatelet properties were investigated with platelet aggregation assay and flow cytometry technique. The production of thromboxane B2, final metabolite of platelet aggregation, was evaluated by radioimmunoassay.

RESULTS

Our study revealed significant anticarcinogenic properties of carvacrol. We observed 30% decrease of 3,4 benzopyrene carcinogenic activity in vivo. Antiproliferative activity of carvacrol (IC(50)) was 90 microM and 67 microM for 24 h and 48 h of incubation of cells, respectively. Carvacrol possessed also mild antiplatelet effect, inducing the decrease of thromboxane A2 production in platelets and as a result - restrictive expression of the GPIIb/IIIa platelet receptor.

CONCLUSION

Our data demonstrated that carvacrol possesses anticarcinogenic, antiproliferative and antiplatelet properties.

Antioxidant protection during the menstrual cycle: the effects of estradiol on ascorbic–dehydroascorbic acid plasma levels and total antioxidant plasma status in eumenorrhoic women during the menstrual cycle

BACKGROUND

Estrogens, apart from their classic role as steroid hormones, also possess significant antioxidant properties. The present study was undertaken to assess the antioxidant potential of the female during the various menstrual phases and to investigate the correlation between ascorbic acid, dehydroascorbic acid plasma levels, total antioxidant plasma status, and estradiol levels.

DESIGN AND METHODS

Thirteen eumenorrhoic women were studied. Ascorbic acid and dehydroascorbic acid plasma levels, total antioxidant plasma status, estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone during time of menstruation, midfollicular phase, time of ovulation, and midluteal phase were determined. Ascorbic-dehydroascorbic acid ratio was also calculated.

RESULTS

A progressive significant rise in ascorbic acid plasma levels (p < 0.01), ascorbic-dehydroascorbic acid ratio (p < 0.001), and total antioxidant plasma status (p < 0.05) from menstruation to ovulation was observed. Moreover, a significant decrease in dehydroascorbic acid was found at the same phases (p < 0.05). Changes of estradiol levels during the menstrual cycle correlated positively with the changes of ascorbic acid levels and total antioxidant plasma status (p < 0.05). Furthermore, estradiol levels correlated positively with ascorbic acid levels (p < 0.05, r < 0.5), ascorbic-dehydroascorbic acid ratio (p < 0.05, r < 0.5), and total antioxidant plasma status (p < 0.05, r < 0.8) in all menstrual phases.

CONCLUSIONS

An elevated antioxidant protection during ovulation and the midluteal phase appears to be present in eumenorrhoic women. Moreover we observed a cyclic variation in the antioxidant parameters we assayed in the females in the present study, which could be due to cyclic changes in estradiol levels.

Effects of cigarette smoking on the antioxidant defence in young healthy male volunteers

Cigarette smoking induces a significant oxidant effect related to variety of free radical-related diseases often affecting the upper respiratory tract, unless it is effectively compensated by the antioxidant barriers of the humans. In the present study, the evaluation of the antioxidant compensatory mechanisms, by estimating the antioxidant capacity of extracellular defence (saliva and plasma) and the intracellular resistance of peripheral lymphocytes to oxidative stress in young healthy smokers, was investigated. Twenty young healthy male smokers and 20 age-matched non-smokers with similar dietary profiles were enrolled in the study. Total saliva and plasma samples were collected from both groups, and total antioxidant capacity (TAC) and lag time were estimated. The latter was also repeated in smokers just after a cigarette smoking. Peripheral lymphocytes isolated from the subjects of both groups were also tested for their inherent DNA damage as well as for their ability to resist H2O2-induced DNA damage by using the comet assay. TAC of plasma was found significantly higher in smokers compared to non-smokers (p <0.004), whereas no difference was recorded in plasma lag time values. Lymphocytes of smokers manifested a significantly decreased oxidant resistance (increased DNA fragmentation) to H2O2, in comparison to non-smokers. Our results indicate that young smokers do not manifest different salivary antioxidant defence than non-smokers. They exhibit, however, a higher plasma antioxidant capacity, but a significantly reduced ability of blood lymphocytes, to resist to H2O2-induced DNA damage.

