Paulo Roberto de Melo Reis

Chemopreventive effect and angiogenic activity of punicalagin isolated from leaves of Lafoensia pacari A. St.-Hil.

Punicalagin is the major ellagitannin constituent from leaves of Lafoensia pacari, a Brazilian medicinal plant widely used for the treatment of peptic ulcer and wound healing. Genotoxic, cytotoxic, antigenotoxic, and anticytotoxic effects of punicalagin were assessed using micronucleus (MN) test and comet assay in mice. Due to the extensive use of L. pacari in the wound healing process, we also assessed the angiogenic activity of punicalagin using the chick chorioallantoic membrane (CAM) angiogenic assay. The highest dose of punicalagin (50mg/kg) showed significant cytotoxic effect by MN test and in the co-treatment with cyclophosphamide (CPA), this cytotoxicity was enhanced. Co-treatment, pre-treatment and post-treatment of punicalagin with CPA led to a significant reduction in the number of DNA breaks and in the frequency of CPA-induced MN, indicating antigenotoxic effect. Using the CAM model, punicalagin exhibited angiogenic activity in all doses mainly at the lowest concentration (12.5μg/μL). Therefore, these findings indicate an effective chemopreventive role of punicalagin and a high capacity to induce DNA repair. Also, the angiogenic activity presented by punicalagin in this study could contribute for the processes of tissue repairing and wound healing.

Avaliação da determinação do tempo de protrombina em amostras de sangue colhidas por duas diferentes técnicas

O presente trabalho tem como objetivo avaliar a interferencia de diferentes tecnicas de coleta sanguinea na determinacao do tempo de protrombina. Duas tecnicas de coleta foram utilizadas: uma, realizada pelo sistema a vacuo; a outra, realizada mediante aspiracao manual com seringa de plastico. Os valores obtidos na determinacao do tempo de protrombina provenientes das duas tecnicas de coleta foram comparados. Foram analisadas amostras de pacientes que apresentavam tempo de protrombina normais e anormais por estarem em tratamento oral com medicacao anticoagulante. A conclusao foi que o processo de coleta utilizando tanto o sistema a vacuo como a aspiracao manual com seringa de plastico nao interfere no resultado do teste, e os valores obtidos, comparando-se os dois metodos de coleta, nao apresentaram diferencas estatisticamente significativas.

Optical properties and antiangiogenic activity of a chalcone derivate

Chalcones and their derivatives exhibit numerous pharmacological activities such as antibacterial, antifungal, cytotoxic, antinociceptive and anti-inflammatory. Recently, they have been assessed aiming for novel application in nonlinear optics and in the treatment of immune diseases and cancers. In this study, we investigate the optical properties of synthetic chalcona 1E,4E-1-(4-chlorophenyl)-5-(2,6,6-trimethylcyclohexen-1-yl)penta-1,4-dien-3-one (CAB7β) and its antiangiogenic potential using the chorioallantoic membrane (CAM) with the S180 sarcoma cell line. Experimental and theoretical results show intense absorption in the UVA-UVC region, which is associated with a π → π* transition with intramolecular charge transfer from the trimethyl-cyclohexen-1-yl ring to the chlorophenyl ring. Quantum chemical calculations of the first hyperpolarizability, accounting for both solvent and frequency dispersion effects, are in very good concordance with hyper-Rayleigh scattering measurements. In addition, two-photon absorption allowed band centered at 650 nm was observed. Concerning antiangiogenic activity, CAB7β causes a significant reduction in the total number, junctions, length and caliber of blood vessels stimulated by S180 cells reducing the presence of blood vessels, inflammatory cells and others elements related to angiogenic process. It is found that CAB7β is a versatile compound and a promising candidate for linear and nonlinear optical applications, in therapy against sarcoma and phototherapy.

Presence of antigenotoxic and anticytotoxic effects of the chalcone 1E,4E-1-(4-chlorophenyl)-5-(2,6,6-trimethylcyclohexen-1-yl)penta-1,4-dien-3-one using in vitro and in vivo assays

Abstract Chalcones are chemically defined as α,β–unsaturated ketones with a 1,3-diphenyl-2-propen-1-one nucleus. These compounds occur naturally in plants and are considered precursors of flavonoids. Given that evaluating genetic toxicology tests is essential in investigating the safe use and chemopreventive potential of different natural and synthetic compounds, this study aimed to assess the genotoxic, cytotoxic, antigenotoxic, and anticytotoxic activity of the chalcone 1E,4E-1-(4-chlorophenyl)-5-(2,6,6-trimethylcyclohexen-1-yl)penta-1,4-dien-3-one (CAB7β). The CAB7β was synthesized via Claisen–Schmidt reaction. The Ames test was applied using the co-treatment model as well as a micronucleus assay of mouse bone marrow with co-, pre- and post-treatment models. Our results indicate no genotoxic effect for CAB7β in any of the tests applied. At all the concentrations used, CAB7β showed a significant DNA protective effect against the mutagenic action of 4-nitroquinoline-1-oxide and sodium azide according to the Ames test, and against doxorubicin in the co-, pre- and post-treatment models of the micronucleus assay. CAB7β alone displayed cytotoxic activity in the micronucleus test. At concentrations of 12,5 and 50 µg/plate, CAB7β showed a moderate cytotoxic profile only in Salmonella typhimurium strain TA98. However, an anticytotoxic effect was observed against S. typhimurium strain TA100 for all the concentrations tested and during co-, pre- and post-treatment in the micronucleus assay. It was concluded that CAB7β exhibited a slightly cytotoxic effect in S. typhimurium strain TA98 and significant antigenotoxic and anticytotoxic effects in cells of mouse, making it a promising candidate in chemoprevention and possibly in the development of new cancer treatments.

Evaluation of wound healing treated with latex derived from rubber trees and Aloe Vera extract in rats

PURPOSE: To compare the use of latex derivative and Aloe vera extract to wound healing. METHODS: Twenty one rats were randomly divided into three groups and each one had a wound made by incision. The treatment consisted in: derivative of latex (GL), Aloe vera extract (GA) and saline solution (GC). The wound area was measured on the 7th, 14th and 21st days and macroscopic and microscopic evaluation were done. RESULTS: The comparison between the measurements of the wounds presented statistical difference in GC and GA from the 7th day of evaluation and GL from the 14th day. The extent of the wound was significantly smaller by the 7th day in GL. Histologically, in GL, the neovascularization was significant on the 7th, 14th and 21st days. On the 21st day the scar was large and little mature. In GA and GC, the findings were similar on the 7th, 14th and 21st days with a slight better organization of skin and collagen on the 21st in GA. CONCLUSIONS: Statistical analysis did not allow for the definition of the best topical agent. The latex had the highest angiogenesis, but a possible foreign body granuloma. Aloe vera has revealed a healing process adequated temporally in histology.