Ana Paula Negreiros Nunes Alves

In vivo growth-inhibition of Sarcoma 180 by piplartine and piperine, two alkaloid amides from Piper

Piplartine {5,6-dihydro-1-[1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)pyridinone} and piperine {1-5-(1,3)-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine} are alkaloid amides isolated from Piper. Both have been reported to show cytotoxic activity towards several tumor cell lines. In the present study, the in vivo antitumor activity of these compounds was evaluated in 60 female Swiss mice (N = 10 per group) transplanted with Sarcoma 180. Histopathological and morphological analyses of the tumor and the organs, including liver, spleen, and kidney, were performed in order to evaluate the toxicological aspects of the treatment with these amides. Administration of piplartine or piperine (50 or 100 mg kg(-1) day(-1) intraperitoneally for 7 days starting 1 day after inoculation) inhibited solid tumor development in mice transplanted with Sarcoma 180 cells. The inhibition rates were 28.7 and 52.3% for piplartine and 55.1 and 56.8% for piperine, after 7 days of treatment, at the lower and higher doses, respectively. The antitumor activity of piplartine was related to inhibition of the tumor proliferation rate, as observed by reduction of Ki67 staining, a nuclear antigen associated with G1, S, G2, and M cell cycle phases, in tumors from treated animals. However, piperine did not inhibit cell proliferation as observed in Ki67 immunohistochemical analysis. Histopathological analysis of liver and kidney showed that both organs were reversibly affected by piplartine and piperine treatment, but in a different way. Piperine was more toxic to the liver, leading to ballooning degeneration of hepatocytes, accompanied by microvesicular steatosis in some areas, than piplartine which, in turn, was more toxic to the kidney, leading to discrete hydropic changes of the proximal tubular and glomerular epithelium and tubular hemorrhage in treated animals.

Antitumor properties of a sulfated polysaccharide from the red seaweed Champia feldmannii (Diaz‐Pifferer)

In recent years, much attention has been focused on polysaccharides isolated from natural sources. The aim of this study was to investigate the in vitro and in vivo antitumor properties of a sulfated polysaccharide isolated from the seaweed C. feldmannii (Cf‐PLS). Hematological, biochemical and histopathological analyses were performed in order to evaluate the toxicological aspects related to Cf‐PLS treatment. Its effects on the immunological system were also investigated. The Cf‐PLS did not show any significant in vitro cytotoxicity at the experimental exposure levels that were used, but showed in vivo antitumor effect. The inhibition rates of sarcoma 180 tumor development were 48.62 and 48.16% at the doses of 10 and 25 mg kg−1, respectively. In addition, Cf‐PLS was also able to increase the response elicited by 5‐fluorouracil (5‐FU) from 48.66 to 68.32%. The histopathological analysis of liver and kidney showed that both organs were moderately affected by Cf‐PLS‐treatment. Neither enzymatic activity of alanine aminotransferase nor urea or creatinine levels were significantly altered. In hematological analysis, leucopeny was observed after 5‐FU treatment, but this effect was prevented when the treatment was associated with the Cf‐PLS. It was also demonstrated that Cf‐PLS acts as an immunomodulatory agent, raising the production of specific antibodies, and increasing the production of OVA‐specific antibodies. It also induced a discreet hyperplasia of lymphoid folicules of the white pulp in the spleen of treated mice. In conclusion, Cf‐PLS has some interesting anticancer activity that could be associated with its immunostimulating properties. Copyright

In-vitro and in-vivo antitumour activity of physalins B and D from Physalis angulata

We have evaluated the in‐vitro and in‐vivo antitumour activity of physalin B and physalin D isolated from the aerial parts of Physalis angulata. In‐vitro, both compounds displayed considerable cytotoxicity against several cancer cell lines, showing IC50 values in the range of 0.58 to 15.18 μg mL−1 for physalin B, and 0.28 to 2.43 μg mL−1 for physalin D. The antitumour activity of both compounds was confirmed in‐vivo using mice bearing sarcoma 180 tumour cells. The in‐vivo antitumour activity was related to the inhibition of tumour proliferation, as observed by the reduction of Ki67 staining in tumours of treated animals. Histopathological examination of the kidney and liver showed that both organs were affected by physalin treatment, but in a reversible manner. These compounds were probably responsible for the previously described antitumour activity of ethanol extracts of P. angulata, and their identification and characterization presented here could explain the ethnopharmacological use of this species in the treatment of cancer.

