Despite the fact that swidden agriculture has been the subject of decades of research, questions remain about the extent to which it is constrained by demographic growth and if it can adapt to environmental limits. In this dissertation I analyze ethnographic and ethnohistorical evidence from the Toledo District, Belize, and suggest that Q'eqchi' Maya swidden agriculture may be more ecologically adaptive than previously thought. I use social network analysis to examine farmer labor exchange networks from a chronosequence of five villages where swidden is used. Results suggest that changes in land-use patterns, network structure, and reciprocity rates may increase the system's resilience to changes in the forest's agricultural productivity. I develop a novel interpretation of labor reciprocity that highlights how unreciprocated exchanges, when they occur within the context of a social network, may limit overexploitation of a common property resource. These results are then interpreted in the context of panarchy theory; I suggest that the structural variability observed in labor exchange networks may explain how Q'eqchi' swidden maintains its identity under changing environmental conditions - a definition of resilience. Thus, the resulting picture of Q'eqchi' swidden is one of socioecological resilience rather than homeostasis; dynamic labor exchange networks help maintain a village's social cohesion, ultimately limiting pioneer settlements and slowing overall rates of deforestation. A historical and demographic analysis of market incursions into southern Belize supports this conclusion.

This thesis examined the antimicrobial activity of select neotropical plants from Costa Rica and traditional Q’eqchi Maya medicines from Belize. In particular the potential for interference with bacterial quorum sensing (QS) and biofilm formation as well as fungal growth were assessed. Of one hundred and twenty six extracts collected from Costa Rica, one third showed significant QS inhibition while 13 species displayed more biofilm inhibitory activities than the positive control allicin. The active species belonged to the Lepidobotryaceae, Melastomataceae, Meliaceae, Sapindaceae, and Simaroubaceae. Twelve Marcgraviaceae species were tested for the same biological activities; of these, three showed similar QS inhibition to that of the positive control Delisea pulchra (Greville) Montagne and five with at least 30% biofilm inhibition. Only one species inhibited fungal growth – Marcgravia nervosa Triana & Planch. Bioassay-guided isolation of this plant resulted in the identification of the active principle as a naphthoquinone, with a minimum inhibitory concentration (MIC) ranging from 85 to 100 μM against Saccharomyces cerevisiae. Similarly, sixty one Q’eqchi’ Maya medicinal plant species were evaluated for their antimicrobial activities. Of these, four species showed more QS inhibition than D. pulchra, seven with comparable biofilm inhibitory activities that of allicin, and two with similarly antifungal activity to berberine. Two spirostanol saponins were isolated from Cestrum schlechtendahlii G.Don, an active antifungal plant. The major saponin showed growth inhibition against Saccharomyces cerevisiae and Fusarium graminearum, with MICs of 16.5 μM and 132 μM, respectively. Further analyses of this compound using chemical genomics suggested that its antifungal mechanism of action is pleiotropic, affecting multiple targets. Taken together, these findings showed that neotropical plants and traditional Q’eqchi’ Maya medicines contain phytochemicals that interfere with bacterial biofilm formation and quorum sensing as well as fungal growth.

