Mikania micrantha silver nanoparticles exhibit anticancer activities against human lung adenocarcinoma via caspase-mediated apoptotic cell death

Green-mediated synthesis of nanoparticles has earned a promising role in the area of nanotechnology due to their biomedical applications. This study describes the synthesis of silver nanoparticles (AgNPs) using Mikania micrantha leaf extract and its functional activities against cancer. The synthesis of AgNPs was confirmed using Ultraviolet-Visible (UV-Vis) spectrum that exhibited an absorption band at 459 nm. The bioactive compounds of M. micrantha leaf extract that functioned as reducing and capping agents were confirmed by a shift in the absorption bands in Fourier Transform Infra-red Spectroscopy (FT-IR). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) studies validated the spherical shape and size of AgNPs, respectively. Energy Dispersive Spectroscopy (EDS) analysis revealed the presence of elemental silver. The crystalline nature of AgNPs was confirmed by the X-ray Diffraction Analysis (XRD). AgNPs effectively induced cytotoxicity and prevented A549 cell colony formation in a dose-dependent manner. Treatment of A549 cells with AgNPs also increased DNA damage, which was coupled with elevated lipid peroxidation and decreased antioxidant enzymes such as glutathione (GSH), glutathione-s-transferase (GST), and superoxide dismutase (SOD). Following AgNPs treatment, the mRNA expression levels of the pro-apoptotic genes as well as the activities of caspases were significantly elevated in A549 cells while the expression levels of anti-apoptotic genes were downregulated. Our study demonstrates the potential of the synthesised AgNPs for cancer therapy possibly targeting the apoptotic pathway.

Research on the antipruritic active ingredients of Mikania micrantha

Mikania micrantha is a perennial liana of the genus Mikania of the Asteraceae family. It is a commonly used medicine in South America for treating fever, malaria, dysentery, snake bites, etc. Because of its strong adaptability and ability to inhibit the growth of its associated plants, Mikania micrantha is considered an invasive species in China and is known as a plant killer. Preliminary studies have shown that Mikania micrantha has an antipruritic effect, but the antipruritic active substance is not yet clear. In this study, a 4-aminopyridine-induced itching model in mice was used to determine the antipruritic effects of petroleum ether, ethyl acetate, ethanol extraction site, and Mikania micrantha volatile oil. GC-MS was used to analyze the components of the antipruritic fractions, combined with mice itch-causing models to study the antipruritic effects of β-caryophyllene and humulene. The safety of β-caryophyllene was preliminarily evaluated through the acute toxicity test of mice skin. The ethyl acetate and volatile oil of Mikania micrantha have apparent antipruritic effects. Humulene and β-caryophyllene have a quantitative-effective relationship to inhibit itching in mice. The acute toxicity test of mouse skin showed that β-caryophyllene has no acute toxicity. This study indicated that the main antipruritic active ingredients of Mikania micrantha are β-caryophyllene and humulene.

Safety evaluation of Mikania glomerata and Mikania laevigata in healthy volunteers: A randomized, open label and multiple dose phase I clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Mikania glomerata (MG) and Mikania laevigata (ML) leaves are used interchangeably in Brazilian ethno-medicine, mainly for the treatment of respiratory diseases, but there is no clinical trial for the safety evaluation of these species at different doses.

AIM OF THE STUDY

To evaluate the safety of two oral solutions from each species, across two weeks of use and two doses.

MATERIALS AND METHODS

A randomized, open-label, multiple dose, two-arm trial. Participants (n = 19) were randomly allocated to one of the arms of the trial. Group 1 received 15 mL of MG oral solution twice daily for 7 days and then 30 mL twice daily for 7 days. Group 2 received ML oral solution in the same manner. After 14 days, the participants went through a washout period of 7 days before cross-over to the other group. Adverse events (AEs), clinical parameters and blood markers were monitored at the beginning (T0) and at the end of each week of the study, which was concluded after six weeks. AEs were classified as mild, moderate or severe, and according to their correlation with the medicine intake, the measured parameters were compared to T0 by generalized estimating equations (GEE) to determine those affected by the use of the oral solutions (p < 0.05).

