Guarana: Revisiting A Highly Caffeinated Plant From The Amazon

Ethnopharmacological relevance Guarana (Paullinia cupana Kunth var. sorbilis (Mart.) Ducke) has been traditionally consumed by indigenous communities of the Amazon region. It is valued mainly for its stimulant property because of its high content of caffeine, which can be up to 6% in the seeds. Aim of the review The purpose of this review is to revisit this typically Brazilian plant, addressing economic considerations, the chemical makeup of the seeds and pharmacological properties so far investigated. Results Guarana is primarily produced in the Brazilian states of Amazonas and Bahia, and approximately 70% of the production is used by the industry of soft and energy drinks. The other 30% becomes guarana powder for direct consumption in capsules or dilution in water, or it serves as a raw material for the pharmaceutical and cosmetics industries. In addition to its stimulant property, guarana has other therapeutic properties, which have aroused the interest of the scientific community. Conclusion This review shows that other guarana properties may be explored and how scarce are the studies regarding agronomic, plant pathology, physiology and breeding. So far, caffeine has been the main reason to study guarana and still will lead the researches because the demand for this alkaloid by food and pharmaceutical industry, and a strongly growing market related with beauty products. However, guarana has other components and there is great interest in studies designed to elucidate the effects of guarana's bioactive components and their potential pharmacological applications. Significant part of the guarana production in Brazil still comes from Indians tribes in the Amazon State, and any improvement in this plant, in any aspect, may propitiate a positive economic impact in their lives. © 2013 Elsevier Ireland Ltd.15011431Alves, A.B., Bragagnolo, N., Determinação simultânea de teobromina, teofilina e cafeína em chás por cromatografia líquida de alta eficiência (2002) Brazilian Journal of Pharmaceutical Sciences, 38, pp. 237-243Andersen, T., Fogh, J., Weight loss and delayed gastric emptying following a South American herbal preparation in overweight patients (2001) Journal of Human Nutrition and Dietetics, 14, pp. 243-250Ângelo, P.C.S., Nunes-Silva, C.G., Brígido, M.M., Azevedo, J.S.N., Assunção, E.N., Sousa, A.R.B., Patrício, F.J.B., Astolfi-Filho, S., Guarana (Paullinia cupana var. sorbilis), an anciently consumed stimulant from the Amazon rain forest: The seeded-fruit transcriptome (2008) Plant Cell Reports, 27, pp. 117-124Angelucci, E., Tocchini, R.P., Lazarine, V.B., Prado, M.A.F., Caracterização química da semente de guaraná (Paullinia cupana var. sorbilis Ducke) (1978) Boletim Do Instituto de Tecnologia de Alimentos, 56, pp. 183-192Antonelli-Ushirobira, T.M., Yamaguti, E., Uemura, L.M., Nakamura, C.V., Dias Filho, B.P., Mello, J.C.P., Chemical and microbiological study of extract from seeds of guaraná (Paullinia cupana var. sorbilis) (2007) Latin American Journal of Pharmacy, 26, pp. 5-9Antunes, E., Gordo, W.M., De Oliveira, J.F., Teixeira, C.E., Hyslop, S., De Nucci, G., The relaxation of isolated rabbit corpus cavernosum by the herbal medicine Catuama® and its constituents (2001) Phytotherapy Research, 15, pp. 416-421Anvisa-Brazil, 1997. Decreto n 2.314, de 4 de setembro de 1997. Regulamenta a Lei n 8.918, de 14 de julho de 1994, que dispõe sobre a padronização, a classificação, o registro, a inspeção, a produção e a fiscalização de bebidas no BrazilAnvisa-Brazil, (2010) Farmacopeia Brasileira, 2 VOL.. , Agência