This thesis investigated the phytochemistry and pharmacology of immunomodulatory medicinal plant species used traditionally by the Q’eqchi’ Maya Healers Association (QMHA) of Belize, and the Cree of Eeyou Istchee (CEI) of northern Quebec. Using quantitative ethnobotanical methodology, we identified 107 plant species belonging to 49 families used by Q’eqchi’ healers in the treatment of symptoms from 14 usage categories related to inflammation. Regression analysis revealed that the Piperaceae, Araceae, and Begoniaceae are preferentially selected by the Maya. Healer consensus for plant species was high, with 56 species (52%) being used by all the healers, and consensus for usage categories was also high, as informant consensus factor (FIC) values for each category were greater than 0.4. Fifty-two Belizean species were evaluated for their TNF-α inhibitory activity in an LPS-stimulated THP-1 monocyte model. Twenty-one species (40%) demonstrated significant TNF-α inhibition when assayed at 100 µg/mL, 8 of which had greater than 50% of the activity of the parthenolide positive control (10 µg/mL). Significant regressions were found between the anti-inflammatory activity and total healer frequency of use (Fuse) and the use reports for 3 usage categories, which indicated that ethnobotanical parameters can in part predict the activity of traditionally used species. Five sesquiterpene lactones were isolated from the leaves of Neurolaena lobata, one of the most active species tested, all of which demonstrated anti-inflammatory activity greater than that of parthenolide (IC50 = 4.79 µM), with IC50s ranging from 0.17-2.32 µM. Lobatin B was the most active isolate tested. Ethanolic and water extracts of 17 species used by Cree healers were evaluated for their immunomodulatory activity. In general, the average anti-inflammatory activity of ethanolic extracts was 1.8 times greater than that of water extracts, and the pro-inflammatory activity of water extracts was 3.7 times greater than ethanolic extracts. Picea mariana and Pinus banksiana were the most anti-inflammatory ethanolic and water extracts, while the water extract of Sarracenia purpurea was the most pro-inflammatory. Picea marina cones, the most anti-inflammatory Cree medicine, were subjected to bioassay guided isolation. This led to the isolation of the anti-inflammatory lignan (+)-lariciresinol-9’-p-coumarate, which had an IC50 of 28.4 µM. Together, these results validate the traditional knowledge shared by our Q’eqchi’ and Cree collaborators, and draw attention to the therapeutic potential of subtropical and boreal plants as culturally appropriate complements to modern medicine. - Cette thèse porte sur la phytochimie et la pharmacologie des espèces de plantes médicinales immunomodulatrices utilisées traditionnellement par le Q’eqchi’ Maya Healers Association (QMHA) du Belize, et les Cris d'Eeyou Istchee (CEI) du nord du Québec. En utilisant une méthodologie ethnobotanique quantitative, nous avons identifié 107 espèces végétales appartenant à 49 familles utilisées par les guérisseurs Q'eqchi’ dans le traitement de symptômes appartenant à 14 catégories d'utilisation liées à l'inflammation. Une analyse de régression a révélé que les familles Piperaceae, Araceae, et Begoniaceae sont préférentiellement choisis par les Mayas. Le consensus entre guérisseurs pour les espèces végétales était élevé, avec 56 espèces (52%) étant utilisés par tous les guérisseurs, et le consensus pour les catégories d'utilisation était également élevé, car les valeurs de facteur de consensus des informants (FIC) pour chaque catégorie étaient supérieurs à 0,4. Cinquante-deux espèces du Belize ont été évaluées pour leur activité inhibitrice de TNF-α dans un modèle de THP-1 monocytes stimulés par le LPS. Vingt-et-une espèces (40%) ont montré une inhibition significative de TNF-α lorsque dosés à 100 µg/mL, dont 8 d’entre elles ont démontrées plus de 50% de l'activité du contrôle positif parthénolide (10 µg/mL). Des régressions significatives ont été observées entre l'activité anti-inflammatoire et la fréquence d'utilisation de guérisseurs totale (Fuse) et les rapports d'utilisation pour 3 catégories d'utilisation, ce qui indique que les paramètres ethnobotaniques peuvent en partie prédire l'activité des espèces traditionnellement utilisées. Cinq lactones sesquiterpéniques ont été isolés à partir des feuilles de Neurolaena lobata, l'une des espèces les plus actives testées, qui a démontré une activité anti-inflammatoire supérieure à celle du parthénolide (CI50 = 4,79 µM), avec des CI50 allant de 0,17 à 2,32 µM. Lobatin B était l’isolât le plus actif testé. Des extraits éthanoliques et aqueux de 17 espèces utilisées par les guérisseurs Cris ont été évalués pour leur activité immunomodulatrice. En général, l'activité anti-inflammatoire moyenne des extraits éthanoliques était 1,8 fois supérieure à celle des extraits d'eau, et l'activité pro-inflammatoire des extraits d'eau était de 3,7 fois supérieure à celle des extraits éthanoliques. Picea mariana et Pinus banksiana étaient les extraits éthanoliques et aqueux avec le plus d’activité anti-inflammatoire, tandis que l'extrait aqueux de Sarracenia purpurea était le plus pro-inflammatoire. Le cône de Picea marina, le médicament traditionnelle Cris le plus anti-inflammatoire, a été soumis à une isolation guidée par essais biologiques. Cela a mené à l'isolement du lignane anti-inflammatoire (+)-lariciresinol-9'-p-coumarate, qui avait une CI50 de 28,4 µM. Ensemble, ces résultats valident les connaissances traditionnelles partagées par nos collaborateurs Q'eqchi' et Cris, et mettent en évidence le potentiel thérapeutique des plantes subtropicales et boréales comme des compléments à la médecine moderne qui sont culturellement appropriées.

