Fluorescence is used in various biological assays due to its high sensitivity, versatility, and precision. In recent years, studies using medicinal plant extracts have increased. However, fluorescence-based assays could be biased by plant metabolites autofluorescence. To address this issue, this study investigated the interference caused by methanolic extracts and chloroform fractions of three medicinal plants in three fluorescence-based assays on gastric cancer stem cells(CSC): resazurin reduction, confocal microscopy, and flow cytometry. CSC were isolated based on CD44 surface marker, incubated with methanolic extracts and chloroform fractions of Buddleja incana, Dracontium spruceanum, Piper aduncum. Resazurin assay evidenced that CSC exposed to extracts and fractions from the three plants showed significant differences in relative fluorescence units (RFU) levels (p < 0.001) compared to the unexposed groups after a 3-hour incubation. In addition, DMSO-treated CSC exposed to extracts and fractions had significantly lower fluorescence levels than living ones, but higher than extracts and fractions without cells. In confocal microscopy, cancer stem cells exposed to extracts and fractions of B. incana and P. aduncum were observed in the same emission spectra of the CSC markers. In flow cytometry, CSC exposed to extracts and fractions without any fluorescent dyes were detected in the double positive quadrants for CSC markers (CD44+/CD133 + ). Among the three plants, D. spruceanum exhibited the least interference. These results show that methanolic extracts and chloroform fractions contain autofluorescent metabolites that interfere with fluorescence-based assays. These results highlight the importance of a prior evaluation for possible fluorescence interference to avoid interpretation biases in fluorescence assays.

Artificial insemination is an important assisted reproductive technology that has been applied in several mammalian species. However, successful cryopreservation of semen of South American camelids has been limited, hindering the commercial application of artificial insemination in alpaca species. In this scenario, the addition of antioxidants to semen extenders provides a strategy to improve the freezability of mammalian sperm. Bioactive metabolites from natural extracts of black maca have shown valuable antioxidant properties. Thus, the objective of this study was to evaluate the effect of the addition of atomized black maca in the freezing medium of epididymal spermatozoa of alpacas. Fifteen pairs of epididymis were collected from a local slaughterhouse. Each sample was divided into six groups: (1) fresh, (2) yolk medium (YM), (3) 10 mg/mL maca, (4) 20 mg/mL maca, (5) 30 mg/mL maca, and (6) resveratrol (as an antioxidant control). Sperm cryopreservation was performed through the slow freezing method. Markers associated with functionality, such as motility, viability, and plasma membrane integrity, as well as markers associated with oxidative damage, such as DNA integrity, total ROS production, and mitochondrial function, were analyzed. The results show that the supplementation with black maca (20 mg/mL) improved the sperm motility, viability, plasma membrane integrity, and mitochondrial function evaluated according to an index of formazan deposits. Similarly, the ROS production decreased with maca at 20 mg/mL, although the DNA integrity did not show any differences among the groups. These results suggest that maca at 20 mg/mL has cytoprotective effects during freezing/thawing of epididymal sperm of alpaca species. Further research will be focused on assessing the effects of maca supplementation on semen extenders by using biomolecular markers (proAKAP4) associated with fertility.

Physalis peruviana L. often known as goldenberry, has increased its commercial growth in the international market in recent years due to its nutritional value and antioxidant potential. This situation has enabled countries such as Peru to increase their production in order to meet the global demand. However, investigations about the genetic diversity of cultivated and wild populations of goldenberry are still in their early stages. FISH mapping of 5s and 45s rDNA loci and flow cytometry estimation of nuclear DNA content were used to assess genetic differences between wild and cultivated goldenberry populations from Ayacucho and Cajamarca. The majority of metaphases had six 5s rDNA sites for all populations and two and four 45s rDNA sites for the cultivated and wild populations, respectively. We were able to characterize nine different types of chromosomes based on their morphology, fluorescence, rDNA location, and conservation across populations by analyzing the chromosomes that contained rDNA. Furthermore, cultivated populations had more nuclear DNA (13.262±0.087 pg) than wild populations (12.955±0.086 pg). The results show genetic differences between wild and cultivated populations of goldenberry at molecular cytogenetic level as well as in genome size. These findings establish a precedent for future cytogenetic and genomic studies in goldenberry populations, enabling future breeding programs.