Nacional de Vigilância Sanitária BrazilAshihara, H., Sano, H., Crozier, A., Caffeine and related purine alkaloids: Biosynthesis, catabolism, function and genetic engineering (2008) Phytochemistry, 69, pp. 841-856Ashihara, H., Suzuki, T., Distribution and biosynthesis of caffeine in plants (2004) Frontiers in Bioscience, 9, pp. 1864-1876Atroch, A.L., (2009) Avaliação e Seleção de Progênies de Meios Irmãos de Guaranazeiro (Paullinia Cupana Var. Sorbilis (Mart.) Ducke) Utilizando Caracteres Morfo-agronômicos, p. 72. , Instituto Nacional de Pesquisas da Amazônia - INPA, Manaus AMAvato, P., Pesante, M.A., Fanizzib, F.P., Aimbiré De Moraes Santos, C., Seed oil composition of Paullinia cupana var. sorbilis (Mart.) Ducke (2003) Lipids, 38, pp. 773-780Basile, A., Ferrara, L., Del Pezzo, M., Mele, G., Sorbo, S., Bassi, P., Montesano, D., Antibacterial and antioxidant activities of ethanol extract from Paullinia cupana Mart (2005) Journal of Ethnopharmacology, 102, pp. 32-36Baumann, T.W., Schulthess, B.H., Hanni, K., Guarana (Paullinia cupana) rewards seed dispersers without intoxicating them by caffeine (1995) Phytochemistry, 39, pp. 1063-1070Bempong, D.K., Houghton, P.J., Dissolution and absorption of caffeine from guarana (1992) Journal of Pharmacy and Pharmacology, 44, pp. 769-771Bentes, J.L.S., Neto, P.Q.C., Variability of Colletotrichum guaranicola using AFLP markers (2011) Acta Amazonica, 41, pp. 251-256Bérubé-Parent, S., Pelletier, C., Doré, J., Tremblay, A., Effects of encapsulated green tea and guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men (2005) British Journal of Nutrition, 94, pp. 432-436Boozer, C.N., Nasser, J.A., Heymsfield, S.B., Wang, V., Chen, G., Solomon, J.L., An herbal supplement containing Ma Huang-Guarana for weight loss: A randomized, double-blind trial (2001) International Journal of Obesity, 25, pp. 316-324Bydlowski, S.P., D'Amico, E.A., Chamone, D.A.F., An aqueous extract of guarana (Paullinia cupana) decreases platelet thromboxane synthesis (1991) Brazilian Journal of Medical and Biological Research, 24, pp. 421-424Cabral, C., O guaraná: Composição e propriedades das sementes, reprodução e cultura (1932) Agricicultura e Pecuária, 4, p. 738Cadet De Gassicourt, C.L., Sur le Guarana (1817) Journal de Pharmacie et des Sciences Accessoires, 6, pp. 259-260Campos, A.R., Barros, A.I.S., Albuquerque, F.A.A., Leal, L., Rao, V.S.N., Acute effects of guarana (Paullinia cupana Mart.) on mouse behaviour in forced swimming and open field tests (2005) Phytotherapy Research, 19, pp. 441-443Campos, A.R., Barros, A.I.S., Santos, F.A., Rao, V.S.N., Guarana (Paullinia cupana Mart.) offers protection against gastric lesions induced by ethanol and indomethacin in rats (2003) Phytotherapy Research, 17, pp. 1199-1202Campos, M.M., Fernandes, E.S., Ferreira, J., Bortolanza, L.B., Santos, A.R.S., Calixto, J.B., Pharmacological and neurochemical evidence for antidepressant-like effects of the herbal product Catuama (2004) Pharmacology Biochemistry and Behavior, 78, pp. 757-764Campos, M.P.D., Riechelmann, R., Martins, L.C., Hassan, B.J., Casa, F.B.A., Del Giglio, A., Guarana (Paullinia cupana) improves fatigue in breast cancer patients undergoing systemic chemotherapy (2011) Journal of Alternative and Complementary Medicine, 17, pp. 505-512Campos, M.P.O., Riechelmann, R., Martins, L.C., Hassan, B.J., Casa, F.B.A., Del Giglio, A., Guarana (Paullinia cupana) improves fatigue in breast cancer patients undergoing systemic chemotherapy (2011) Journal of Alternative and Complementary Medicine, 17, pp. 505-512Carlson, M., Thompson, R.D., Liquid chromatographic