Chemical Diversity and Biological Activities of Essential Oils from Licaria, Nectrandra and Ocotea Species (Lauraceae) with Occurrence in Brazilian Biomes.

Lauraceae species are known as excellent essential oil (EO) producers, and their taxa are distributed throughout the territory of Brazil. This study presents a systematic review of chemical composition, seasonal studies, occurrence of chemical profiles, and biological activities to EOs of species of Licaria, Nectandra, and Ocotea genera collected in different Brazilian biomes. Based on our survey, 39 species were studied, with a total of 86 oils extracted from seeds, leaves, stem barks, and twigs. The most representative geographic area in specimens was the Atlantic Forest (14 spp., 30 samples) followed by the Amazon (13 spp., 30 samples), Cerrado (6 spp., 14 samples), Pampa (4 spp., 10 samples), and Caatinga (2 spp., 2 samples) forests. The majority of compound classes identified in the oils were sesquiterpene hydrocarbons and oxygenated sesquiterpenoids. Among them, ß-caryophyllene, germacrene D, bicyclogermacrene, caryophyllene oxide, α-bisabolol, and bicyclogermacrenal were the main constituents. Additionally, large amounts of phenylpropanoids and monoterpenes such as safrole, 6-methoxyelemicin, apiole, limonene, α-pinene, ß-pinene, 1,8-cineole, and camphor were reported. Nectandra megatopomica showed considerable variation with the occurrence of fourteen chemical profiles according to seasonality and collection site. Several biological activities have been attributed to these oils, especially cytotoxic, antibacterial, antioxidant and antifungal potential, among other pharmacological applications.

The chemistry and biological activities of Peperomia pellucida (Piperaceae): A critical review.

ETHNOPHARMACOLOGICAL RELEVANCE: Peperomia pellucida (L.) Kunth is an annual weed with a preference to humid places with reduced solar radiation. This plant is mainly distributed in the Neotropics, Africa, Southeast Asia, and Australia. It is popularly employed in the treatment of a variety of health conditions such as abscesses, abdominal pain, skin sores, conjunctivitis, measles, and kidney troubles. Several studies have also described its antimicrobial, cytotoxic, antidiabetic and a variety of other bioactivities. THE AIM OF THE REVIEW: The aim of this work is to evaluate, using a critical review, the present ethnomedicinal applications, phytochemistry and pharmacological studies of P. pellucida essential oils (EOs) and extracts from different locations around the world. MATERIALS AND METHODS: This review was performed through an online survey of the ethnomedicinal practices, chemical compositions and pharmacological applications of P. pellucida EOs and extracts. The data were mainly obtained from online journals and books published in English, Portuguese and Spanish. The information was collected from websites such as Google, Google Scholar, PubMed, Science Direct, ResearchGate and other online databases that provided more information about this herb. RESULTS: Peperomia pellucida bioactivities such as antimicrobial, cytotoxic, antioxidant, fracture healing, antidiabetic and anti-hypercholesterolemia have been described in several literature sources. Nonetheless, most reports only provide the phytochemical screening of extracts, which does not allow the identification of the active compounds. From these studies, some reported constituents are not included in the Dictionary of Natural Products (DNP), which raises questions toward their identification. In addition, some biological assays were even performed without standard controls for comparison which also makes these results questionable. CONCLUSION: This review evaluates data regarding the phytopharmaceutical potential of P. pellucida. In general, several important aspects were questionable or missing in these manuscripts, which points out the need of more investigation on the pharmacological properties and phytochemical compositions of this herb.