Oxidative stress in blood and testicle of rat following intraperitoneal administration of aluminum and indium.

Aluminum (Al) and indium (In) have embryotoxic, neurotoxic and genotoxic effects, oxidative stress being one of the possible mechanisms involved in their cytotoxicity. We have recently demonstrated that indium intraperitoneal (ip) administration induced histological disorganization of testicular tissue. In the present research we aimed at investigating the effect of Al and In ip administration on systemic and testicular oxidative stress status. Studies were performed on Wistar rats ip injected with Al, In or physiological solution for two weeks. Our results showed that In significantly decreased the absolute weight of testicles. Measurements of lactate dehydrogenase (LDH) and paraoxonase (PON) activities showed that In induced a significant augmentation in the first parameter but no changes were observed in the second. Both Al and In caused oxidative stress in testicles by increasing malondialdehyde (MDA) and protein carbonyls (PC) production. Concomitantly, thiol group (-SH) and glutathione (GSH) level were enhanced in the testicles. In the blood, while concentrations of MDA was not changed, those of GSH was significantly decreased in the Al and In groups. Our results indicated that Al and In cause oxidative stress both in blood and testicles but In has cytotoxic effect as well as negative impact on testicle weights. These findings could explain the testicular histological alterations previously described after In ip administration.

Chemopreventive effects of Calluna vulgaris and Vitis vinifera extracts on UVB-induced skin damage in SKH-1 hairless mice.

Solar ultraviolet radiation (UV) is a major cause of non-melanoma skin cancer in humans. Photochemoprevention with natural products represents a simple but very effective strategy in the management of cutaneous neoplasia. The study investigated the protective activity of Calluna vulgaris (Cv) and red grape seeds (Vitis vinifera L, Burgund Mare variety) (BM) extracts in vivo on UVB-induced deleterious effects in SKH-1 mice skin. Forty SKH-1 mice were randomly divided into 4 groups (n=10): control, UVB irradiated, Cv + UVB irradiated, BM+UVB irradiated. Both extracts were applied topically on the skin in a dose of 4 mg/40 µl/cm(2) before UVB exposure - single dose. The effects were evaluated in skin 24 hours after irradiation through the presence of cyclobutane pyrimidine dimers (CPDs) and sunburn cells, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6 levels. The antioxidant activity of BM extract was higher than those of Cv extract as determined using stable free radical DPPH assay and ABTS test. One single dose of UVB generated formation of CPDs (p<0.0001) and sunburn cells (p<0.0002) and increased the cytokine levels in skin (p<0.0001). Twenty hours following irradiation BM extract inhibited UVB-induced sunburn cells (p<0.02) and CPDs formation (p<0.0001). Pretreatment with Cv and BM extracts resulted in significantly reduced levels of IL-6 and TNF-α compared with UVB alone (p<0.0001). Our results suggest that BM extracts might be a potential candidate in preventing the damages induced by UV in skin.

Non-invasive oxidative stress markers for liver fibrosis development in the evolution of toxic hepatitis.

Oxidative stress is related to the liver fibrosis, anticipating the hepatic stellate cells' (HSC) activation. Our aim was to correlate oxidative stress markers with the histological liver alterations in order to identify predictive, noninvasive parameters of fibrosis progression in the evolution of toxic hepatitis.CCl4 in sunflower oil was administered to rats intragastrically, twice a week. After 2, 3, 4 and 8 weeks of treatment, plasma levels of malondialdehyde (MDA), protein carbonyls (PC), hydrogen donor capacity (HD), sulfhydryl groups (SH), and glutathione (GSH) were measured and histological examination of the liver slides was performed. Dynamics of histological disorders was assessed by The Knodell score. Significant elevation of inflammation grade was obtained after the second week of the experiment only (p=0.001), while fibrosis started to become significant (p=0.001) after 1 month of CCl4 administration. Between plasma MDA and liver fibrosis development a good correlation was obtained (r=0.877, p=0.05). Correlation between PC dynamics and liver alterations was marginally significant for inflammation grade (r=0.756, p=0.138). HD evolution revealed a marginally inverse correlation with inflammation grade (r=-0.794, p=0.108). No correlations could be established for other parameters with either inflammation grade or fibrosis stage.Our study shows that MDA elevation offers the best prediction potential for fibrosis, while marginal prediction fiability could be attributed to high levels of plasma PC and low levels of HD.

