Nano-engineering of biomedical prednisolone liposomes: evaluation of the cytotoxic effect on human colon carcinoma cell lines.

OBJECTIVES: Liposomes have attracted the attention of researchers due to their potential to act as drug delivery systems for cancer treatment. The present investigation aimed to develop liposomes loaded with prednisolone base and the evaluation of the antiproliferative effect on human colon carcinoma cell lines. METHODS: Liposomes were elaborated by following a reproducible thin film hydration technique. The physicochemical characterization of liposomes included photon correlation spectroscopy, microscopy analysis, Fourier transform infrared spectroscopy, rheological behaviour and electrophoresis. On the basis of these data and drug loading values, the best formulation was selected. Stability and drug release properties were also tested. KEY FINDINGS: Resulting liposomes exhibited optimal physicochemical and stability properties, an excellent haemocompatibility and direct antiproliferative effect on human colon carcinoma T-84 cell lines. CONCLUSIONS: This study shows direct antitumour effect of prednisolone liposomal formulation, which opens the door for liposomal glucocorticoids as novel antitumour agents.

Allicin enhances chemotherapeutic response and ameliorates tamoxifen-induced liver injury in experimental animals.

CONTEXT: Tamoxifen (TAM) is widely used for treatment of hormone-dependent breast cancer; however, it may be accompanied with hepatic injury. Allicin is the most abundant thiosulfinate molecule from garlic with the potential to provide beneficial effects on various diseases. OBJECTIVE: To elucidate the effect of commercially available allicin on both antitumor activity and liver injury of TAM. MATERIALS AND METHODS: The cytotoxicity of TAM and/or allicin was evaluated in vitro using cultured Ehrlich ascites carcinoma (EAC) cells and in vivo against murine tumor (solid) model of EAC. TAM induced liver injury in rats by intraperitoneally (i.p.) injection at a dose of 45 mg/kg, for 7 successive days. RESULTS: TAM at a dose of 3 µM (IC50) significantly decreased percent survival of EAC to 52%. TAM combination with allicin (5 or 10 µM) showed a significant cytotoxic effect compared with the TAM-treated group as manifested by a decrease in percent survival of EAC to 35% and 29%, respectively. Allicin (10 mg/kg, orally) enhanced the efficacy of TAM (1 mg/kg, i.p.) in mice as manifested by a significant increase in solid tumor growth inhibition by 82% compared with 70% in the TAM group. In rats, TAM intoxication resulted in a significant decline in SOD, GSH, and total protein with significant elevation in TBARS, ALT and AST, ALP, LDH, total bilirubin, γGT, and TNF-α levels. These changes are abrogated by allicin treatment. DISCUSSION AND CONCLUSION: The results suggest the beneficial role of allicin as an adjuvant to TAM in cancer treatment by alleviating liver injury.

Effects of Acer okamotoanum sap on the function of polymorphonuclear neutrophilic leukocytes in vitro and in vivo.

Sap is a plant fluid that primarily consists of water and small amounts of mineral elements, sugars, hormones and other nutrients. Acer mono (A. mono) is an endemic Korean mono maple which was recently suggested to have health benefits due to its abundant calcium and magnesium ion content. In the present study, we examined the effects of sap from Acer okamotoanum (A. okamotoanum) on the phagocytic response of mouse neutrophils in vivo and rat and canine neutrophils in vitro. We tested the regulation of phagocytic activity, oxidative burst activity (OBA) and the levels of filamentous polymeric actin (F-actin) in the absence and presence of dexamethasone (DEX) in vitro and in vivo. Our results showed that DEX primarily reduced OBA in the mouse neutrophils, and that this was reversed in the presence of the sap. By contrast, the phagocytic activity of the mouse cells was not regulated by either DEX or the sap. Rat and canine polymorphonuclear neutrophilic leukocytes (PMNs) responded in vitro to the sap in a similar manner by increasing OBA. However, regulation of phagocytic activity by the sap was different between the species. In canine PMNs, phagocytic activity was enhanced by the sap at a high dose, while it did not significantly modulate this activity in rat PMNs. These findings suggest that the sap of A. okamotoanum stimulates neutrophil activity in the mouse, rat and canine by increasing OBA in vivo and in vitro, and thus may have a potential antimicrobial effect in the PMNs of patients with infections.

