Lippia Graveolens Kunth Research Articles

Antifungal Activity of Mexican Oregano (Lippia graveolens Kunth) Extracts from Industrial Waste Residues on Fusarium spp. in Bean Seeds (Phaseolus vulgaris L.)

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.

Solid-State Fermentation for Phenolic Compounds Recovery from Mexican Oregano (Lippia graveolens Kunth) Residual Leaves Applying a Lactic Acid Bacteria (Leuconostoc mesenteroides)

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.

Optimized Ultrasonic Extraction of Essential Oil from the Biomass of Lippia graveolens Kunth Using Deep Eutectic Solvents and Their Effect on Colletotrichum asianum

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.

Antioxidant and Antibacterial Activity of Mexican Oregano Essential Oil, Extracted from Plants Occurring Naturally in Semiarid Areas and Cultivated in the Field and Greenhouse in Northern Mexico.

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.

Long-Term Refrigerated Storage of Beef Using an Active Edible Film Reinforced with Mesoporous Silica Nanoparticles Containing Oregano Essential Oil (Lippia graveolens Kunth).

Beef is a fundamental part of the human diet, but it is highly susceptible to microbiological and physicochemical deterioration which decrease its shelf life. This work aimed to formulate an active edible film (AEF) incorporated with amino-functionalized mesoporous silica nanoparticles (A-MSN) loaded with Mexican oregano (Lippia graveolens Kunth) essential oil (OEO) and to evaluate its effect as a coating on fresh beef quality during refrigerated storage. The AEF was based on amaranth protein isolate (API) and chitosan (CH) (4:1, w/w), to which OEO emulsified or encapsulated in A-MSN was added. The tensile strength (36.91 ± 1.37 MPa), Young's modulus (1354.80 ± 64.6 MPa), and elongation (4.71%) parameters of AEF made it comparable with synthetic films. The antimicrobial activity of AEF against E. coli O157:H7 was improved by adding 9% (w/w) encapsulated OEO, and interactions of glycerol and A-MSN with the polymeric matrix were observed by FT-IR spectroscopy. In fresh beef, after 42 days, AEF reduced the population growth (Log CFU/cm2, relative to uncoated fresh beef) of Brochothrix thermosphacta (5.5), Escherichia coli (3.5), Pseudomonas spp. (2.8), and aerobic mesophilic bacteria (6.8). After 21 days, odor acceptability of coated fresh beef was improved, thus, enlarging the shelf life of the beef and demonstrating the preservation capacity of this film.

Medicinal plants used by rural communities in the arid zone of Viesca and Parras Coahuila in northeast Mexico

This study is the first record of medicinal plants in the southwest of the Coahuila state, an arid zone where extreme dry conditions prevail. One hundred twenty-two residents (in sixteen communities) were interviewed. The residents were questioned with a questionnaire-guided ethnomedical survey protocol about the various plants used. Seventy-seven species of medicinal plants belonging to 36 botanical families were cited. The highest use-value (UV) was calculated for Lippia graveolens Kunth (0.30); Aloe vera (L.) Burm.f. (0.20); Eucalyptus abdita Brooker & Hopper, Chamaemelum nobile (L.) All. (0.16); Mentha spicata L. (0.15) and Salvia officinalis L. (0.10). Informant consensus factor (ICF) about usages of medicinal plants ranges from 0.41 to 0.80; the highest level of agreement was determined between the informants and Respiratory System Diseases (0.80). The highest fidelity level (FL) values (100%) were identified in Flourensia cernua DC., Artisia ludoviciana Nutt., and Parthenium incanum Kunth to Gastro-intestinal System Diseases; Eucalyptus abdita Brooker & Hopper, Bougainvillea berberidifolia Heimerl, and Lippia graveolens Kunth to Respiratory System Diseases (RSD) and Cyclolepis genistoides D.Don and Ephedra antisyphilitica Berland. ex C.A.Mey. to Obstetrics, Gynecology and Urinary tract Diseases. These last two medicinal plant species (“palo azul” and “pitoreal”) used by the rural communities in Viesca in the treatment of urinary tract infections and kidney stones have not been reported previously. These findings can provide new research directions for further phytochemical studies. The present study revealed that the residents are rich in ethno-medicinal knowledge and actively use medicinal plants to treat various diseases. New phytochemical and pharmacological research are needed to confirm the therapeutic potential and safety of the identified plants.

