Hamelia Patens Research Articles

Medicinal plants used in the traditional management of diabetes and its sequelae in Central America: A review

Ethnopharmacological relevanceGlobally 387 million people currently have diabetes and it is projected that this condition will be the 7th leading cause of death worldwide by 2030. As of 2012, its total prevalence in Central America (8.5%) was greater than the prevalence in most Latin American countries and the population of this region widely use herbal medicine. The aim of this study is to review the medicinal plants used to treat diabetes and its sequelae in seven Central American countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama. Materials and methodsWe conducted a literature review and extracted from primary sources the plant use reports in traditional remedies that matched one of the following disease categories: diabetes mellitus, kidney disease, urinary problems, skin diseases and infections, cardiovascular disease, sexual dysfunctions, visual loss, and nerve damage. Use reports were entered in a database and data were analysed in terms of the highest number of use reports for diabetes management and for the different sequelae. We also examined the scientific evidence that might support the local uses of the most reported species. ResultsOut of 535 identified species used to manage diabetes and its sequelae, 104 species are used to manage diabetes and we found in vitro and in vivo preclinical experimental evidence of hypoglycaemic effect for 16 of the 20 species reported by at least two sources. However, only seven of these species are reported in more than 3 studies: Momordica charantia L., Neurolaena lobata (L.) R. Br. ex Cass., Tecoma stans (L.) Juss. ex Kunth, Persea americana Mill., Psidium guajava L., Anacardium occidentale L. and Hamelia patens Jacq. Several of the species that are used to manage diabetes in Central America are also used to treat conditions that may arise as its consequence such as kidney disease, urinary problems and skin conditions. ConclusionThis review provides an overview of the medicinal plants used to manage diabetes and its sequelae in Central America and of the current scientific knowledge that might explain their traditional use. In Central America a large number of medicinal plants are used to treat this condition and its sequelae, although relatively few species are widely used across the region. For the species used to manage diabetes, there is variation in the availability and quality of pharmacological, chemical and clinical studies to explain traditional use.

Anti-inflammatory, free radical scavenging and alpha-glucosidase inhibitory activities of Hamelia patens and its chemical constituents

Context Hamelia patens Jacq. (Rubiaceae) is traditionally used to treat wounds, inflammation and diabetes. However, there is still a lack of scientific evidence to support these applications.Objective The objective of this study is to evaluate the anti-inflammatory, antioxidant and antidiabetic activities of Hamelia patens, and identify its bioactive compounds.Materials and methods Four extracts were obtained by maceration and liquid–liquid extraction: HEX, DCM–EtOAc, MeOH–EtOAc and MeOH–Aq. The anti-inflammatory effect was evaluated orally on rat paw carrageenan-induced oedema over 6 h (50, 200 and 500 mg/kg), and topically in mouse ear oedema induced by 12-tetradecanoylphorbol-13-acetate (TPA) after 4 h (0.5 and 1 mg/ear). We also evaluated myeloperoxidase levels in ear tissue, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and in vitro α-glucosidase inhibition. The chemical compounds were separated by column chromatography and identified by spectroscopic analysis.Results We found that the oral administration of the HEX extract at 500 and 200 mg/kg significantly decreased the carrageenan-induced inflammation after 1 and 3 h, respectively. The MeOH–EtOAc extract significantly inhibited myeloperoxidase activity (83.5%), followed by the DCM–EtOAc extract (76%), β-sitosterol/stigmasterol (72.7%) and the HEX extract (55%), which significantly decreased oedema induced by TPA at both doses, giving a similar effect to indomethacin. We also found that the MeOH–EtOAc, MeOH–Aq and DCM–EtOAc extracts showed good DPPH scavenging activity (IC50 values of 18.6, 93.9 and 158.2 μg/mL, respectively). The HEX extract showed the lowest α-glucosidase inhibition (an IC50 value of 26.07 μg/mL), followed by the MeOH–EtOAc extract (an IC50 value of 30.18 μg/mL), β-sitosterol/stigmasterol (IC50 34.6 μg/mL) and compound A ((6E,10E,14E,18E)-2,6,10,14,18,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, an IC50 value of 114.6 μg/mL), which were isolated for the first time from Hamelia patens.Discussion and conclusion Hamelia patens possesses anti-inflammatory, antioxidant and α-glucosidase inhibitory activities, which support its traditional use. These effects can be attributed to the identified compounds.

