Rebeca Pérez-Morales

Characterization of Different Capsicum Varieties by Evaluation of Their Capsaicinoids Content by High Performance Liquid Chromatography, Determination of Pungency and Effect of High Temperature

The chili pepper is a very important plant used worldwide as a vegetable, as a spice, and as an external medicine. In this work, eight different varieties of Capsicum annuum L. have been characterized by their capsaicinoids content. The chili pepper fruits were cultivated in the Comarca Lagunera region in North of Mexico. The qualitative and quantitative determination of the major and minor capsaicinoids; alkaloids responsible for the pungency level, has been performed by a validated chromatographic procedure (HPLC-DAD) after a preliminary drying step and an opportune extraction procedure. Concentrations of total capsaicinoids varied from a not detectable value for Bell pepper to 31.84 mg g−1 dried weight for Chiltepín. Samples were obtained from plants grown in experimental field and in greenhouse without temperature control, in order to evaluate temperature effect. Analysis of the two principal capsaicinoids in fruits showed that the amount of dihydrocapsaicin was always higher than capsaicin. In addition, our results showed that the content of total capsaicinoids for the varieties Serrano, Puya, Ancho, Guajillo and Bell pepper were increased with high temperature, while the content of total capsaicinoids and Scoville heat units (SHU) for the varieties De árbol and Jalapeño decreased. However, the pungency values found in this study were higher for all varieties analyzed than in other studies.

Polymorphism of CYP1A1*2C, GSTM1*0, and GSTT1*0 in a Mexican Mestizo Population: A Similitude Analysis

Abstract Cytochrome 1A1 (CYP1A1), glutathione transferase M1 (GSTM1), and glutathione transferase T1 (GSTT1) catalyze the bioactivation and detoxification of a wide variety of xenobiotic compounds that are mutagenic and/or carcinogenic (e.g., polycyclic aromatic hydrocarbons). Genetic polymorphisms of these metabolizing enzymes have been shown to affect individual susceptibility to environmental carcinogenic compounds. Although several studies have been published on the relationship between CYP1A1*2C, GSTM1*0, or GSTT1*0 polymorphism and cancer, not all findings can be extrapolated to other populations because of interethnic variability. Here, we investigate the frequency of CYP1A1*2C, GSTM1*0, or GSTT1*0 in a sample of Mexican Mestizos. We find that the frequency of GSTM1*0 is 0.335, that of GSTT1*0 is 0.121, and that of GSTM1*0 + GSTT1*0 is 0.023. The frequency of CYP1A1*2C is 0.54. Similitude analysis sets the Latin American populations in a common cluster near the Asian population, suggesting that the CYP1A1*2C polymorphism may have originated from this population and suffered a founder effect in the American population. Analysis of CYP1A1*2C, GSTM1*0, and GSTT1*0 haplotypes reveals that 35% of the population has some combination of risk genotypes. Taken together, these results point to a high susceptibility of the Mexican Mestizo population to the effects of environmental carcinogens.

The GSTM1null (deletion) and MGMT84 rs12917 (Phe/Phe) haplotype are associated with bulky DNA adduct levels in human leukocytes

Tobacco smoke and air pollutants contain carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and tobacco specific nitrosamines (TSNA), that are substrates of metabolizing enzymes generating reactive metabolites that can bind to DNA. Variation in the activity of these enzymes may modify the extent to which these metabolites can interact with DNA. We compared the levels of bulky DNA adducts in blood leukocytes from 93 volunteers living in Mexico City with the presence of 13 single nucleotide polymorphisms (SNPs) in genes related to PAH and TSNA metabolism (AhR rs2044853, CYP1A1 rs1048943, CYP1A1 rs1048943, CYP1A1 rs1799814, EPHX1 rs1051740, EPHX1 rs2234922, GSTM1 null, GSTT1 null and GSTP1 rs947894), DNA repair (XRCC1 rs25487, ERCC2 rs13181 and MGMT rs12917) and cell cycle (TP53 rs1042522). (32)P-postlabeling analysis was used to quantify bulky DNA adduct formation. Genotyping was performed using PCR-RFLP. The mean levels of bulky DNA adducts were 8.51±3.66 adducts/10(8) nucleotides (nt) in smokers and 8.38±3.59 adducts/10(8) nt in non-smokers, being the difference not statistically significant. Without taking into account the smoking status, GSTM1 null individuals had a marginally significant lower adduct levels compared with GSTM1 volunteers (p=0.0433) and individuals heterozygous for MGMT Leu/Phe had a higher level of bulky adducts than those who were homozygous wild type (p=0.0170). A multiple regression analysis model showed a significant association between the GSTM1 (deletion) and MGMT rs12917 (Phe/Phe) haplotype and the formation of DNA adducts in smokers (R(2)=0.2401, p=0.0215). The presence of these variants conferred a greater risk for higher adduct levels in this Mexican population.