RESULTS

MG was not correlated to any of the reported AEs; its use affected three of the evaluated parameters: total protein, diastolic blood pressure and urea, although all the changes were within the normal range for healthy individuals. ML was correlated to one moderate AE of pyrosis and the alteration of 12 parameters: erythrocytes, hemoglobin, hematocrit, monocytes, time of prothrombin, time of thromboplastin, albumin, alkaline phosphatase, total protein, urea, potassium and sodium. All changes were within the normal range for healthy individuals.

CONCLUSION

ML and MG are considered safe for humans under the dose regimen tested.

Mikania micrantha Kunth: An Ethnopharmacological Treasure Trove of Therapeutic Potential

Mikania micrantha is utilized as a therapeutic for the treatment of various human ailments including insect bites, rashes and itches of skin, chicken pox, healing of sores and wounds, colds and fever, nausea, jaundice, rheumatism, and respiratory ailments. This study aimed at summarizing the traditional uses, phytochemical profile, and biological activities of M. micrantha based on obtainable information screened from different databases. An up-to-date search was performed on M. micrantha in PubMed, Science Direct, clinicaltrials.gov, and Google Scholar databases with specific keywords. No language restrictions were imposed. Published articles, theses, seminar/conference papers, abstracts, and books on ethnobotany, phytochemistry and pharmacological evidence were considered. Based on the inclusion criteria, this study includes 53 published records from the above-mentioned databases. The results suggest that fresh leaves and whole plant are frequently used in folk medicine. The plant contains more than 150 different phytochemicals under the following groups: essential oils, phenolics and flavonoids, terpenes, terpene lactones, glycosides, and sulfated flavonoids. It contains carbohydrates and micronutrients including vitamins and major and trace minerals. M. micrantha possesses antioxidant, anti-inflammatory, anti-microbial, anti-dermatophytic, anti-protozoal, anthelmintic, cytotoxic, anxiolytic, anti-diabetic, lipid-lowering and antidiabetic, spasmolytic, memory-enhancing, wound-healing, anti-aging, and thrombolytic activities. No clinical studies have been reported to date. M. micrantha might be one of the potential sources of phytotherapeutic compounds against diverse ailments in humans. Studies are required to confirm its safety profile in experimental animals prior to initiating clinical trials. Moreover, adequate investigation is also crucial to clarify exact mechanism of action for each biological effect.

Phytochemical and underlying mechanism of Mikania micrantha Kunth on antibiotic resistance genes, and pathogenic microbes during chicken manure composting

Chicken manure is a source of antibiotic resistance genes (ARGs) and pathogenic microbes. Mikania micrantha Kunth (MM) is an invasive plant containing phytochemicals as antimicrobial agents. To explore its impacts on ARGs and pathogen-host interactions (PHIs), MM was added to composting mixtures. The findings indicated that compared with control (CK), MM significantly improved the phytochemical abundances, particularly stilbenoids and diarylheptanoids (4.87%), and ubiquinones (2.66%) in the treatment (T) compost. Besides, significant ARGs reduction was noted, where rpoB2, RbpA, FosB1, vatC, and vatB were removed from T compost. PHIs significantly declined in T compost, where the growth of Xanthomonas citri, Streptococcus pneumoniae, Fusarium graminearum, Vibrio cholerae, and Xanthomonas campestris were inhibited. Multiple variable analyses demonstrated that temperature and pH revealed a significant role in ARGs and PHIs decline. Accordingly, this study considerably recommends MM as a promising compost additive in terms of its antimicrobial potential toward pathogenic microbes and ARGs.

High-capacity removal of oxytetracycline hydrochloride from wastewater via Mikania micrantha Kunth-derived biochar modified by Zn/Fe-layered double hydroxide

Antibiotic contamination in water has been an increasing global concern, and how to effectively remove antibiotics (e.g., oxytetracycline [OTC] hydrochloride) from wastewater becomes imperative. In this study, the biochar derived from an invasive plant (Mikania micrantha Kunth) was synthesized with Zn/Fe- layered double hydroxide (LDH) by co-precipitation method (ZnFe-LDH/MBC) to remove OTC from water. ZnFe-LDH/MBC posed the highest OTC removal performance of 426.61 mg/g. ZnFe-LDH/MBC exhibited stability and efficiency in OTC adsorption at different pH levels and under interfering conditions with co-existing ions, as well as outstanding regeneration capabilities during adsorption-desorption cycles. Furthermore, the removal of OTC by ZnFe-LDH/MBC was mediated by several processes including pore filling, hydrogen bonding force, electrostatic interaction, π-π interaction, as well as complexation. Consequently, ZnFe-LDH/MBC has excellent potential for the purification of OTC pollutants that is low-cost, efficient, and environmentally friendly.