Inhibitory effect of Mexican oregano (Lippia graveolens Kunth) extracts on digestive enzymes in vitro, and beneficial impact on carbohydrates and lipids absorption in vivo

Ethnopharmacological relevanceAlthough Mexican oregano inhibits digestive enzymes in vitro its effect on the absorption of carbohydrates and lipids in vivo has not been addressed. Aim of the studyAssess the effect of Mexican oregano (Lippia graveolens Kunth) on carbohydrates and lipids absorption in vivo. The antioxidant activity also was investigated. Materials and methodsEnzymatic inhibitory action of lipase, α-amylase, and α-glucosidase was evaluated in vitro. Oral lipid (OLTT) and starch tolerance tests (OSTT) were conducted with L. graveolens acetone (O-A) and ethanol (O-E) extracts (at 102 mg/kg body weight equivalent to a 1 g human doses) in male Wistar rats. The antioxidant activity was evaluated through inhibition of lipid peroxidation and scavenging radical. ResultsBoth extracts exhibited higher inhibitory median concentration (IC50) of lipase activity (1.9 μg/μL for O-E and 1.8 μg/μL for O-A) than the positive control (Orlistat) (0.07 μg/μL). The IC50 of α-amylase was higher (41.8 μg/μL for O-E and 25.2 μg/μL for O-A) than the Acarbose (2.5 μg/μL); while α-glucosidase results showed not statistically differences between groups (∼1.7 μg/μL). The OLTT results showed that both extracts significantly reduced serum triglycerides (∼147 mg/dL for O-E and ∼155 mg/dL for O-A) as compared with negative control group (only lipid load). In the OSTT, glucose levels showed a significant decrease (∼31 mg/dL for O-E and ∼17 mg/dL for O-A) than the negative control group (only starch load). About in vitro antioxidant evaluation, not statistically differences between extracts and positive control (Trolox) were observed for scavenged free radicals (∼2.0 μg/μL); whereas O-A inhibited lipid peroxidation similar to the Trolox (∼0.8 μg/μL IC50). The main chemical composition of both extracts was coumaric acid, luteolin, rutinoside, naringenin, and carvacrol. ConclusionsBoth extracts reduce lipid absorption; whereas O-E decreases carbohydrate absorption in vivo. Both extracts inhibit lipid peroxidation and scavenging free radicals in vitro.

Efecto de las condiciones de extracción sobre la concentración de compuestos fenólicos en residuos de orégano mexicano (Lippia graveolens Kunth)

Introduction: Mexican oregano (Lippia graveolens Kunth) leaves are marketed for use in food and for essential oil extraction. Phenolic compounds with antioxidant properties can be obtained from the residues (leaves without oil and stems) under appropriate extraction conditions. Objective: To evaluate the effect of extraction solvent and mass/volume ratio on phenolic compounds concentration and their antioxidant capacity in oregano residues. Materials and methods: Residual leaf (without oil) and stems of oregano were used to obtain extracts with 30, 50 and 80 % aqueous ethanol (ET30, ET50, ET80, respectively) and solvent mass/ volume ratios (1:10, 1:20 and 1:30). Yield in solids, total phenols concentration and flavonoids, and antioxidant capacity were evaluated in the extracts. Similarity analysis between extracts was performed by HPLC-DAD and the main phenols were identified by UPLC-MS. Results and discussion: Extract yields, phenol concentrations and flavonoids and antioxidant capacity for leaves were higher than for stems. The maximum concentration of phenols was obtained with ET80 and 1:30 ratio, which indicates better dissolution in ethanol than in water. The extracts ET50 and ET80 had chromatographic similarity of phenols in both residues; naringenin, taxifolin, eriodictyol, caffeic acid and luteolin were the major compounds. Conclusion: Ethanol-water concentrations and mass/solvent ratios are feasible for obtaining flavonoid and non-flavonoid phenolic compounds with antioxidant capacity from oil-free leaves and stems of oregano.

Mexican Oregano (Lippia graveolens Kunth) as Source of Bioactive Compounds: A Review.

