Luis Poveda

A consensus ethnobotany of the Q’eqchi’ Maya of Southern Belize

An ethnobotany study in collaboration with Q’eqchi’ Maya healers of Southern Belize led to a collection of 169 medicinal plant species, belonging to 67 different families. The data show the use of a majority of species from primary or secondary semi-evergreen rainforests of Southern Belize, rather than weedy species. The medicinal uses of the plants were grouped into 17 usage categories. The frequency of use for each plant and the informant consensus factor for each usage category reveals a consensus among the healers on the use of plant species as well as on the diseases treated. These results suggest a well-defined medicinal tradition.ResumenUne étude ethnobotanique en collaboration avec les guérisseurs Mayas Q’eqchi’ du Sud du Belize a mené à la récolte de 169 espèces de plantes médicinales appartenant à 67 families différentes. Les données montrent l’utilisation d’une majorité d’espèces provenant des forêts tropicales humides primaires ou secondaires du Sud du Belize, plutôt que de mauvaises herbes. Les utilisations médicinales de ces plantes ont été classées dans 17 catégories d’usage. La fréquence d’utilisation de chaque plante et le facteur de consensus calculé pour chaque catégorie d’usage révèle un haut degré de consensus parmi les guérisseurs aussi bien pour l’utilisation des plantes que pour les maladies traitées par ces dernières. Ces résultats suggèrent une tradition médicinale bien définie.

Traditionally-Used Antimalarials from the Meliaceae

A quantitative ethnobotanical approach to antimalarial drug discovery led to the identification of Lansium domesticum Corr. Ser. (Meliaceae) as an important antimalarial used by Kenyah Dyak healers in Indonesian Borneo. Triterpenoid lansiolides with antimalarial activity were isolated from the bark and shown to have activity in both in vitro bioassays with Plasmodium falciparum, and in mice infected with P. berghei. A survey of African and tropical American Meliaceae led to further development of the limonoid gedunin from the traditionally used medicinal plants, tropical cedar, Cedrela odorata L., and neem, Azadirachta indica A. Juss. Gedunin has significant in vitro activity but initially showed poor in vivo activity. In vivo activity was improved by (1) incorporation into an easy to absorb suspension, (2) preparation of a more stable compound, 7-methoxygedunin; and (3) synergism with dillapiol, a cytochrome P450 3A4 inhibitor. The results show the potential for both antimalarial drug and phytomedicine development from traditionally used plants.

Sesquiterpene lactones from two Tithonia species

Abstract From two Tithonia species, in addition to known compounds, nine new sesquiterpene lactones were isolated: eight germacranolides and one eudesmanolide. The structures were elucidated by means of spectroscopic methods.

Plant use by the Q'eqchi' maya of Belize in ethnopsychiatry and neurological pathology

Plant Use by the Q’eqchi’ Maya of Belize in Ethnopsychiatry and Neurological Pathology. Economic Botany 59(4):326–336, 2005. Neurological and mental health disorders are extremely debilitating, and sufferers in developing countries often rely on traditional practitioners for these medical needs. Few studies have focused on botanical remedies used in this context, although these offer interesting treatment alternatives. The present study investigated plant use for the treatment of neurological and mental health disorders by Qeqchi Maya healers of southern Belize. We found that these healers generally recognize and treat epilepsy/seizures, headache, madness, fright (susto), depression, numbness, insomnia, and stress with herbal remedies. Quantitative analyses showed that there is selection for the use of certain species and botanical families, namely for species of the Pteridophyta division and for plants from the Piperaceae family. This study denotes the importance and selectivity of plant use by Qeqchi healers of southern Belize for the treatment of neurological and mental conditions and points to a possible underrepresentation of these disorders in the ethnobotanical literature.

Novel steroids from Trichilia hirta as identified by nanoprobe INADEQUATE 2D-NMR spectroscopy

Abstract Two novel steroids, 3-hydroxypregnane-2,16-dione [ 1 ] and 2-hydroxyandrosta-1,4-diene-3,16 dione [ 2 ], were isolated from ethanolic extracts of the wood and bark of Trichilia hirta . The structure of 1 was rigorously determined from 2D-INADEQUATE NMR data that was: 1) acquired with a new higher-sensitivity 13 C probe called a Nano·nmr probe, and; 2) processed with a new NMR-analysis program called FRED, which automatically generated the complete carbon structure (as shown). In this first known application of both a Nanoprobe and FRED software to an unknown compound, the complete carbon skeleton was easily determined using only 11 mg (30 μmoles) of sample.