Odontogenic tumors: a 5-year retrospective study in a Brazilian population and analysis of 3406 cases reported in the literature

OBJECTIVE The objective of this study was to analyze the frequency and distribution of odontogenic tumors in Fortaleza, Brazil, and compare the findings with those reported in the literature. STUDY DESIGN A total of 6231 oral lesions retrieved from 5 anatomic pathology services in Fortaleza, Brazil, over a 5-year period, were reviewed. In addition, the literature was searched for studies on odontogenic tumors (OTs) according to the 2005 WHO classification. RESULTS Within the total 6231 oral lesions, 185 (2.97%) were OTs, all benign. OTs presented a female predilection, with a male:female ratio of 0.62:1.00. These neoplasms occurred over a wide range of ages (1 to 78 years), with a mean of 30.5 years. Ameloblastomas, keratocystic odontogenic tumors, and odontomas were the most frequent OT types. CONCLUSIONS OTs are rare neoplasms and appear to show geographic variations. In Fortaleza, Brazil, they are more common in female patients, with ameloblastoma followed by keratocystic odontogenic tumors as the most frequent OTs.

Antitumor Activity of the Essential Oil from the Leaves of Croton regelianus and Its Component Ascaridole

Croton regelianus Muell. Arg., popularly known as ‘velame‐de‐cheiro’, is a native plant from the Northeast of Brazil used in folk medicine to treat diseases of different kinds, including malignant tumors. In this study, the in vitro and in vivo antitumor effects of the essential oil from the leaves of C. regelianus and ascaridole, one of the main constituents, were investigated. In vitro, the essential oil and ascaridole displayed cytotoxicity, showing IC50 values in the range of 22.2 to 48.0 μg/ml in HL‐60 and SF‐295 cell lines for the essential oil, and 6.3 to 18.4 μg/ml in HL‐60 and HCT‐8 cells lines for ascaridole, respectively. The in vivo study, using sarcoma 180 as a tumor model, demonstrated inhibition rates of 28.1 and 31.8% for essential oil, at the 50 and 100 mg/kg, while ascaridole inhibition rates were 33.9% at 10 mg/kg and 33.3% at 20‐mg/kg doses. Histopathological examination showed that the organs were only weakly affected by the treatment. In conclusion, ascaridole has an interesting antitumor activity in sarcoma 180 murine model, probably related to the described cytotoxic activity, and, moreover, its presence in the essential oil from the leaves of C. regelianus could explain, at least in part, the ethnopharmacological use of this plant in the treatment of cancer.

Antitumor effect of laticifer proteins of Himatanthus drasticus (Mart.) Plumel - Apocynaceae

ETHNOPHARMACOLOGICAL RELEVANCE Himatanthus drasticus (Mart.) Plumel - Apocynaceae is a medicinal plant popularly known as Janaguba. Its bark and latex have been used by the public for cancer treatment, among other medicinal uses. However, there is almost no scientific research report on its medicinal properties. AIM OF THE STUDY The aim of this study was to investigate the antitumor effects of Himatanthus drasticus latex proteins (HdLP) in experimental models. MATERIALS AND METHODS The in vitro cytotoxic activity of the HdLP was determined on cultured tumor cells. HdLP was also tested for its ability to induce lysis of mouse erythrocytes. In vivo antitumor activity was assessed in two experimental models, Sarcoma 180 and Walker 256 carcinosarcoma. Additionally, its effects on the immunological system were also investigated. RESULTS HdLP did not show any significant in vitro cytotoxic effect at experimental exposure levels. When intraperitoneally administered, HdLP was active against both in vivo experimental tumors. However, it was inactive by oral administration. The histopathological analysis indicates that the liver and kidney were only weakly affected by HdLP treatment. It was also demonstrated that HdLP acts as an immunomodulatory agent, increasing the production of OVA-specific antibodies. Additionally, it increased relative spleen weight and the incidence of megakaryocyte colonies. CONCLUSION In summary, HdLP has some interesting anticancer activity that could be associated with its immunostimulating properties.

In vitro and in vivo antiproliferative activity of Calotropis procera stem extracts

The cytotoxic potential of stem organic extracts from Calotropis procera (Asclepiadaceae) was firstly evaluated against cancer cell lines by MTT assay. Subsequently, samples considered cytotoxic were tested for antimitotic activity on sea urchin egg development and for in vivo antiproliferative activity in mice bearing Sarcoma 180 tumor. Among the five extracts (hexane, dichloromethane, ethyl acetate, acetone and methanol), ethyl acetate and acetone extracts displayed higher cytotoxic potential against tumor cells, with IC50 ranging from 0.8 to 4.4 microg/mL, while methanolic extract was weakly cytotoxic. Cytotoxic extracts also exhibited cell division inhibition capacity by antimitotic assay, revealing IC50 values lower than 5 microg/mL. In the in vivo antitumor assessments, ethyl acetate- and acetone-treated animals showed tumor growth inhibition ratios of 64.3 and 53.1%, respectively, with reversible toxic effects on liver and kidneys. Further studies are in progress in order to identify C. procera cytotoxic compound(s) and to understand the mechanism of action responsible for this tumor-decreasing potential.