Lippia graveolens is a traditional crop and a rich source of bioactive compounds with various properties (e.g., antioxidant, anti-inflammatory, antifungal, UV defense, anti-glycemic, and cytotoxicity) that is primarily cultivated for essential oil recovery. The isolated bioactive compounds could be useful as additives in the functional food, nutraceuticals, cosmetics, and pharmaceutical industries. Carvacrol, thymol, β-caryophyllene, and p-cymene are terpene compounds contained in oregano essential oil (OEO); flavonoids such as quercetin O-hexoside, pinocembrin, and galangin are flavonoids found in oregano extracts. Furthermore, thermoresistant compounds that remain in the plant matrix following a thermal process can be priced in terms of the circular economy. By using better and more selective extraction conditions, the bioactive compounds present in Mexican oregano can be studied as potential inhibitors of COVID-19. Also, research on extraction technologies should continue to ensure a higher quality of bioactive compounds while preventing an undesired chemical shift (e.g., hydrolysis). The oregano fractions can be used in the food, health, and agricultural industries.

Microbiological and Physicochemical Properties of Meat Coated with Microencapsulated Mexican Oregano (Lippia graveolens Kunth) and Basil (Ocimum basilicum L.) Essential Oils Mixture

Microencapsulated essential oils (EOs) are increasingly used to protect the safety of foods due to their natural origin. The aim of this work was to determine the chemical composition of Mexican oregano (Lippia graveolens Kunth) (MOEO) and basil (Ocimum basilicum L.) (BEO) EOs, their combined effect against E. coli O157:H7, Lactobacillus plantarum, Brochothrix thermosphacta and Pseudomonas fragi, and their effect on microbiological and physicochemical properties of coated pork meat. EOs chemical composition was determined by GC/MS, their microencapsulated mixture (4 mg MOEO/mL/11 mg BEO/mL) was added to a filmogenic dispersion. Fluorescent probes were used to study the antimicrobial filmogenic active dispersion (FD) effect. Pork meat pieces were coated without microencapsulated EOs (CC), using FD (AC), or uncoated (C), vacuum packed and stored 28 days at 4 °C. Thymol (28.9%) and linalool (23.7%) were the major components of MOEO and BEO, respectively. The cell membrane of all bacteria was damaged by contact with FD. FD-coated samples (AC) exhibited the lowest concentration of 2-thiobarbituric acid reacting substances (TBARS) (0.027 ± 0.001 mg malonaldehyde/kg meat) and natural microbiota growth, while odor and color were the most accepted by untrained judges (range > 6). Coatings added with microencapsulated EOs mixture are a natural food preservation alternative to increase the shelf life of refrigerated meat products.

Integrating ecological and socioeconomic criteria in a GIS-based multicriteria-multiobjective analysis to develop sustainable harvesting strategies for Mexican oregano Lippia graveolens Kunth, a non-timber forest product

Mexican oregano is a non-timber forest product harvested in natural vegetation and represents an important source of income for rural families. Recent reports have highlighted decreases in natural populations caused by increased harvest intensity. Oregano leaf harvesting is a complex problem, involving different components and views, and has a clear spatial dimension. We proposed an analytical framework based on multi-criteria-multi-objective analyses. GIS tools were used as the platform for managing, displaying and analyzing ecological and socioeconomic information from different sources in order to evaluate land suitability of three different management strategies for two competing land objectives: oregano Harvest and oregano Regeneration.The incorporation of environmental evaluation criteria in the analysis allowed the identification of new potential oregano harvesting areas which were neither reported by harvesters, nor registered during harvesting trips. Socio-economic criteria, such as land tenure, highlighted the fact that a substantial proportion of current oregano harvesting areas are located outside ejido limits resulting in potential conflicts for resource access. The proposed Balanced oregano management strategy, in which the same proportion of suitable area (50%) was assigned to both objectives, represents the most favorable management strategy. This option allows harvesters to continue earning an income from oregano leaf harvest; and at the same time helps in the selection of the best areas for oregano regeneration. It also represents a management strategy with a smaller impact on oregano populations and on the harvesters´ income, as well as lower monitoring costs. The proposed analytical framework may contribute to advance the application of systematic approaches for solving decision-making problems in areas where oregano leaves and other NTFP are harvested.