Blood oxidative stress generation after intraperitoneal administration of functionalized single-walled carbon nanotubes in rats.

Single-walled carbon nanotubes (SWCNTs) have been proposed for various medical applications. However, their safety for human administration has not been yet fully demonstrated. In vitro studies have pointed oxidative stress as a mechanism involved in their cytotoxic effects. In the present study we have evaluated the capacity of DNA functionalized SWCNTs to induce oxidative stress in blood after intraperitoneal (ip) administration in rats. The presence of SWCNTs in blood was confirmed by Raman spectroscopy 30 minutes after their ip administration. Oxidative stress parameters (malondialdehyde - MDA, protein carbonyls - PC, antioxidant capacity measured as hydrogen donating capacity - HD, sulfhydryl groups - SH, glutathione - GSH and nitrites - NO) were assessed in blood at 3, 6, 24, respectively, and 48 hours after ip injection. MDA, PC and NO exhibited a significant increase at 3-6 hours interval from exposure, followed by a recovery trend. The levels of HD reached a bottom level at 6 hours after administration, while SH strongly decreased at 3 hours interval and increased slightly up to 48 hours without attending the initial values. GSH level recorded an increasing tendency at the 3rd hour, an incomplete recovery process at 24 hours followed by a secondary significant increase following a 48-hour interval. Significant inverse correlations were obtained between the PC and SH levels and between the NO and HD values. In conclusion, the ip administration of DNA functionalized SWCNT in rats results in oxidative stress generation in plasma, with a transient pattern of evolution.

Oxidative photodamage induced by photodynamic therapy with methoxyphenyl porphyrin derivatives in tumour-bearing rats.

The oxidative effects of photodynamic therapy with 5,10,15,20-tetrakis(4-methoxyphenyl) porphyrin (TMP) and Zn-5,10,15,20-tetrakis(4-methoxyphenyl) porphyrin (ZnTMP) were evaluated in Wistar rats subcutaneously inoculated with Walker 256 carcinoma. The animals were irradiated with red light (λ = 685 nm; D = 50 J/cm2; 15 min) 3 h after intra-peritoneal administration of 10 mg/kg body weight of porphyrins. The presence of free radicals in tumours after photodynamic therapy with TMP and ZnTMP revealed by chemiluminescence of luminol attained the highest level at 18 h after irradiation. Lipid peroxides measured as thiobarbituric-reactive substances and protein carbonyls, which are indices of oxidative effects produced on susceptible biomolecules, were significantly increased in tumour tissues of animals 24 h after photodynamic therapy. The levels of thiol groups and total antioxidant capacity in the tumours were decreased. The activities of antioxidant enzymes superoxide dismutase and glutathione peroxidase were also increased in tumour tissues after photodynamic therapy. Increased levels of plasma lipid peroxides as well as changes in the levels of erythrocyte antioxidant enzyme activities suggest possible systemic effects of photodynamic therapy with TMP and ZnTMP.