The objective of this study was to evaluate the effect of the addition of atomized black Maca in the cryopreservation medium of epididymal spermatozoa of alpaca species. Fifteen pares of testes and epididymis from alpacas of reproductive age were collected from a local (Huancavelica) slaughterhouse and transported in NaCl 0,9% at 10°C to the laboratory. Each sample of epididymal sperm was divided into six groups: 1) Fresh, 2) Yolk medium (YM), 3) YM+10mg/ml Maca, 4) YM+20mg/ml Maca, 5) YM+30mg/ml Maca, and 6) YM+ Resveratrol (antioxidant positive control). Sperm cryopreservation was performed through the slow-freezing method. Markers associated with functionality such as motility, vitality and plasma membrane integrity. Cellular markers associated with oxidative damage, such as DNA fragmentation, total ROS production and lipid peroxidation, were analyzed before and after freezing. The results showed that the supplementation with black Maca at 20mg/ml improved the sperm motility, viability and integrity of the membrane. Similarly, total ROS production decreased with Maca at 10 mg/ml (25 ± 2.23%) and 20mg/ml (20 ± 2.52%) (P<0.05). However, DNA fragmentation and lipid peroxidation were similar in all groups. These results suggest that Maca at 20mg/ml has a protective effect during the freezing/thawing process of epididymal sperm of alpaca species.

Glutathione-S-Transferase T1 (GSTT1) and M1 (GSTM1) are key enzymes involved in phase II detoxification. Null genotypes resulting from gene deletions are known to cause a complete loss of enzymatic activity and have been associated with altered xenobiotic metabolism in previous studies. Although genotype frequencies vary across ethnic groups, data from non-European populations, particularly Andean populations, remain limited. In this cross-sectional study, the frequency of GSTM1 and GSTT1 null genotypes was determined in 206 individuals from Cusco and Junín. Genotyping was performed by PCR using genomic DNA extracted from peripheral blood. The frequency of the GSTM1 null genotype was 49.51%, whereas that of GSTT1 was 25.24%. Combined genotype analysis showed that 63.11% of participants carried at least one null genotype and 11.65% carried both null variants. No significant differences were observed between Cusco and Junín. Compared with previously reported data, these frequencies were similar to those observed in Peruvian coastal and several South American populations. At the intercontinental level, frequencies were comparable to Europe, the Middle East, and Asia but differed from Sub-Saharan Africa and Native American populations. This first molecular characterization of GSTM1 and GSTT1 null genotypes in Andean populations provides a population-specific genetic baseline for pharmacogenetics and precision medicine research in high-altitude settings.

Glutathione-S-Transferase T1 (GSTT1) and M1 (GSTM1) are key enzymes involved in phase II detoxification. Null genotypes resulting from gene deletions lead to a complete loss of enzymatic activity, reducing the capacity to metabolize xenobiotics and increasing the risk of adverse effects. Although genotype frequencies vary across ethnic groups, data from non-European populations, particularly Andean populations, remain limited. In this cross-sectional study, the frequency of GSTM1 and GSTT1 null genotypes was determined in 206 individuals from Cusco and Junín. Genotyping was performed by PCR using genomic DNA extracted from peripheral blood. The frequency of the GSTM1 null genotype was 49.51%, whereas that of GSTT1 was 25.24%. Combined genotype analysis showed that 63.11% of participants carried at least one null genotype and 11.65% carried both null variants. No significant differences were observed between Cusco and Junín. Compared with previously reported data, these frequencies were similar to those observed in Peruvian coastal and several South American populations. At the intercontinental level, frequencies were comparable to Europe, the Middle East, and Asia, but differed from Sub-Saharan Africa and Native American populations. This first molecular characterization of GSTM1 and GSTT1 null genotypes in Andean populations provides a baseline for pharmacogenetics and precision medicine research in high-altitude settings.