Asclepias Curassavica Research Articles

Enhanced chitosan and Carboxymethylcellulose scaffolds with natural fiber reinforcement for hernia repair meshes

AbstractChitosan (Chi) and carboxymethylcellulose (CMC) scaffolds, with and without reinforcement by Luffa cylindrica (Lc) or Asclepias curassavica (Ac), were synthesized to evaluate their potential application as hernia repair meshes. These meshes are crucial as they provide structural support to weakened tissues, reducing the risk of hernia recurrence and promoting faster recovery. They improve patient outcomes by enhancing the durability and effectiveness of hernia repairs. Chi scaffolds exhibited lower porosity compared to CMC scaffolds, with fiber inclusion enhancing porosity. The CMC4‐Ac scaffold demonstrated the highest porosity at 67.2%, which is crucial for supporting cell growth and tissue regeneration. All scaffolds exhibited exceptional hydration levels, which is vital for cell growth. Scanning electron microscope (SEM) images revealed open pores in the CMC4 scaffolds, which enhances tissue formation. Tensile strength tests indicated that all scaffolds surpassed the minimum requirements, with CMC4‐Ac standing out for its exceptional properties. CMC scaffolds showed greater degradation, which was mitigated by fiber reinforcement. Chi scaffolds absorbed more Croton draco extract (Cdext) but exhibited lower release rates compared to CMC scaffolds. No hemolytic and non‐cytotoxicity effects were observed. CMC4‐Ac emerged as the most promising scaffold due to its superior properties, making it suitable for hernia repair meshes.

Exploring the interplay between host plant structural defences and origin on behavioural and life‐history traits of two Neotropical danaines

AbstractFactors that mediate insect herbivore sabotaging behaviour of host plant latex defences remain under debate. The most prominent hypothesis suggests that the anatomy of the host plant's laticifers determines trenching or vein‐cutting behaviour, but there are inconsistencies in the literature. In addition to latex, other plant defences have been shown to affect plant natural enemies, but experimental studies comparing the effects of multiple defences on herbivore performance and behaviour are scarce. In this study, we investigated the anatomy of the laticifers of Calotropis procera (Aiton) W.T. Aiton (Apocynaceae), an exotic milkweed of southeastern Brazil, as well as the sabotaging behaviour of larvae of southern monarch, Danaus erippus (Cramer), and queen butterfly, Danaus gilippus (Cramer) (Lepidoptera: Nymphalidae) on this host plant. We also reviewed the sabotaging behaviour of larvae reared on the native milkweed Asclepias curassavica L. (Apocynaceae) from previous studies, as well as the description of the anatomy of its laticifers. As we found no correspondence between sabotaging behaviour of southern monarchs and queens and the anatomy of the host plants' laticifers, we tested whether structural defences of C. procera leaves (latex, waxes and trichomes) affected sabotaging behaviour and larval performance of southern monarch larvae. The structural barriers of this well‐defended host affected larvae in different ways: Southern monarchs developed more slowly on control leaves than on leaves from which wax had been removed, and only latex removal reduced the frequency of sabotaging behaviour. Regardless of the defence removal treatment, frequencies of trenching behaviour decreased and vein‐cutting behaviour increased as larvae developed. Overall, our results show that several factors in addition to the anatomy of laticifers affect sabotaging behaviour of southern monarchs and queens, including larval ontogeny, danaine species and latex outflow. This evidence suggests a behavioural plasticity in the sabotaging behaviour of larvae of both southern monarchs and queens.

Target and non-target effects of insecticide use during ornamental milkweed production.