Effects of elevated CO2 concentration and nitrogen addition on foliar phosphorus fractions of Mikania micranatha and Chromolaena odorata under low phosphorus availability

Invasive plants rapidly spread in habitats with low soil phosphorus (P) availability and have triggered a sharp decline in the diversity of native species. However, no studies have explored how widespread invasive species acclimate to low soil P availability via changing foliar P fractions, especially under elevated atmospheric CO₂ concentrations ([CO₂ ]) and nitrogen (N) deposition. Here, an open-top chamber experiment was conducted to explore the effect of nutrient addition and elevated [CO₂ ] on leaf traits and foliar functional P fractions (i.e., Pi, metabolite P, lipid P, nucleic acid P, and residual P) of two aggressive invasive species (Mikania micranatha and Chromolaena odorata). We found that foliar N/P ratios were more than 20, and P addition significantly increased plant biomass. Both results indicated P-limited plant growth at our studied site. Elevated [CO₂ ], N and N + P addition greatly increased plant biomass, photosynthetic rates, and photosynthetic P-use efficiency (PPUE) in invasive species, but PPUE decreased with increasing P addition. Nitrogen addition slightly decreased the concentration of leaf total P, decreased foliar residual P, but increased metabolite P concentrations in invasive species. Similar changes in foliar P fractions were found under N + P addition. Phosphorus addition increased foliar P concentrations, which was strongly correlated with an increase in metabolite P concentrations in invasive species. Elevated [CO₂ ] alleviated these effects and increased PPUE. The present results suggest that future elevated [CO₂ ] and N deposition allow the invasive species to acclimate to low soil P availability and support their successful invasion by greatly reducing P allocation to non-metabolite foliar P fractions (i.e., nucleic acid P and residual P) to meet their demand of metabolite P for photosynthesis and exhibit a high PPUE.

Adventitious roots support population expansion of the invasive plant Mikania micrantha Kunth

Mikania micrantha Kunth is a serious invasive alien plant characterized by the formation of an adventitious root system in its prostrate growth form. Unlike the initial roots from seed germination, adventitious roots gradually appear above the stem and branch nodes. Little is known about adventitious roots play on plant growth and population expansion of M. micrantha. We hypothesized that adventitious roots provide an advantage for plant growth and nutrient availability. To test this hypothesis, plant growth, physiology, and nutrition characteristics of M. micrantha were measured under four soil surface conditions allowing various plant parts to touch the soil to stimulate variable adventitious root formation. The results showed that the biomass, stem length, branch number, and adventitious root biomass of M. micrantha were significantly increased (P < 0.05) with increasing nodes bearing adventitious roots. As the number of nodes with adventitious roots increased, the net photosynthetic rate, antioxidant enzyme activities like superoxide dismutase, catalase, peroxidase, and malondialdehyde, chlorophyll content, and plant nutrient contents (N, P, and K) of M. micrantha were increased (P < 0.05), with higher values in main stem leaves than in those of branch leaves. The concentrations of soil organic matter, total N, total P, total K, available N, available P, and available K were greater (P < 0.05) in initial soil (CK) than in treatment soil (with M. micrantha) and were significantly reduced by adventitious roots. Our study was the first to show that plant growth, physiology and nutrition status of M. micrantha were strongly promoted by adventitious roots in the prostrate growth form.

Educational Approaches Help Bridge Perception Gaps of Invasive Alien Species (Mikania micrantha) between Managers and Non-managers

Invasive alien species (IAS) significantly impact biodiversity, human health, and economies, and considerable resources are often used to manage their spread. Few studies have focused on the human perception of IAS management, and little is known about approaches to improve stakeholder perception. This study examined perception gaps between managers and non-managers of a notorious weed Mikania micrantha and the preference for educational approaches to bridge those gaps. Household questionnaires and key informant interviews were conducted in the China-Myanmar Border Region (China), and ordinal logistic regressions and Wilcoxon rank sum tests were used in statistical analyses. We found a high level of perception of M. micrantha among stakeholders, and a significant influence of socio-demographic factors including gender, educational level, ethnic group, and geographical location. Scores of the identification, damage, control measure, and manual treatment of M. micrantha were significantly higher for managers than those for non-managers, indicating that there were certain perception gaps between two stakeholder groups. Nine educational approaches were identified as being effective in improving stakeholder perception of IAS, of which training workshops were mostly preferred, followed by brochures (or leaflets) and other promotional materials. Additionally, we propose that well-designed and well-conducted educational approaches would benefit stakeholder perception of IAS, and that integration of IAS management into a comprehensive rural development scheme would improve its long-term performance in marginalized rural communities.

