Essential Oils from Brazilian Plants: A Hidden Treasure

Brazil is home to a unique landscape called canga. This is a type of rocky terrain that is rich in iron. It is also home to many plants that are found nowhere else in the world. Two of these plants are Lippia hermannioides and Matayba marginata. These plants grow in a specific type of environment known as ferruginous rupestrian fields. These fields are found on the remaining canga at Federal University of Ouro Preto. Researchers have been studying the essential oils from these two plants. Essential oils are concentrated liquids taken from plants. They are often used in aromatherapy and natural remedies. The oils from Lippia hermannioides and Matayba marginata were extracted from fresh leaves using a process called hydrodistillation. This method involves steaming the leaves to release the oils, which are then collected. The chemical makeup of these essential oils was analyzed using a technique called GC-MS. This stands for Gas Chromatography-Mass Spectrometry. It is a method used to identify different substances within a test sample. In the oil from Lippia hermannioides, 32 compounds were identified. In the oil from Matayba marginata, 15 compounds were found. These compounds made up almost all of the volatile content in the oils. Volatile content refers to the parts of the oil that evaporate easily. The main types of compounds in both oils were sesquiterpene hydrocarbons. These are a class of organic compounds. They were the most abundant in both oils. The specific compounds found in each oil varied. In Lippia hermannioides, the major compounds were elemicin and β-caryophyllene. In Matayba marginata, the main compounds were germacrene A and β-elemene. These essential oils were also tested for their antimicrobial and antioxidant properties. Antimicrobial properties refer to the ability to kill or inhibit the growth of microorganisms. Antioxidant properties refer to the ability to neutralize harmful molecules called free radicals. The oils showed strong bactericidal activity against Gram-positive bacteria. This means they were effective at killing these types of bacteria. The oil from Lippia hermannioides was more effective than the oil from Matayba marginata. However, the oils did not show significant antioxidant activity. This was tested using two different methods: the ORACFL assay and the DPPH radical-scavenging activity test. The oil from Lippia hermannioides did show some weak antioxidant activity in the DPPH test. This is a method used to measure the ability of a substance to neutralize free radicals. This research is important because it provides new information about the chemical composition and biological activities of these two plants. The findings contribute to the broader understanding of the Lippia and Matayba genera. This knowledge could potentially lead to new applications in medicine or natural remedies. However, more research is needed to fully understand the potential benefits of these essential oils.