Toxicity and antinociceptive effects of Hamelia patens

Many medicinal herbs are used in folk medicine without taking into account their toxicity. Hamelia patens Jacq. (Rubiaceae), a Mexican endemic species, is used for the empirical treatment of pain. The aim of this work was to evaluate the toxicity and antinociceptive effects of ethanolic extracts of H. patens leaves. The toxicity of H. patens leaves (500–5000mg/kg) was evaluated in acute (14 days) and subacute (28 days) assays. In the subacute assay, a blood analysis (both hematology and chemistry) was carried out. The antinociceptive effects of H. patens leaves (50–200mg/kg) were evaluated using thermal-induced nociception (hot plate) and the chemical-induced nociceptive tests (acid acetic and formalin). In the acute toxicity test, the LD50 estimated for H. patens leaves was 2964mg/kg i.p. and >5000mg/kg p.o., whereas in the subacute test HPE did not affect hematological or biochemical parameters. In chemical-induced nociception models, H. patens (100 and 200mg/kg p.o.) showed antinociceptive effects with similar activity than 100mg/kg naproxen. In the hot plate test, HPE at 100mg/kg (17%) and 200mg/kg (25%) showed moderate antinociceptive effects. HPE could be a good source of antinociceptive agents because of its good activity and low toxicity.

In vitro and in vivo antifungal activity, liver profile test, and mutagenic activity of five plants used in traditional Mexican medicine

Berberis hartwegii Benth., Berberidaceae, Hamelia patens Jacq., Rubiaceae, Dendropanax arboreus (L.) Decne & Planch., Araliaceae, Erythrina herbacea L., Fabaceae, and Zanthoxylum caribaeum Lam., Rutaceae, acetone extracts were selected on the basis of their use in traditional Mexican medicine to treat scabies or skin diseases. Anti-dermatophyte activity in vitro was evaluated using the agar dilution assay, and the therapeutic efficacy of B. hartwegii and Z. caribaeum were tested against experimental tinea pedis. The infected animals were treated intragastrically daily for seven days with 2.5 and 5mg/kg of acetone extracts. The acetone extract of H. patens exhibited 100% growth inhibition against T. mentagrophytes and E. floccosum at 100.0 and 50.0μg/ml, respectively, and B. hartwegii inhibited growth of M. canis and T. mentagrophytes at 100.0μg/ml. Effective treatments with 2.5mg/kg of Z. caribaeum and B. hartwegii extract were comparable with 1mg/kg of clotrimazole in mice. Liver profile tests and histological analyses did not exhibit any signs of toxicity and the Ames test indicated that both extracts were safe when evaluated in strains TA98, TA100 and TA102. Our results suggest the potential for the future development of new antifungal drugs from B. hartwegii or Z. caribaeum.

Ethnopharmacological field study of the plants used to treat type 2 diabetes among the Cakchiquels in Guatemala

Ethnopharmacological relevanceType 2 diabetes is characterized by tissue resistance to the action of insulin, combined with a relative deficiency in insulin secretion. In Guatemala, type 2 diabetes results in significant mortality rates. The low incomes of the indigenous population results in the use of alternative therapies such as medicinal plants to treat the illness. We could not find any previous study related to the use of medicinal plants to treat diabetes in Guatemala. The aim of this work is to determine the most effective plant species used in traditional medicine to treat type 2 diabetes. Materials and methodsWe performed an ethnopharmacological field study among the Cakchiquels of Chimaltenango to select the most prominent plants used to treat the disease. Type 2 diabetic patients from their community health centers were interviewed using structured questionnaires. Two mathematical tools were used to identify potential plant species: the Disease Consensus Index and the Use Value. International databases, including SCOPUS, PubMed, and Google Scholar, were used to identify whether the plants with the highest scores were known to elicit hypoglycemic effects. ResultsAfter analyzing the data, we can propose the following plants as the most prominent among the Cakchiquels of Chimaltenango to treat type 2 diabetes: Hamelia patens Jacq., Neurolaena lobata (L.) R.Br.ex Cass., Solanum americanum Mill., Croton guatemalensis Lotsy, and Quercus peduncularis Née. ConclusionsThe Cakchiquel patients interviewed did not understand type 2 diabetes; however, they associated the onset of their disease with a negative emotion, such as shock, sadness or anger. Despite changes in lifestyle, influences of advertising, the availability of innovative treatments and the use of oral hypoglycemic treatments provided by health facilities serving indigenous communities, the Cakchiquel continue to use medicinal plants as adjunctive treatment. While they are unaware whether the plants can cause additional harm, they consider their consumption beneficial because they feel better. There were 11 plants identified with UVs greater than 0.5 and high DCIs; from these 64% of the plants have been identified as having hypoglycemic effects; this finding supports the traditional selection by the Cakchiquels of medicinal plants to treat T2D.