There are widespread public efforts to conserve wildlife in urbanized landscapes via the installation of nursery-grown plants that support Lepidoptera taxa. Insecticides are commonly used during nursery production to suppress key plant pests, and many products have extended periods of toxicity and affect a wide range of herbivore taxa. While there are plentiful toxicological data on bee species, predominantly the Western honey bee (Apis mellifera L.), little is known about how insecticides affect nonpest lepidopterans. Lepidoptera has different modes of exposure (e.g., leaf-feeding) and differences in susceptibility to insecticide target sites compared to bees. Consequently, many products compatible with bee conservation pose an uncertain risk to nonpest lepidopterans and thus may represent an under-recognized conflict with conservation efforts. Using the monarch butterfly (Danaus plexippus, L.), tropical milkweed (Asclepias curassavica, L.), and oleander aphid (Aphis nerii, Fonscolombe, 1841) system, we conducted leaf and whole-plant feeding assays to evaluate effects of acute and chronic monarch exposure to industry standard and alternative reduced-risk insecticides used during nursery production. We also evaluated the efficacy of these insecticides against their target pest, the oleander aphid. Our results indicate that insecticides used to control pests on ornamental milkweed can cause monarch larval mortality up to 4 wk after treatment application. Furthermore, the duration of aphid suppression is often shorter than the duration of adverse effects on monarchs. This study demonstrates a conflict between insect pest management and Lepidoptera conservation during ornamental plant production and has implications for the conservation value of ornamentals after retail sale.

Pharmacognostic Study of <I>Asclepias curassavica</I> Linn.

Asclepias curassavica L. (Family: Asclepiadaceae), commonly known as 'Kakatundi' an important Ayurvedic drug used as emetic, astringent, anthelmintic and a remedy in piles and gonorrhoea. All the parts are used in the indigenous system of medicine. The present investigation deals with the macro-microscopical structure of the leaf, micro chemical tests, quantitative study, study of the powdered drug, fluorescence analysis and determination of physical constant values. Leaf is dorsi-ventral, stomata present on both the surfaces. Latex is present in laticifers.

Chemical components of different solvent extracts of Asclepias curassavica L. and antibacterial effect of the extracts on tomato pathogens

The use of environmentally friendly and sustainable agricultural methods in the control of diseases and pests is of great importance. In both conventional and organic agricultural production systems, the utilization of various plant extracts as part of integrated pest management has gained significance in recent years. The chemical constituents of various solutions derived from the flowers, leaves, and roots of the Asclepias curassavica L. plant were investigated, along with the possibilities of utilizing these solutions in the control of tomato plant pathogenic bacteria. As a result of the analysis, acetic acid in 60% and 80% ethanol solutions, as well as acetic acid methy ester in 60% and 80% methanol solutions, were detected in the flowers, leaves, and roots. The effects of A. curassavica flower, leaf, and root extracts, prepared using three different solvents (water, methanol, and ethanol), were investigated on eight different pathogenic bacteria (Agrobacterium tumefaciens, Clavibacter michiganensis, Dickeya zeae, Pectobacterium caratovorum, Pseudomonas phaseolicola, Pseudomonas tomato, Pseudomonas viridiflava, and Xanthomonas euvesicatoria) that cause diseases in plants. Several main compounds such as acetic acid, acetic acid. methyl ester, Furfural, 2-Furanmethanol, 4H-Pyran-4-one. 2.3-dihydro-3.5-dihydroxy-6-methyl-, Glycerin, Benzo furan. 2.3-dihydro- and 5-Hydroxy methyl furfural were identified as analyzed by GC-MS with different concentrations of ethanol and methanol solutions used for the flower, leaves and root of A. curassavica plants. The flower extract prepared with 80% ethanol exhibited a higher inhibition zone (ranging from 1.5 mm to 5.3 mm) in all pathogens, compared to other applications. The successful suppression effect of A. curassavica flower extracts on this disease is promising, especially in organic farming areas. Additionally, since it is environmentally friendly and sustainable, it can be included in integrated control methods to prevent the loss of productivity caused by diseases.

Aphid infestations reduce monarch butterfly colonization, herbivory, and growth on ornamental milkweed.