The role of ascorbic acid, selenium, and glutathione on benzo[a]pyrene-induced carcinogenesis in wistar rats

PURPOSE

The carcinogenic action of polycyclic aromatic hydrocarbons (PAHs) can be inhibited by endogenous or exogenous compounds. This study was designed to elucidate the modifying action of 3 endogenous inhibitors- ascorbic acid (vit C) used alone, and selenium (Se) used in combination with glutathione (GSH).

MATERIALS AND METHODS

Chemical carcinogenesis was induced by benzo[a]pyrene(BaP). A hundred wistar rats were divided into 3 groups: the first group (G I) consisted of 42 animals, representing the control group. The two experimental groups (G II and G III) consisted of 38 and 20 rats, respectively. All groups were injected with BaP(10.08 mg subcutaneously-s.c). The first experimental G II was given only vit C (520 mg in 2% sugar solution per os - p.o.). The second experimental G III was given Se (0.1 mg p.o.) with GSH (200 mg p.o.). Tumor incidence and mean survival time were determined. Histological examination of the developed and excised tumors took place following death. The carcinogenic potency (CP) and anticarcinogenic potency (AP) of the substances used were calculated.

RESULTS

A statistically significant difference regarding the mean survival time in the two experimental groups (238.4-/+31 days and 344.9-/+48 days, respectively) compared to the control group (183.8-/+28 days) was found (p < 0.001). The CP of each of the 3 groups was 54.3, 41.2, and 28.9 units, respectively. The AP of vit C used alone was 13.1 units, representing a significant anticarcinogenic effect. The combination of Se + GSH showed an AP of 25.4 units, resulting in a significant prolongation of the mean survival time, which is considered a potent anticarcinogenic effect. Furthermore, a statistically significant difference was found also when the mean survival time of G III animals was compared with G II.

CONCLUSION

Vit C on its own and Se in combination with GSH represent strong endogenous inhibitors that can inhibit/reduce the carcinogenic action of BaP-induced carcinogenesis in wistar rats. The combination therapy used offered better in vivo results.

Effects of Cupressus sempervirens cone extract on lipid parameters in Wistar rats

BACKGROUND

Lipid-lowering drugs have been developed to treat hyperlipidemia, but they are expensive, while serious side-effects may occasionally occur. In Albania, a hydroalcoholic extract of the cones of Cupressus sempervirens is used to treat a variety of disorders, including hyperlipidemia. The purpose of our study was to assess the effects of Cupressus sempervirens cone extract (CSE) on the lipid profile of Wistar rats.

MATERIALS AND METHODS

The animals were divided into two groups. Group I (30 animals) served as a control group. Serum lipid parameters, muscle and liver enzymes, red and white blood count, platelets, and serum concentrations of uric acid and creatinine were determined at baseline and at weeks 6, 12, 18 and 24 of the study.

RESULTS

The oral administration of the extract resulted in a substantial decrease of serum total cholesterol, which was significant even after 6 weeks of treatment. Moreover, these animals exhibited lower total cholesterol levels compared to the controls after the initiation of treatment (p < 0.001) during the study period. The administration of the extract led to a substantial reduction in serum triglycerides (p < 0.05) in Group I, comparing 0 week to 6-24 weeks. However no significant differences in triglyceride levels were observed between CSE animals (Group I) and controls (Group II) during the entire study period. No significant changes in HDL-cholesterol in the other parameters occurred in either group.

CONCLUSION

The administration of CSE has an important lipid-lowering effect in Wistar rats.

Inhibition of benzo(a)pyrene-induced carcinogenesis by vitamin C alone and by vitamin C/vitamin E and selenium/glutathione

The reduction on peroxidation caused by benzopyrenes by some naturally occurring antineoplastic agents was studied in this experimental work. Inhibition/reduction of experimental carcinogenesis induced by benzo(a)pyrene by vitamin C alone and by vitamin C/vitamin E and selenium/ glutathione was attempted in 224 female Wistar rats divided in four groups. Injected with 10.08 mL benzo(a)pyrene, the animals were treated with some naturally occurring substances like vitamin C alone and a combination of anticarcinogens. By calculating the carcinogenic potency of benzo(a)pyrene and the anticarcinogenic potency of substances used as well as histological examination of developed tumors and survival time of treated animals, it was found that vitamin C exerts a significant anticarcinogenic effect of 8.3 units and that the combination of the two anticarcinogens used produced a significant prolongation of the animals survival time with anticarcinogenic potency of 22.1 and 22.2 units, respectively. This is considered a potent anticarcinogenic effect. The question of an additional supportive administration of such agents complementary to the conventional cancer chemotherapy in humans is raised. Of course, further studies are needed.