Possible in vivo mechanisms involved in photodynamic therapy using tetrapyrrolic macrocycles

Photodynamic therapy (PDT) mediated by oxidative stress causes direct tumor cell damage as well as microvascular injury. To improve this treatment new photosensitizers are being synthesized and tested. We evaluated the effects of PDT with 5,10,15,20-tetrakis(4-methoxyphenyl)-porphyrin (TMPP) and its zinc complex (ZnTMPP) on tumor levels of malondialdehyde (MDA), reduced glutathione (GSH) and cytokines, and on the activity of caspase-3 and metalloproteases (MMP-2 and -9) and attempted to correlate them with the histological alterations of tumors in 3-month-old male Wistar rats, 180 ± 20 g, bearing Walker 256 carcinosarcoma. Rats were randomly divided into five groups: group 1, ZnTMPP+irradiation (IR) 10 mg/kg body weight; group 2, TMPP+IR 10 mg/kg body weight; group 3, 5-aminolevulinic acid (5-ALA+IR) 250 mg/kg body weight; group 4, control, no treatment; group 5, only IR. The tumors were irradiated for 15 min with red light (100 J/cm², 10 kHz, 685 nm) 24 h after drug administration. Tumor tissue levels of MDA (1.1 ± 0.7 in ZnTMPP vs 0.1 ± 0.04 nmol/mg protein in control) and TNF-α (43.5 ± 31.2 in ZnTMPP vs 17.3 ± 1.2 pg/mg protein in control) were significantly higher in treated tumors than in controls. Higher caspase-3 activity (1.9 ± 0.9 in TMPP vs 1.1 ± 0.6 OD/mg protein in control) as well as the activation of MMP-2 (P < 0.05) were also observed in tumors. These parameters were correlated (Spearman correlation, P < 0.05) with the histological alterations. These results suggest that PDT activates the innate immune system and that the effects of PDT with TMPP and ZnTMPP are mediated by reactive oxygen species, which induce cell membrane damage and apoptosis.

Possible in vivo mechanisms involved in photodynamic therapy using tetrapyrrolic macrocycles.

Photodynamic therapy (PDT) mediated by oxidative stress causes direct tumor cell damage as well as microvascular injury. To improve this treatment new photosensitizers are being synthesized and tested. We evaluated the effects of PDT with 5,10,15,20-tetrakis(4-methoxyphenyl)-porphyrin (TMPP) and its zinc complex (ZnTMPP) on tumor levels of malondialdehyde (MDA), reduced glutathione (GSH) and cytokines, and on the activity of caspase-3 and metalloproteases (MMP-2 and -9) and attempted to correlate them with the histological alterations of tumors in 3-month-old male Wistar rats, 180 ± 20 g, bearing Walker 256 carcinosarcoma. Rats were randomly divided into five groups: group 1, ZnTMPP+irradiation (IR) 10 mg/kg body weight; group 2, TMPP+IR 10 mg/kg body weight; group 3, 5-aminolevulinic acid (5-ALA+IR) 250 mg/kg body weight; group 4, control, no treatment; group 5, only IR. The tumors were irradiated for 15 min with red light (100 J/cm², 10 kHz, 685 nm) 24 h after drug administration. Tumor tissue levels of MDA (1.1 ± 0.7 in ZnTMPP vs 0.1 ± 0.04 nmol/mg protein in control) and TNF-α (43.5 ± 31.2 in ZnTMPP vs 17.3 ± 1.2 pg/mg protein in control) were significantly higher in treated tumors than in controls. Higher caspase-3 activity (1.9 ± 0.9 in TMPP vs 1.1 ± 0.6 OD/mg protein in control) as well as the activation of MMP-2 (P < 0.05) were also observed in tumors. These parameters were correlated (Spearman correlation, P < 0.05) with the histological alterations. These results suggest that PDT activates the innate immune system and that the effects of PDT with TMPP and ZnTMPP are mediated by reactive oxygen species, which induce cell membrane damage and apoptosis.

The dynamics of reactive oxygen species in photodynamic therapy with tetra sulfophenyl-porphyrin.

