Evaluación genotóxica de las moléculas con efectos tripanocida y leishmanicida cantin-6-ona y 5-metoxicantin-6-ona en células de médula ósea de ratones / Genotoxic evaluation of the molecules with trypanocidal and leishmanicidal effects, canthin-6-one and 5-methoxycanthin-6-one in mouse bone marrow cells

La tripanosomiasis americana y la leishmaniasis son problemas de salud pública relevantes en Iberoamérica. Las drogas utilizadas actualmente para el tratamiento de estas enfermedades poseen efectos colaterales tóxicos severos. Varios grupos de investigación están abocados a la búsqueda de productos naturales y sintéticos para encontrar nuevos agentes terapéuticos efectivos que no presenten reacciones colaterales adversas. En la evaluación de compuestos de la especie vegetal Zanthoxylum chiloperone (Rutaceae), se demostró que compuestos aislados del extracto presentaban actividad leishmanicida, tripanocida y antifúngica in vivo. Teniendo como antecedentes estos resultados, en el presente estudio se evaluaron los efectos genotóxico y citotóxico del cantín-6-ona y del 5-metoxicantin-6-ona, moléculas aisladas de la planta, en células de médula ósea de animales tratados. El estudio de los efectos genotóxicos se hizo a través del ensayo de modificaciones en la frecuencia de micronúcleos y el efecto citotóxico por modificaciones en la relación entre eritrocitos policromáticos y eritrocitos normocromáticos. Se realizaron 2 ensayos independientes y en cada ensayo los animales fueron divididos en tres grupos de tratamiento: GRUPO I: control negativo que recibió 200 uL de agua y 2.1% de DMSO, vía oral, GRUPO II: compuesto a ser evaluado (canthin-6-ona o 5-methoxicantin-6-ona) con 2.1% de DMSO, y GRUPO III: control positivo que recibió ciclofosfamida 50mg/kg/peso del animal, vía intraperitoneal. El análisis estadístico mostró que ambos compuestos no presentaron efectos genotóxicos ni citotóxicos. Estos resultados permiten proponer a estas moléculas como candidatas a ser sometidas a estudios más detallados como potenciales fármacos contra estas dos enfermedades

American trypanosomiasis and leishmaniasis are relevant public health problems in Latin America. The drugs currently used to treat these diseases have severe toxic side effects. Several research groups are dedicated to the search of natural and synthetic products to find new effective therapeutic agents that do not present adverse collateral reactions. In the evaluation of compounds of the plant species Zanthoxylum chiloperone (Rutaceae), it was shown that isolated compounds of the extract had leishmanicidal, trypanocidal and antifungal in vivo activities. Based on these results, the genotoxic and cytotoxic effects of canthin-6-one and 5-methoxycanthin-6-one, molecules isolated from the plant, on bone marrow cells of treated mice were evaluated in the present study. The study of genotoxic effects was made through the test of modifications in the frequency of micronuclei and the cytotoxic effects by modifications in the relationship between polychromatic erythrocytes and normochromic erythrocytes. Two independent assays were performed and in each assay the animals were divided into three treatment groups: GROUP I: negative control that received 200 µL of water and 2.1% of DMSO, orally, GROUP II: compound to be evaluated (canthin-6 -one or 5-methoxycanthin-6-one) with 2.1% DMSO, and GROUP III: positive control that received cyclophosphamide 50mg /kg animal weight, intraperitoneal. Statistical analysis showed that both compounds had neither genotoxic nor cytotoxic effects. These results allow these molecules to be proposed as candidates to be subjected to more detailed studies as potential drugs against these two diseases

Assessment of toxicity and differential antimicrobial activity of methanol extract of rhizome of Simaba ferruginea A. St.-Hil. and its isolate canthin-6-one.

ETHNOPHARMACOLOGICAL RELEVANCE: Simaba ferruginea A. St.-Hil., Simaroubaceae, popularly known as "calunga" is a typical subtropical shrub used in Central Brazil mainly for infection, anti-inflammatory, analgesic and gastric duodenal-ulcers. It presents in its composition the alkaloid canthin-6-one, an alkaloid indole ß-carboxylic. AIM: This study aims to investigate the toxicity, antimicrobial activities of methanol extract of Simaba ferruginea (MESf) and canthin-6-one by using different experimental models. METHODS: The present study evaluated the phytochemical analysis by high performance liquid chromatography (HPLC), toxicological potential of MESf and canthin-6-one, using the cytotoxicity, genotoxicity assays with CHO-K1 cells and in vivo acute test in mice. Antimicrobial activity was evaluated by the broth microdilution assays, while the antimicrobial mechanism of action was also assessed using different in vitro bacterial and fungal models. RESULTS: The HPLC analysis of MESf revealed the presence of canthin-6-one, kaempferol and morin. Differential in vitro toxicities were observed between MESf and canthin-6-one. In the cytotoxicity assay, MESf presented toxicity against CHO-K1, while canthin-6-one did not. In the case of in vitro genotoxicity, both showed to be potentially genotoxic. In the in vivo toxicity study, both MESf (up to 1000 mg/kg) and cantin-6-one (up to 100 mg/kg) caused no toxicologically relevant alterations and are thus considered not to be toxic. MESf was shown to be relatively safe with NOAEL (100 mg/kg) when administrate in mice. Both MESf and canthin-6-one also showed differential antimicrobial activities. On one hand, MESf demonstrated good spectrum of antibacterial action against Staphylococcus aureus (MIC 12.5 µg/mL) and Escherichia coli (MIC 25 µg/mL) and moderate activity against Enterococcus faecalis and Shigella flexneri (MIC 200 µg/mL) but no antifungal effect. On the hand, canthin-6-one showed no antibacterial activity, except against Staphylococcus aureus (100 µg/mL), but potent in vitro fungicidal activity against clinically important Aspergillus niger and Candida species at MFC intervals ranging from 3.12 to 25 µg/mL. Both MESf and canthin-6-one were bacteriostatic in action. MESf antimicrobial mechanism of actions are associated with changes in the permeability of bacterial membranes, evidenced by the increased entry of hydrophobic antibiotic in Shigella flexneri, intense K+ efflux (Shigella flexneri, Staphylococcus aureus) and nucleotides leakage (Staphylococcus aureus). In the antifungal mode of action, canthin-6-one inhibited Saccharomyces cerevisiae growth and including alteration in the cell membrane of Neurospora crassa. CONCLUSION: The results of this work demonstrated the differential antimicrobial activities of MESf and its alkaloid isolate, canthin-6-one with antibacterial and antifungal activities, respectively. The present study support the popular use of Simaba ferruginea in combatting afflictions related to bacterial infections, and demonstrate that canthin-6-one as a promising antifungal agent. Both MESf and canthin-6-one are considered non-toxic based on the in vitro toxicological study.

Huberine, a New Canthin-6-One Alkaloid from the Bark of Picrolemma huberi.

A new alkaloid, Canthin-6-one, Huberine (1), together with three known compounds including 1-Hydroxy-canthin-6-one (2), Canthin-6-one (3) and stigma sterol (4), were isolated from the stem bark of Picrolemma huberi. The isolation was achieved by chromatographic techniques and the purification was performed on a C18 column using acetonitrile/water (90:10, v/v) with 0.1% formic acid as the mobile phase. The structural elucidation was performed via spectroscopic methods, notably 1D- and 2D-NMR, UV, IR, MS and HRMS. The antiplasmodial activity of the compounds was studied.