Soil nitrogen dynamics and competition during plant invasion: insights from Mikania micrantha invasions in China

Invasive plants often change a/biotic soil conditions to increase their competitiveness. We compared the microbially mediated soil nitrogen (N) cycle of invasive Mikania micrantha and two co-occurring native competitors, Persicaria chinensis and Paederia scandens. We assessed how differences in plant tissue N content, soil nutrients, N cycling rates, microbial biomass and activity, and diversity and abundance of N-cycling microbes associated with these species impact their competitiveness. Mikania micrantha outcompeted both native species by transferring more N to plant tissue (37.9-55.8% more than natives). We found total soil N to be at lowest, and available N highest, in M. micrantha rhizospheres, suggesting higher N cycling rates compared with both natives. Higher microbial biomass and enzyme activities in M. micrantha rhizospheres confirmed this, being positively correlated with soil N mineralization rates and available N. Mikania micrantha rhizospheres harbored highly diverse N-cycling microbes, including N-fixing, ammonia-oxidizing and denitrifying bacteria and ammonia-oxidizing archaea (AOA). Structural equation models indicated that M. micrantha obtained available N via AOA-mediated nitrification mainly. Field data mirrored our experimental findings. Nitrogen availability is elevated under M. micrantha invasion through enrichment of microbes that participate in N cycling, in turn increasing available N for plant growth, facilitating high interspecific competition.

Predicting the invasive trend of exotic plants in China based on the ensemble model under climate change: A case for three invasive plants of Asteraceae

Ageratina adenophora, Eupatorium odoratum, and Mikania micrantha are three highly destructive invasive plants of Compositae in China. Through the screening of SDMs, random forest (RF), gradient boosting model (GBM), artificial neural network (ANN), and flexible discriminant analysis (FDA) with TSS greater than 0.8 are selected to construct a high-precision ensemble model (EM) as the prediction model. We use specimen sites and environmental variables containing climate, soil, terrain, and human activities to simulate and predict the invasion trend of three invasive weeds in China in current, the 2050s, and the 2070s. Results indicate that the highly invasive risk area of three exotic plants is mostly distributed along the river in the provinces south of 30° N. In the future scenario, the three exotic plants obviously invade northwards Yunnan, Sichuan, Guizhou, Jiangxi and Fujian. Climate is the most important variable that affects the spread of three kinds of alien plant invasions. Temperature and precipitation variables have a similar effect on A. adenophora and E. odoratum, while M. micrantha is more sensitive to temperature. It has been reported that Ipomoea batatas and Vitex negundo can prevent the invasion of three invasive plants. Hence, we also simulate the suitable planting areas for I. batatas and V. negundo. The results show that I. batatas and V. negundo are suitable to be planted in the areas where the three weeds show invasion tendency. In the paper, predicting invasion trends of exotic plants and simulating the planting suitability of crops that can block invasion, to provide a practical significance reference and suggestion for the management, prevention, and control of the invasion of exotic plants in China.

for Cd2+ and Cu2+ removal

Exotic invasive plants endanger the integrity of agricultural and natural systems throughout the world. Thus, the development of cost-effective and economic application of invasive plants is warranted. Here, we characterized fifteen biochars derived from five invasive plants at different temperatures (300, 500, and 700 °C) by determining their yield, ash content, pH, CEC, surface area, elementary composition, functional groups, and mineral composition. We conducted batch adsorption experiments to investigate the adsorption capacity and efficiency for Cd²⁺ and Cu²⁺ in wastewater. Our results suggest that all invasive plants are appropriate for biochar production, temperature and plant species had interacting effects on biochar properties, and the biochars pyrolyzed at 500 and 700 °C exhibited high metal adsorption capacity in neutral (pH = 7) solutions. The adsorption kinetics can be explained adequately by a pseudo-second-order model. BBC500 (Bidens pilosa L. derived biochar at 500 °C) and MBC500 (Mikania micrantha) exhibited higher metal equilibrium adsorption capacities (38.10 and 38.02 mg g^-1 for Cd²⁺, 20.01 and 20.10 mg g^-1 for Cu²⁺) and buffer abilities to pH than other biochars pyrolyzed at 500 °C. The Langmuir model was a better fit for IBC500 (Ipomoea cairica), MBC500, and LBC500 (Lantana camara L.) compared to the Freundlich model, whereas the opposite was true for BBC500 and PBC500 (Praxelis clematidea). These results suggest that the adsorption of metals by IBC500, MBC500, and LBC500 was mainly monolayer adsorption, while that by BBC500 and PBC500 was mainly chemical adsorption. Our results are important for the utilization and control of invasive plants as well as the decontamination of aqueous pollution.

