In vitro genotoxic evaluation of three alpha-asarone analogues.

alpha-Asarone has shown a significant capacity to reduce the level of lipids, including cholesterol. However, several toxic and genotoxic studies have determined that its use may pose a risk to human health. Therefore, a series of compounds structurally analogous to alpha-asarone were prepared in order to maintain the same pharmacological properties but with low toxicity. In this study we evaluated the potential of three alpha-asarone analogues to induce mutagenicity using the Ames test (strains TA98 and TA100 in the presence of metabolic activation), as well as the induction of sister chromatid exchanges (SCE) in cultured human lymphocytes. The tested compounds were: 1-(2,4,5-trimethoxyphenyl)propan-1-one (D1), 1-(2-chloro-4,5-dimethoxyphenyl)propan-1-one (D2), and 1-(4,5-dimethoxy-2-nitrophenyl)propan-1-ol (D3). The results in the first assay showed no mutagenic effect for the three tested analogues; in the TA100 strain, certain cytotoxicity did appear in the case of D2 and D3 only at high concentrations. In regard to the SCE assay, compounds D1 and D2 presented no statistical differences in comparison with the control culture values; however, the high dose of D3 (300 microg/ml) produced a significant increment in SCE (68% above the control value). With respect to the mitotic index and the cellular proliferation kinetics, we observed a reduction when compounds D2 and D3 were used at the higher concentrations. Our results encourage further preclinical studies of these compounds in both in vitro and in vivo models (particularly for analogues D1 and D2), to determine their toxicological profile and establish the possibility of using them in humans.

Synthesis and hypolipidemic activity of modified side chain alpha-asarone homologues.

A series of homologues of alpha-asarone (1), containing variable size and functionality on the side chain attached to the aromatic ring, has been subjected to a study of structure-activity relationship. For most of the prepared derivatives, either with a carbonyl (8a-8e), a hydroxy group (9a-9e), or with a conjugated double bond (10a-10d), significant effects on serum lipoprotein cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides were displayed. The results showed an enhancement of the hypocholesterolemic activity as the length of the chain is decreased. Theoretical conformational and electrostatic potential analyses of I and olefins 10 suggest unfavorable steric interactions in the bulky superior side-chain homologues as the deactivating biological effect.

Regio- and stereoselectivity of captodative olefins in 1,3-dipolar cycloadditions. A DFT/HSAB theory rationale for the observed regiochemistry of nitrones.

Captodative olefins 1-acetylvinyl carboxylates proved to be highly regioselective dipolarophiles in 1,3-dipolar cycloadditon to propionitrile oxide, arylphenylnitrile imines, diazoalkanes, and nitrones to yield the corresponding 5-substituted heterocycles. The addition of the latter was also stereoselective, being slightly susceptible to steric demand of the carboxylate substituent in the olefin. All atempts to cleave the isoxazolidine N-O bond under reductive conditions failed, providing diverse products with side-group reduction. FMO theory was unsuccessful to explain the regioselectivity observed with nitrones, since the opposite orientation was predicted. The recently formulated DFT/HSAB theoretical model was able to rationalize this regioselectivity, identifying the nucleophilic and electrophilic atoms involved in the process via calculation of interaction energies, suggesting the specific direction of the electronic process at each of the reaction sites.

Dominant lethal study of alpha-asarone in male and female mice after sub-chronic treatment.

Dominant lethal studies were conducted in male and female mice with alpha-asarone, the active hypolipidaemic component of Guatteria gaumeri Greenman, by per os sub-chronic treatment (10 and 20 mg/kg, 5 days/week, for 8 weeks) and subsequent mating. alpha-Asarone did not produce germinal mutations in either males or females. Epididymal sperm examination of male mice immediately after treatment failed to reveal any alteration in sperm count on shape. No significant alterations were observed in testicular or epididymal weights or testicular histology.

Synthesis and hypolipidaemic evaluation of a series of alpha-asarone analogues related to clofibrate in mice.