Antitumour and toxic effects on Wistar rats of two new platinum complexes

BACKGROUND

Cancer chemotherapy in humans based on metal complexes started at the clinical level in the late 1970s with the use of cisplatin, which forms intra-strand cross-links with DNA.

METHODS

Two new platinum complexes of cis-geometry with the amino acids inosine (ino) and l-alanine (ala), Pt(ino)2Cl2 and cis-[Pt(NH3)2(ala)](NO3), respectively, were synthesized and pure samples were obtained by means of flash chromatography. These complexes were tested on benzo(a)pyrene-induced tumours in Wistar rats to detect their antitumour and toxic effects.

RESULTS

There was a statistically significant prolongation of the mean survival time of the animals in the two groups tested (272 +/- 18 days and 246 +/- 26 days, respectively) compared to the control group (195 +/- 22 days) (P < 0.001). Toxic effects included a decrease in leucocyte cell count, mild haemolysis, mild haematuria, mild hepatotoxicity, elevated body temperature and hair loss. All of these effects were reversible after drug discontinuation.

CONCLUSIONS

The two new platinum complexes described here appear to have an effective antitumour activity without severe toxicity when tested on Wistar rats.

Antiproliferative and anticarcinogenic effects of an aqueous preparation of Abies alba and Viscum album se abies, on a L-1210 malignant cell line and tumor-bearing Wistar rats

Extracts of plants have been widely tested for possible anticarcinogenic properties. In the present study a traditional remedy, consisting of an aqueous extract of mixed parts of the tree Abies alba and its mistletoe Viscum album se abies was tested on benzo(alpha)pyrene(BaP)-induced tumors in Wistar rats and on the L-1210 malignant cell line. Two main groups of male Wistar rats subcutaneously injected by 10 mg of BaP, a dose inducing 100% carcinogenesis, a control group (C-G, 15 rats) and a treatment group(TR-G, 18 rats), were used for the study. Five animals bearing BaP-induced tumors were also tested (TR-1-G). Animals of the TR-G were orally administered with the aqueous extract at doses of 50 ml/kg b.w, from the day of BaP injection and of the TR-1-G, from the 120th day of injection, till death. L-1210 malignant cells in cultivation, were administered with a powder obtained by condensation and lyophilization of the extract, at various concentrations and cytotoxicity was measured by the microculture tetrazolium assay. Autopsy of the rats, revealed metastasis in the lungs of the animals of all groups and the tumors developed were histologically identified as leiomyosarcomas. The results indicated that the extract of the above plants possess anticarcinogenic effects, documented by: a) its antiproliferative effects on L-1210 cells (IC50 = 49.6 +/- 1.4 micrograms/ml), b) the significant prolongation of life and reduction of tumor growth rate of the animals of the TR-G in comparison to the C-G, c) the inhibition by 16.6% of tumor induction in the TR-G and d) the prolongation of life and the necrotic effects of the extract on the tumors of the animals in the TR-1-G. The antiproliferative effects of the Abies alba and Viscum album se abies extract may be due to the lectins and thionins contained in Viscum album, as well as to the monoterpenes contained in Abies alba. Soft tissue tumors sensitive to the extract, are widespread among human organs, even in larynx, and are usually resistant to chemotherapy.

Beneficial effects of a vanadium complex with cysteine, administered at low doses on benzo(alpha)pyrene-induced leiomyosarcomas in Wistar rats

BACKGROUND

Vanadium is a potent environmental and body metal, possessing remarkable antitumor and antidiabetic properties. Vanadium salts and complexes have been widely investigated for their anticarcinogenic properties in experimental carcinogenesis. In the present study the antitumor effects of a new vanadium complex with cysteine in relation to identical doses of vanadyl sulfate and cysteine, in tumor bearing rats are investigated.

