Search Results (29)

Some oregano species have been related to antiproliferative activity against various types of cancer cells, such as colon, liver, and breast; this has been mainly associated with their rich content of flavonoid-type compounds due to their ability to induce the activation of intracellular signaling pathways, such as apoptosis induction. This study aimed to determine the antiproliferative activity mechanism of the polyphenol extract of Mexican oregano (Lippia graveolens Kunth) on MDA-MB-231 breast cancer cells. The flavonoid content with the antiproliferative potential was quantified by ESI-QTOF-MS/MS chromatography, finding naringenin in a higher concentration (7758.71 µg/g extract) compared to the other identified compounds (quercetin, luteolin, and apigenin). Subsequently, the cytotoxicity of the extract was evaluated in the normal human fibroblasts CCD-18Co cell line, where the extract did not present cytotoxic activity at the evaluated concentration (150 µg/mL). In MDA-MB-231 cells treated with the same extract concentration, the activation of proteins associated with apoptosis was observed by western blot. Therefore, the previous antiproliferative activity shown by this extract on breast cancer cells may be due to the activation of this cell death pathway. Thus, the polyphenol extract of Mexican oregano L. graveolens has the potential for future research as an adjuvant in treating breast cancer. Full article

This work reports the synthesis of two monometallic catalysts, Cu/Al₂O_3, and Pd/Al₂O₃, using a green approach based on Mexican oregano (Lippia graveolens), a common food condiment. Its extract has been largely overlooked as a high-technology reactive for synthesizing catalysts, metallic or oxide nanoparticles, unlike other green leaf plants. The green synthesis was compared with a conventional catalyst synthesis methodology using commercial chemical reducing agents. Oregano extract shows promise for novel applications extending beyond its culinary use, valorizing it as a chemical reducer to produce catalysts. Thus, this kind of application could significantly elevate the value of oregano, empowering communities that rely on its cultivation for economic benefit and transforming the plant from a low-profit agro-industrial product to a high-added-value crop. The reduction kinetics involved in the formation of nanoparticles were monitored up to the first stage of nucleation and a first-order model adequately described the data. Activation energy analysis showed that the chemical reaction mechanism has a dominant role in controlling the reaction, compared to mass transfer effects. Notoriously, the Pd/Al₂O₃ green synthesis catalyst showed the smallest mean particle size (4.85 ± 1.30 nm). These findings underscore the potential of green synthesis as an economically viable and environmentally friendly alternative for producing catalysts. Concerning the 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) as a biomass-derived molecule, its oxidation with H₂O₂ using both Pd/Al₂O₃ catalysts (by green and chemical synthesis methods) exhibited significantly higher selectivity toward 2,5-diformylfuran (DFF) compared to Cu/Al₂O₃ catalysts, suggesting a possible inhibitory effect. Full article

Strongyloidiasis represents a public health problem in tropical and subtropical regions. The medicinal plants demonstrate the potential of plants as a source of molecules with helminthic activity. In this research, we assessed the potential of five extracts medicinally used in Mexico against Strongyloides venezuelensis third-stage infective larvae (L3). Plant methanol (MeOH) extracts of Argemone mexicana (chicalote), Jatropha dioica (Sangre de Drago), Lippia graveolens (oregano), Thymus vulgaris (tomillo), and Kalanchoe daigremontiana (aranto) were prepared by the maceration technique. The toxicity of the extracts was evaluated in human red blood cells by the hemolysis test and in monkey kidney epithelial cells (Vero cells) using the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, we showed their antioxidant potential by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The methanolic extracts of A. mexicana, J. dioica, L. graveolens, and T. vulgaris exhibited significant activity against L3 cultures at 72 and 96 h post-incubation. None of the extracts showed hemolytic effects on red cells or Vero cells. L. graveolens demonstrated the strongest antioxidant activity, with an EC₅₀ of 19.80 µg/mL. Plant MeOH extracts used in this study showed a promising anthelmintic effect in vitro, making it a suitable candidate for future research in nematocidal therapies. Full article

Botanical extracts are being considered for integration into disease management programs to control plant pathogenic fungi and oomycetes. A promising extract with potential is the essential oil of Lippia graveolens. However, its extraction process has not been optimized. Since optimizing process conditions can impact fungicidal and/or oomyceticidal effects, this research implemented time, temperature, and solid/liquid ratio conditions to maximize the fungicidal and oomyceticidal effects. The effectiveness was evaluated through parameters of mycelial growth inhibition, spore germination inhibition, minimum inhibitory and fungicidal/oomyceticidal concentration for the fungi Gilbertella persicaria, Agroathelia rolfsii, and Colletotrichum gloeosporioides, as well as the oomycete Phytophthora capsici. Optimal conditions were as follows: time: 46.27 min; temperature: 329.34 °C; and solid/liquid ratio: 80.35 g/L. In general, the optimized treatment was more effective in A. rolfsii ≥ P. capsica > G. persicaria ≥ C. gloeosporioides in all assays. These results demonstrate the fungicidal and oomiceticidal effects of L. graveolens essential oil, with potential for commercial product formulation. Full article

