The effect of ß-carotene against adriamycin toxicity on the embryo formation.

UNLABELLED: Adriamycin is an anthracycline antibiotic widely used for the treatment of many types of cancer. The cytotoxic effect of Adriamycin occurs by a free radical-mediated mechanism. Thus, to prevent or reduce the toxic effect of Adriamycin, it is possible to use it in combination with antioxidants. The aim of this study was to evaluate a potential effect of ß-carotene against Adriamycin-induced toxicity on the embryo formation. MATERIALS AND METHODS: Pregnant rats were treated with Adriamycin, ß-carotene, and their combination during the critical stages of embryogenesis. The first group was control group. Adriamycin was administered on day 9 (group 2a) and day 12 (group 2b) of gestation by a single intraperitoneal injection at a dose of 5 mg/kg. ß-Carotene was given at a dosage of 0.6 mg/(kg·day) from day 6 to 10 or from day 9 (group 3a) to 13 (group 3b) of gestation 5 times per os; in the case of their combination, ß-carotene was given per os 3 times before Adriamycin injection, one time simultaneously with Adriamycin and one time after its injection (groups 4a and 4b). Animals were euthanized on day 21 of gestation. Embryo resorptions and alive fetuses were counted, weighed, and measured. The embryos of each litter were examined macroscopically after the Buen solution fixation for the embryo defects. In order to render the skeleton visible, the soft tissues were macerated using caustic soda, stained with alizarin red, and cleared with glycerin. RESULTS: Adriamycin induced embryotoxicity; the combination of Adriamycin and ß-carotene decreased the number of Adriamycin-induced embryo resorptions about two times. A gavage with Adriamycin alone decreased fetal body weights (P<0.05), while giving it in combination, the fetal body weight was similar to that in the control group. Adriamycin induced the retardation of skeletogenesis and external fetal malformations (microphthalmia, hydrocephaly, anencephaly, and others). After an exposure to ß-carotene, external malformations (diaphragmatic hernia) of embryos were found only occasionally. ß-Carotene in combination with Adriamycin produced no positive effect on Adriamycin-induced skeletodysgenesis or external malformations. CONCLUSIONS: Antioxidant ß-carotene in combination with Adriamycin slightly reduced the Adriamycin-induced embryotoxicity, but produced no positive effect on Adriamycin-induced skeleto-dysgenesis or external malformations.

Potentiating effect of beta-glucans on photodynamic therapy of implanted cancer cells in mice.

Photodynamic therapy (PDT) combines a drug or photosensitizer with a specific type of light to kill cancer cells. The cellular damage induced by PDT leads to activation of the DNA damage repair, which is an important factor for modulating tumor sensitivity to this treatment. beta-Glucans are natural polysaccharides that bind complement receptor 3 on the effector cells, thereby activating them to kill tumor cells during PDT. The hypothesis of the present study was that adjuvant therapy with beta-glucans would increase the efficacy of PDT. C57BL/6 female mice were subcutaneously implanted with Lewis lung carcinoma cells. Ten days after implantation, the mice were administered intravenously sodium porfimer (10 mg/kg) 24 h prior to laser irradiation, with or without oral administration of beta-glucan (400 microg/d/mouse, 5 days) from either barley, baker's yeast, or marine brown algae that contains the storage glucan, laminarin. Tumor volume and necrotic area in excised tumors were measured. The expression of proliferating cell nuclear antigen (PCNA) was determined as an indicator of the activity of the DNA damage repair system. PDT in combination with each beta-glucan significantly reduced tumor growth (P < 0.05, n = 10) and expression of PCNA (P < 0.001, n = 9), and increased necrosis in tumor tissues (P < 0.001, n = 9). Furthermore, each structurally different

Cisplatin increases urinary sodium excretion in rats: gender-related differences.

OBJECTIVE. There are well-documented reports of cisplatin-associated hyponatremia in the literature, but there are no data on gender-dependent differences. The aim of the present study was to define characteristics of 24-hour urinary sodium excretion in young adult Wistar rats of both genders and to evaluate the gender-related effect of cisplatin. MATERIALS AND METHODS. Twelve control Wistar rats (6 males and 6 females) and 12 cisplatin-treated Wistar rats (6 males and 6 females) after a single and repeated injection of cisplatin (once a day for 3 days) at a dose of 2.5 mg/kg body weight into the caudal vein were examined. The experiment was carried out by measuring 24-h urinary sodium, potassium, chloride, magnesium, creatinine excretion and pH in the urine of age-matched male and female rats. RESULTS. The 24-h urinary sodium excretion, sodium/chloride ratio, and diuresis showed no gender-related differences in control rats. After a single administration of 2.5 mg/kg cisplatin, 24-h urinary sodium excretion was not significantly higher in cisplatin-treated rats than in gender-matched controls. After repeated cisplatin administration, 24-h urinary sodium excretion was significantly higher in cisplatin-treated male rats as compared to matched controls (P<0.05). No such effect was found in cisplatin-treated female rats. CONCLUSION. The study data show that cisplatin enhances urinary sodium excretion in male but not in female rats. The mechanism of such a gender-related effect is not yet clear. Further investigations are necessary to elucidate the mechanism of this pharmacological effect of cisplatin.

mTHPC-mediated photodynamic treatment of Lewis lung carcinoma in vitro and in vivo.