Anthropogenic disturbance is driving global biodiversity loss, including the monarch butterfly (Danaus plexippus), a dietary specialist of milkweed. In response, ornamental milkweed plantings are increasingly common in urbanized landscapes, and recent evidence indicates they have conservation value for monarch butterflies. Unfortunately, sap-feeding insect herbivores, including the oleander aphid (Aphis nerii), frequently reach high densities on plants in nursery settings and urbanized landscapes. Aphid-infested milkweed may inhibit monarch conservation efforts by reducing host plant quality and inducing plant defenses. To test this, we evaluated the effects of oleander aphid infestation on monarch oviposition, larval performance, and plant traits using tropical milkweed (Asclepias curassavica), the most common commercially available milkweed species in the southern U.S. We quantified monarch oviposition preference, larval herbivory, larval weight, and plant characteristics on aphid-free and aphid-infested milkweed. Monarch butterflies deposited three times more eggs on aphid-free versus aphid-infested milkweed. Similarly, larvae fed aphid-free milkweed consumed and weighed twice as much as larvae fed aphid-infested milkweed. Aphid-free milkweed had higher total dry leaf biomass and nitrogen content than aphid-infested milkweed. Our results indicate that oleander aphid infestations can have indirect negative impacts on urban monarch conservation efforts and highlight the need for effective Lepidoptera-friendly integrated pest management tactics for ornamental plants.

Larval diet impacts flight performance in monarch butterflies

Abstract Few studies have described the effects of larval diet quality on adult insect flight performance. Flight muscle development and high‐powered flight in insects are associated with costly energetic demands. Because larval diet is the energy source that powers these mechanisms, we asked whether larval diet has an impact on flight performance and metabolism in the monarch butterfly (Danaus plexippus Linnaeus). Monarch caterpillars from the eastern North American and Puerto Rican populations were fed a diet of either Asclepias incarnata L. (native to the eastern North American population) or Asclepias curassavica L. (native to the Puerto Rican population and uncommon in eastern North America). We flew the monarchs on a tethered flight mill to acquire flight performance metrics including velocity, distance, duration, power, and oxygen consumption rate. Monarchs reared on the A. incarnata L. milkweed showed slower, shorter, and less powerful flights than those fed on A. curassavica L. However, eastern North American and Puerto Rican monarchs, which were reared under summer conditions, did not differ in flight metrics or post‐flight metabolic rates. The results suggest that flight in eastern North American and Puerto Rican monarchs is similar during the breeding season, yet the milkweed the caterpillars consume has important implications for flight performance.

Productivity and Phytochemicals of Asclepias curassavica in Response to Compost and Silver Nanoparticles Application: HPLC Analysis and Antibacterial Activity of Extracts.

The application of compost and metallic nanoparticles has a significant impact on the productivity and chemical composition of horticulture plants. In two subsequent growing seasons, 2020 and 2021, the productivity of Asclepias curassavica L. plants treated with various concentrations of silver nanoparticles (AgNPs) and compost was assessed. In the pot experiments, the soil was amended with 25% or 50% compost, and the plants were sprayed with 10, 20, and 30 mg/L of AgNPs. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and dynamic light scattering (DLS) were used to characterize AgNPs. The TEM measurements of AgNPs showed that the particles had spherical forms and ranged in size from roughly 5 to 16 nm. Leaf methanol extracts (LMEs) were prepared from the treated plants and assayed against the growth of two soft rot bacteria, Dickeya solani and Pectobacterium atrosepticum. The maximum plant height, diameter, number of branches/plant, total fresh weight (g), total dry weight (g), and leaf area (cm2) was recorded when levels of 25% compost + AgNPs 20 mg/L, 25% compost, or 50% + AgNPs 20 mg/L, 25% compost + AgNPs 30 mg/L or 50% compost + AgNPs 20 mg/L, 50% compost + AgNPs 20 mg/L, 50% compost + AgNPs 30 or 20 mg/L, and 25% compost + AgNPs 30 mg/L, respectively, were applied. The plants treated with 25% or 50% compost + 30 mg/L AgNPs showed a high chlorophyll content, while the plants treated with 50% compost + AgNPs 30 mg/L or 20 mg/L showed the highest extract percentages. The highest inhibition zones (IZs), 2.43 and 2.2 cm, against the growth of D. solani were observed in the LMEs (4000 mg/L) extracted from the plants treated with compost (v/v) + AgNPs (mg/L) at the levels of 50% + 30 and 25% + 30, respectively. The highest IZs, 2.76 and 2.73 cm, against the growth of P. atrosepticum were observed in the LMEs (4000 mg/L) extracted from the plants treated at the levels of 50% + 30 and 25% + 30, respectively. Several phenolic compounds such as syringic acid, p-coumaric acid, chlorogenic acid, cinnamic acid, ellagic acid, caffeic acid, benzoic acid, gallic acid, ferulic acid, salicylic acid, pyrogallol, and catechol, as well as flavonoid compounds such as 7-hydroxyflavone, naringin, rutin, apigenin, quercetin, kaempferol, luteolin, hesperidin, catechin, and chrysoeriol, were identified in the LMEs as analyzed by HPLC with different concentrations according to the treatment of compost + AgNPs used for the plants. In conclusion, the specific criteria that were utilized to measure the growth of A. curassavica revealed the novelty of compost and AgNPs combination treatments, particularly at a concentration of 50% compost + AgNPs 30 mg/L or 20 mg/L, which is better for the growth and phytochemical production of A. curassavica in the field.

