Hibiscus sabdariffa (Roselle) is in high demand worldwide due to its beneficial health properties owing to the polyphenols content, mainly in the flower calyx. The objective of this study was to find the best conditions (time and liquid: solid ratio) to extract polyphenols from Roselle using Ultrasound-Assisted Extraction (UAE) (40 kHz, 180 W), with ethanol how solvent; as well as determine the yield of phenols, anthocyanin, flavonoids, tannins, antioxidant activity (DPPH) and antigenotoxic effect (comet assay). A traditional solid-liquid extraction was applied as a reference. Extraction times of 40 and 60 min resulted in the highest polyphenols (13.019 mg GAE/g dry weight (dw)), flavonoids (4.981 CE/g dw), anthocyanins (1.855 mg Cya3GE/g dw), and tannins (0.745 CE/g dw) recoveries and an antioxidant activity (DPPH) of 74.58%. Extracts from white calyces contained similar amounts of phenols and flavonoids, but very little condensed tannins (0.049 CE/g dw) and practically no anthocyanins. Extracts from red and white calyces, showed antigenotoxic activity and repaired capacity of damage caused by mutagens in human lymphocytes.

There is considerable controversy regarding the genotoxicity of glyphosate (N-(phosphonomethyl) glycine). It has been suggested that the genotoxicity of this herbicide is increased by the adjuvants added to commercial formulations based on glyphosate. The effect of various concentrations of glyphosate and three commercial glyphosate-based herbicides (GBH) on human lymphocytes was evaluated. Human blood cells were exposed to glyphosates of 0.1, 1, 10 and 50 mM as well as to equivalent concentrations of glyphosate on commercial formulations. Genetic damage (p < 0.05) was observed in all concentrations with glyphosate and with FAENA and TACKLE formulations. These two commercial formulations showed genotoxicity that was concentration-dependent but in a higher proportion compared to pure glyphosate only. Higher glyphosate concentrations increased the frequency and range of tail lengths of some migration groups, and the same was observed for FAENA and TACKLE, while in CENTELLA the migration range decreased but the frequency of migration groups increased. We show that pure glyphosate and commercial GBH (FAENA, TACKLE and CENTELLA) gave signals of genotoxicity in human blood samples in the comet assay. The genotoxicity increased in the formulations, indicating genotoxic activity also in the added adjuvants present in these products. The use of the MG parameter allowed us to detect a certain type of genetic damage associated with different formulations.

Glyphosate is a controversial herbicide. Its genotoxicity and presence in various ecosystems have been reported. The use of ascorbic acid and resveratrol could protect different organisms from glyphosate-induced genetic damage. In the present study, specific genetic damage induced by glyphosate was evaluated in erythrocytes of Oreochromis niloticus, Ambystoma mexicanum and human lymphocytes. Simultaneously, the antigenotoxic capacity of various concentrations of ascorbic acid and resveratrol was evaluated by means of pretreatment and simultaneous treatment protocols. The 0.03, 0.05 and 0.07 mM concentrations of glyphosate induced significant genotoxic activity (p < 0.05) in human lymphocytes and in erythrocytes of the species studied, and could cause genomic instability in these populations. The reduction in genetic damage observed in human lymphocytes exposed to high concentrations of glyphosate is only apparent: excessive genetic damage was associated with undetectable excessive tail migration length. A significant (p < 0.05) antigenotoxic effect of ascorbic acid and resveratrol was observed in all concentrations, organisms and protocols used. Both ascorbic acid and resveratrol play an important role in maintaining the integrity of DNA. Ascorbic acid in Oreochromis niloticus, Ambystoma mexicanum reduced glyphosate-induced genetic damage to a basal level. Therefore, our data indicate that these antioxidants could help preserve the integrity of the DNA of organisms exposed to glyphosate. The consumption of antioxidants is a useful tool against the genotoxicity of glyphosate.

Satureja macrostema is a plant that is located in various regions of Mexico and is used in a traditional way against illness. Essential oils (EOs) were obtained from leaves Satureja macrostema and the chemical composition was evaluated by gas chromatography–mass spectrometry (GC-MS). The antioxidant effect of the oil was assayed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and by Trolox Equivalent Antioxidant Capacity (TEAC). In vitro antibacterial activity against Escherichia coli and Staphylococcus aureus was determined using a broth microdilution assay and thin layer chromatography–direct bioautography (TLC-DB) to identify active antibacterial compounds. The EOs analysis showed 21 compounds, 99% terpenes, and 96% oxygenated monoterpenes, with trans-piperitone epoxide (46%), cis-piperitone epoxide (22%), and piperitenone oxide (11%) as more abundant compounds. Likewise, S. macrostema EOs showed an antioxidant activity of DPPH = 82%, with 50% free radical scavenging (IC₅₀) = 7 mg/mL and TEAC = 0.005, an antibacterial effect against E. coli of 73% inhibition, and 81% over S. aureus at dose of 100 µL of undiluted crude oil. The TLC-DB assay showed that the most active compounds were derived from piperitone. The comparison with other studies on S. macrostema shows variability in the compounds and their abundances, which can be attributed to climatic factors and the maturity of plants with similar antioxidant and antibacterial activities.

A new point of view for genetic damage assessment using the comet assay is proposed based on the number of migration groups, the number of comets in each group, and the groups with the highest number of comets. Human lymphocytes were exposed to different concentrations of Methyl Methane Sulfonate (MMS), Maleic Hydrazide (MH), 2,4-Dichlorophenoxyacetic (2,4-D), and N-nitroso diethylamine (NDEA). Using comet assay, the migration means of the comets were determined and later grouped arbitrarily in migration groups with no higher differences than 1 µc. The number of migration groups, the number of comets in each group, and the groups with the highest number of comets (modes) were determined. All four of the genotoxic agents studied showed a significant increase (p < 0.05) in the tail length and the number of migration groups compared to the negative control. The number of migration groups did not show a significant variation between the four-genotoxic agents nor within their different concentrations. However, the comparison of the modes did show differences between the genotoxic agents, but not within the concentrations of a same genotoxic agent, which indicated a determined chemical interaction on the DNA. These parameters can improve the detection of genetic damage associated with certain genotoxic agents.

Mistletoe ( Psittacanthus calyculatus ) is used for the prevention and treatment of numerous diseases. Samples of leaves from P. calyculatus were collected in April of 2019, and prepared an aqueous extract. The extract was lyophilized, and its polyphenols, flavonoids, and anthocyanins content...