Evaluation of rotary drum composting for the management of invasive weed Mikania micrantha Kunth and its toxicity assessment

Mikania micrantha Kunth is an abhorrent weed that destroys agricultural output. It contains toxic compounds that are detrimental to the natural ecosystem and have negative impacts on the economic and aesthetic aspects of the environment. This study depicts the treatment and management of this plant by in-vessel composting using a 550 L rotary drum composter. Six different mix proportions of biomass, cow dung, and sawdust were used for the study. Rotary drum (RD2) with 2.71% has the highest Total Kjeldahl Nitrogen (TKN). Total Organic Carbon (TOC) decreased to 19.72% at the end of the 20th day. Final C/N ratio falls between 7 and 14 in all the reactors. The phytotoxicity test of Mikania was evaluated using Vigna radiata and Allium cepa. The findings of the study suggest that Mikania can be efficiently utilised to produce mature and stable compost that might be recommended for field application as the process can reduce toxicity.

Mikania micrantha invasion enhances the carbon (C) transfer from plant to soil and mediates the soil C utilization through altering microbial community

Exotic plant invasion alters the structure and coverage of terrestrial vegetation and affects the carbon (C) stocks in ecosystems. Previous studies have shown the increases in the C stocks with increasing invasive plants, but these results remain contentious. Soil microbial communities are usually altered by plant invasion, which potentially influences the C cycling underground. We hypothesized that the plant invasion-caused dynamic changes in soil microbes would lead to the corresponding change in soil C accumulation. Using greenhouse experiments we simulated different invader intensities through varying the relative abundance of invasive species Mikania micrantha and its co-occurring native species Paederia scandens. By analyzing ¹³C-phospholipid fatty acid we found the invasive M. micrantha assimilated more ¹³C and transferred faster the fixed ¹³C through different tissues to soils, as compared to native P. scandens. Soil microbial components, i.e., i15:0, 16:0, 10Me16:0, 18:1w9c and 18:2w6,9 were mainly using the photo-assimilated ¹³C. In addition, we found a hump-shaped relationship between soil net ¹³C accumulate rate and rhizosphere microbial biomass, indicating that the soil C accumulation may be either enhanced or reduced in invaded ecosystems, depending on microbe abundance.

Evaluation of the short-term and long-term performance of biological invasion management in the China-Myanmar border region

Invasive alien species pose great threats to ecological and economic health and cause enormous losses to global ecosystems. The Mikania micrantha management program is a source of great theoretical and practical insights for regional agricultural and forestry development. In this paper, the invasion history and distribution patterns of M. micrantha in the China-Myanmar Border Region are summarized, and the short-term and long-term performance of the current post-border management program are evaluated. A literature survey found that M. micrantha was mainly distributed in 85 townships of five municipalities along the border in China with Myanmar, suggesting an explicit border-crossing scenario of M. micrantha. The M. micrantha management program has produced positive but short-term results due to the conduction of general investigations, establishment of an extensive monitoring network, development of integrated measures, and improvements of public awareness and participation. However, the long-term management performance was hampered by overlapping departmental functions, lagging and unreliable public feedback, inadequate funding, and biased and passive strategies. We suggest that invasive species committees, social media tools, public-private partnership, and forest restoration and conservation and biological control could greatly improve the situation. This regional-scale research provides referential insights for the development of biological invasion management systems in developing economies under transboundary contexts.