Differential accumulation of cardenolides from Asclepias curassavica by large milkweed bugs does not correspond to availability in seeds or biological activity on the bug Na+/K+-ATPase

Milkweed–herbivore systems are characterized by cardenolide chemical defenses and specialized herbivore adaptations such as physiological target site insensitivity. Cardenolide defenses in milkweeds can vary in terms of the total concentration, differences in the polarity of individual cardenolides, and the substitution of the steroidal structures that can contribute to the molecule's reactivity. The variability in cardenolide defenses could represent the plant's response to natural selection and adaptation of resistant herbivores and is a characteristic of phenotype-matching between defensive and offensive traits resulting from coevolution. Here, we test the phenotypic match of the cardenolide composition of seeds of Asclepias curassavica and those sequestered by nymphs and adults of the specialized seed herbivore Oncopeltus fasciatus, combined with tests of the inhibitory capacity of a subset of seed cardenolides against the Na+/K+-ATPase of O. fasciatus and a non-adapted insect (Drosophila melanogaster). We compare this with the inhibitory capacity against the highly sensitive porcine Na+/K+-ATPase. Among the five most abundant cardenolides present in milkweed seeds, glucopyranosyl frugoside, glucopyranosyl gofruside, and glucopyranosyl calotropin were significantly more abundant in the seeds than in the adults and nymphs; the bugs contained higher concentrations of the deglucosylated compounds. The most abundant compound, glucopyranosyl frugoside, was also the most inhibitory for O. fasciatus, but O. fasciatus was significantly more tolerant to all compounds compared to D. melanogaster and the highly sensitive porcine enzyme. Our results add to the evidence that O. fasciatus sequesters specific individual cardenolides from its Asclepias host plants that are not directly linked to the concentration and inhibitory potency.

Spatial metabolomics reveal divergent cardenolide processing in the monarch (Danaus plexippus) and the common crow butterfly (Euploea core).

Although being famous for sequestering milkweed cardenolides, the mechanism of sequestration and where cardenolides are localized in caterpillars of the monarch butterfly (Danaus plexippus, Lepidoptera: Danaini) is still unknown. While monarchs tolerate cardenolides by a resistant Na+ /K+ -ATPase, it is unclear how closely related species such as the non-sequestering common crow butterfly (Euploea core, Lepidoptera: Danaini) cope with these toxins. Using novel atmospheric-pressure scanning microprobe matrix-assisted laser/desorption ionization mass spectrometry imaging, we compared the distribution of cardenolides in caterpillars of D. plexippus and E. core. Specifically, we tested at which physiological scale quantitative differences between both species are mediated and how cardenolides distribute across body tissues. Whereas D. plexippus sequestered most cardenolides from milkweed (Asclepias curassavica), no cardenolides were found in the tissues of E. core. Remarkably, quantitative differences already manifest in the gut lumen: while monarchs retain and accumulate cardenolides above plant concentrations, the toxins are degraded in the gut lumen of crows. We visualized cardenolide transport over the monarch midgut epithelium and identified integument cells as the final site of storage where defenses might be perceived by predators. Our study provides molecular insight into cardenolide sequestration and highlights the great potential of mass spectrometry imaging for understanding the kinetics of multiple compounds including endogenous metabolites, plant toxins, or insecticides in insects.