This thesis investigated the phytochemistry and pharmacology of immunomodulatory medicinal plant species used traditionally by the Q’eqchi’ Maya Healers Association (QMHA) of Belize, and the Cree of Eeyou Istchee (CEI) of northern Quebec. Using quantitative ethnobotanical methodology, we identified 107 plant species belonging to 49 families used by Q’eqchi’ healers in the treatment of symptoms from 14 usage categories related to inflammation. Regression analysis revealed that the Piperaceae, Araceae, and Begoniaceae are preferentially selected by the Maya. Healer consensus for plant species was high, with 56 species (52%) being used by all the healers, and consensus for usage categories was also high, as informant consensus factor (FIC) values for each category were greater than 0.4. Fifty-two Belizean species were evaluated for their TNF-α inhibitory activity in an LPS-stimulated THP-1 monocyte model. Twenty-one species (40%) demonstrated significant TNF-α inhibition when assayed at 100 µg/mL, 8 of which had greater than 50% of the activity of the parthenolide positive control (10 µg/mL). Significant regressions were found between the anti-inflammatory activity and total healer frequency of use (Fuse) and the use reports for 3 usage categories, which indicated that ethnobotanical parameters can in part predict the activity of traditionally used species. Five sesquiterpene lactones were isolated from the leaves of Neurolaena lobata, one of the most active species tested, all of which demonstrated anti-inflammatory activity greater than that of parthenolide (IC50 = 4.79 µM), with IC50s ranging from 0.17-2.32 µM. Lobatin B was the most active isolate tested. Ethanolic and water extracts of 17 species used by Cree healers were evaluated for their immunomodulatory activity. In general, the average anti-inflammatory activity of ethanolic extracts was 1.8 times greater than that of water extracts, and the pro-inflammatory activity of water extracts was 3.7 times greater than ethanolic extracts. Picea mariana and Pinus banksiana were the most anti-inflammatory ethanolic and water extracts, while the water extract of Sarracenia purpurea was the most pro-inflammatory. Picea marina cones, the most anti-inflammatory Cree medicine, were subjected to bioassay guided isolation. This led to the isolation of the anti-inflammatory lignan (+)-lariciresinol-9’-p-coumarate, which had an IC50 of 28.4 µM. Together, these results validate the traditional knowledge shared by our Q’eqchi’ and Cree collaborators, and draw attention to the therapeutic potential of subtropical and boreal plants as culturally appropriate complements to modern medicine. - Cette thèse porte sur la phytochimie et la pharmacologie des espèces de plantes médicinales immunomodulatrices utilisées traditionnellement par le Q’eqchi’ Maya Healers Association (QMHA) du Belize, et les Cris d'Eeyou Istchee (CEI) du nord du Québec. En utilisant une méthodologie ethnobotanique quantitative, nous avons identifié 107 espèces végétales appartenant à 49 familles utilisées par les guérisseurs Q'eqchi’ dans le traitement de symptômes appartenant à 14 catégories d'utilisation liées à l'inflammation. Une analyse de régression a révélé que les familles Piperaceae, Araceae, et Begoniaceae sont préférentiellement choisis par les Mayas. Le consensus entre guérisseurs pour les espèces végétales était élevé, avec 56 espèces (52%) étant utilisés par tous les guérisseurs, et le consensus pour les catégories d'utilisation était également élevé, car les valeurs de facteur de consensus des informants (FIC) pour chaque catégorie étaient supérieurs à 0,4. Cinquante-deux espèces du Belize ont été évaluées pour leur activité inhibitrice de TNF-α dans un modèle de THP-1 monocytes stimulés par le LPS. Vingt-et-une espèces (40%) ont montré une inhibition significative de TNF-α lorsque dosés à 100 µg/mL, dont 8 d’entre elles ont démontrées plus de 50% de l'activité du contrôle positif parthénolide (10 µg/mL). Des régressions significatives ont été observées entre l'activité anti-inflammatoire et la fréquence d'utilisation de guérisseurs totale (Fuse) et les rapports d'utilisation pour 3 catégories d'utilisation, ce qui indique que les paramètres ethnobotaniques peuvent en partie prédire l'activité des espèces traditionnellement utilisées. Cinq lactones sesquiterpéniques ont été isolés à partir des feuilles de Neurolaena lobata, l'une des espèces les plus actives testées, qui a démontré une activité anti-inflammatoire supérieure à celle du parthénolide (CI50 = 4,79 µM), avec des CI50 allant de 0,17 à 2,32 µM. Lobatin B était l’isolât le plus actif testé. Des extraits éthanoliques et aqueux de 17 espèces utilisées par les guérisseurs Cris