determination of methylxanthines and catechins in herbal preparations containing guarana (1998) Journal of AOAC International, 81, pp. 691-701(2012) Guaraná. Comissão Executiva Do Plano da Lavoura Cacaueira - CEPLAC (Online Document:), , http://www.ceplac.gov.br/radar/guarana.htm, CEPLAC-Brazil Visited in Feb. 2012Corrêa, M.P., (1926) Dicionário das Plantas Úteis Do Brasil e das Exóticas Cultivadas, , Serviço de Informação Agrícola, Rio de JaneiroCunha, G.M., (2006) Informações de Mercado Sobre Guaraná, , http://201.2.114.147/bds/bds.nsf/EA4413F15EF0A2938325754C0063C9C8/ $File/NT0003DC32.pdf, Serviço Apoio Micro Pequenas Empresas - SEBRAE. (On line document:). Visited in Feb. 2012Dalonso, N., Petkowicz, D.L.C.O., Guarana powder polysaccharides: Characterisation and evaluation of the antioxidant activity of a pectic fraction (2012) Food ChemistryDalonso, N., Petkowicz, D.L.C.O., Guarana powder polysaccharides: Characterisation and evaluation of the antioxidant activity of a pectic fraction (2012) Food Chemistry, 134, pp. 1804-1812Ducke, A., Diversidade dos guaranás (1937) Rodriguésia, 3, pp. 155-156Edwards, H.G.M., Farwell, D.W., Oliveira, L.F.C.D., Alia, J.-M., Hyaric, M.L., Ameida, M.V.D., FT-Raman spectroscopic studies of guarana and some extracts (2005) Analytical Chimica Acta, 532, pp. 177-186Escobar, J.R., Effective female flower variation estimate of guarana tree Paullinia cupana var. sorbilis (1985) Pesquisa Agropecuaria Brasileira, 20, pp. 1365-1371Espinola, E.B., Dias, R.F., Mattei, R., Carlini, E.A., Pharmacological activity of guarana (Paullinia cupana Mart.) in laboratory animals (1997) Journal of Ethnopharmacology, 55, pp. 223-229(2001) 1a Reunião Técnica da Cultura Do Guaraná, p. 48. , Embrapa Agropecuária Ocidental Embrapa Agropecuária Ocidental (Ed.), Documentos, Manaus-AM(2005) Cultura Do Guaranazeiro No Amazonas, p. 40. , Embrapa Agropecuária Ocidental Embrapa Agropecuária Ocidental (Ed.), Sistemas de Produção, fourth ed, ManausFigueiredo, L.C., Faria-Campos, A.C., Astolfi-Filho, S., Azevedo, J.L., Identification and isolation of full-length cDNA sequences by sequencing and analysis of expressed sequence tags from guarana (Paullinia cupana) (2011) Genetics and Molecular Research, 10, pp. 1188-1199Fukumasu, H., Avanzo, J.L., Heidor, R., Silva, T.C., Atroch, A., Moreno, F.S., Dagli, M.L.Z., Protective effects of guarana (Paullinia cupana Mart. var. sorbilis) against DEN-induced DNA damage on mouse liver (2006) Food and Chemical Toxicology, 44, pp. 862-867Fukumasu, H., Avanzo, J.L., Nagamine, M.K., Barbuto, J.A., Rao, K.V., Dagli, M.L.Z., Paullinia cupana Mart var. sorbilis, guaraná, reduces cell proliferation and increases apoptosis of B16/F10 melanoma lung metastases in mice (2008) Brazilian Journal of Medical and Biological Research, 41, pp. 305-310Fukumasu, H., Latorre, A.O., Zaidan-Dagli, M.L., Paullinia cupana Mart. var. sorbilis, guarana, increases survival of Ehrlich ascites carcinoma (EAC) bearing mice by decreasing cyclin-D1 expression and inducing a G0/G1 cell cycle arrest in EAC cells (2011) Phytotherapy Research, 25, pp. 11-16Fukumasu, H., Silva, T.C.D., Avanzo, J.L., Lima, C.E.D., Mackowiak, I.I., Atroch, A., Spinosa, H.D.S., Dagli, M.L.Z., Chemopreventive effects of Paullinia cupana Mart var. sorbilis, the guaraná, on mouse hepatocarcinogenesis (2006) Cancer Letters, 233, pp. 158-164Gentry, A.H., The distribution and evolution of climbing plants (1991) The Biology of Vines, pp. 3-53. , F.E. Putz, H.A. Mooney, Cambridge University Press CambridgeHaskell, C.F., Kennedy, D.O., Wesnes, K.A., Milne, A.L., Scholey, A.B., A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guaraná