Developments in the systemic treatment of endometrial cancer.

Systemic treatment represents the cornerstone of endometrial cancer management in advanced, relapsed and metastatic disease, which is still characterized by poor prognosis. Progestins remain an effective option for patients with low grade, estrogen and/or progesterone receptor positive disease, with some of them achieving prolonged survival. Platinum compounds, anthracyclines and more recently taxanes have been implemented in combination regimens achieving response rates more than 50% and resulting in overall survival above 1 year in randomized trials. Adjuvant chemotherapy with the same agents may be useful for patients with early stage disease and high-risk features, such as high grade or non-endometrioid histology. Combination of chemotherapeutic agents with radiotherapy remains investigational. Hematologic, cardiac toxicity and neurotoxicity represent the main concern of chemotherapy and increase the risk for treatment-related morbidity and death, especially in pretreated patients bearing substantial co-morbidities. The gradual elucidation of the molecular aspects of endometrial carcinogenesis has led to the development of novel, selective antineoplastic agents, targeting specific molecular pathways and mediators of signal transduction implemented in cell proliferation, survival and angiogenesis. In the current review, we report on the recent advances regarding systemic therapy of endometrial carcinoma with special emphasis on results of large, randomized phase III clinical trials. Biomarkers with potent prognostic significance or predictive value for response to treatment are presented and novel molecular agents showing promising results in early clinical trials are discussed.

Caffeic acid phenethyl ester protects against tamoxifen-induced hepatotoxicity in rats.

Tamoxifen (TAM) is widely used in the treatment and prevention of breast cancer. Adverse effects of TAM include hepatotoxicity. Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been used in folk medicine for diverse ailments. In the current study, the protective effects of CAPE against TAM-induced hepatotoxicity in female rats were evaluated. TAM (45 mg/kg/day, i.p., for 10 consecutive days) resulted in an elevation of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), depletion of liver reduced glutathione (GSH) and accumulation of oxidized glutathione (GSSG) and lipid peroxidation (LPO). Also, TAM treatment resulted in inhibition of hepatic activity of glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT). Further, it raised liver tumor necrosis factor-alpha (TNF-alpha) level and induced histopathological changes. Pretreatment with CAPE (2.84 mg/kg/day; i.p., for 20 consecutive days, starting 10 days before TAM injection) significantly prevented the elevation in serum activity of the assessed enzymes. CAPE significantly inhibited TAM-induced hepatic GSH depletion and GSSG and LPO accumulation. Consistently, CAPE normalized the activity of GR, GPx, SOD and CAT, inhibited the rise in TNF-alpha and ameliorated the histopathological changes. In conclusion, CAPE protects against TAM-induced hepatotoxicity.

Validation of the sheep as a large animal model for the study of vertebral osteoporosis.

Rats have long been the animal of choice for research in the field of osteoporosis. In the search for a complementary large animal model the sheep appears useful but hitherto the extent of bone loss from the spine has failed to reach a level that is generally accepted as osteoporotic in humans. Osteoporosis was induced in ten sheep using ovariectomy, low calcium diet and steroid injection for 6 months. Bone samples of iliac crest (IC), lumbar spine (LS), and proximal femur (PF) from the osteoporotic sheep were compared with those from four normal sheep using densitometry, histomorphometry, biochemistry and basic mechanical testing. The differences were examined using an analysis of variance with Tukey-Kramer test. Overall, the bone mineral density at LS and PF decreased more than 25% after treatment. Trabecular bone volume decreased by 29.2, 33.4 and 42.6% in IC, LS and PF, respectively. The failure load of the LS in axial compression was reduced to 2,003 from 6,140 N. The extent of bone loss was sufficient to categorise these sheep as osteoporotic although the pattern of bone loss varied between sites. Reduced mechanical competence in LS confirmed the suitability of this model for evaluation of potential treatments for osteoporosis.