History of colonisation and updated distribution of the Monarch butterfly Danaus plexippus (Linnaeus, 1758) and its hostplants in mainland Portugal, Azores and Madeira

The first observations of the Monarch butterfly (Danaus plexippus) in Iberia date from 1886, although breeding records emerged almost a century later: 1960 in Spain, 1980s–1990s in Madeira and Azores, and 2003 in mainland Portugal. We reviewed the history of the colonisation of mainland and insular Portugal by the Monarch butterfly and its hostplants (Gomphocarpus fruticosus, G. physocarpus and Asclepias curassavica). We also compiled available historical and recent occurrence records as a basis for countrywide surveys of the butterfly and hostplants, to update their current distributions in Portugal. Locations for only a few of the older records represented newly rediscovered populations in the field, although recent occurrences were often confirmed. Hostplants were scarce and monarchs absent in northern and central mainland Portugal, but both were quite common in the southwest. In Madeira, hostplants were found in two locations, while monarchs were common and widespread. In the Azores, small hostplant patches were observed on four of seven surveyed islands, whereas monarchs were rare and restricted to two islands. Abandoned/semi-abandoned orange orchards represent the butterfly’s stronghold in Portugal, with the species being increasingly scarce along rivers and road verges where hostplants are declining. Hostplant persistence is unstable, with many patches removed, while others have expanded or colonised new areas. Overall, hostplants appear to be declining, with implications for the persistence of monarch butterflies in the country.

New Structures, Spectrometric Quantification, and Inhibitory Properties of Cardenolides from Asclepias curassavica Seeds.

Cardiac glycosides are a large class of secondary metabolites found in plants. In the genus Asclepias, cardenolides in milkweed plants have an established role in plant-herbivore and predator-prey interactions, based on their ability to inhibit the membrane-bound Na+/K+-ATPase enzyme. Milkweed seeds are eaten by specialist lygaeid bugs, which are the most cardenolide-tolerant insects known. These insects likely impose natural selection for the repeated derivatisation of cardenolides. A first step in investigating this hypothesis is to conduct a phytochemical profiling of the cardenolides in the seeds. Here, we report the concentrations of 10 purified cardenolides from the seeds of Asclepias curassavica. We report the structures of new compounds: 3-O-β-allopyranosyl coroglaucigenin (1), 3-[4'-O-β-glucopyranosyl-β-allopyranosyl] coroglaucigenin (2), 3'-O-β-glucopyranosyl-15-β-hydroxycalotropin (3), and 3-O-β-glucopyranosyl-12-β-hydroxyl coroglaucigenin (4), as well as six previously reported cardenolides (5-10). We test the in vitro inhibition of these compounds on the sensitive porcine Na+/K+-ATPase. The least inhibitory compound was also the most abundant in the seeds-4'-O-β-glucopyranosyl frugoside (5). Gofruside (9) was the most inhibitory. We found no direct correlation between the number of glycosides/sugar moieties in a cardenolide and its inhibitory effect. Our results enhance the literature on cardenolide diversity and concentration among tissues eaten by insects and provide an opportunity to uncover potential evolutionary relationships between tissue-specific defense expression and insect adaptations in plant-herbivore interactions.

Molecular Networking and On-Tissue Chemical Derivatization for Enhanced Identification and Visualization of Steroid Glycosides by MALDI Mass Spectrometry Imaging.