Aprovechamiento sostenible y conservación de las plantas medicinales en Cantarranas, Huehuetla, Hidalgo, México, como un medio para mejorar la calidad de vida en la comunidad

Este estudio se realizó en Cantarranas, Huehuetla, Hidalgo, México, donde el tipo de vegetación dominante es bosque tropical perennifolio. Cantarranas presenta alto grado de marginación, limitado acceso a servicios de salud y pocas oportunidades para incrementar sus ingresos económicos. El objetivo fue planear el aprovechamiento sostenible y conservación de plantas medicinales usadas en la comunidad como una alternativa para resolver problemas ambientales y sociales. Las especies fueron evaluadas con métodos etnobotánicos y ecológicos. Se usaron entrevistas estructuradas para documentar el valor cultural de las especies, nivel de fidelidad, prácticas e intensidad de manejo, usos y padecimientos tratados. La distribución y abundancia se obtuvo con el método de transectos lineales. Las 19 especies evaluadas son usadas para atender 51 padecimientos, los desórdenes gastrointestinales se tratan mayormente mediante las plantas medicinales. Las especies con mayor índice de valor cultural fueron Equisetum myriochaetum (0.69), Psidium guajava (0.37), Jaegeria macrocephala (0.26592) y Costus scaber (0.25496). Hamelia patens registró el mayor nivel de ? delidad (96%), seguida de E. myriochaetum (88%). Los valores de intensidad de manejo fueron más altos en C. scaber (9.2) y P. guajava (9). La densidad poblacional osciló entre 1 y 387 individuos por hectárea, según la especie y forma de vida. Mediante la vinculación sociedad y Universidad, se desarrolló e impartió un diplomado para los miembros de la comunidad, relacionado con el uso y aprovechamiento sostenible de plantas medicinales. Se constituyó una Sociedad Cooperativa con mujeres de la comunidad, ellas trabajan en la conservación y aprovechamiento sostenible de plantas medicinales.

Estrogenic and progestagenic effects of medicinal plants used for women's reproductive health in Guatemala

Many medicinal plants are used by the Maya of Guatemala to treat all aspects of women's reproductive health. As part of an international collaboration, the eight medicinal plants were collected and extracted including Plantago major L., Wigandia urens (Ruiz & Pavón) Kunth., Hamelia patens Jacq., Smilax domingensis Willd., Pimenta guatemalensis (Lundell) Lundell, Phlebodium pseudoaureum (Cav.) Lellinger, Cecropia peltata L. and Euphorbia lancifolia Schldt. The plant extracts were tested in a wide range of bioassays including ERα and β and PR binding assays, COX-2 binding and functional assays, serotonin (5-HT1A) binding assays. Active extracts were further tested in cell based SEAP reporter gene assays in transiently transfected MCF-7 cells and endogenous gene expression in MCF-7 cells. Five plant extracts bound both to ERα and β (EC50 range 28.9 – 51.5 µg/ml); three plants bound to the PR receptor; and two bound to the 5HT1A receptor. Treatment of MCF-7 cells with the extracts (20 µg/ml) induced a SEAP reporter gene in transiently transfected MCF-7 cells, indicating estrogen agonist and antagonist effects. Smilax domingensis extracts (20 µg/ml) enhanced the expression of an ERE reporter gene, and the expression of PR mRNA in MCF-7 cells. Phlebodium pseudoaureum and Euphorbia lancifolia were not active in any assays tested.