Effect of cyclodextrins and Mexican oregano (Lippia graveolens Kunth) chemotypes on the microencapsulation of essential oil

Lippia graveolens (Kunth) essential oil (EO) contains the bioactive compounds carvacrol and thymol in different concentrations according to their chemotype. We evaluated the effect of the essential oil chemical composition, and different cyclodextrins (CD), β- and γ, on the microencapsulation process and its efficiency. Complex formation of L. graveolens EO with β-CD and γ-CD was determined by Scanning Electron Microscopy, X-Ray Diffraction, Thermogravimetric Analysis, and Fourier Transform Infrared Spectroscopy. Carvacrol and thymol concentrations in the γ-CD complexes were higher than in the β-CD complexes, as demonstrated by Gas Chromatography analysis. After 14 days of storage, carvacrol concentration in the β-CD complex remained similar to the initial values; while in the γ-CD complex the concentration was significantly reduced. In the case of thymol concentrations, no significant losses were observed after storage in the complexes obtained with β-CD or γ-CD. Our results confirmed that the microencapsulation of L. graveolens EO with CDs retained the bioactive compounds, carvacrol and thymol. Based on the amount of bioactive terpenes in these complexes and their relative stability, the best combinations to be used as delivery systems were the complexes formed between chemotypes thymol- γ-cyclodextrin and carvacrol-β-cyclodextrin.

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Plant species which produce essential oils are important in the healthcare of rural Guatemalans. Steam distilled essential oils from 22 medicinal plant species were analyzed for activity against tongue, skin, and stomach cancer cell lines using a neutral red assay, Vero C1008 cells to assess cytotoxicity, and [3H]-thymidine incorporation assay to assess inhibition of cancer cell proliferation. IC50, CC50, and therapeutic indices were determined. IC50 values indicated that all oils showed inhibitory activity against one or more cancer cell lines. Highly inhibitory IC50 values (0.10 μL/mL or less) indicated that Citrus aurantiifolia (Christm.) Swingle (Rutaceae) oil was significantly inhibitory to all three cancer cell lines, Origanum vulgare L. (Lamiaceae) and Teloxys ambrosioides (L.) W. A. Weber (Chenopodiaceae) oils were highly inhibitory to two cell lines, and Lippia graveolens Kunth (Verbenaceae) oil was highly inhibitory to one cell line. TI values equal to or greater than one showed significantly higher cytotoxicity to cancer cells compared to the Vero cell line for Ruta chalepensis L. (Rutaceae), Citrus limetta Risso (Rutaceae), C. aurantium L. (Rutaceae), Rosmarinus officinalis L. (Lamiaceae), and O. vulgare. Essential oils from L. graveolens, O. vulgare, and T. ambrosioides yielded high percentages (>96%) of decreased cell proliferation at low oil concentration (0.05 μL/mL). Results indicate that essential oils were more toxic to cancer cells than to cells from an established cell line, and such oils can be highly suppressive to DNA synthesis and cancer cell growth. Key words: Essential oils, medicinal plants, IC50, anticancer activity, Guatemala.

Effect of Nanoemulsified and Microencapsulated Mexican Oregano (Lippia graveolens Kunth) Essential Oil Coatings on Quality of Fresh Pork Meat.

Fresh meat is a highly perishable food. This work aimed to evaluate the influence of Mexican oregano (Lippia graveolens Kunth) incorporated into active coatings (ACs) spread on fresh pork meat as free (FEO), nanoemulsified (NEO), and microencapsulated (MEO) essential oil (EO), on its microbiological, physicochemical and sensory properties during 15 d at 4 ± 1 °C. Thymol and γ-terpinene were identified in the EO. In vitro effect of 2.85 mg EO/cm2 was tested against Brochothrix thermosphacta, Micrococcus luteus, Lactobacillus plantarum, Pseudomonas fragi, and Salmonella Infantis. FEO antioxidant capacity (DPPH assay) was significantly higher than that of thymol, NEO and MEO (93.53%, 89.92%, 77.79%, and 78.50% inhibition, respectively), and similar to BHA (96.03%) and gallic acid (95.57%). FEO, NEO, and MEO ACs on meat caused growth inhibition of lactic acid bacteria (5 log population reduction) and Pseudomonas spp. (4 log reduction), whereas ≤1.5 log population reduction was observed for B. thermosphacta and Salmonella Infantis. Meat microbiota was more efficiently controlled by MEO than by FEO or NEO. ACs delayed lipid and oxymyoglobin oxidation of fresh pork meat. After 15 d of cold storage meat added with EO coatings was desirable for panelists, whereas untreated (UT) samples were undesirable. Active coatings are a significant alternative method for fresh meat preservation.