Improved synthesis of unique estradiol-linked platinum(II) complexes showing potent cytocidal activity and affinity for the estrogen receptor alpha and beta.

We have recently reported the synthesis of a platinum(II) complex, made of estradiol, the female sex hormone, and a cisplatin analog, an anticancer drug, linked together by an eleven carbon atoms chain. The novel estradiol-Pt(II) hybrid molecule was synthesized in nine chemical steps with 10% overall yield. This new compound has been tested in vitro on estrogen-dependent (MCF-7) and -independent (MDA-MD-231) (ER(+) and ER(-)) cell lines. Interestingly, the biological activity was quite significant, more potent than that of cisplatin, the compound currently used in chemotherapy. The estrogen receptor binding affinity (ERBA) of this compound was very similar to that of 17beta-estradiol (E(2)) on both estrogen receptors (ERs), alpha and beta. In order to further study this type of molecule, we have decided to synthesize several analogs with the same estrogenic scaffold but with various chain lengths separating the estradiol from the toxic part of the molecule. This was planned in order to study the effect of the length of the linking chain on the biological activity of the hybrids. Four E(2)-Pt(II) hybrid molecules having 6-14 carbon atoms linking chain have been synthesized using a new synthetic methodology. They are synthesized in only eight chemical steps with 21% overall yield. The 17beta-estradiol-linked platinum(II) complexes have been tested for their receptor binding affinity as well as for their cytocidal activity on several breast cancer cell lines. The synthesis and biological results are reported herein.

Anastrozole-associated sclerosing glomerulonephritis in a patient with breast cancer.

OBJECTIVE: Anastrozole is a selective aromatase inhibitor and is used for the hormonal treatment of postmenopausal breast cancer. There are major side effects of anastrozole including decrease in both lumbar spine and total hip bone mineral density, increase in the incidence of all bone fractures (especially fractures of spine, hip and wrist), joint disorders and increase in the cholesterol level. CASE SUMMARY: We report a case of a 73-year-old postmenopausal woman with stage T2N0M0 breast cancer. Adjuvant chemotherapy was not indicated and anastrozole hormonotherapy was started. Diagnosis of sclerosing glomerulonephritis occurred in this patient during anastrozole use, suggesting a newly defined side effect of anastrozole. DISCUSSION: Renal elimination is not a significant pathway of elimination for anastrozole, clearance of anastrozole is unchanged even in severe renal impairment. Dosing adjustment in patients with renal dysfunction is not necessary for anastrozole. We believe that the acute renal failure in our patient was associated with anastrozole. Renal injury due to anastrozole has not been published in the English literature. CONCLUSIONS: Anastrozole may be the causative factor in patients with sclerosing glomerulonephritis.

Catechin prevents tamoxifen-induced oxidative stress and biochemical perturbations in mice.