MATERIALS AND METHODS

Male wistar rats were injected with benzo(alpha)pyrene and divided into four groups of 21 rats each. Control group was treated only with BaP. The first group(TR-1) was treated by vanadyl sulfate per os at daily doses of 0.5 mg of V/kg b.w per day. The second (TR-2) by cysteine at doses of 4.5 mg/kg b.w per day and the third group (TR-3), by the complex V(III)-cysteine at daily doses of V 0.5 mg/kg b.w (containing cysteine at concentrations of 4.5 mg/b.w). Treatment was started when tumors were developed (evidenced from a palbable mass at the site of Bap injection) and went on till death. Toxicological tests were performed in 27 rats divided into a control group and two test groups; T-1 administered with vanadyl sulfate at daily doses of 18.5 mg V/kg b.w and T-2 group with V(III)-cysteine complex at daily doses of 18.5 V/kg b.w, for 9 weeks. Mean survival time, death rate, tumor growth rate, the carcinogenic potency of BaP, and the anticarcinogenic potency in relation to histological findings in each treatment group were calculated in each group in order to evaluate the antitumor effects of the substances used.

RESULTS

Vanadyl sulfate, cysteine and V(III)-cysteine exerted antitumor effects on leiomyosarcoma bearing Wistar rats. However, V(III)-complex exerted much more potent effects than the other treatments, significantly prolonging mean survival time, retarding tumor growth rate and decreasing the carcinogenic potency of BaP in the TR-3 group, in comparison to the control and the TR-1 and TR-2 groups. Moreover V(III)-cysteine complex resulted in complete remission of 4 (19.7%) of the tumor bearing rats. Blood, urine, biochemical routine tests as well as autopsy did not reveal any toxic effects either of vanadyl sulafate or V(III)-cysteine complex.

CONCLUSIONS

Vanadyl sulfate, cysteine and V(III)-cysteine complex exerted antitumor effects in tumor bearing rats. The V(III)-cysteine complex, however, exerts much more potent effects, as evident from the results of the present study. These beneficial effects of the above complex, in combination with its low toxicity provide evidence suggest its possible application in the treatment of human malignant diseases.

Comparison of the therapeutic effects of two vanadium complexes administered at low dose on benzo[a]pyrene-induced malignant tumors in rats

The antitumor effects of low dose administration of the vanadium(III) complexes with L-cysteine (complex 1) and N-(2-mercaptopropionyl)-glycine (complex 2) were compared on benzo[a]pyrene (BaP)-induced tumors in Wistar rats. Male Wistar rats, injected with 10.0 mg of BaP, were divided into one control (C-G) and two treatment (TR-G) groups of 17 animals each. Animals of the first treatment group were administered complex 2 (TR-2 group) and those of the second group were administered complex 1 (TR-1 group) at doses of 100 microg of vanadium per os daily, starting from the day a palpable tumor was developed till their death. BaP injection induced a 100% tumor (leiomyosarcomas) development in the animals of all groups. Administration of complex 1 to the animals resulted in a significant prolongation of the mean survival time, a complete remission of 17.6% of the tumors developed, a significant reduction of the carcinogenic potency (CP) of BaP and of the tumor growth rate (TGR) in TR-1 group animals, compared to the control and the TR-2 group. In marked contrast, complex 2 failed at the doses administered to exert any significant modulation of the above mentioned parameters. Results indicate that at low (100 micro/day) concentrations of vanadium, complex 1 exerts a significant anticarcinogenic effect on experimentally-induced leiomyosarcomas in rats, whereas complex 2 has no effect when administered at the same low concentrations of vanadium.