in humans (2007) Journal of Psychopharmacology, 21, pp. 65-70Heard, C.M., Johnson, S., Moss, G., Thomas, C.P., In vitro transdermal delivery of caffeine, theobromine, theophylline and catechin from extract of guarana, Paullinia cupana (2006) International Journal of Pharmaceutics, 317, pp. 26-31Heckman, M.A., Weil, J., Gonzalez De Mejia, E., Caffeine (1,3,7-trimethylxanthine) in foods: A comprehensive review on consumption, functionality, safety, and regulatory matters (2010) Journal of Food Science, 75, pp. 77-87Henman, A.R., Guarana (Paullinia cupana var. sorbilis): Ecological and social perspectives on an economic plant of the central Amazon basin (1982) Journal of Ethnopharmacology, 6, pp. 311-338Henman, A.R., (1986) Vida Natural. O Guaraná: Sua Cultura, Propriedades, Formas de Preparação e Uso, , second ed. Global/Ground São Paulo(2011) Levantamento Sistemático da Produção Agrícola LSPA, p. 82. , IBGE-Brazil Estatística, I.B.d.G.e. (Ed.)Kennedy, D.O., Haskell, C.F., Robertson, B., Reay, J., Brewster-Maund, C., Luedemann, J., Maggini, S., Scholey, A.B., Improved cognitive performance and mental fatigue following a multi-vitamin and mineral supplement with added guarana (Paullinia cupana) (2008) Appetite, 50, pp. 506-513Kennedy, D.O., Haskell, C.F., Wesnes, K.A., Scholey, A.B., Improved cognitive performance in human volunteers following administration of guarana (Paullinia cupana) extract: Comparison and interaction with Panax ginseng (2004) Pharmacology Biochemistry and Behavior, 79, pp. 401-411Kofink, M., Papagiannopoulos, M., Galensa, R., Enantioseparation of catechin and epicatechin in plant food by chiral capillary electrophoresis (2007) European Food Research and Technology, 225, pp. 569-577Krewer, C.C., Ribeiro, E.E., Ribeiro, E.A.M., Moresco, R.N., Rocha, M.I.U.M., Montagner, G.F.S., Machado, M.M., Cruz, I.B., Habitual intake of guarana and metabolic morbidities: An epidemiological study of an elderly amazonian population (2011) Phytotherapy Research, 25, pp. 1367-1374Krewer, C.D., Ribeiro, E.E., Ribeiro, E.A.M., Moresco, R.N., Da Rocha, M., Montagner, G., Machado, M.M., Da Cruz, I.B.M., Habitual intake of guarana and metabolic morbidities: An epidemiological study of an elderly amazonian population (2011) Phytotherapy Research, 25, pp. 1367-1374Kuri, C.M.B., The Guaraná Industry in Brazil (2008) International Business and Economics Research Journal, 7, pp. 87-98Lima, W.P., Carnevali, Jr.L.C., Eder, R., Costa Rosa, L.F.B.P., Bacchi, E.M., Seelaender, M.C.L., Lipid metabolism in trained rats: Effect of guarana (Paullinia cupana Mart.) supplementation (2005) Clinical Nutrition, 24, pp. 1019-1028Lodewijks, M.P., (1986) Aspects of the Growth of Guaraná (Paullinia Cupana Var. Sorbilis), A "relatório" for Agro Brahma and the Centro de Pesquisas Do Cacau (CEPEC), p. 25. , Dept. of Forestry, Agric. University WageningenLunguinho, L.G., (2007) Padrão Do Florescimento em Clones de Guaranazeiro (Paullinia Cuapana Var. Sorbilis), p. 85. , Universidade Federal do Amazonas - UFAM, Manaus-AMLyra, M.B., Aspectos bromatológicos do guaraná (1953) Arquivos de Bromatologia, 1, pp. 33-45Majhenic, L., Skerget, M., Knez, Z., Antioxidant and antimicrobial activity of guarana seed extracts (2007) Food Chemistry, 104, pp. 1258-1268Maravalhas, N., Casca do guaraná - Matéria-prima para cafeína - Método Industrial de extração (1965) Estudos Sobre O Guaraná e Outras Plantas Produtoras de Cafeína, pp. 5-11. , Química Instituto Nacional de Pesquisas da Amazônia (INPA) ManausMarx, F., Analysis of guarana seeds II. Studies on the composition of the tannin