Spatial metabolomics describes the spatially resolved analysis of interconnected pathways, biochemical reactions, and transport processes of small molecules in the spatial context of tissues and cells. However, a broad range of metabolite classes (e.g., steroids) show low intrinsic ionization efficiencies in mass spectrometry imaging (MSI) experiments, thus restricting the spatial characterization of metabolic networks. Additionally, decomposing complex metabolite networks into chemical compound classes and molecular annotations remains a major bottleneck due to the absence of repository-scaled databases. Here, we describe a multimodal mass-spectrometry-based method combining computational metabolome mining tools and high-resolution on-tissue chemical derivatization (OTCD) MSI for the spatially resolved analysis of metabolic networks at the low micrometer scale. Applied to plant toxin sequestration in Danaus plexippus as a model system, we first utilized liquid chromatography (LC)-MS-based molecular networking in combination with artificial intelligence (AI)-driven chemical characterization to facilitate the structural elucidation and molecular identification of 32 different steroidal glycosides for the host-plant Asclepias curassavica. These comprehensive metabolite annotations guided the subsequent matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) analysis of cardiac-glycoside sequestration in D. plexippus. We developed a spatial-context-preserving OTCD protocol, which improved cardiac glycoside ion yields by at least 1 order of magnitude compared to results with untreated samples. To illustrate the potential of this method, we visualized previously inaccessible (sub)cellular distributions (2 and 5 μm pixel size) of steroidal glycosides in D. plexippus, thereby providing a novel insight into the sequestration of toxic metabolites and guiding future metabolomics research of other complex sample systems.

Published Evidence Enhances Occurrence Data Resolution for Invasive Species in India

Photo 1. Mile-a-minute (Mikania micrantha Kunth) plant, one of the 100 most invasive species in the world, has 562 occurrences in the dataset. It increases the data resolution of global databases like the Global Biodiversity Information Facility (GBIF), which had 15 records in 2021. Photo credit: Achyut Kumar Banerjee. Photo 2. The blood flower (Asclepias curassavica L.), an invasive plant species with medicinal and ornamental values in India, has occurrence records from 10 Indian states, from temperate Jammu and Kashmir to tropical Kerala. Photo credit: Achyut Kumar Banerjee. Photo 3. The occurrence records of Redflower rag leaf (Crassocephalum crepidioides (Benth.) S. Moore), an aggressive invasive species in India, in the dataset represent the species' distribution in the eastern, northern, and southern states of the country. Photo credit: Achyut Kumar Banerjee. These photographs illustrate the article “An Occurrence Data Set for Invasive and Naturalized Alien Plants in India” by Authors: Jyoti Prajapati, Abhijit Singh, Kshitij Patil, Amiya Ranjan Bhowmick, Abhishek Mukherjee, Yelin Huang, and Achyut Kumar Banerjee published in Ecology. https://doi.org/10.1002/ecy.3794

Laticifer growth pattern is guided by cytoskeleton organization.

Laticifers are secretory structures that produce latex, forming a specialized defense system against herbivory. Studies using anatomical approaches to investigate laticifer growth patterns have described their origin; however, their mode of growth, i.e., whether growth is intrusive or diffuse, remains unclear. Studies investigating how cytoskeleton filaments may influence laticifer shape establishment and growth patterns are lacking. In this study, we combined microtubule immunostaining and developmental anatomy to investigate the growth patterns in different types of laticifers. Standard anatomical methods were used to study laticifer development. Microtubules were labelled through immunolocalization of α-tubulin in three types of laticifers from three different plant species: nonanastomosing (Urvillea ulmacea), anastomosing unbranched with partial degradation of terminal cell walls (Ipomoea nil), and anastomosing branched laticifers with early and complete degradation of terminal cell walls (Asclepias curassavica). In both nonanastomosing and anastomosing laticifers, as well as in differentiating meristematic cells, parenchyma cells and idioblasts, microtubules were perpendicularly aligned to the cell growth axis. The analyses of laticifer microtubule orientation revealed an arrangement that corresponds to those cells that grow diffusely within the plant body. Nonanastomosing and anastomosing laticifers, branched or not, have a pattern which indicates diffuse growth. This innovative study on secretory structures represents a major advance in the knowledge of laticifers and their growth mode.