Dose-related preventive and therapeutic effects of antioxidants-anticarcinogens on experimentally induced malignant tumors in Wistar rats

A combination of antioxidants-anticarcinogens, consisting of vitamins C and E, selenium and 2-mercaptopropionyl glycine (2-MPG), was administered orally for the prevention (PRG) and treatment (TRG) of benzo(a)pyrene (BaP)-induced malignant tumors (leiomyosarcomas), in Wistar rats. In order to evaluate dose-related effects, a low dose vitamin (0.15 g/kg b.w. per day of vit.C and 0.05 g/kg b.w. per day of vit.E) and a high dose (1.5 g/kg b.w. per day of vit.C and 0.5 g/kg b.w. per day of vit.E) combination was administered, in prevention and treatment groups. Selenium was administered in doses of 2 microg/kg b.w. per day and 2-MPG in 15 mg/kg b.w. per day, in all groups. Daily estimations of 24 h urine volume levels of thiobarbituric acid reacting substances (MDA) were performed in 20 animals, divided into a control group, a BaP-injected group, a tricapryline-injected group and a BaP-injected and treated by the low dose combination group. Results revealed that the low dose combination failed to exert any beneficial effect on mean survival time of animals treated either preventitively or therapeutically. An increased number of animals bearing a second (lung) tumor was, in addition, found in autopsy and histological examination in the low dose combination (PRG and TRG) and the high dose TRG groups. The high dose combination groups manifested a significant prolongation of the mean survival time of animals; complete remission of tumors developed in 16.8% of the animals in the treatment group and a 5.2% prevention of tumor formation in the preventive group, without any evidence of an increased number of double tumor formation in the PRG group. Urine MDA increased significantly in animals injected by BaP during the first 10 days and since the 90th day (formation of palpable tumors) after injection, in relation to control and tricapryline-injected groups. Complete prevention of urine MDA-increased values was obtained in BaP-injected and treated by the low dose combination animals. Results indicate that high doses (megadoses) of the antioxidant-anticarcinogen vitamins C and E in combination with carefully selected other antioxidants possessing supplementary actions, are probably needed in order to achieve a sufficient prevention and treatment of malignant diseases.

Enhancement of the antineoplastic effect of anticarcinogens on benzo[a]pyrene-treated Wistar rats, in relation to their number and biological activity

Naturally occurring anticarcinogens, such as vitamins C and E, and the microelement selenium were found to inhibit the induction of benzo[a]pyrene-induced malignant tumors in Wistar rats to various extends. The antineoplastic effect of the tested anticarcinogens is gradually increased according to the number of inhibitors selected. To date the maximum action against malignancy is manifested by use of the above three inhibitors. In the group of rats receiving vitamins C, E and selenium, the prolongation of life induced by adding more than one anticarcinogen to the treatment regime reached, and in some cases surpassed, the normal life expectancy of the rats. It is expected that by adding even more anticarcinogens, the antineoplastic potency (Ap) of the inhibitors will be further improved. These results encouraged us to conduct a clinical trial in terminal human cancer cases, in conjunction with the usual treatments of surgery or chemotherapy and irradiation.

Trimetazidine for prevention of hepatic injury induced by ischaemia and reperfusion in rats

OBJECTIVE

To assess the effect of trimetazidine (an anti-anginal drug that acts as a scavenger of oxygen free radicals) in the protection of hepatocytes after a 90 minute period of warm ischaemia followed by reperfusion in rats.

DESIGN

Prospective study.

MATERIAL

80 Wistar rats.

INTERVENTIONS

20 Rats were given a single dose of trimetazidine 2.5 mg/kg intravenously 30 minutes before the induction of ischaemia; 20 received the same dose intraperitoneally twice a day for five days before the experiment and one dose intravenously 30 minutes before; 20 were given a single dose of 2.5 mg/kg intravenously after reperfusion had been started; and 20 acted as controls. All rats underwent liver biopsy through a laparotomy incision on postoperative days 2, 7, and 21, and the activities of liver enzymes in their blood were measured before induction of ischaemia and two, seven, 14, and 21 days afterwards.

OUTCOME MEASURES

Histological changes and serum enzyme activities.

RESULTS

The amount of centrilobular necrosis of hepatocytes, and the activity of hepatic enzymes were greatest on day 2, as was the reduction in superoxide dismutase activity in the erythrocytes. A single dose of trimetazidine, whether given before or after the ischaemic episode, gave significant protection to hepatocytes, but pretreatment for five days was even more effective.

CONCLUSION

Trimetazidine protected rats' livers from injury after a period of warm ischaemia and reperfusion.