Measurement of Capsaicinoids in Chiltepin Hot Pepper: A Comparison Study between Spectrophotometric Method and High Performance Liquid Chromatography Analysis

Direct spectrophotometric determination of capsaicinoids content in Chiltepin pepper was investigated as a possible alternative to HPLC analysis. Capsaicinoids were extracted from Chiltepin in red ripe and green fruit with acetonitrile and evaluated quantitatively using the HPLC method with capsaicin and dihydrocapsaicin standards. Three samples of different treatment were analyzed for their capsaicinoids content successfully by these methods. HPLC-DAD revealed that capsaicin, dihydrocapsaicin, and nordihydrocapsaicin comprised up to 98% of total capsaicinoids detected. The absorbance of the diluted samples was read on a spectrophotometer at 215–300 nm and monitored at 280 nm. We report herein the comparison between traditional UV assays and HPLC-DAD methods for the determination of the molar absorptivity coefficient of capsaicin ( and  M−1 cm−1) and dihydrocapsaicin ( and  M−1 cm−1), respectively. Statistical comparisons were performed using the regression analyses (ordinary linear regression and Deming regression) and Bland-Altman analysis. Comparative data for pungency was determined spectrophotometrically and by HPLC on samples ranging from 29.55 to 129 mg/g with a correlation of 0.91. These results indicate that the two methods significantly agree. The described spectrophotometric method can be routinely used for total capsaicinoids analysis and quality control in agricultural and pharmaceutical analysis.

Associations between sperm quality, DNA damage, and CYP1A1, GSTT1 and GSTM1 polymorphisms with 1-hydroxypyrene urinary levels in men occupationally exposed to polycyclic aromatic hydrocarbons

PurposeDuring recent decades, several reports have suggested a decrease in semen quality and DNA damage due in part to environmental toxicants and industrial chemicals. Among these xenobiotics, polycyclic aromatic hydrocarbons (PAHs) are of particular concern because of their remarkable mutagenic and carcinogenic properties and because several experimental and epidemiological studies have reported adverse effects of PAHs on male reproductive health and DNA structure. The aim of the study was to evaluate the association between 1-hydroxypyrene (1-OHP) urinary levels and sperm quality, DNA damage and the frequency of CYP1A1, GSTT1, and GSTM1 polymorphisms.MethodsSemen, urine and blood samples were taken for sperm-quality assessment, 1-OHP urinary level measurement, DNA damage evaluation and polymorphism frequency analysis of three genes implicated in PAH metabolism in a total of 70 Mexican subjects exposed and nonexposed to PAHs.ResultsA significant decrease in sperm quality and increased DNA damage were registered in occupationally exposed volunteers. Polymorphisms modified the 1-OHP urinary levels; however, no associations were found between them. Inverse associations were registered between the sperm concentration/mL and 1-OHP levels and between tail lengths and the GSMT1 null genotype.ConclusionsOur data showed an inverse association between 1-OHP urinary levels and both sperm quality and the DNA integrity. Additionally, the heterozygote variants of CYP1A1-m1 and CYP1A1-m2 significantly increased the urinary excretion of 1-OHP, and the GSTM1 null variant was inversely associated with the comet parameters evaluated.

CHRNA3 rs1051730 and CHRNA5 rs16969968 polymorphisms are associated with heavy smoking, lung cancer, and chronic obstructive pulmonary disease in a mexican population

Smoking is a major public health problem worldwide. Polymorphisms in CHRNA3, CHRNA5, and CHRNB4 receptors play a critical role in nicotine dependence, lung cancer (LC) risk, and chronic obstructive pulmonary disease (COPD). This study characterized the CHRNA3 rs1051730 and CHRNA5 rs16969968 polymorphisms in a Mexican population and its association with nicotine dependence, LC, and COPD.

Differences in 4-hydroxyestradiol levels in leukocytes are related to CYP1A1(∗)2C, CYP1B1(∗)3 and COMT Val158Met allelic variants.

Exposure to estrogen and its metabolites, including catechol estrogens (CEs) and catechol estrogen quinones (CE-Qs) is closely related to breast cancer. Polymorphisms of the genes involved in the catechol estrogens metabolism pathway (CEMP) have been shown to affect the production of CEs and CE-Qs. In this study, we measured the induction of CYP1A1, CYP1B1, COMT, and GSTP1 by 17β-estradiol (17β-E2) in leukocytes with CYP1A1(∗)2C, CYP1B1(∗)3, COMT Val158Met and GSTP1 Ile105Val polymorphisms by semi quantitative RT-PCR and compared the values to those of leukocytes with wild type alleles; we also compared the differences in formation of 4- hydroxyestradiol (4-OHE2) and DNA-adducts. The data show that in the leukocytes with mutant alleles treatment with 17β-E2 up-regulates CYP1A1 and CYP1B1 and down-regulates COMT mRNA levels, resulting in major increments in 4-OHE2 levels compared to leukocytes with wild-type alleles. Therefore, we propose induction levels of gene expression and intracellular 4-OHE2 concentrations associated with allelic variants in response to exposure of 17β-E2 as a noninvasive biomarker that can help determine the risk of developing non-hereditary breast cancer in women.