BACKGROUND AND OBJECTIVE: The ongoing search for the enhancement of efficacy of photodynamic therapy stimulates the interest in molecular mechanisms of the response to the treatment. Looking for the cell line suitable for investigation of cellular response both in vivo and in vitro, we evaluated phototoxicity of m-tetrakis-(3-hydroxyphenyl)-chlorin (mTHPC) on viability of Lewis lung carcinoma (LLC1) cells in vitro, growth of murine transplantable tumor, and mice survival. MATERIAL AND METHODS: LLC1 cell culture and male C57BL/6 mice bearing Lewis lung carcinoma were used for the experiments. Photodynamic treatment was mediated by m-tetrakis-(3-hydroxyphenyl)-chlorin as a photosensitizer. Light emitting diode array was used for illumination. The effect of the photodynamic treatment was evaluated by comparison of viability of control and treated cells, growth of tumors, and survival of the control and treated mice. RESULTS: In vitro, a cytotoxic dose inducing a reduction in viability of LLC1 cells by 50% was achieved at 60 mJ/cm(2) and approximately 400 ng/mL of the photosensitizer, or 30 mJ/cm(2) and 600 ng/mL of mTHPC. Both the concentration of the photosensitizer and duration of light exposure were significant determinants of cytotoxic effect. In vivo, an injection of 0.25 mg/kg of mTHPC to mice bearing Lewis lung tumor and illumination at 120 J/cm(2) taking place after 24 h significantly inhibited tumor growth and prolonged mice survival. However, the tumors regained their growth potential after 9 days. CONCLUSIONS: Photodynamic treatment mediated by m-tetrakis-(3-hydroxyphenyl)-chlorin had a significant effect on LLC1 cells in vitro and growth of Lewis lung carcinoma in vivo.

Treatment of Lewis lung carcinoma by photodynamic therapy and glucan from barley.

OBJECTIVE: During the photodynamic treatment, complement system is activated and tumor cells are opsonized with iC3b fragment. beta-glucans can enhance cytotoxicity of iC3b-opsonized cells due to their specific interaction with complement receptor 3 (CR3; CD11b/CD18) on the surface of the effector cells. In contrast to microorganisms, tumor cells lack beta-glucan as a surface component and cannot trigger complement receptor 3-dependent cellular cytotoxicity and initiate tumor-killing activity. This mechanism could be induced in the presence of beta-glucans. This study aimed at determining the influence of coadministration of beta-glucan from barley on the efficacy of photodynamic tumor therapy (PDT). MATERIAL AND METHODS: C57 Bl/6 female mice bearing Lewis lung carcinoma were used throughout the study. Mice were randomized into groups (15 in each group) and exposed to the treatment with intravenous Photofrin injection (dose, 10 mg/kg) and after 24 h following laser illumination, or with oral administration of beta-glucan from barley at a dose of 400 microg/mouse per day up to 5 days, or with their combination. Tumor growth dynamics and survival of the treated and untreated mice were monitored. RESULTS: Tumor volume in all treated groups was significantly lower (P<0.001) than that in the control group. The most effective tumor growth suppression (P=0.033) was achieved in mice treated with combination of PDT and beta-glucan from barley as compared with PDT alone. The best survival was achieved in the same group, but difference was not significant as compared to the control group (P=0.143) and to PDT alone group (P=0.319). CONCLUSIONS: The present study demonstrates that coadministration of beta-glucan from barley can enhance efficacy of photodynamic therapy.

[Accumulation of photosensitizer in rat embryos (a spectroscopic study)]. / Fotovaisto pasiskirstymas ziurkes ir embriono audiniuose (spektroskopinis tyrimas).

UNLABELLED: The aim of the present study was to investigate the accumulation of photosensitizer Photofrin II in the different organs as well as the placenta and embryos of pregnant rats and to determine during which stage of embryogenesis the photosensitizer is accumulated the most effectively. MATERIALS AND METHODS: The experiments were carried out on 25 fetuses from 10 Wistar rats (weight 160-240 g). Female rats were mated with male rats in the evening. Vaginal smears were collected from each female rat next morning and were examined by microscope in order to determine the presence of sperm. The day when sperm was detected in the vagina was considered to be pregnancy day 0. Photofrin II (a dose of 5 mg/kg) was administered intravenously to pregnant rats on days 7, 14, 16, 18 and 20 of embryogenesis. Rats were euthanized 24 hours after intravenous injection of Photofrin II and the following organs were taken: brain, spleen, liver, kidneys, lungs, uterus, placenta, and embryos. The accumulation of the photosensitizer was observed in the samples prepared from these parts of body. Fluorescence measurements ex vivo were performed with an S2000-FI fluorescence spectrometer (Ocean Optics Inc., Florida, USA) by exciting the samples with a blue light emitting diode (lambda=400 nm). RESULTS: A comparative study of fluorescence spectra on days 7, 14, 16, 18 and 20 of embryogenesis showed that the most intense accumulation of Photofrin II in the embryo was on day 7, while on the other days of embryogenesis the accumulation of Photofrin II increased obviously in the uterus and placenta. CONCLUSIONS: The obtained data show that the accumulation of Photofrin II in the embryo depended on the stage of embryogenesis as well as on permeability of the placental barrier. Further photodynamic therapy studies are necessary to determine the total effect of Photofrin II on the embryo.