A series of alpha-asarone analogues related to clofibrate, containing an acetic acid group at C-2 of the aromatic ring, has been prepared as the acids or as the ethyl and methyl esters. The corresponding alcohols were also synthesized by reduction of the ethyl esters. The compounds were examined in hyperlipidaemic male mice to evaluate their ability to modify serum lipoprotein cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides after oral administration of 40 and 80 mg kg(-1) for 6 days. Except for methyl 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetate at either dose, these clofibrate-related phenoxyacetic acid derivatives were found to have significant hypocholesterolaemic activity. Levels of low-density lipoprotein cholesterol and triglycerides were significantly reduced and those of high-density lipoprotein cholesterol were elevated. 2-Methoxy-5-nitro-4-(2-propenyl)phenoxyacetic acid was active at both doses in all the tests. Clofibrate (150 mg kg(-1)) was more potent at reducing low-density lipoprotein cholesterol. No activity was detected for the alcohol derivatives. These preliminary results suggest that this class of compound might have more promise as potential hypolipidaemic agents than other alpha-asarone derivatives. Further investigation and characterization should be performed to determine the mode of action of these agents on lipid metabolism.

Dominant lethal study of alpha-asarone in male mice.

Alpha-asarone is a hypolipidaemic agent obtained from Guatteria gaumeri, a medical plant used in Mexico to treat hypercholesteraemia and cholelithiasis. alpha-Asarone has been shown to be hepatocarcinogenic and mutagenic in a human lymphocyte assay, a murine bone marrow cell assay and in an unscheduled DNA synthesis assay. In this study, alpha-asarone was tested for dominant lethal effects in male CF1 mice. The drug was given orally at doses of 0, 10 and 30 mg/kg per day for 5 days. Males were mated weekly with eight consecutive batches of naive, nulliparous female mice. Repeated matings revealed no perceptible effect of alpha-asarone on the incidence of pregnancy. Examination of surgically exposed uteri and ovaries of pregnant females on day 13-15 of gestation revealed an increased incidence of post-implantation loss. Semen examination of a separate group of mice showed a decreased concentration and motility of spermatozoa. These results suggest a dominant lethal mutation as well as direct alpha-asarone toxicity to spermatozoa by in treated mice.

Thalidomide and its metabolites have no effect on human lymphocyte proliferation.

Thalidomide is a drug that is being used in several diseases with an immunological component, but the effects on the different immune functions have only been studied partially. Therefore, we studied the effect of thalidomide on PPD-or Con-A-induced proliferation of human mononuclear cells. We found no direct effect of thalidomide at up to 50 micrograms/ml on the cultures. Cells taken from subjects 6 h after ingestion of 200 mg of thalidomide proliferated equally well to PPD and Con-A than cells taken prior to drug administration. Plasma taken from subjects that ingested 200 mg of thalidomide 6 h before did not affect the proliferative response of their own cells when added to the cultures. Plasma from rabbits that were injected with doses 5 or 15 times higher than the dose given to humans did not diminish the proliferative response of human mononuclear cells to PPD. We conclude that neither thalidomide nor its metabolites affect the proliferative response of human mononuclear cells.

Neoplasias del aparato digestivo. Revision de 70,055 casos de material quirurgico y necropsias. / Digestive system neoplasms.Review of 70,055 cases of surgical specimens and necropsies