ont été évalués pour leur activité immunomodulatrice. En général, l'activité anti-inflammatoire moyenne des extraits éthanoliques était 1,8 fois supérieure à celle des extraits d'eau, et l'activité pro-inflammatoire des extraits d'eau était de 3,7 fois supérieure à celle des extraits éthanoliques. Picea mariana et Pinus banksiana étaient les extraits éthanoliques et aqueux avec le plus d’activité anti-inflammatoire, tandis que l'extrait aqueux de Sarracenia purpurea était le plus pro-inflammatoire. Le cône de Picea marina, le médicament traditionnelle Cris le plus anti-inflammatoire, a été soumis à une isolation guidée par essais biologiques. Cela a mené à l'isolement du lignane anti-inflammatoire (+)-lariciresinol-9'-p-coumarate, qui avait une CI50 de 28,4 µM. Ensemble, ces résultats valident les connaissances traditionnelles partagées par nos collaborateurs Q'eqchi' et Cris, et mettent en évidence le potentiel thérapeutique des plantes subtropicales et boréales comme des compléments à la médecine moderne qui sont culturellement appropriées.

A study was undertaken of plants used for treatment of diabetic symptoms by traditional healers of the Eeyou Istchee Cree (Canada), Lukomir Highlanders (Bosnia & Herzegovina), and Q’eqchi’ Maya (Belize). All antidiabetic plants were ranked by syndromic importance value (SIV) based on 15 symptoms, all of which were recognized by the Cree and Maya and 8 by the Highlanders. The Cree used only 18 species, the Highlanders 41, and the Maya 150, numbers which reflect the diversity of flora in their region. Vaccinium (Ericaceae) was one of the few genera in all three regions and the only consensus genus between the Cree and Highlander study sites. The Q’eqchi’ Maya ethnobotany did not present any cross-cultural consensus genera with Cree or Highlander medicinal plants, perhaps due to major biogeographic differences. In ethnopharmacological studies, Vaccinium species and Q’eqchi’ antidiabetic plants were tested in an assay relevant to diabetes, the advanced glycation endproduct (AGE) inhibition assay. Boreal and tropical Vaccinium species were potent inhibitors of AGEs and demonstrated concentration dependent inhibition, with a half maximal inhibitory concentration (IC50) range of 5.93–100 µg/mL. Phenolic content ranged from 80.3 to 201 µg/mL in boreal samples and from 1470 to 2170 µg/mL in tropical samples. Tropical species have a greater phenolic content and AGE inhibition. Seven Q’eqchi’ antidiabetic plant species were tested and all plant extracts showed AGE-inhibition. The IC50s ranged from 40.8 to 733 µg/mL, and the most active was Tynanthus guatemalensis Donn.. Tynanthus guatemalensis IC50 was about fives times greater (less active) than the mean ± SE IC50 reported for six tropical Vaccinium species of Vaccinium (8.77 ± 0.79 μg/mL). The highest consensus and most active Maya antidiabetic plant, Tynanthus guatemalensis Donn. Sm. was discovered to be an important plant recorded in archeological artifacts from the Late Classic Maya period (~750 CE). Ancient Maya used a cross shaped sign (k’an glyph) as a decorative element on Late Classic polychrome vessels and murals. The sign was believed to be the xylem template for a plant used as a flavouring in cacao drinks. However, the plant was incorrectly identified in the literature as Pimenta dioica (L.) Merr. (common name: Allspice) based on a common name and aromatic plant quality – not from a botanical voucher specimen. Pimenta dioica wood does not have a cross shape visible in the xylem but a unique character visible after a cross section of T. guatemalensis, is the xylem's cross shape organization. Wood of T. guatemalensis' also has an "allspice" aroma. Tynanthus guatemalensis is most likely the true botanical template behind the ancient Maya k’an glyph and this finding would show the continuity of use of this medicinal plant from ancient to modern times. Vaccinium was selected for an in depth phytochemical analysis using modern metabolomic methods. Nuclear magnetic resonance (1H NMR) was used to evaluate leaf extract spectra to provide information on (1) the taxonomic identity and (2) quantities of bioactive metabolites across multiple sites. Spectra clearly differentiated leaf samples of V. angustifolium, V. boreale, V. corymbosum, V. macrocarpon, V. myrtilloides, V. myrtillus, V. ovalifolium, and V. uliginosum according to generic, subgeneric, specific, phenotypic circumscriptions. Quantification of chlorogenic acid and hyperoside were replicated with a method that is highly reproducible across multiple sites with different NMR equipment. This methodology provides an important new approach to taxonomy and quality control for plants and natural health products.

