Lantana camara L. is a species that belongs to the verbenaceae family, native to Brazil and Uruguay, typical of Africa and tropical and subtropical America.[1,2] This species was introduced as an ornamental in several countries such as, Mozambique, Cape Verde, South and East Europe, East and West Africa, Madagascar, Mauritania, North America, Caribbean, India, China, Asia, Australia and New Zealand, and is currently considered one of the most invasive weeds and harmful in the world.[3,4] However, L. camara is used for several medicinal purposes, since all its parts have biological or pharmacological activity, such as antimicrobial, fungicide, insecticide, nematicide, antioxidant, anti-inflammatory and diuretic activity.[ 2]
In Mozambique, the species L. camara is called m'bulimuthi, chauwunké, chamarenke, n'teja, n'toja or n'tuja, and in Brazil the vernacular name of the species is cambarazinho or lantana-cambará.[5, 6] It is a shrub, with branched stem, from 30 cm to 2 m or a little higher, has a very penetrating and characteristic aroma. Its branches are quadrangular, light brown, with small thorns, opposite leaves, very thick, rough, ovate, aromatic. Inflorescence in corimbiform chapters, of small, sessile flowers, of various colors such as yellow, pink, purple or orange. When ripe, the fruits have a bluish color and initially green, where they are toxic as a means of plant defense. [2, 6, 7]
Secondary metabolites are important for the adaptation and propagation of plant species. The main classes of metabolites identified in plant species are nitrogenous compounds, phenolic compounds and terpenoids. [2]
In a study carried out in Brazil, on the phytochemical and antimicrobial prospecting of L.camara and Lantana trifoliate extracts, using the maceration method and the disk diffusion method, verified for the extract of the dried leaves of L. camara, a diameter of 7 ± 0 mm inhibition zone, also for E. coli and S. aureus. While, for Lantana trifoliate, the inhibition zone was 13.66 ± 1.15 mm for S. aureus and no inhibitory zone was detected for E. coli. Phytochemical analyzes indicate the presence of alkaloids, cardiotonic glycosides, volatile coumarins, flavonoids, tannins, saponins, triterpenes and / or steroids and anthracene derivatives. [6]
Studies by Bhargaya et al. (2008) and Nayak et al. (2008) proved that the methanol extract of L. camara leaves has an antimicrobial action and that it was effective in healing gastric ulcers and preventing the development of duodenal ulcers in rats. The infusion of the leaves is used in the treatment of fever, eczema and rash. Its fruits are useful in tumors and rheumatism. [8, 9]
Bacterial resistance to antibiotics is considered as a set of adaptation equipment that makes a bacterium resist the action of the drugs to which they are being exposed. [10, 11] Currently, bacterial resistance is associated with several environments and, in addition to occurring in hospital environments, it can reach qualified people.[12] The use of combined therapy is an alternative that can be adopted in an attempt to solve the problem of bacterial resistance.[13] However, the excessive and inappropriate use of antibiotics, poor hygiene conditions, continuous flow of travelers, the increase in immunocompromised patients and the delay in the diagnosis of bacterial infections have favored the increase in resistance.[12]
A S. aureus species is the most pathogenic of its kind, a cause of a wide variety of infections in humans, from spines and boils to pneumonia, food poisoning and infections in surgical wounds, and is also a cause of major hospital infections. [14, 15] This species is Gram-positive coconut with clusters, immobile and not spore-forming, belonging to the micrococcaceae family. It is characterized by the production of the enzyme coagulase, positive catalase and fermentation of mannitol. [10, 13]
E.coli is the most common and clinically important species of the genus, causing more than 80% of all community-acquired urinary tract infections, as well as many hospital infections, and gastroenteritis in developing countries.[15, 16] This microorganism is a Gram-negative bacillus evaluated as a latose fermenter, facultative anaerobic and oxidase-negative.[15]
In several studies, the resistance of these pathogens to antibiotics of first choice has been found, including chloramphenicol and ampicillin. As they are, the main causes of diarrheal diseases, which are the second main cause of infant mortality worldwide. [17]
In view of this great therapeutic problem for public health, currently, several studies are being carried out to test the antibacterial activity of various medicinal plants, in an attempt to develop new antibiotics or to enhance the action of antibiotics of known clinical use.[18] Therefore, the main objective of this work is to analyze the chemical composition and antibacterial activity of the extract of the leaves of L. camara against E. coli and S. aureus.