RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Because of the recent increase in type 2 diabetes and the need for complementary treatments in remote communities in many parts of the world, we undertook a study of treatments for diabetic symptoms used by traditional Q'eqchi' Maya healers of Belize. We used quantitative ethnobotany to rank culturally important taxa and subsequent pharmacological and phytochemical studies to assess bioactivity. MATERIALS AND METHODS: Antidiabetic plants identified in field interviews with traditional healers were ranked by syndromic importance value (SIV) based on 15 symptoms of diabetes. Species ranked with high SIV were tested in an assay relevant to many diabetes complications, the advanced glycation endproduct (AGE) inhibition assay. Active principles were identified by phytochemical analysis and bioassay. RESULTS: We collected over 70 plant species having a promising SIV score. The plants represented a broad range of neotropical taxa. Selected Q'eqchi' antidiabetic plants with high SIV were collected in bulk and tested in the advanced glycation endproduct (AGE) inhibition assay. All plant extracts showed AGE inhibition and the half maximal inhibitory concentration (IC50) ranged from 40.8 to 733⯵g/mL, while the most active species was Tynanthus guatemalensis Donn (Bignoniaceae). A linear regression showed a significant relationship between 1/ IC50 and SIV. Phytochemical analysis revealed the presence of verbascoside, as a major component and active principle of the T guatemalensis which had an IC50 =â¯5.1⯵g/mL, comparable to the positive control quercetin. CONCLUSION: The results reveal a rich botanical tradition of antidiabetic symptom treatments among the Q'eqchi'. Study of highly ranked plants revealed their activity in AGE inhibition correlated with SIV. T. guatemalensis was identified as a promising species for further evaluation and local use.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes , Fitoterapia , Preparações de Plantas , Belize , Produtos Finais de Glicação Avançada/efeitos dos fármacos , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Medicina Tradicional , Preparações de Plantas/farmacologia , Preparações de Plantas/uso terapêutico , Plantas MedicinaisRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: A previous pilot ethnobotanical and ethnopharmacological study with the Q'echi׳ Maya identified the family Piperaceae, as an important taxonomic group traditionally used for the treatment of epileptic and culture-bound anxiety disorders and possessing activity in the GABA system. Following that lead, a botanical survey was conducted in Peru, where 47 species of Piperaceae were collected including 21 plants traditionally used for folk illnesses by the Yanesha of Peru, an indigenous Amazonian group. MATERIALS AND METHODS: Two high throughput bioassays were used to quantify the in vitro activity of botanical extracts on the GABA system. RESULTS: Plant extracts demonstrated moderate to high affinity to the γ-aminobutyric acid benzodiazepine (GABA-BZD) receptor. In addition, extracts demonstrated low to moderate activity in the inhibition of the GABA-transaminase, with select plants exhibiting significant activity. Plants indicated by the Yanesha showed comparable activity to the other Piperaceae plants collected. Piper cremii was the most active plant in the GABA-BZD receptor assay, and Drymaria cordata (Caryophyllaceae) in the GABA-T assay. CONCLUSION: The study provides evidence that there is a pharmacological basis behind the use of plants in the treatment of susto and mal aire in both Central and South America, and we propose that the possible mechanism of action includes an interaction with the GABA-T enzyme and/or the GABAA-BZD receptor.
Assuntos
4-Aminobutirato Transaminase/antagonistas & inibidores , Piperaceae , Extratos Vegetais/farmacologia , Receptores de GABA-A/metabolismo , 4-Aminobutirato Transaminase/metabolismo , Bioensaio , Medicina Tradicional , PeruRESUMO
One aspect of plant defense is the production of constitutive secondary compounds that confer toxicity on herbivores and pathogens. The purpose of this study was to compare patterns of plant tissue toxicity across gradients of irradiance and nutrient content. We measured the potential toxicity (1/LC50) of extracts of six species of herbaceous Asteraceae grown under controlled conditions of temperature (25 degrees C), humidity (80%), photoperiod (16 h/day), in a range of concentrations of a modified Hoagland hydroponic solution (full-strength, 1/5 dilute, 1/10 dilute, and 1/50 dilute) and under two different light intensities (250 and 125 micromol/m2/s). The plants grew from seed for 42 days post-germination, and randomly chosen plants were harvested each 7 days. We did a general measure of potential phytochemical toxicity using an alcohol extraction of secondary compounds followed by brine shrimp (Artemia sp.) bioassay. Contrary to the carbon/nutrient balance hypothesis, tissue toxicity generally increased with decreasing irradiance and nutrient levels, so that plants whose growth was most restricted had tissues that were most toxic, although there were species-specific differences in this trend.