The antibacterial and antifungal activity of essential oils extracted from Guatemalan medicinal plants

Context: Essential oils are prevalent in many medicinal plants used for oral hygiene and treatment of diseases.Objective: Medicinal plant species were extracted to determine the essential oil content. Those producing sufficient oil were screened for activity against Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans.Materials and methods: Plant samples were collected, frozen, and essential oils were extracted by steam distillation. Minimum inhibitory concentrations (MIC) were determined using a tube dilution assay for those species yielding sufficient oil.Results: Fifty-nine of the 141 plant species produced sufficient oil for collection and 12 species not previously reported to produce essential oils were identified. Essential oil extracts from 32 species exhibited activity against one or more microbes. Oils from eight species were highly inhibitory to S. mutans, four species were highly inhibitory to C. albicans, and 19 species yielded MIC values less than the reference drugs.Discussion: Results suggest that 11 species were highly inhibitory to the microbes tested and merit further investigation. Oils from Cinnamomum zeylanicum Blume (Lauraceae), Citrus aurantiifolia (Christm.) Swingle (Rutaceae), Lippia graveolens Kunth (Verbenaceae), and Origanum vulgare L. (Lamiaceae) yielded highly significant or moderate activity against all microbes and have potential as antimicrobial agents.Conclusion: Teas prepared by decoction or infusion are known methods for extracting essential oils. Oils from 11 species were highly active against the microbes tested and merit investigation as to their potential for addressing health-related issues and in oral hygiene.

Effect of Mexican Oregano (Lippia graveolens Kunth) on Streptozotocin Induced Diabetic Mice and its Role in Regulating Carbohydrate Metabolic Enzymes and Their inhibitory Effect on the Formation of Advanced Glycation end Products

Aim of the Study: The aim was to evaluate the effect of extracts of the leaves of Lippia graveolens in streptozotocin-induced mildly diabetic (MD) and severely diabetic (SD) miceand on the formation of advanced glycation end products (AGEs). Study Design: Diabetes has emerged as a major global challenge in healthcare delivery, particularly in recent times, with the global incidence reaching epidemic proportions. Because of this there is an increasing demand to research for natural products with antidiabetic activity Place and Duration of Study: Laboratory of Natural Products Research. School of chemical engineering, National Polytechnic Institute between August 2013 and April 2014. Methodology: Extracts were orally administered to MD and SD rats for 30 days, and a set of biochemical parameters were studied: glucose, cholesterol, triglycerides, lipid peroxidation, glycogen, SOD, CAT, GSH, GPX, glucose-6-phosphatase, glucokinase, hexokinase activities, SGOT, SGPT, ALP and insulin level. In this study, we investigate the Original Research Article Annual Research & Review in Biology, 4(23): 3470-3491, 2014 3471 inhibitory effects In vitro on the formation of specific AGE representatives including AGEsBSA formation, Amadorin activity, methylglyoxal (MGO). In vivo was to investigate the effect of extracts on oxidative stress, glycation of hemoglobin and MGO, glycolaldehyde (GA) levels, TBA-reactive substance level in kidney mitochondrial instreptozotocin-induced diabetic mice. Results: Methanol extract (LG-M) reduced the intake of food, water and body weight loss as well as levels of blood glucose, serum cholesterol, triglyceride, lipoprotein and increase HDL-cholesterol, antioxidant enzymes, improves TBARS–reactive substance, marker enzymes of hepatic function. These results, support that improves glucose metabolism by reducing insulin resistance. LG-M is an inhibitor of fluorescent AGE, methylglyoxal and the glycation of haemoglobin. Conclusions: This study demonstrated that Lippia graveolens possesses considerable anti-AGE and hepatoprotective role, inhibits hyperglycemic, hyperlipidemic and oxidative stress indicating that these effects may be mediated by interacting with multiple target operating in diabetes mellitus.

Effect of Phytogenic Feed Additives in Soybean Meal on In vitro Swine Fermentation for Odor Reduction and Bacterial Community Comparison.