Intercropping with Shrub Species That Display a ‘Steady-State’ Flowering Phenology as a Strategy for Biodiversity Conservation in Tropical Agroecosystems

Animal species in the Neotropics have evolved under a lower spatiotemporal patchiness of food resources compared to the other tropical regions. Although plant species with a steady-state flowering/fruiting phenology are rare, they provide predictable food resources and therefore may play a pivotal role in animal community structure and diversity. I experimentally planted a supplemental patch of a shrub species with a steady-state flowering/fruiting phenology, Hamelia patens Jacq., into coffee agroforests to evaluate the contribution of this unique phenology to the structure and diversity of the flower-visiting community. After accounting for the higher abundance of captured animals in the coffee agroforests with the supplemental floral resources, species richness was 21% higher overall in the flower-visiting community in these agroforests compared to control agroforests. Coffee agroforests with the steady-state supplemental floral patch also had 31% more butterfly species, 29% more hummingbird species, 65% more wasps and 85% more bees than control coffee agroforests. The experimental treatment, together with elevation, explained 57% of the variation in community structure of the flower-visiting community. The identification of plant species that can support a high number of animal species, including important ecosystem service providers, is becoming increasingly important for restoration and conservation applications. Throughout the Neotropics plant species with a steady-state flowering/fruiting phenology can be found in all aseasonal forests and thus could be widely tested and suitable species used throughout the tropics to manage for biodiversity and potentially ecosystem services involving beneficial arthropods.

Nectar Feeding Habits of Loten’s Sunbird Cinnyris lotenius and Purple-rumped Sunbird Leptocoma zeylonica in the Royal Botanical Gardens, Peradeniya, Sri Lanka

Sunbirds (Nectariniidae) are small passerines that feed largely on nectar. The aim of thiswork was to observe the relationship of the purple-rumped sunbird Leptocoma zeylonica andLoten’s sunbird Cinnyris lotenius with their host flowers, and to examine their relationshipwith the glucose concentration of nectar, flower count and the length of corolla. The studywas carried out in the Royal Botanical Gardens, Peradeniya, Sri Lanka, between February2013 and September 2013. For each observation, plant species visited for nectar feeding,method of obtaining food, glucose concentration of nectar, length of corolla, and flower countwere recorded. Both species of sunbirds visited Hamelia patens, Sanchezia speciosa,Heliconia rostrata, Megaskepasma erythrochlamys, Strobilanthes flaccidifolius,Graptophyllum pictum and Pachystachys spicata. The male Loten’s sunbird’s occurrence ona given flower is biased by the presence of female (Pearson correlation coefficient: 0.874; PValue:<0.001). The Purple-rumped female’s occurrence is biased by the presence of male(Pearson correlation coefficient: 0.819; P-Value: <0.001). The results also indicated that therewas no significant correlation between the occurrence of the bird and the glucoseconcentration of the flower (Pearson correlation coefficients: -0.045; P-Value: 0.740;[Loten’s male]; -0.094; P-Value: 0.489; [Loten’s female]; -0.061; P-Value: 0.653; [Purplerumpedmale]; 0.001; P-Value: 0.997; [Purple-rumped female]). Similarly, there was nosignificant correlation between the flower count with the occurrence of the bird (Pearsoncorrelation coefficients: 0.160; P-Value: 0.239; [Loten’s male], 0.171; P-Value: 0.208;[Loten’s female]; 0.172; P-Value: 0.595; [Purple rumped male]; 0.211; P-Value: 0.118;[Purple-rumped female]). The Loten’s sunbird has no significant correlation with flowercorolla length (Pearson correlation coefficients: -0.240; P-Value: 0.075; [Loten’s male]; -0.142; P-Value: 0.297; [Loten’s female]). The Purple-rumped sunbird has a significantcorrelation with the flower corolla length. (Pearson correlation coefficient: -0.399; P-Value:0.020; [Purple rumped male]; -0.452; P-Value: <0.001; [Purple-rumped female]). Dependingon the length of corolla, the nectar obtaining method varied as probing or piercing.

In vitro Antifungal Potentials of Hamelia patens Jacq. (Rubiaceae) Aqueous Extracts of Leaves, Flowers and Fruits

Hamelia patens Jacq. of Rubiaceae is a medicinal shrub. The aqueous leaf, flower and fruit extracts were tested for antifungal potentials against Aspergillus fumigatus NCBT 112, Candida albicans NCBT 140, Fusarium oxysporum NCBT 156 and Rhizoctonia solani NCBT 194. The leaf and fruit extracts at 10.0% concentration resulted 100% growth inhibition for A. fumicatus as well as for C. albicans. The leaf, flower and fruit extracts at 10.0% concentration revealed 100% growth inhibition for F. oxysporum and R. solani. The fruit extract at 5.0% inhibited 100% growth in F. oxysporum and the same concentration of leaf extract inhibited 100% growth in R. solani. The 100% inhibition of leaf, flower and fruit aqueous extract can be comparable with positive control (Control-1) with bavistin 0.5% concentration.