Balamuthia mandrillaris is a free-living amoeba pathogenic to humans, causing amoebic granulomatous encephalitis (GAE). Due to the associated mortality rates of <95%, the absence of treatments, and a clear understanding of the pathogenesis of this amoeba, Lippia graveolens could be an interesting alternative since it has been used against bacteria, fungi, and other pathogenic protozoa. This study employed RNA sequencing to analyze differentially expressed genes (DEGs), following treatment with two fractionated L. graveolens extracts (concentration: 150 µg/mL) at 48, 96, and 120 h. The DEGs identified are associated with several functions such as stress responses (Prohibitin domain-containing protein), and oxidative damage repair and cell stability (Peroxiredoxin). Genes implicated in virulence and host interaction also showed significant expression changes, such as the ADP ribosylation factor (Arf) GTPase and ephrin type-A receptor, alongside transcription factors involved in the phagocytosis of amoebas. Additionally, the analysis of Gene Ontology categories revealed terms including transmembrane signaling receptor and protein tyrosine activity, DNA replication initiation, the mitotic M phase, and membrane integrity. These results provide valuable insights into the molecular mechanisms utilized by B. mandrillaris to respond to environmental stressors and the repression of genes related to essential functions, which could serve as potential targets for developing novel strategies. Full article

Food security is essential to ensure everyone can access sufficient nutritious food. Cereals and legumes are fundamental foods worldwide. Phaseolus vulgaris L., the common bean, is an essential staple food in many nations worldwide. However, it is vulnerable to fusariosis, a disease caused by the fungus Fusarium spp. that can significantly decrease crop quality and yield. To combat plant diseases, industrial residues and plant residues are valuable due to their bioactive compounds with biotechnological applications. This study proposes using ethanolic extracts with phytochemical compounds, such as flavonoids, different from those reported in essential oils, to reduce the growth of Fusarium species both in vitro and in vivo. Industrial residues that are produced after extracting essential oils offer a promising alternative to develop organic biopesticides, promoting more sustainable and environmentally friendly agriculture. Full article

The Mexican oregano by-products are a source of bioactive molecules (polyphenols) that could be extracted using solid-state fermentation (SSF). This study fermented the by-products via SSF (120 h) with a lactic acid bacteria (LAB) Leuconostoc mesenteroides. Sequentially, a bioactive and chemical determination was made according to the phenolic content, antioxidant activity (DPPH^●/FRAP), bioactive properties (α-amylase inhibition and antimicrobial activity against Escherichia coli), and chemical composition (HPLC-MS). The results showed that the total phenolics and flavonoid content, as well as the antioxidant activity, increased (0.60, 2.55, and 3.01 times, respectively) during the SSF process compared with unfermented material. Also, the extracts showed antimicrobial activity against E. coli and α-amylase inhibition. These inhibitory results could be attributed to bioactive compounds identified via HPLC, such as gardenin B, trachelogenin, ferulic acid, and resveratrol 3-O-glucoside. Therefore, the application of L. mesenteroides under SSF on oregano by-products comprises an eco-friendly strategy for their valorization as raw materials for the recovery of phenolic compounds that could be natural alternatives against synthetic antioxidant and antimicrobial agents, promoting a more circular and sustainable supply system within the oregano industry. Full article

Essential oils are emerging as alternatives to conventional pest control chemicals. Lippia graveolens Kunth (Mexican oregano) is a source of essential oils and during conventional extraction, the biomass generated is discarded as waste; however, reports show that this biomass is still a rich source of essential oils. Conventional essential oil extraction causes contamination and utilizes toxic solvents. Deep eutectic solvents (DESs) offer low toxicity, biodegradability, high selectivity, and yields comparable to organic solvents. This study obtained essential oil from Lippia graveolens biomass via hydrodistillation with ultrasound-assisted DES pretreatment. This research aimed to optimize the extraction of essential oil from Lippia graveolens biomass using ultrasound-assisted DESs and assess its in vitro and in vivo inhibitory effect on C. asianum. The response variables were extraction yield and total reducing capacity. Optimal conditions were determined using a central composite rotatable design, considering solid-to-liquid ratio (0.38 g/mL), ultrasonic amplitude (45.05%), and time (7.47 min). The optimized oil, with thymol (48%) as the predominant component, exhibited more volatile compounds than conventional hydrodistillation. Fungicidal assays highlighted its potential in controlling anthracnose in papaya fruits caused by C. asianum, making ultrasound-assisted DES pretreatment a promising alternative for obtaining essential oil from botanical byproducts. Full article

