Genetic diversity and chemical variability of Lippia spp. (Verbenaceae).

BACKGROUND: The genus Lippia comprises 150 species, most of which have interesting medicinal properties. Lippia sidoides (syn. L. origanoides) exhibits strong antimicrobial activity and is included in the phytotherapy program implemented by the Brazilian Ministry of Health. Since species of Lippia are morphologically very similar, conventional taxonomic methods are sometimes insufficient for the unambiguous identification of plant material that is required for the production of certified phytomedicines. Therefore, genetic and chemical analysis with chemotype identification will contribute to a better characterization of Lippia species. METHODS: Amplified Length Polymorphism and Internal Transcribed Spacer molecular markers were applied to determine the plants' genetic variability, and the chemical variability of Lippia spp. was determined by essential oil composition. RESULTS: Amplified Length Polymorphism markers were efficient in demonstrating the intra and inter-specific genetic variability of the genus and in separating the species L. alba, L. lupulina and L. origanoides into distinct groups. Phylogenetic analysis using Amplified Length Polymorphism and markers produced similar results and confirmed that L. alba and L. lupulina shared a common ancestor that differ from L. origanoides. Carvacrol, endo-fenchol and thymol were the most relevant chemical descriptors. CONCLUSION: Based on the phylogenetic analysis it is proposed that L. grata should be grouped within L. origanoides due to its significant genetic similarity. Although Amplified Length Polymorphism and Internal Transcribed Spacer markers enabled the differentiation of individuals, the genotype selection for the production of certified phytomedicines must also consider the chemotype classification that reflects their real medicinal properties.

Isolation of flavonoids from Anemopaegma arvense (Vell) Stellf. ex de Souza and their antifungal activity against Trichophyton rubrum

Anemopaegma arvense (Vell) Stellf. ex de Souza belongs to the family Bignoniaceae, and is popularly known as catuaba. To evaluate the cytotoxic and antimicrobial activity of A. arvense, fraction F3 and flavonoids 1 (quercetin 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside) (rutin) and flavonoid 2 (quercetin 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-galactopyranoside) were isolated from the leaves of this plant. Fraction F3 and flavonoids 1 and 2 exhibited no antibacterial activity. Furthermore, no cytotoxic activity of fraction 3 or flavonoids 1 and 2 was observed against the tumor cells tested. However, analysis of the antifungal activity of flavonoids 1 and 2 revealed minimum inhibitory concentrations of 0.5 and 0.25 mg/mL, respectively, against the Trichophyton rubrum strains tested (wild type and mutant). This study demonstrates for the first time the antifungal activity of isolated flavonoids, validating the same activity for A. arvense.

Anemopaegma arvense pertence à família Bignoniaceae, sendo conhecida popularmente como Catuaba. