Development and validation of an analytical method by HPLC-DAD for determination of caffeine in products based on guarana extracts (Paullinia cupana)

Abstract Guarana (Paullinia cupana) is a native plant from the Amazon whose seeds contain a high concentration of caffeine. Aqueous extract of guarana is widely used in the world. In this study, the objective was to develop and validate a High-Performance Liquid Chromatography method for the determination of caffeine in extracts and commercial beverages based on guarana. A sensitive, simple, and viable high performance liquid chromatographic method without the need of an analyte extraction procedure was developed and validated according to Brazilian and international requirements. The method presented high performance, fulfilling Brazilian and international requirements, in addition to allowing product compliance tests. Results confirmed high selectivity and linearity (>0.999) between 5 to 135 ug/mL, with no significant matrix effect. Detection and quantification limits were 0.02 µg/mL and 2 µg/mL, respectively. Precision was less than 4 %, and accuracy varied from 99.9-120 %. Applicability of the method was demonstrated by conducting a limited evaluation in products containing caffeine. Commercial extracts showed quite different caffeine levels, while carbonated drinks follow Brazilian and American recommendations. Our results indicate that the developed method can be used to evaluate the quality of the guarana extract and of products containing caffeine

Neuroprotective potential of the Amazonian fruits Euterpe oleracea Mart. and Paullinia cupana Kunth

Abstract Acai (Euterpe oleracea Mart.) and guarana (Paullinia cupana Kunth) are native species from the Amazon Forest that in folk medicine are used to treat several diseases due to their anti-inflammatory and antioxidant properties. This review brings together findings from different studies on the potential neuroprotective effects of acai and guarana, highlighting the importance of the conservation and sustainable exploitation of the Amazon Forest. A bibliographic survey in the PubMed database retrieved indexed articles written in English that focused on the effects of acai and guarana in in vitro and in vivo models of neurodegenerative diseases. In general, treatment with either acai or guarana decreased neuroinflammation, increased antioxidant responses, ameliorated depression, and protected cells from neurotoxicity mediated by aggregated proteins. The results from these studies suggest that flavonoids, anthocyanins, and carotenoids found in both acai and guarana have therapeutic potential not only for neurodegenerative diseases, but also for depressive disorders. In addition, acai and guarana show beneficial effects in slowing down the physiological aging process. However, toxicity and efficacy studies are still needed to guide the formulation of herbal medicines from acai and guarana.

Consumo de psicoestimulantes por estudantes de medicina em um centro universitário privado / Consumption of psychostimulants by medical students in a private university center

O consumo de psicoestimulantes tem crescido exponencialmente, sobretudo entre estudantes de medicina, na busca por aumentar o rendimento acadêmico. Atualmente, a extensa carga horária de aulas e estudos, exigências de produtividade e altos níveis de estresse podem desencadear o uso. Objetivo: Analisar o uso de psicoestimulantes por estudantes do curso de Medicina de um Centro Universitário privado em Minas Gerais. Métodos: Foi realizado um estudo descritivo, quantitativo, com delineamento transversal entre os discentes do 1° ao 5° ano do curso de Medicina no 2° semestre de 2021. Os participantes responderam ao questionário semi-estruturado elaborado pelos autores. Os dados obtidos foram tabulados no software Statistical Product and Service Solutions. Resultados: Dos 244 entrevistados, cerca de 57.4% faziam uso de algum psicoestimulante. Houve maior uso entre os estudantes do 2° ano e as principais substâncias utilizadas foram: cafeína (85%), energético (65%) e metilfenidato (60%). A melhora na concentração (97%) foi o efeito mais percebido pelos usuários, seguido de redução do sono (83%) e melhora de raciocínio (80%). Muitos consideraram que os estimulantes cerebrais têm o potencial de melhorar o rendimento acadêmico, mas pode reduzir a qualidade do sono e consequentemente torná-los susceptíveis a outras enfermidades. Conclusão: É notável que existe uso abusivo de estimulantes cerebrais, sendo fundamental o trabalho em conjunto entre instituição de ensino e familiares, em prol da prevenção e do controle de danos causados por esse hábito

The consumption of psychostimulants has grown exponentially, especially among medical students, in the quest to increase academic performance. Currently, the extensive workload of classes and studies, productivity demands and high levels of stress can trigger use. Objective: To analyze the use of psychostimulants by medical students at a private University Center in Minas Gerais. Methods: A descriptive, quantitative, cross-sectional study was carried out among students from the 1st to the 5th year of the medicine course in the 2nd semester of 2021. The participants answered the semi-structured questionnaire prepared by the authors. The data obtained were tabulated in the Statistical Product and Service Solutions software. Results: Of the 244 respondents, about 57.4% used some psychostimulant. There was greater use among 2nd year students and the main substances used were: caffeine (85%), energy drink (65%) and methylphenidate (60%). Improved concentration (97%) was the effect most perceived by users, followed by reduced sleep (83%) and improved thinking (80%). Many considered that brain stimulants have the potential to improve academic performance, but can reduce sleep quality and consequently make them susceptible to other illnesses. Conclusion: It is notable that there is abusive use of brain stimulants, and it is essential to work together between educational institutions and family members in order to prevent and control the damage caused by this habit