Screening of Venezuelan plants for anti-inflammatory activity. Results from an in vitro nitric oxide assay

Due to its geographical location in the north of South America, Venezuela is considered to be one of the richest and varied countries in terms of plant diversity. Estimates of the total flora of Venezuela near 30,000 species, of which more than 1,500 are used for medicinal purposes by indigenous and local communities. However, only a relatively small proportion of these have been evaluated in terms of their anti-inflammatory activity. Our botanical database (MedPlant) now contains over 4,000 collections representing over 2,000 species. Most of the plants were collected in three states of Venezuela, Amazonas, Bolívar and Cojedes, from 1999 to the present. In this study, we evaluated 165 extracts from 92 species for inhibition of nitric oxide production (Griess assay) by the LPS- stimulated monocyte/macrophage cell line RAW 264.6, as a possible indicator of anti-inflammatory activity. The most promising extracts (50% inhibition of NO at < 40 µg/ml, without cytotoxic effect) were from Tapirira guianensis, Jacaranda copaia, Oxycaryum cubense, Croton cuneatus, Cochlosperm vitifolium, Datura inoxia, Hamelia patens, Ipomoea carnea, Machaerium madeirense, Euterpe precatoria and Costus scaber. Some of these have reported anti-inflammatory activity (Croton cuneatus, Cochlosperm vitifolium, Hamelia patens), while others, such as Datura inoxia, Tapirira guianensis and Oxycaryum cubense have not been reported to show such activity until now. A selection of these plants is now under study using bioassay-guided fractionation.

A New Monoterpenoid Oxindole Alkaloid from Hamelia Patens Micropropagated Plantlets

Chemical studies on Hamelia patens (Rubiaceae) micropropagated plantlets allowed production of a new monoterpenoid oxindole alkaloid, named (-)-hameline (7), together with eight known alkaloids, tetrahydroalstonine (1), aricine (2), pteropodine (3), isopteropodine (4), uncarine F (5), speciophylline (6), palmirine (8), and rumberine (9). The structure of the new alkaloid was assigned on the basis of 1D and 2D NMR spectroscopy, mass spectrometry, and molecular modeling.

Screening of Venezuelan Medicinal Plant Extracts for Cytostatic and Cytotoxic Activity Against Tumor Cell Lines

There are estimated to be more than 20,000 species of plants in Venezuela, of which more than 1500 are used for medicinal purposes by indigenous and local communities. Only a relatively small proportion of these have been evaluated in terms of their potential as antitumor agents. In this study, we screened 308 extracts from 102 species for cytostatic and cytotoxic activity against a panel of six tumor cell lines using a 24-h sulphorhodamine B assay. Extracts from Clavija lancifolia, Hamelia patens, Piper san-vicentense, Physalis cordata, Jacaranda copaia, Heliotropium indicum, and Annona squamosa were the most cytotoxic, whereas other extracts from Calotropis gigantea, Hyptis dilatata, Chromolaena odorata, Siparuna guianensis, Jacaranda obtusifolia, Tapirira guianensis, Xylopia aromatica, Protium heptaphyllum, and Piper arboreum showed the greatest cytostatic activity. These results confirm previous reports on the cytotoxic activities of the above-mentioned plants as well as prompting further studies on others such as C. lancifolia and H. dilatata that have not been so extensively studied.

국립수목원 열대식물자원연구센터 내 진딧물류 해충의 생물학적 방제 효과에 관한 연구

This study was performed in the Tropical Plant Resources Research Center of Korea National Arboretum to assess the effects of natural enemy attack on aphid population feeding on tropical plants. We measured the density of leaf-feeding aphids, Myzus persicae and Aphis gossypii, cohabiting with 5 types of tropical plants at intervals of approximately 2 weeks after introducing their natural enemy, Aphidius colemani. The density of aphids cohabiting with 4 types of tropical plants-Sanchezia parvibracteata, Hibiscus rosa-chinensis, Ficus kurzii, and Aloysia triphylla-started decreasing after 2 weeks of observation and was completely in control after 4 weeks of observation; however, the density of aphids cohabiting with the tropical plant, Hamelia patens, increased during 22 weeks of observation but decreased after the <TEX>$23^{rd}$</TEX> week of observation. We suggest that a banker plant is necessary for the maintenance of A. colemani in tropical greenhouses, and monitoring studies on H. patens, which was weakest against the aphids, should be performed. Our results indicate that biological pest management strategies using their natural enemies were formulated for the construction of new tropical greenhouses.