Natural antioxidants like catechin are now known to have a modulatory role on physiological functions and biotransformation reactions involved in the detoxification process, thereby affording protection from toxic metabolic actions of xenobiotics. Reactive oxygen intermediates have been demonstrated to play an etiological role in anticancer drug-induced toxicity. This study was performed to explore the modulatory and protective effect of catechin on the toxicity of an anticancer drug, tamoxifen (TAM) with special reference to protection against disruption of glutathione metabolizing and antioxidant enzymes. TAM treatment resulted in a significant increase in the lipid peroxidation (LPO), H(2)O(2) generation and protein carbonyl (PC) contents in the liver and kidney as compared to controls while catechin+TAM-treated group showed significant decrease in LPO levels, H(2)O(2) generation and PC contents in liver and kidney when compared with TAM-treated group. Non-enzymatic antioxidants like reduced glutathione (GSH) and low molecular antioxidants like ascorbic acid (AsA) also showed normalcy due to exogenous catechin administration. Catechin pre-treatment showed restoration in the level of cytochrome P450 (CYP) content and in the activities of glutathione metabolizing enzymes, viz., glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx) and other antioxidant enzymes such as, glucose-6-phosphate dehydrogenase (G6-PD), catalase (CAT) and superoxide dismutase (SOD) in both liver and kidney when compared to TAM-treated animals. The results of the study show that catechin supplementation might be helpful in abrogation of TAM toxicity during chemotherapy. Additionally, it makes it a prophylactic and preventive agent of anticancer drug-induced oxidative stress.

Hepatoprotective effect of green tea (Camellia sinensis) extract against tamoxifen-induced liver injury in rats.

Tamoxifen citrate (TAM), is widely used for treatment of breast cancer. It showed a degree of hepatic carcinogenesis. The purpose of this study was to elucidate the antioxidant capacity of green tea (Camellia sinensis) extract (GTE) against TAM-induced liver injury. A model of liver injury in female rats was done by intraperitoneal injection of TAM in a dose of 45mg Kg(-1) day(-1), i.p. for 7 successive days. GTE in the concentration of 1.5 %, was orally administered 4 days prior and 14 days after TAM-intoxication as a sole source of drinking water. The antioxidant flavonoid; epicatechin (a component of green tea) was not detectable in liver and blood of rats in either normal control or TAM-intoxicated group, however, TAM intoxication resulted in a significant decrease of its level in liver homogenate of tamoxifenintoxicated rats. The model of TAM-intoxication elicited significant declines in the antioxidant enzymes (glutathione-S-transferase,glutathione peroxidase, superoxide dismutase and catalase) and reduced glutathione concomitant with significant elevations in TBARS (thiobarbituric acid reactive substance) and liver transaminases; sGPT (serum glutamate pyruvate transaminase) and sGOT (serum glutamate oxaloacetate transaminase) levels. The oral administration of 1.5 % GTE to TAM-intoxicated rats, produced significant increments in the antioxidant enzymes and reduced glutathione concomitant with significant decrements in TBARS and liver transaminases levels. The data obtained from this study speculated that 1.5 % GTE has the capacity to scavenge free radical and can protect against oxidative stress induced by TAM intoxication. Supplementation of GTE could be useful in alleviating tamoxifen-induced liver injury in rats.

A novel in vitro and in vivo breast cancer model for testing inhibitors of estrogen biosynthesis and its action using mammary tumor cells with an activated int-5/aromatase gene.

We recently showed that the cellular gene int-5/aromatase in BALB/c mammary alveolar hyperplastic nodule (D2 HAN/D2 tumor cells) is activated as a result of mouse mammary tumor virus integration within the 3' untranslated region of the aromatase gene. In the present study, we evaluated the effect of various aromatase inhibitors on androstenedione-mediated tumor cell growth. Also, we compared the effect of the non-steroidal aromatase inhibitor (CGS 16949A) on the inhibition of tumor growth. Our results show that D2 tumor cells respond well to various aromatase inhibitors and antiestrogens. We examined the usefulness of this model by using D2 tumor cells to simulate postmenopausal breast cancer employing both in vitro cell culture and in vivo ovariectomized (OVX) nude mouse. Unlike DMBA-induced tumors or other models, D2 tumor cells form very rapid tumors within a few days in intact mice or OVX nude mice with androstenedione supplementation and respond well to an aromatase inhibitor. This model with its known mechanism of aromatase activation should be useful for studying the role of intra-tumoral estrogen in mammary cancer, for evaluating the effects of aromatase inhibitors and antiestrogens, and for comparing breast cancer treatments.