Inhibition of Bacterial Quorum Sensing and Biofilm Formation by Extracts of Neotropical Rainforest Plants

Bacterial biofilms are responsible for many persistent infections by many clinically relevant pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. Biofilms are much more resistant to conventional antibiotics than their planktonic counterparts. Quorum sensing, an intercellular communication system, controls pathogenesis and biofilm formation in most bacterial species. Quorum sensing provides an important pharmacological target since its inhibition does not provide a selective pressure for resistance. In this study, we investigated the quorum sensing and biofilm inhibitory activities of 126 plant extracts from 71 species collected from neotropical rainforests in Costa Rica. Quorum sensing and biofilm interference were assessed using a modified disc diffusion bioassay with Chromobacterium violaceum ATCC 12,472 and a spectrophotometric bioassay with Pseudomonas aeruginosa PA14, respectively. Species with significant anti-quorum sensing and/or anti-biofilm activities belonged to the Meliaceae, Melastomataceae, Lepidobotryaceae, Sapindaceae, and Simaroubaceae families. IC50 values ranged from 45 to 266 µg/mL. Extracts of these active species could lead to future development of botanical treatments for biofilm-associated infections.

Anxiolytic activity of a supercritical carbon dioxide extract of Souroubea sympetala (Marcgraviaceae).

The purpose of this work was to develop an extraction technique to yield a betulinic acid‐(BA) enriched extract of the traditional anti‐anxiety plant Souroubea sympetala Gilg (Marcgraviaceae). Five extraction techniques were compared: supercritical carbon dioxide extraction (SCE), conventional solvent extraction with ethyl acetate (EtOAc), accelerated solvent extraction (ASE), ultrasonic assisted extraction (UAE) and soxhlet extraction (Sox). The EtOAc and SCE extraction methods resulted in BA‐enriched extracts, with BA concentrations of 6.78 ± 0.2 and 5.54 ± 0.2u2009mg/g extract, respectively, as determined by HPLC‐APCI‐MS. The bioactivity of the BA‐enriched extracts was compared in the elevated plus maze (EPM), a validated rodent anxiety behaviour assay. Rats orally administered a 75u2009mg/kg dose of SCE extract exhibited anxiolysis as compared with vehicle controls, with a 50% increase in the percent time spent in the open arms, a 73% increase in unprotected head dips and a 42% decrease in percent time spent in the closed arms. No significant differences were observed between the SCE and EtOAc extracts for these measures, but the animals dosed with SCE extract had significantly more unprotected head dips than those dosed with the EtOAc extract. The SCE extract demonstrated a dose‐response in the EPM, with a trend toward decreased anxiety at 25u2009mg/kg, and significant anxiolysis was only observed at 75u2009mg/kg dose. This study demonstrates that SCE can be used to generate a betulinic acid‐enriched extract with significant anxiolysis in vivo. Further, the study provides a scientific basis for the ethnobotanical use of this traditional medicine and a promising lead for a natural health product to treat anxiety. Copyright

Constituents of two Acalypha species

The stem extract of Acalypha macrostachya yielded, in addition to known compounds, two new friedolabdanes and a new curcumene derivative. A. diversifolia gave a known amide. The structures were elucidated by high-field NMR spectroscopy.

Q’eqchi’ Maya healers’ traditional knowledge in prioritizing conservation of medicinal plants: culturally relative conservation in sustaining traditional holistic health promotion

This ethnobotanical study in the spirit of transdisciplinarity, and in collaboration with Q’eqchi’ Maya traditional healers, compares traditional Q’eqchi’ Maya ecosystem constructs or environmental zones with scientific ecosystems. To determine which categorization method better accommodates Q’eqchi’ Maya medicinal plant diversity, we analized 26 transects representing 160 medicinal plant occurrences. Our transect array encompasses a representative sampling of Q’eqchi’ Maya medicinal plant repertoire with use values broadly distributed over 17 usage categories. With a cumulative frequency of 2,235 medicinal plants through ecological zones, we conducted one-way ANOVA on the mean number of medicinal plant species identified in transects of the two conceptual schemes being contested. Our analysis reveals the Q’eqchi Maya environmental zones are the most salient. That is, knowledge of the Q’eqchi’ Maya environmental zones improves one’s ability to predict whether there will be a high or low abundance of Q’eqchi’ Maya medicinal plant species in a particular region, whereas knowledge of scientific ecosystems does not accomplish this feat as well. This is a notable finding as it suggests that if indeed Q’eqchi’ Maya medicinal plant diversity is better accounted for by the zones as envisioned by the Q’eqchi’ Maya, then it should be this mode of conceptualization that should be adopted by scientists and conservationists when trying to locate and protect regional Q’eqchi’ Maya medicinal plant diversity. These efforts serve as a model internationally in the conservation of medicinal plant biodiversity supportive of culturally relative holistic health promotion.

Melampolides from Oyedaea verbesinoides

Abstract The aerial parts of Oyedaea verbesinoides contained, in addition to known compounds, six new sesquiterpene lactones, viz., two melampolides, two cis , cis -germacranolides and two 4,5-dihydromelampolides. Their structures were elucidated using high-field NMR spectroscopy.