Assuntos
Adaptação Fisiológica , Asteraceae/química , Asteraceae/crescimento & desenvolvimento , Luz , Nitrogênio/metabolismo , Asteraceae/metabolismo , Cadeia Alimentar , Dose Letal Mediana , Fenômenos Fisiológicos da Nutrição/fisiologia , FotossínteseRESUMO
Um dos aspectos da defesa das plantas é a produção de compostos secundários constitutivos que são tóxicos para herbívoros e patógenos. O objetivo deste estudo foi comparar padräes de toxidez nas folhas em diferentes gradientes de nutrientes e intensidade luminosa. Foi medida a potencial toxidez (1/CL50) em extratos de seis espécies herbáceas de Asteraceae, desenvolvidas sob condiçäes controladas de temperatura (25§C), umidade (80%) e fotoperíodo (16 h/dias), com diferentes concentraçäes de solução hidropônica de Hoagland modificada (completa, 1/5, 1/10 e 1/50 diluídas) e sob três intensidades de luminosidade (250 e 125 mmol/m2/s). As plantas germinadas foram acompanhadas por 42 dias e, então, 15 indivíduos de cada espécie foram coletados ao acaso a cada 7 dias. Foi realizada uma medida geral da toxidez fitoquímica potencial usando extração alcoólica de compostos secundários das plantas estudadas, seguida do teste biológico com Artemia sp. Contrariando a hipótese de carbono/nutriente, a toxidez do tecido geralmente aumenta com a redução dos níveis de nutrientes e luminosidade. Isto é, plantas que tiveram crescimento restringido apresentaram-se mais tóxicas, embora as espécies tivessem tendências diferentes.
Assuntos
Adaptação Fisiológica , Asteraceae , Luz , Nitrogênio , Cadeia Alimentar , Ciências da Nutrição , FotossínteseRESUMO
Two extracts of different collections of the traditional medicine uña de gato (Uncaria tomentosa) from Peru were characterized by High Pressure Liquid Chromatography as containing approximately 6 mg/g total oxindole content prior to studies with alveolar macrophages. The plant preparations greatly stimulated IL-1 and IL-6 production by rat macrophages in a dose dependent manner in the range of 0.025-0.1 mg/ml. They were also able to enhance IL-1 and -6 in lipopolysaccharide-stimulated macrophages. The results suggest a strong immunostimulant action of this plant.
Assuntos
Interleucina-1/metabolismo , Interleucina-6/metabolismo , Macrófagos Alveolares/efeitos dos fármacos , Rubiaceae/química , Animais , Cromatografia Líquida de Alta Pressão , Macrófagos Alveolares/metabolismo , Peru , Extratos Vegetais/farmacologia , Plantas Medicinais , RatosRESUMO
The CHCl3-soluble extract of Piper guanacastensis (Piperaceae) was found to have noteworthy insecticidal activity to Aedes atropalpus mosquito larvae (LC50 80.5 micrograms/mL). Bioassay-guided fractionation afforded methyl 4-hydroxy-3-(3'-methyl-2'-butenyl)benzoate (1) as the major bioactive constituent (LC50 20.5 micrograms/mL). The separation of compound 1 from its transesterification artifact (2), ethyl 4-hydroxy-3-(3'-methyl-2'-butenyl)benzoate, was achieved by recycling reversed-phase HPLC. The flavonoids acacetin, chrysin, and pinostrobin were also isolated from the active fraction but did not display insecticidal properties.
Assuntos
Inseticidas/isolamento & purificação , Parabenos/isolamento & purificação , Plantas Medicinais/química , Aedes , Animais , Cromatografia em Camada Fina , Inseticidas/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Parabenos/farmacologia , Espectrofotometria UltravioletaRESUMO
The traditional herbal remedy from Psidium guajava leaves has been medically proposed in Mexico as effective treatment of acute diarrhea. A methanolic leaf extract was subjected to a bioassay-guided isolation of spasmolytic constituents. Six fractions were separated on a polyvinylpolypyrrolidine (PVPP) column using a water methanol-gradient. The fraction containing flavonols inhibited peristalsis of guinea pig ileum in vitro. A trace of quercetin aglycone together with five glycosides was isolated from this active fraction and identified as quercetin 3-O-alpha-L-arabinoside (guajavarin); quercetin 3-O-beta-D-glucoside (isoquercetin); quercetin 3-O-beta-D-galactoside (hyperin); quercetin 3-O-beta-L-rhamnoside (quercitrin) and quercetin 3-O-gentobioside. Biological activity of each pure compound was studied in the same bioassay. Obtained results suggest that the spasmolytic activity of the Psidium guajava leaf remedy is mainly due to the aglycone quercetin, present in the leaf and in the extract mainly in the form of five flavonols, and whose effect is produced when these products are hydrolyzed by gastrointestinal fluid.
Assuntos
Antidiarreicos , Glicosídeos , Íleo/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Quercetina/análogos & derivados , Quercetina/farmacologia , Animais , Avaliação Pré-Clínica de Medicamentos , Ácido Gástrico/metabolismo , Cobaias , Hidrólise , Masculino , Metanol , México , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Parassimpatolíticos/isolamento & purificação , Parassimpatolíticos/metabolismo , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Quercetina/isolamento & purificação , Quercetina/metabolismoRESUMO
Mimosa tenuiflora (Willd.) Poir, is a tree from the south areas of Mexico. This bark is popularly used as remedy to treat different skin lesions. The present study demonstrates the in vitro antimicrobial properties of the water and ethanolic extracts prepared with the dried and powdered bark of this plant. A clear inhibition growth effect was observed in all the gram positive and gram negative organisms, yeasts and dermatophytes used.