Asclepain cI, a proteolytic enzyme from Asclepias curassavica L., a south American plant, against Helicobacter pylori.

Helicobacter pylori is a Gram negative bacterium most frequently associated with human gastrointestinal infections worldwide. The increasing occurrence of antibiotic-resistant isolates of H. pylori constitutes a challenge. The eradication of the microorganism is currently being considered a “high priority” by the World Health Organization (WHO). In this context, bioactive compounds found in natural products seem to be an effective therapeutic option to develop new antibiotics against the pathogen. In this study, we investigated the effect of asclepain cI, the main purified proteolytic enzyme of the latex of petioles and stems from Asclepia curassavica L. (Asclepiadaceae), a South American native plant, against H. pylori; in order to obtain a natural therapeutic adjuvant and a safe nutraceutical product. Asclepain cI showed antibacterial activity against reference strains and drug-resistant clinical isolates of H. pylori in vitro. A range of minimal inhibitory concentration (MIC) from 1 to 2 μg/ml and minimal bactericidal concentration (MBC) from 2 to 4 μg/ml was obtained, respectively. The action of asclepain cI on the transcription of omp18, ureA, flaA genes showed a significantly decreased expression of the selected pathogenic factors. Furthermore, asclepain cI did not induce toxic effects at the concentrations assayed. Asclepain cI could be considered a highly feasible option to be used as a natural therapeutic adjuvant and a safe nutraceutical product against H. pylori.

Ethnomedicinal plants used by malayali tribals in yercaud hills, salem district, tamil nadu, india

The present study highlights the importance of some medicinal plants in the health care system of Malayali tribal community of Yercaud Hills, Salem district, Tamil Nadu, India. Ethnomedicinal information was collected from malayali tribes through personal interviews and group discussions with 8 randomly selected informants. Use value (UV), fidelity level (FL) and Informant Consensus factor (ICF) were determined. During the data collection 20 species distributed in 16 families for treating 44 different ailments. Ethnomedicinal plants like Abrus pulchellus, Wall, Andrographis paniculata, Wall.ex.Nees, Asclepias curassavica, L, Asparagus racemosus, Wild, Azadirachta indica, A. Juss, Cassia fistula, Linn, Centella asiatica, Urb, Corallocarpus epigaeus, Hook.f, Curculigo orchioides, Gaertn, Emblica officinalis, Gaerth,Enicostemma littirale, Blume, Hemidesmus indicus, R. Br, Holarrhena pubescens (Buch.Ham.) Wall.ex.G.Don, Leucas aspera, Spreng, Mimosa pudica, Linn, Myrica esculenta, Buch. Ham, Pergularia daemia (Forsk.) chiov, Terminalia bellerica, Roxb, Terminalia chebula, Retz and Toddalia asiatica, Lamk were documented during the study. UV of the encountered plant species ranged from 0.38 to 1.13. The uppermost FCI value is reported for Ejaculation of semen and Bone fracture. In the present investigation, the FL varied from 50 to 100%.

Evidence for tissue-specific defence-offence interactions between milkweed and its community of specialized herbivores.