Mikania laevigata syrup does not induce side effects on reproductive system of male Wistar rats

Mikania laevigata (Asteraceae) is a native plant from South America and popularly used as antispasmodic and to treat respiratory diseases. Coumarin is the major chemical substance found in this plant, which have been shown to have antifertility activity in female rats. This study evaluates the toxicity of the exposure to the Mikania laevigata syrup using coumarin as chemical marker on reproductive endpoints in male Wistar rats. Endpoints including reproductive organs weight, sperm and spermatids numbers and sperm morphology were evaluated. Animals were treated daily with Mikania laevigata syrup (3.5; 7.0 and 14.0mg/kg of coumarin) during 90 days by oral gavage. No alterations were observed in body and organ weights, sperm and spermatids numbers as well as sperm morphology of the male rats after the exposure to the Mikania laevigata syrup. Results therefore suggest absence of male reproductive toxicity of the Mikania laevigata syrup at tested doses.

glomerata, and their effects on allergic pneumonitis

The leaves of guaco (Mikania glomerata and M. laevigata) are widely used for the treatment of asthma and bronchitis. An LC method for the quantification of coumarin and O-coumaric acid in medicinal extracts was developed and validated for linearity, limit of detection, accuracy, precision, as well as intra- and inter-day variations. Extracts and isolated markers were tested in the mice allergic pneumonitis model and the histopathological profile of the lung tissue was analysed. The values found for coumarin and O-coumaric acid in a fluid extract were 1.53 and 1.69 mg/mL, respectively, for M. glomerata, and 0.96 and 0.38 mg/mL for M. laevigata. The values found for the lyophilised aqueous extract were 0.22 and 0.11 mg/mL of coumarin and O-coumaric acid in M. glomerata and 0.05 and 0.02 mg/mL in M. laevigata, respectively . The analysed samples from the species M. glomerata presented more coumarin and O-coumaric acid than the analogous M. laevigata species. Both coumarin and O-coumaric acid are part of the phytocomplex which is responsible for the therapeutic activity of the guaco species. The lyophilisation process generated some alterations in the extract, in comparison with the fresh aqueous extract, and these extracts did not present anti-inflammatory activity. Comparing the histopathological images of the groups tested, a haemorrhagic profile of lung tissue of animals treated with lyophilised extract, O-coumaric acid and coumarin is observed, but not for the group treated with hydroalcoholic extract. It is probable that some protective effect of the whole extract (lost during the lyophilisation process) blocks the harmful effects of the isolated markers.

Antiophidian properties of the aqueous extract of Mikania glomerata

Aqueous extracts, prepared from dried or fresh roots, stems or leaves of Mikania glomerata, a plant found in Mata Atlântica in Southeastern Brazil, were able to efficiently neutralize different toxic, pharmacological, and enzymatic effects induced by venoms from Bothrops and Crotalus snakes. Phospholipase A(2) activity and the edema induced by Crotalus durissus terrificus venom were inhibited around 100 and approximately 40%, respectively, although this inhibition was only partial for Bothrops venoms. The hemorrhagic activity of Bothrops venoms (Bothrops altenatus, Bothrops moojeni, Bothrops neuwiedi, and Bothrops jararacussu) was significantly inhibited by this vegetal species, while the clotting activity of Crotalus durissus terrificus, Bothrops jararacussu, and Bothrops neuwiedi venoms was totally inhibited. Although, the mechanism of action of Mikania glomerata extract is still unknown, the finding that no visible change was detected in the electrophoretic pattern of snake venom after incubation with the extract excludes proteolytic degradation as a potential mechanism. Since the extract of Mikania glomerata significantly inhibited the studied snake venoms, it may be used as an alternative treatment to serumtherapy and, in addition, as a rich source of potential inhibitors of PLA(2)s, metalloproteases and serineproteases, enzymes involved in several physiopathological human and animal diseases.

Effects of Mikania genus plants on growth and cell adherence of mutans streptococci

The present study evaluated the chemical composition and the antimicrobial activity of the extracts and fractions of Mikania laevigata and Mikania glomerata on growth and cell adherence of mutans streptococci. Ethanolic extract, hexane and ethyl acetate fractions of Mikania laevigata and Mikania glomerata were chemically identified by chromatographic methods and tested on mutans streptococci from culture collection and clinical isolates. Twenty-two compounds were identified in both Mikania extracts, including coumarin, 1-octadecene, and diterpenic, cupressenic and kaurenoic acids. Antimicrobial activity was assessed by determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and inhibition of cell adherence to a glass surface. Hexane fraction from both plant extracts was the most effective in inhibiting the growth of the bacterial strains tested (MIC values between 12.5 microg/ml and 400 microg/ml, and MBC values between 25 microg/ml and 400 microg/ml). In addition, sub-MIC levels of the crude extracts and their hexane fractions significantly inhibited the adherence of the microorganisms to a glass surface. The data indicate that the biologically active compounds are present mostly in the hexane fraction of both Mikania species, which showed remarkable inhibitory activities against mutans streptococci. Mikania genus plant is a promising source for novel antimicrobial agents against oral pathogens.