The effect of different phytogenic feed additives on reducing odorous compounds in swine was investigated using in vitro fermentation and analyzed their microbial communities. Soybean meal (1%) added with 0.1% different phytogenic feed additives (FA) were in vitro fermented using swine fecal slurries and anaerobically incubated for 12 and 24 h. The phytogenic FAs used were red ginseng barn powder (Panax ginseng C. A. Meyer, FA1), persimmon leaf powder (Diospyros virginiana L., FA2), ginkgo leaf powder (Ginkgo biloba L., FA3), and oregano lippia seed oil extract (Lippia graveolens Kunth, OL, FA4). Total gas production, pH, ammonia-nitrogen (NH3-N), hydrogen sulfide (H2S), nitrite-nitrogen (NO2−-N), nitrate-nitrogen (NO3−-N), sulfate (SO4−−), volatile fatty acids (VFA) and other metabolites concentration were determined. Microbial communities were also analyzed using 16S rRNA DGGE. Results showed that the pH values on all treatments increased as incubation time became longer except for FA4 where it decreased. Moreover, FA4 incubated for 12 and 24 h was not detected in NH3-N and H2S. Addition of FAs decreased (p<0.05) propionate production but increased (p<0.05) the total VFA production. Ten 16S rRNA DGGE bands were identified which ranged from 96 to 100% identity which were mostly isolated from the intestine. Similarity index showed three clearly different clusters: I (FA2 and FA3), II (Con and FA1), and III (FA4). Dominant bands which were identified closest to Eubacterium limosum (ATCC 8486T), Uncultured bacterium clone PF6641 and Streptococcus lutetiensis (CIP 106849T) were present only in the FA4 treatment group and were not found in other groups. FA4 had a different bacterial diversity compared to control and other treatments and thus explains having lowest odorous compounds. Addition of FA4 to an enriched protein feed source for growing swine may effectively reduce odorous compounds which are typically associated with swine production.

Acaricidal Effect of Essential Oils From Lippia graveolens (Lamiales: Verbenaceae), Rosmarinus officinalis (Lamiales: Lamiaceae), and Allium sativum (Liliales: Liliaceae) Against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Acaricidal effects of three essential oils extracted from Mexican oregano leaves (Lippia graveolens Kunth), rosemary leaves (Rosmarinus officinalis L.), and garlic bulbs (Allium sativum L.) on 10-d-old Rhipicephalus (Boophilus) microplus (Canestrini) tick larvae were evaluated by using the larval packet test bioassay. Serial dilutions of the three essential oils were tested from a starting concentration of 20 to 1.25%. Results showed that both Mexican oregano and garlic essential oils had very similar activity, producing high mortality (90-100%) in all tested concentrations on 10-d-old R. microplus tick larvae. Rosemary essential oil produced >85% larval mortality at the higher concentrations (10 and 20%), but the effect decreased noticeably to 40% at an oil concentration of 5%, and mortality was absent at 2.5 and 1.25% of the essential oil concentration. Chemical composition of the essential oils was elucidated by gas chromatography-mass spectrometry analyses. Mexican oregano essential oil included thymol (24.59%), carvacrol (24.54%), p-cymene (13.6%), and y-terpinene (7.43%) as its main compounds, whereas rosemary essential oil was rich in a-pinene (31.07%), verbenone (15.26%), and 1,8-cineol (14.2%), and garlic essential oil was rich in diallyl trisulfide (33.57%), diallyl disulfide (30.93%), and methyl allyl trisulfide (11.28%). These results suggest that Mexican oregano and garlic essential oils merit further investigation as components of alternative approaches for R. microplus tick control.

Antioxidant and Antimutagenic Activities of Mexican Oregano (Lippia graveolens Kunth)

Free essential oil methanolic extracts from three different geographical populations of Lippia graveolens in México were screened for antioxidant and antimutagenic properties by the DPPH and Kado microsuspension assay, respectively. Total phenolic and flavonoid contents as well as HPLC identification and quantification of naringenin and rosmarinic acid were also carried out. In addition, a taxonomical phenetic analysis was performed. The L. graveolens extracts showed varying content of phenols and flavonoids. Significant concentration of rosmarinic acid was found for the first time in the species. All the extracts were capable of scavenging DPPH radicals in a concentration dependent fashion; the IC50 values correlate with the phenolic content. None of the extracts was toxic to TA100 and TA98 strains at the concentrations tested; moreover, the extracts at a concentration equivalent to 200 microg of gallic acid inhibited a 39 and 30% the mutagenicity induced by 4-nitro-o-phenylenediamine and sodium azide, respectively. The results suggest that the Mexican oregano is a source of polar bioactive ingredients for the food industry.