Postoperative bleeding after dental extraction in liver pretransplant patients.

PURPOSE The aim of this prospective observational study was to evaluate the incidence of postoperative bleeding after dental extraction in candidates for liver transplantation and the efficacy of the association of tranexamic acid and absorbable hemostatic sponges. PATIENTS AND METHODS All individuals referred for oral health evaluation requiring extraction were considered in this study. Patients were included in the analysis when the blood examinations showed a platelet count of 30,000/mm(3) or greater and an international normalized ratio (INR) of 3.0 or less. In group 1 local pressure was applied by use of gauze soaked with tranexamic acid, and in group 2 gauze without tranexamic acid was used. Absorbable hemostatic sponges and cross sutures were used as a standard hemostatic measure. RESULTS In the 23 patients included in this study, 84 simple extractions were performed during 35 dental surgical procedures. The main preoperative blood tests found the following: a mean hematocrit level of 34.54% (SD, 5.84%; range, 21.7%-44.4%), platelet counts from 31,000/mm(3) to 160,000/mm(3), and a mean INR of 1.50 (SD, 0.39; range, 0.98-2.59). Postoperative bleeding occurred during only 1 procedure (2.9%), and local pressure with gauze was effective for achieving hemostasis. No statistically significant difference in the time to hemostasis was found between the 2 groups. CONCLUSIONS This study found a low risk of bleeding for tooth extractions in patients with liver cirrhosis, INRs of 2.50 or less, and platelet counts of 30,000/mm(3) or greater. Blood transfusions were not needed, and in the case of postoperative bleeding, the use of local hemostatic measures was satisfactory.

Effect of different doses of zoledronic acid in establishing of bisphosphonate-related osteonecrosis

OBJECTIVES To establish osteonecrosis of the jaws in rats treated with different doses of zoledronic acid (ZA). METHODS Male Wistar rats (n=6-7) received three consecutive weekly intravenous ZA infusions at doses of 0.04, 0.20 or 1.00mg/kg ZA or saline (control). Four weeks after the last administration, the animals were submitted to simple extraction of the lower left first molar. An additional dose of ZA was administered seven days later, and the animals were sacrificed 28 days after exodontia. Weight was measured and blood was collected weekly for analysis. The jaw was radiographically and microscopically examined along with the liver, spleen, kidney and stomach. RESULTS All ZA doses showed a higher radiolucent area than the control (p<0.0001), but the dose of 0.04mg/kg did not show BRONJ. Doses of 0.20 and 1.00mg/kg ZA showed histological evidence of bone necrosis (p=0.0004). Anaemia (p<0.0001, r(2)=0.8073) and leucocytosis (p<0.0001, r(2)=0.9699) are seen with an increase of lymphocytes (p<0.0001, r(2)=0.6431) and neutrophils and monocytes (p=0.0218, r(2)=0.8724) in all the animals treated with an increasing dose of ZA. Haemorrhage and ectasia were observed in the spleen (p=0.0004) and stomach (p=0.0168) in a dose-dependent manner, and the animals treated with ZA showed a lower rate of weight gain (p<0.0001). CONCLUSIONS We designed a bisphosphonate-related osteonecrosis of the jaw model that reproduces radiographic and histological parameters and mimics clinical alterations such as leucocytosis, anaemia and idiosyncratic inflammatory post infusion reactions.

Oxygen metabolism in oral cancer: HIF and GLUTs (Review)

Oral cancer is a significant cause of morbidity and mortality, and has a poor prognosis. This has encouraged additional studies into factors that may affect the development of this disease. The biological behavior of malignant neoplasms is complex. Studies have investigated the energy metabolism of tumor cells, in an endeavor to elucidate the tumor biology. The identification of molecular signatures and mechanisms, in order to understand tumor progression, may facilitate the identification of novel predictive and prognostic markers. Pathways that influence tumor progression, such as those involving hypoxia-inducible factor (HIF) and glucose transporter (GLUT) proteins, have been the targets of recent studies.