Coevolution between plants and herbivores often involves escalation of defence-offence strategies, but attack by multiple herbivores may obscure the match of plant defence to any one attacker. As herbivores often specialize on distinct plant parts, we hypothesized that defence-offence interactions in coevolved systems may become physiologically and evolutionarily compartmentalized between plant tissues. We report that roots, leaves, flower buds and seeds of the tropical milkweed (Asclepias curassavica) show increasing concentrations of cardenolide toxins acropetally, with latex showing the highest concentration. In vitro assays of the physiological target of cardenolides, the Na+ /K+ -ATPase (hereafter "sodium pump"), of three specialized milkweed herbivores (root-feeding Tetraopes tetrophthalmus, leaf-feeding Danaus plexippus, and seed-feeding Oncopeltus fasciatus) show that they are proportionally tolerant to the cardenolide concentrations of the tissues they eat. Indeed, molecular substitutions in the insects' sodium pumps predicted their tolerance to toxins from their target tissues. Nonetheless, the relative inhibition of the sodium pumps of these specialists by the concentration versus composition (inhibition controlled for concentration, what we term "potency") of cardenolides from their target versus nontarget plant tissues revealed different degrees of insect adaptation to tissue-specific toxins. In addition, a trade-off between toxin concentration and potency emerged across plant tissues, potentially reflecting coevolutionary history or plant physiological constraints. Our findings suggest that tissue-specific coevolutionary dynamics may be proceeding between the plant and its specialized community of herbivores. This novel finding may be common in nature, contributing to ways in which coevolution proceeds in multispecies communities.

Two cardenolide glycosides from the seed fairs of Asclepias curassavica and their cytotoxic activities.

Two cardenolide glycosides, corotoxigenin 3-O-[β-D-glucopyranosyl-(1→4)-6-deoxy-β-D-glucopyranoside] (1) and coroglaucigenin 3-O-[β-D-glucopyranosyl-(1→4)-6-deoxy-β-D-glucopyranoside] (2), were isolated from the seed fairs of Asclepias curassavica. The structures of 1-2 were determined based on the combination of the analysis of their MS, NMR spectroscopic data and acid hydrolysis. The inhibitory effects of compounds 1 and 2 on human colorectal carcinoma cells (HCT116), non-small cell lung carcinoma cells (A549) and hepatic cancer cells (SMMC-7721) were evaluated. The results showed that both compounds 1 and 2 significantly inhibited the viability, proliferation, and migration of A549, HCT116 and SMMC-7721 cells, suggesting that compounds 1 and 2 can be applied in the treatment of lung, colon and liver cancers in clinical practice. This study may not only provide a scientific basis for clarifying the active ingredients in A. curassavica, but also help to understand its antitumor activity, which can promote the application of A. curassavica in clinical treatment of various cancers.

Host Plant Species Influences the Composition of Milkweed and Monarch Microbiomes.

Plants produce defensive chemicals for protection against insect herbivores that may also alter plant and insect associated microbial communities. However, it is unclear how expression of plant defenses impacts the assembly of insect and plant microbiomes, for example by enhancing communities for microbes that can metabolize defensive chemicals. Monarch butterflies (Danaus plexippus) feed on milkweed species (Asclepias spp.) that vary in production of toxic cardiac glycosides, which could alter associated microbiomes. We therefore sought to understand how different milkweed species, with varying defensive chemical profiles, influence the diversity and composition of monarch and milkweed (root and leaf) bacterial communities. Using a metabarcoding approach, we compared rhizosphere, phyllosphere and monarch microbiomes across two milkweed species (Asclepias curassavica, Asclepias syriaca) and investigated top-down effects of monarch feeding on milkweed microbiomes. Overall, monarch feeding had little effect on host plant microbial communities, but each milkweed species harbored distinct rhizosphere and phyllosphere microbiomes, as did the monarchs feeding on them. There was no difference in diversity between plants species for any of the microbial communities. Taxonomic composition significantly varied between plant species for rhizospheres, phyllospheres, and monarch microbiomes and no dispersion were detected between samples. Interestingly, phyllosphere and monarch microbiomes shared a high proportion of bacterial taxa with the rhizosphere (88.78 and 95.63%, respectively), while phyllosphere and monarch microbiomes had fewer taxa in common. Overall, our results suggest milkweed species select for unique sets of microbial taxa, but to what extent differences in expression of defensive chemicals directly influences microbiome assembly remains to be tested. Host plant species also appears to drive differences in monarch caterpillar microbiomes. Further work is needed to understand how monarchs acquire microbes, for example through horizontal transfer during feeding on leaves or encountering soil when moving on or between host plants.