Photodynamic therapy (PDT) is a promising therapy especially in skin cancer, using the systemic administration of a photosensitizer (PS), followed by the local irradiation of the tumor with visible light. The antitumor effects of PDT are determined especially by the generation of cytotoxic reactive oxygen species (ROS). The 5,10,15,20-tetra-sulfo-phenyl-porphyrin (TSPP) is a synthetic photosensitizer, which proved its efficiency in in vitro studies. Our study evaluates the effects of PDT with TSPP upon the tumor levels of ROS and upon the metalloproteinases 2 (MMP2) activities on Wistar male rats bearing 256 Walker carcinosarcoma in correlation with the accumulation of PS in the tumor and with the intratumor histological alterations. The evaluations were performed dynamically, at 3 hours, 6 hours, 24 hours and 14 days after the PDT with TSPP. Our results emphasize that 24 hours after the PDT with TSPP, the ROS generation increases, as revealed by protein carbonyls and malondialdehyde levels and the antioxidant capacity (hydrogen donors, thiol groups) decreases in the tumor tissue. These parameters were correlated with the appearance of the histological disorders. The MMP-2 activity increases exponentially in the 24 hours-14 days post PDT interval. PDT with TSPP offers, in vivo , consistent results regarding ROS generation, MMP2 activation and cytotoxic capacity.

Photochemoprevention of cutaneous neoplasia through natural products.

Non-melanoma skin cancers such as squamous cell carcinoma and basal cell carcinoma are the most common types of human tumors, representing 30% of the new cases of malignancies diagnosed each year. Ultraviolet radiation (UV) from the sun is a major cause of non-melanoma skin cancer in humans. The prevention and mainly the photochemoprevention with natural products represent a simple but very effective strategy in the management of cutaneous neoplasia. Here we review the progress in the research of new and existing agents developed to protect the skin exposed to UV. We also discuss the current state of knowledge on their photosuppression mechanism in humans as well as in animal models, and efficiency in cancer prevention.

Effects of PDT with 5-aminolevulinic acid and chitosan on Walker carcinosarcoma.

UNLABELLED: Porphyrins and new chitosan hydrogels based composites with porphyrins are used as active cytotoxic antitumor agents in photodynamic therapy (PDT). AIM: The present study evaluates the effects of photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) and 5-ALA associated with chitosan (CS) using Walker carcinosarcoma in rats as experimental model. METHODS: The animals were irradiated with red light ( lambda = 685 nm, D = 50 J/cm(2), 15 min) 3 h after i.p. administration of 5-ALA (250 mg/kg b.w.) or a mixture of 5-ALA (250 mg/kg b.w.) and CS (1.5 mg/kg b.w.). The animals were sacrificed at 1, 3, 6, 24 h and 14 days after the treatment. The effects of PDT were investigated by morphological studies, monitoring the 5-ALA induced protoporphyrin IX (Pp IX) level in tumor tissue and serum, MMP 2 and 9 (gelatinases) activity in tumor and malondialdehyde level (MDA), marker of the lipoperoxidation process, in tumor and serum. RESULTS: Zymography revealed an increased activity of MMP 2 in tumors from animals treated with 5-ALA PDT. PDT with 5-ALA induced a higher lipid peroxidation in tumor tissue compared with 5-ALA-CS. CS associated to 5 ALA PDT enhanced the accumulation of PS in tumors inducing earlier necrotic changes. In the same time CS reduced MMP 2 activity. CONCLUSION: Our results suggest that MMPs activation and oxygen reactive species are involved in PDT effects.

Iodide excess exerts oxidative stress in some target tissues of the thyroid hormones.

Environmental iodine deficiency continues to be a significant public health problem worldwide. On the other hand, iodide excess results principally from the use of iodine-containing medicinal preparations or radiographic contrast media. For this reason we intended to explore iodide excess impairment on prooxidant/antioxidant balance of the thyroid gland, hepatic tissue and in blood and the effect of selenium administration on oxidative stress markers under the same circumstances. Experiments were performed for 10 days with white, male, Wistar rats, as follows: group 1: control-normal iodine supply group; 2: high iodine diet, group; 3: high iodine diet and selenium; group 4: high iodine diet and Carbimasole. Oxidative stress markers such as lipid peroxides were determined in thyroid gland, hepatic tissue and in blood. Measuring H+ donor ability of the sera and catalase activity in thyroid gland and in hepatic tissue assessed antioxidant defense. Iodide excess had prooxidant effects, leading to an increased lipid peroxides level and catalase activity in target tissues and in blood and to a decreased H+ donor ability of the sera. Selenium supplementation had opposite effects. Present data allow us to conclude that the alterations due to iodide excess in thyroid gland, hepatic tissue and in blood are mediated through oxidative stress.