A study was undertaken of plants used for treatment of diabetic symptoms by traditional healers of the Eeyou Istchee Cree (Canada), Lukomir Highlanders (Bosnia & Herzegovina), and Q’eqchi’ Maya (Belize). All antidiabetic plants were ranked by syndromic importance value (SIV) based on 15 symptoms, all of which were recognized by the Cree and Maya and 8 by the Highlanders. The Cree used only 18 species, the Highlanders 41, and the Maya 150, numbers which reflect the diversity of flora in their region. Vaccinium (Ericaceae) was one of the few genera in all three regions and the only consensus genus between the Cree and Highlander study sites. The Q’eqchi’ Maya ethnobotany did not present any cross-cultural consensus genera with Cree or Highlander medicinal plants, perhaps due to major biogeographic differences. In ethnopharmacological studies, Vaccinium species and Q’eqchi’ antidiabetic plants were tested in an assay relevant to diabetes, the advanced glycation endproduct (AGE) inhibition assay. Boreal and tropical Vaccinium species were potent inhibitors of AGEs and demonstrated concentration dependent inhibition, with a half maximal inhibitory concentration (IC50) range of 5.93–100 µg/mL. Phenolic content ranged from 80.3 to 201 µg/mL in boreal samples and from 1470 to 2170 µg/mL in tropical samples. Tropical species have a greater phenolic content and AGE inhibition. Seven Q’eqchi’ antidiabetic plant species were tested and all plant extracts showed AGE-inhibition. The IC50s ranged from 40.8 to 733 µg/mL, and the most active was Tynanthus guatemalensis Donn.. Tynanthus guatemalensis IC50 was about fives times greater (less active) than the mean ± SE IC50 reported for six tropical Vaccinium species of Vaccinium (8.77 ± 0.79 μg/mL). The highest consensus and most active Maya antidiabetic plant, Tynanthus guatemalensis Donn. Sm. was discovered to be an important plant recorded in archeological artifacts from the Late Classic Maya period (~750 CE). Ancient Maya used a cross shaped sign (k’an glyph) as a decorative element on Late Classic polychrome vessels and murals. The sign was believed to be the xylem template for a plant used as a flavouring in cacao drinks. However, the plant was incorrectly identified in the literature as Pimenta dioica (L.) Merr. (common name: Allspice) based on a common name and aromatic plant quality – not from a botanical voucher specimen. Pimenta dioica wood does not have a cross shape visible in the xylem but a unique character visible after a cross section of T. guatemalensis, is the xylem's cross shape organization. Wood of T. guatemalensis' also has an "allspice" aroma. Tynanthus guatemalensis is most likely the true botanical template behind the ancient Maya k’an glyph and this finding would show the continuity of use of this medicinal plant from ancient to modern times. Vaccinium was selected for an in depth phytochemical analysis using modern metabolomic methods. Nuclear magnetic resonance (1H NMR) was used to evaluate leaf extract spectra to provide information on (1) the taxonomic identity and (2) quantities of bioactive metabolites across multiple sites. Spectra clearly differentiated leaf samples of V. angustifolium, V. boreale, V. corymbosum, V. macrocarpon, V. myrtilloides, V. myrtillus, V. ovalifolium, and V. uliginosum according to generic, subgeneric, specific, phenotypic circumscriptions. Quantification of chlorogenic acid and hyperoside were replicated with a method that is highly reproducible across multiple sites with different NMR equipment. This methodology provides an important new approach to taxonomy and quality control for plants and natural health products.