This research focuses on assessing the synergistic effects of Mexican oregano (Lippia graveolens) essential oil or carvacrol when combined with the antibiotic imipenem, aiming to reduce the pathogenic viability and virulence of Acinetobacter baumannii and Pseudomonas aeruginosa. The study highlighted the synergistic effect of combining L. graveolens essential oil or carvacrol with imipenem, significantly reducing the required doses for inhibiting bacterial growth. The combination treatments drastically lowered the necessary imipenem doses, highlighting a potent enhancement in efficacy against A. baumannii and P. aeruginosa. For example, the minimum inhibitory concentrations (MIC) for the essential oil/imipenem combinations were notably low, at 0.03/0.000023 mg/mL for A. baumannii and 0.0073/0.000023 mg/mL for P. aeruginosa. Similarly, the combinations significantly inhibited biofilm formation at lower concentrations than when the components were used individually, demonstrating the strategic advantage of this approach in combating antibiotic resistance. For OXA-51, imipenem showed a relatively stable interaction during 30 ns of dynamic simulation of their interaction, indicating changes (<2 nm) in ligand positioning during this period. Carvacrol exhibited similar fluctuations to imipenem, suggesting its potential inhibition efficacy, while thymol showed significant variability, particularly at >10 ns, suggesting potential instability. With IMP-1, imipenem also displayed very stable interactions during 38 ns and demonstrated notable movement and positioning changes within the active site, indicating a more dynamic interaction. In contrast, carvacrol and thymol maintained their position within the active site only ~20 and ~15 ns, respectively. These results highlight the effectiveness of combining L. graveolens essential oil and carvacrol with imipenem in tackling the difficult-to-treat pathogens A. baumannii and P. aeruginosa. Full article

The sand fly, Phlebotomus papatasi (Scopoli, 1786), is a major vector for Leishmania major in the Middle East, which has impacted human health and US military operations in the area, demonstrating the need to develop effective sand fly control and repellent options. Here, we report the results of spatial repellency and avoidance experiments in a static air olfactometer using the female P. papatasi testing essential oils of Lippia graveolens (Mexican oregano), Pimenta dioica (allspice), Amyris balsamifera (amyris), Nepeta cataria (catnip), Mentha piperita (peppermint), and Melaleuca alternifolia (tea tree); the 9–12 carbon saturated fatty acids (nonanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid); and the synthetic repellents DEET and IR3535. The materials applied at 1% exhibited varying activity levels but were not significantly different in mean repellency and avoidance from DEET and IR3535, except in regards to nonanoic acid. Some materials, particularly nonanoic and undecanoic acids, produced sand fly mortality. The observed trends in mean repellency over exposure time included the following: (1) P. dioica oil, M. alternifolia oil, decanoic acid, undecanoic acid, DEET, and IR3535 exhibited increasing mean repellency over time; (2) oils of N. cataria, A. balsamifera, M. piperita, and dodecanoic acid exhibited relatively constant mean repellency over time; and (3) L. graveolens oil and nonanoic acid exhibited a general decrease in mean repellent activity over time. These studies identified the essential oils of N. cataria and A. balsamifera as effective spatial repellents at reduced concentrations compared to those of DEET. Additional research is required to elucidate the modes of action and potential synergism of repellents and essential oil components for enhanced repellency activity. Full article

Strawberries (Fragaria xannanasa) are susceptible to mechanical, physical, and physiological damage, which increases their incidence of rot during storage. Therefore, a method of protection is necessary in order to minimize quality losses. One way to achieve this is by applying polymer coatings. In this study, multisystem coatings were created based on polymer nanocapsules loaded with Lippia graveolens essential oil, and it was found to have excellent optical, mechanical, and water vapor barrier properties compared to the control (coating formed with alginate and with nanoparticles without the essential oil). As for the strawberries coated with the multisystem formed from the polymer nanocapsules loaded with the essential oil of Lippia graveolens, these did not present microbial growth and only had a loss of firmness of 17.02% after 10 days of storage compared to their initial value. This study demonstrated that the multisystem coating formed from the polymer nanocapsules loaded with the essential oil of Lippia graveolens could be a viable alternative to preserve horticultural products for longer storage periods. Full article