El cancer del aparato digestivo es una causa frecuente de mortalidad, sin embargo su prevalencia en nuestro medio se desconece. En este trabajo se informan los resultados obtenidos en un analisis retrospectivo de 70,055 estudios histopatologicos; 61,533 correspondieron a material quirurgico-biopsia o pieza operatoria - de cinco anos (1975-1980), de ellos 673 (1.09%) presentaban proceso neoplasico maligno del aparato digestivo; los restantes 8, 522 correspondieron o protocolos de necropsia de 20 anos (1960-1980) en los que 352 (4.13%) presentaban igual patologia.Tanto en piezas operatorias como en necropsias la variedad histologica mas frecuente fue el carcinoma 82.6% y 92.8% respectivamente, seguida del linfoma. Por lo que hace a la localizacion del proceso los resultados varian igualmente segun el material motivo de estudio; en piezas operatorias los carcinomas mas frecuentes fueron: estomago (37.95%), vesicula y vias biliares (24.29%), colon (19.25%); mientras que al estudiar el material de necropsias la frecuencia fue: vesiculas y vias biliares (35.47%) pancreas (22.62%) y estomago (18.45%).Se senalan aspectos epidemiologicos, clinicos y terapeuticos de las neoplasias mas frecuentes informadas en esta revision

[Cytology by gastric washing in the diagnosis of gastric neoplasms]. / La citología por lavado en el diagnóstico de las neoplasias gástricas.

A prospective and comparative study between the citology obtained through gastric washing and endoscopic (biopsy and brushing) for the diagnostic of the gastric neoplasias was carried at the Hospital de Especialidades del Centro Médico La Raza. Twenty one patients with benign gastric ulcer and 18 patients with gastric neoplasia (Two lymphomas and 16 adenocarcinomas) which we checked through surgery, necropsy or clinic evolution were studied. From 21 cases of gastric ulcer, the washing produced enough material for diagnosis in 17 of them (81%); in 16 of these neoplasia was excluded (94.1%) with false positive (5.9%). The endoscopic regained 100% of useful material and in a 100% ignored neoplasia. From 18 neoplasia cases, gastric washing produced material for 14 of them (77.8%); in 10 of these (71.4%) it made a diagnostic with 4 false negatives (28.6%); Endoscopic collected material in a 100% and the accuracy diagnostic was of 17 (94.4%) with one false negative (5.6%). Gastric washing has a high index of uselless for diagnostic from 39 samples, 8 were useless and from these, autolisis was the mein cause. Citology through gastric washing is usefull for neoplasm diagnosis in those cases in which endoscopy would be contraindicated or in those in which it is absent.

[Aspiration biopsy of the pancreas]. / La biopsia del páncreas por aspiración.

Biopsy of the pancreas frequently is followed by complications, this is why the transoperative aspiration biopsy has been recomended. During the last 2 years we used this procedure in 46 patients; in each case, one or several aspirations were done in the more-representative area of the pancreatic pathology. With the aspirated material a smear was fixed and treated with H-E stain. Biopsy was negative for carcinoma in 30 patients (65.2%), positive in 12 (26.0%), insuficient material results in other 4 (8.6%) we consider that the procedure was useful in the 82.6% of the cases and help to elect more adecuate surgical tecnic. There were no complications and we concluded that this is not a harmful procedure. The correct interpretation of the citology depends on the experience of the pathologyst with this method, to increase the percentage of correct diagnosis.

Germ-cell tumors of the mediastinum, postmortem findings.

Autopsy findings in 20 cases of clinical extragonadal germ-cell tumors arising in the anterior mediastinum are presented. The histologic types were: 2 choriocarcinomas, 3 seminomas, 3 malignant teratomas, 3 embryonal carcinomas, and 9 mixed germ-cell tumors. All of the patients were men, and the ages ranged from 14 to 45 years, with a mean of 32.5 years. The mean survival for these patients after diagnosis was 10.9 months. Local recurrence was characteristic of non-seminomatous tumors. In patients with seminoma, local control of the disease was good, but distant metastases were the cause of death. The most frequent sites of metastases were lungs, bones and liver. In all 20 cases, the testes were carefully step-sectioned. Occult tumor was found in only one case of embryonal carcinoma and a well-defined testicular scar with calcification in a patient with choriocarcinoma. Both patients had lower retroperitoneal metastases. These findings support the premise that, in the majority of cases, these tumors had a primary extragonadal origin.