Antiulcerogenic activity of a crude hydroalcoholic extract and coumarin isolated from Mikania laevigata Schultz Bip

The leaves of Mikania (Asteraceae) species are used in folk medicine as antispasmodic, antiulcerogenic and antirheumatic agents. Phytochemical screening of the crude hydroalcoholic 70% extract (CHE) of Mikania laevigata Shultz Bip. revealed coumarins, terpenes and organic acids. Antiulcerogenic activity of CHE was evaluated, employing different experimental models in rats, to discern the pharmacological mechanism of action. Both the antisecretory and the cytoprotection hypothesis were evaluated. The crude hydroalcoholic extract (1000 mg/kg body wt., vo) decreased the ulcerative lesion index produced by indomethacin, ethanol, stress and reserpine in rats by 85%, 93%, 82% and 50%, respectively. In the pyloric ligation model, a decrease of hydrogenionic concentration (53%) was observed, suggesting that the pharmacological mechanism has a relationship to antisecretory activity. The antisecretory mechanisms of CHE and the coumarin isolated from M. laevigata were confirmed by acid hypersecretion induced by histamine, pentagastrin and bethanechol. Duodenal administration of CHE (1000 mg/kg body wt.) and coumarin (100 mg/kg body wt.) inhibited only the gastric acid secretion produced by bethanecol. These results suggest that both CHE and coumarin may influence the secretion control mediated by the parasympathetic system.

Trypanocidal properties of Mikania stipulacea and Mikania hoehnei isolated terpenoids

The in vitro trypanocidal properties of isolated terpenoids from Mikania stipulacea and Mikania hoehnei were investigated in Trypanosoma cruzi Y strain. Both compounds, the diterpene ent-9alpha-hydroxy-15beta-E-cinnamoyloxy-16-kauren-19-oic acid (1) and the sesquiterpene lactone 8beta-hydroxyzaluzanin D (2) were active.

Evaluation of long-term exposure to Mikania glomerata (Sprengel) extract on male Wistar rats' reproductive organs, sperm production and testosterone level

Many plant substances are known for their interference with the reproductive system. Mikania glomerata is a plant popularly used to treat respiratory diseases and is reported to have flavonoids and coumarin, which have been shown to have antifertility activity in male dogs and female rats, respectively. This work analyzes the effect of a high dose of M. glomerata extract administered during the spermatogenic cycle of rats. Adult Wistar rats were treated with 1 mL of a M. glomerata extract at a dose level of 3.3 g/kg of body weight for 52 days. Body and organ weights, sperm production, circulating testosterone level and food consumption were evaluated. The results showed that the administration of the M. glomerata extract during the rat spermatogenic cycle did not significantly alter the body and organ weights nor did it interfere with gamete production, serum testosterone level or food intake.

Mutagenic and antimutagenic potential of the medicinal plants M. laevigata and C. xanthocarpa

Aqueous extracts of medicinal plants (Mikania laevigata and Campomanesia xanthocarpa) were screened for the presence of mutagenic activity in the Salmonella/microsome assay. The extracts of Campomanesia xanthocarpa showed frameshift (TA97a strain) signs of mutagenic activity without exogenous metabolism (S9 fraction). The infusions of Mikania laevigata, negative for mutagenic activity, showed high percentages of inhibition of mutagenesis induced by mutagens 2AF (2-amino fluorene), in the presence of exogenous metabolism (S9 fraction), for frameshift (TA98) and base pair substitution (TA100) lesions. In addition, these inhibitions were observed against mutagen SAZ (sodium azide) in assays with the TA100 strain, without exogenous metabolism (S9 fraction). A synergistic effect was also observed in frameshift mutagenic events, with direct action in the presence of 4NQO (4-oxide-1-nitroquinoline) and a tendency to a low percentage of action enhancement, in the presence of the 2AF mutagen. The variable responses observed in the extract assays show the potentials for interaction of the different active principles in genetic material.