fraction (1990) Zeitschrift für Lebensmittel-Untersuchung und -Forschung, 190, pp. 429-431Mattei, R., Dias, R.F., Espínola, E.B., Carlini, E.A., Barros, S.B.M., Guarana (Paullinia cupana): Toxic behavioral effects in laboratory animals and antioxidant activity in vitro (1998) Journal of Ethnopharmacology, 60, pp. 111-116Mazzafera, P., Catabolism of caffeine in plants and microorganisms (2004) Frontiers in Bioscience, 9, pp. 1348-1359Mazzafera, P., Which is the by-product: Caffeine or decaf coffee? (2012) Food and Energy Security, 1, pp. 70-75Mazzafera, P., Baumann, T.W., Shimizu, M.M., Silvarolla, M.B., Decaf and the steeplechase towards decaffito - The coffee from caffeine-free Arabica plants (2009) Tropical Plant Biology, 2, pp. 63-76McCusker, R.R., Goldberger, B.A., Cone, E.J., Caffeine content of specialty coffees (2003) Journal of Analytical Toxicology, 27, pp. 520-522Meurer-Grimes, B., Berkov, A., Beck, H., Theobromine, theophylline, and caffeine in 42 samples and products of guarana (Paullinia cupana, Sapindaceae) (1998) Economic Botany, 52, pp. 293-301Miura, T., Tatara, M., Nakamura, K., Suzuki, I., Effect of Guarana on exercise in normal and epinephrine-induced glycogenolytic mice (1998) Biological and Pharmaceutical Bulletin, 21, pp. 646-648Monteiro, M.Y., (1965) Antropogeografia Do Guarana, , Amazônia, I.N.d.P.d. (Ed.), Cadernos da Amazônia(2012) Tropicos, , http://www.tropicos.org/, Missouri Botanical Garden acessed in Feb.2012Nascimento Filho, F.J., Atroch, A.L., Cruz, C.D., Carneiro, P.C.S., Adaptabilidade e estabilidade de clones de guaraná (2009) Pesquisa Agropecuaria Brasileira, 44, pp. 1138-1144Nazaré, R.F.R., Figueiredo, F.J.C., (1982) Contribuição Ao Estudo Do Guaraná, p. 40. , (Embrapa/CPATU), C.d.P.A.d.T.Ú. (Ed.), Documentos, BelémOkada, M., Tocchini, R.P., Nori, E.E.M., Angelucci, E., Estudos sobre a secagem e torração do guaraná (1977) Coletânea Do ITAL, 8, pp. 519-529Oliveira, D.M., Barreto, G., Galeano, P., Romero, J.I., Holubiec, M.I., Badorrey, M.S., Capani, F., Alvarez, L.D.G., Paullinia cupana Mart. var. sorbilis protects human dopaminergic neuroblastoma SH-SY5Y cell line against rotenone-induced cytotoxicity (2011) Human & Experimental Toxicology, 30, pp. 1382-1391Oliveira, E.R.N., (2010) Características Morfofisiológicas e Bioquímicas de Clones de Guaraná Paullinia Cupana Kunt. Var. Sorbilis (Mart.) Ducke Cultivados Sob Plantio Comercial, Botânica, p. 125. , Instituto Nacional de Pesquisas da Amazônia - INPAOpala, T., Rzymski, P., Pischel, I., Wilczak, M., Wozniak, J., Efficacy of 12 weeks supplementation of a botanical extract based weight loss formula on body weight, body composition and blood chemistry in healthy, overweight subjects - A randomised double blind placebo controlled clinical trial (2006) European Journal of Medical Research, 11, pp. 343-350Otobone, F.J., Sanches, A.C., Nagae, R.L., Martins, J.V.C., Obici, S., Mello, J.C.P.D., Audi, E.A., Effect of crude extract and its semi purified constituents from guaraná seeds [Paullinia cupana var. sorbilis (Mart.) lucke] on cognitive performance in Morris water maze in rats (2005) Brazilian Archives of Biology and Technology, 48, pp. 723-728Peckolt, T., (1868) Analyses de Materia Medica Brasileira Dos Produtos Que Forão Premiados Nas Exposições Nacionais e Na Exposição, , Universal de Paris em 1867. Laemmert, E.Laemmert, H. (Eds.), Rio de JaneiroPires, J.M., Guaraná e cupana (1949) Sociedade de Agrônomos e Veterinários Do Pará, 1, pp. 9-20Polo, S.H.O., (2006) Estrutura e Desenvolvimento de Sementes de Paullinia L. (Sapindaceae), p. 118. , Unicamp, CampinasRibeiro, B.D., Coelho, M.A.Z., Barreto, D.W., Obtenção