Investigation into the Sleep-Promoting Effects of the Traditional Use of Passionflower (<i>Passiflora</i> spp.), Chamomile (<i>Matricaria chamomilla</i> L.) and Mulungu (<i>Erythrina</i> spp.) in Brazil

Background/Objectives: Sleep is essential to human health, playing a vital role in physical and mental well-being. Sleep disorders can lead to significant health complications, such as cardiovascular problems, diabetes, obesity, and depression. In Brazil, plants such as passionflower (<i>Passiflora</i> spp.), chamomile (<i>Matricaria chamomilla</i> L.) and mulungu (<i>Erythrina</i> spp.) are widely used in folk medicine for their sleep-promoting properties. This article reviews the existing literature on the sleep-promoting effects of these plants, focusing on the Brazilian context and popular knowledge of their use. Methods: An integrative literature review was conducted, including scientific articles in English and Portuguese from PubMed, Scielo and Google Scholar databases. Ethnobotanical studies documenting the traditional use of these plants in Brazil and clinical and preclinical research on their sleep-promoting effects were included. Results: The juice and infusion of the leaves and fruits of passionflower are mainly used to treat anxiety and insomnia, chamomile flower tea is used for its sedative effects, and mulungu bark decoctions are used for their sedative and anxiolytic properties. These popular uses are supported by scientific studies demonstrating the efficacy of these plants in treating insomnia, anxiety, and stress. Conclusions: The recognition of traditional knowledge and the inclusion of these plants in RENISUS highlights their importance for public health in Brazil. However, more rigorous clinical trials are needed to confirm their efficacy and safety and ensure their safe integration into modern medicine.