The contribution of plant species with a steady‐state flowering phenology to native bee conservation and bee pollination services

Abstract. 1. Neotropical organisms have evolved in an environment of relatively low temporal variation in food availability, but when neotropical forests are converted to agriculture, the temporal patchiness of food resources is increased. Plant species with a continuous (i.e. steady‐state) flowering/fruiting phenology are unique to the tropics and may more evenly distribute food resources temporally in agroecosystems.2. Here, we test the effects of an experimentally planted supplemental steady‐state floral resource, Hamelia patens Jacq., on bee diversity and pollination services in coffee agroforests. In addition, we evaluate effects of the steady‐state resource during low‐density and mass coffee blooms.3. Malaise trap data indicated that bee species density was significantly higher in coffee agroforests with the supplemental steady‐state floral resources [11.89 ± 1.62 (SE)] compared to those without (8.88 ± 1.10).4. The steady‐state floral resource had a negative impact on native bee visits to coffee flowers and a positive impact on Apis mellifera visits to coffee flowers (e.g. during low‐density blooms agroforests with steady‐state resources had 76% fewer native bee and 130% more A. mellifera visits to coffee flowers). Although coffee initial fruit set rates were higher across all agroforests during low‐density blooms (0.74 ± 0.03) compared to the mass bloom (0.59 ± 0.03), steady‐state floral resources did not affect initial fruit set rates (Z = −1.05, P = 0.29).5. Our results suggest that plants with a steady‐state phenology can provide more reliable resources for bees, supporting the conservation of wild bees in agroforests. However, steady‐state flowering may draw native bees away from the focal crop, especially during low‐density flowering.

Nectar Meals of a Mosquito-Specialist Spider

Evarcha culicivora, an East African jumping spider, is known for feeding indirectly on vertebrate blood by actively choosing blood-carrying mosquitoes as prey. Using cold-anthrone tests to detect fructose, we demonstrate thatE. culicivoraalso feeds on nectar. Field-collected individuals, found on the plantLantana camara, tested positive for plant sugar (fructose). In the laboratory,E. culicivoratested positive for fructose after being kept withL. camaraor one of another ten plant species (Aloe vera, Clerodendron magnifica, Hamelia patens, Lantana montevideo, Leonotis nepetaefolia, Parthenium hysterophorus, Ricinus communis, Senna didymobotrya, Striga asiatica, andVerbena trivernia). Our findings demonstrate thatE. culicivoraacquires fructose from its natural diet and can ingest fructose directly from plant nectaries. However, experiments in the laboratory also show thatE. culicivoracan obtain fructose indirectly by feeding on prey that have fed on fructose, implying a need to consider this possibility when field-collected spiders test positive for fructose. In laboratory tests, 53.5% of 1,215 small juveniles, but only 3.4% of 622 adultE. culicivora, left with plants for 24 hours, were positive for fructose. These findings, along with the field data, suggest that fructose is especially important for early-instar juveniles ofE. culicivora.

Identification and characterisation of incompatibility factors in Hamelia patens Jacq. (Rubiaceae)

SummaryHamelia patens Jacq., commonly called firebush, is a fast-growing, semi-woody, evergreen, perennial shrub in the family Rubiaceae. It is native to central southern Florida, USA and is cultivated on a wider scale as an ornamental plant in home gardens of India. From previous analyses, it was found that sexual reproduction in H. patens was limited due to self-incompatibility and was overcome by intraspecific pollination between morphologically different accessions. Diffusion plate assays, spectrophotometric analysis, and in vitro bioassays were conducted to measure RNase activity among stigma proteins. After compatible cross-pollination, the RNase activity was less than during incompatible pollination. RNase activity was present in extracts as well as leachates of the stigma. Diffusion plate assays and spectrophotometric assays were used to measure the RNase activity. In vitro assays revealed that RNase activity was essential for the inhibition of pollen tube growth. Our study confirmed that RNase-based gametophytic self-incompatibility operates in H. patens.