de extratos de guaraná ricos em cafeína por processo enzimático e adsorção de taninos (2012) Brazilian Journal Food Technology, 15, pp. 261-270Roncon, C.M., Almeida, C.B., Klein, T., Mello, J.C., Audi, E.A., Anxiolytic effects of a semipurified constituent of guarana seeds on rats in the elevated T-maze test (2011) Planta Medica, 77, pp. 236-241Roncon, C.M., Biesdorf De Almeida, C., Klein, T., De Mello, J.C., Audi, E.A., Anxiolytic effects of a semipurified constituent of guarana seeds on rats in the elevated T-maze test (2011) Planta Medica, 77, pp. 236-241Ruxton, C.H.S., Kirkwood, L., McMillan St, B., John, D., Evans, C.E.L., Effectiveness of a herbal supplement (Zotrim™) for weight management (2007) British Food Journal, 109, pp. 416-428Secretaria da Agricultura, Irrigação e Reforma Agrária do Estado da Bahia (2010) Guaraná, , http://www.seagri.ba.gov.br/noticias.asp?qact=view&exibir= clipping&notid=21790, Sagri-Brazil Visited April 2012Saldaña, M.D.A., Mohamed, R.S., Baer, M.G., Mazzafera, P., Extraction of purine alkaloids from maté (Ilex paraguariensis) using supercritical CO2 (1999) Journal of Agricultural and Food Chemistry, 47, pp. 3804-3808Saldaña, M.D.A., Zetzl, C., Mohamed, R.S., Brunner, G., Extraction of methylxanthines from guaraná seeds, maté leaves, and cocoa beans using supercritical carbon dioxide and ethanol (2002) Journal of Agricultural and Food Chemistry, 50, pp. 4820-4826Santos, S.C., Mello, J.C.P., Taninos (2007) Farmacognosia da Planta Ao Medicamento, pp. 615-656. , C.M.O. Simões, fifth ed. Editora da Universidade Federal do Rio Grande do Sul Porto AlegreSchmidt, F., (1941) O Guaraná, Sua Cultura e Indústria, , Serviço de Informação Agrícola, Ministério da Agricultura Rio de Janeiro(2010) Plant Profiler: Guarana (Paullinia Cupana), , http://www.sigmaaldrich.com/life-science/nutrition-research/ learning-center/plant-profiler/paullinia-cupana.html, Sigma-Aldrich Visited June 2012Smith, N., Atroch, A.L., Guaraná's journey from regional tonic to aphrodisiac and global energy drink (2007) Evidence-Based Complementary and Alternative Medicine, 7, pp. 279-282Sousa, S.A., Pascoa, H., Conceição, E.C.D., Alves, S.F., Diniz, D.G.A., Paula, J.R., Bara, M.T.F., Dissolution test of herbal medicines containing Paullinia cupana: Validation of methods for quantification and assessment of dissolution (2011) Brazilian Journal of Pharmaceutical Sciences, 47, pp. 269-277Souza, A.G.C., Souza, N.R., Silva, S.E.L., Nunes, C.D.M., Canto, A.C.A.C.L.A., (1996) Fruteiras da Amazônia, , EMBRAPA-CPAA, ManausSouza, A.L., (2010) Análise Proteômica de Semente e Pericarpo de Guaraná em Diferentes Estádios de Maturação, p. 140. , Universidade Federal do Amazonas - UFAM ManausSouza, V.C., Lorenzi, H., (2008) Botânica Sistemática - Guia Ilustrado Para Identificação das Famílias de Angiospermas da Flora Brasileira, Baseado em APG II, , Plantarum Nova OdessaSpencer, C.M., Cai, Y., Martin, R., Gaffney, S.H., Goulding, P.N., Magnolato, D., Lilley, T.H., Haslam, E., Polyphenol complexation - Some thoughts and observations (1988) Phytochemistry, 27, pp. 2397-2409Spoladore, D.S., Boaventura, M.A.M., Sáes, L.A., Teor de cafeína em sementes de matrizes do guaranazeiro (1987) Bragantia, 46, pp. 425-429Subbiah, M.T.R., Guarana consumption: A review of health benefits and risks (2005) Alternative and Complementary Therapies, 11, pp. 212-213Taha, M.M.E., Salga, M.S., Ali, H.M., Abdulla, M.A., Abdelwahab, S.I., Hamid, A.H.A., Gastroprotective activities of Turnera diffusa Willd. ex Schult. revisited: Role of arbutin (2012) Journal of Ethnopharmacology, 141