The effect of BCG-activated macrophages on the B-16 melanoma.

The effects of BCG-activated lund and peritoneal macrophages on the development of the primary tumor and metastases of B-16 melanoma in C57B1 mice have been studied. The BCG-activated macrophages reduced significantly the incidence of metastases in all treated animals and prolonged the mean survival time only in mice with Winn type of neutralization test. The possible mechanisms implied in this biological process are discussed.

In vitro interrelations between axillary lymph nodes and breast carcinomas from patients immunostimulated before surgery.

When stage I and II mammary carcinomas and their homolateral axillary lymph nodes were grown in the same organ culture, a phenomenon of lymphocyte migration from the nodal explants to the tumoral explants in 34% of the cases was observed. This was followed by lymphocytic infiltration in and around tumor nodules and tumoral cytotoxic effects, concomitantly with lymphocytic depletion in the nodal explants. Lymphocyte migration was particularly apparent when the axillary lymph nodes showed hyperplasia of the paracortical area and/or sinus histiocytosis. No correlation was found between the lymphocyte migration and the histologic type of disease or the degree of malignancy, but a strong correlation was observed between the lymphocyte migration and 1) the presence or absence of metastases in the explanted lymph nodes and 2) the extent of the metastatic involvement in vivo. If before surgery the patients were pretreated with a polymicrobial suspension (polidin), this immunostimulant induced a strong stimulation of the lymphocyte migration and infiltration which appeared in 92% of the cases, independently of the metastatic involvement in vivo and the presence of metastases in the nodal explants.

In vitro cytochemical and cytophysiological study of in vivo BCG-activated mouse peritoneal macrophages.

The morphological, cytochemical (acid phosphatase activity) and cytophysiological (phagocytosis) features of mouse peritoneal macrophages activated in vivo by BCG, were investigated in vitro. BCG induced an increase in cytochemical and phagocytic activities of the activated peritoneal macrophages.

Effect of nonspecific immune stimulation with BCG and polidin on the Ehrlich ascites tumor growth.

Investigations were performed to study: 1) the antitumor effect of BCG pretreatment on the development of Ehrlich ascites tumor in mice; 2) the effect of BCG administration in relation to the period of time before tumor inoculation and the dose levels used, and 3) the antitumor effect of an associated pretreatment of BCG and Polidin on the development of Ehrlich ascites tumor. BCG administered prior to Ehrlich ascites tumor inoculation have a protective effect evidenced by a delay in tumor development, a prolonged survival of the tumor host and, in some cases, even inhibition of tumor growth. The effect of BCG was highly dependent on 1) the dose and the time of administration of BCG and) 2 the combined pretreatment of BCG and Polidin.

The effect of nonspecific immune stimulation with Corynebacterium parvum and polidin on the Ehrlich ascites tumor growth.

Investigations were performed: a) to compare the effect of two nonspecific immunostimulants, Polidin and Corynebacterium parvum, on the development of Ehrlich ascites carcinoma in mice; b) to determine whether the effects are dependent on the tumor cell dose inoculated into the animals. C. parvum and Polidin administered prior to Ehrlich ascites tumor inoculation have a protective effect evidenced by a delay in tumor development, a retardation in tumor growth and a prolonged survival of the tumor host. The effect of immunostimulants was highly dependent on the tumor cell dose inoculated into mice and was more marked with C. parvum.