Essential oils are known to exhibit diverse antimicrobial properties, showing their value as a natural resource. Our work aimed to investigate the primary mode of action of Cuban Lippia graveolens (Kunth) essential oil (EO) against Salmonella enterica subsp. enterica serovar Typhimurium (S. enterica ser. Typhimurium). We assessed cell integrity through various assays, including time-kill bacteriolysis, loss of cell material with absorption at 260 and 280 nm, total protein leakage, and transmission electron microscopy (TEM). The impact of L. graveolens EO on membrane depolarization was monitored and levels of intracellular and extracellular ATP were measured by fluorescence intensity. The minimum inhibitory and bactericidal concentrations (MIC and MBC) of L. graveolens EO were 0.4 and 0.8 mg/mL, respectively. This EO exhibited notable bactericidal effects on treated cells within 15 min without lysis or leakage of cellular material. TEM showed distinct alterations in cellular ultrastructure, including membrane shrinkage and cytoplasmic content redistribution. We also observed disruption of the membrane potential along with reduced intracellular and extracellular ATP concentrations. These findings show that L. graveolens EO induces the death of S. enterica ser. Typhimurium, important information that can be used to combat this foodborne disease-causing agent. Full article

Acinetobacter baumannii is a nosocomial pathogen known for its ability to form biofilms, leading to persistent infections and antibiotic resistance. The limited effective antibiotics have encouraged the development of innovative strategies such as using essential oils and their constituents. This study evaluated the efficacy of oregano (Lippia graveolens) essential oil (OEO) and its terpene compounds, carvacrol and thymol, in inhibiting A. baumannii biofilms. These treatments showed a minimum inhibitory concentration of 0.6, 0.3, and 2.5 mg/mL and a minimum bactericidal concentration of 1.2, 0.6, and 5 mg/mL, respectively. Sub-inhibitory doses of each treatment and the OEO significantly reduced biofilm biomass and the covered area of A. baumannii biofilms as measured by fluorescence microscopy. Carvacrol at 0.15 mg/mL exhibited the most potent efficacy, achieving a remarkable 95% reduction. Sub-inhibitory concentrations of carvacrol significantly reduced the biofilm formation of A. baumannii in stainless steel surfaces by up to 1.15 log CFU/cm² compared to untreated bacteria. The OEO and thymol exhibited reductions of 0.6 log CFU/cm² and 0.4 log CFU/cm², respectively, without affecting cell viability. Moreover, the terpenes inhibited twitching motility, a crucial step in biofilm establishment, with carvacrol exhibiting the highest inhibition, followed by OEO and thymol. The study provides valuable insights into the potential of terpenes as effective agents against A. baumannii biofilms, offering promising avenues for developing novel strategies to prevent persistent infections and overcome antibiotic resistance. Full article

In recent years, the determination of the antioxidant and antibacterial activity of essential oils in wild plants, such as Mexican oregano (Lippia graveolens Kunth), has become increasingly important. The objective was to compare the antioxidant and antibacterial activity of Mexican oregano essential oil obtained from plants occurring naturally in semiarid areas (Wild1 and Wild2), and those cultivated in the field (CField) and greenhouse (CGreenhouse) in northern Mexico. The Mexican oregano essential oil extraction was performed using the hydrodistillation method, the antioxidant activity was determined using the ABTS method, and the antibacterial activity was assessed through bioassays under the microwell method at nine different concentrations. The aim was to determine the diameter of the inhibition zone and, consequently, understand the sensitivity level for four bacterial species. The results revealed an antioxidant activity ranging from 90% to 94% at the sampling sites, with Wild1 standing out for having the highest average antioxidant activity values. Likewise, six out of the nine concentrations analyzed showed some degree of sensitivity for all the sampling sites. In this regard, the 25 µL mL⁻¹ concentration showed the highest diameter of inhibition zone values, highlighting the Wild2 site, which showed an average diameter greater than 30 mm for the four bacteria tested. Only in the case of S. typhi did the CGreenhouse site surpass the Wild2, with an average diameter of the inhibition zone of 36.7 mm. These findings contribute to the search for new antioxidant and antibacterial options, addressing the challenges that humanity faces in the quest for opportunities to increase life expectancy. Full article

Lippia graveolens is one of the most important aromatic species in Mexico due to antioxidant and antibiotic activities reported in its essential oil. The aim of this work was to assess the effect of irrigation with aquaculture wastewater and salicylic acid addition on the production of phenolic compounds in L. graveolens. L. graveolens plants (14) were irrigated with aquaculture wastewater and (14) using Steiner solution for 28 days; at the same time, salicylic acid was exogenously applied at 0.0 (control), 0.5 and 1.0 mM concentrations in both treatments at 5 and 19 experimental days. The total phenolic content was measured by Folin–Ciocalteu, the flavonoid content was determined by the aluminum chloride method, and the antioxidant capacity was measured by DPPH and FRAP assays. The results showed an increase in the total phenolic and flavonoid content in plants irrigated with aquaculture wastewater solution (17.25 ± 2.35 to 38.16 ± 4.47 mg eq GA·g⁻¹ W). The antioxidant capacity was higher in plants irrigated with Steiner solution (98.52 mg eq T·g⁻¹ W). In conclusion, L. graveolens irrigated with aquaculture wastewater leads to an increase in the total phenolic content and Steiner-solution antioxidant capacity in plants. Full article