Intra and inter-annual variation in seed rain in a secondary dry tropical forest excluded from chronic disturbance

Domestic livestock grazing and firewood extraction are chronic and pervasive disturbances in dry secondary forest that reduce diversity and modify composition. Exclosure of such disturbances may allow the reestablishment of original diversity. To investigate potential vegetation recovery following 30 years of perturbation, seed rain was evaluated monthly during 3 years in 96 0.78 m 2 seed traps located in eight exclosures established in 2006 in a species-poor secondary dry forest in central Mexico. Twelve additional seed traps were located outside the exclosures in 2010 for comparison purposes. Baseline diversity of seed sources (trees, ⩾5 cm DBH) was recorded to compare standing tree composition with seed rain. Also, baseline diversity of potential primary (birds) and secondary (ants) dispersal vectors were registered to infer current plant–animal interactions. Total seed rain over 3 years within the exclosures comprised 180,375 seeds from 61 woody species, an average of 1.12 seeds/m 2/month. Half of these species (31) and 95% of the seeds falling within the exclosures belonged to trees typical of perturbed sites. Sixty percent of all recorded seeds belonged to an early-successional, bird-dispersed shrub ( Hamelia patens Jacq., Rubiaceae). Seed rain at one non-excluded plot was dominated by the wind-dispersed early-successional tree Heliocarpus sp. (Tiliaceae). Richness and seed density increased significantly in the second year of exclusion; however, by the third year, richness remained constant while seed density decreased. Seed rain was richer and more abundant during the dry season and was dominated by wind-dispersed species. Phenology, successional status and the dispersal modes of woody species explained most variance in richness and seed density of seed rain in early-successional dry forest. Seeds of early-successional species were dispersed in equal measure by abiotic and biotic vectors, whereas biotic vectors dispersed a higher density of late-successional seeds. The amount and timing of fall of abiotically dispersed seeds of the three most abundant species in the standing tree community may prolong their current domination of the landscape. However, even when richness in the seed rain within exclosures remained constant through time, composition was gradually shifting towards animal-dispersed species which may start a positive feedback producing an increase in animal visitation and a further increase of richness.

Herbivore-induced changes in fruit-frugivore interactions

Summary 1. Herbivore attack can induce dramatic changes in plant chemical defences. These responses protect plants against future herbivory, but can also have important physiological and ecological costs. Ecological costs of defence have received recent theoretical attention; however, many proposed costs have not yet been demonstrated empirically. In particular, field data are lacking as to whether induced responses in leaves can lead to correlated changes in fruit palatability that reduce fruit removal by mutualist seed dispersers. 2. Using the tropical shrub, Hamelia patens (Rubiaceae), we examined changes in fruit removal, palatability and maturation time following various treatments to the subtending leaves, including herbivory, mechanical damage and/or application of methyl jasmonate (MeJA). 3. Fewer fruits were removed from herbivory- and MeJA-treated branches than from controls, and results from three bioassays with ants and fungi suggested that this response was mediated by changes in fruit palatability. In addition, fruits from MeJA-treated branches matured more quickly than those from control branches. 4. Synthesis. Taken together, our results provide novel evidence that induced responses to herbivory can affect fruit–frugivore interactions through two mechanisms: changes in fruit palatability and changes in fruit development time. This highlights the importance of physiological linkages between leaf and fruit traits in determining the overall costs of plant defence and the fitness outcomes of multispecies interactions.

Ethnopharmacology of the Popoluca, Mexico: an evaluation.

Medicinal plants are an essential part of indigenous pharmaceutical systems. We studied the medicinal plants used by the Popoluca of the Sierra Santa Marta (Eastern Mexico). This study is part of a series on the ethnopharmacology of various Macro-Mayan groups. During 16 months of ethnobotanical fieldwork, 614 taxa used medicinally and 4488 individual use-reports were documented. The data are analysed using the concept of the "healers' consensus" in order to identify culturally important medicinal plants. The medicinal uses of the plants were grouped into 13 illness categories. The responses for each species were summarized for each of the categories and were ordered by frequency of mention. The most frequently recorded medicinal plants of the Popoluca are Hamelia patens, used to stop bleeding from wounds, and Byrsonima crassifolia, used against diarrhoea. The high-ranked medicinal species were assessed pharmacognostically using published phytochemical and pharmacological data. Popoluca medicinal uses were fairly consistent with published data on active ingredients for those plants for which such data exist. However, data is still lacking for many other species. Toxicological studies are particularly scarce. This study will be used as a basis for subsequent studies on the pharmacology and phytochemistry of medicinal plant species.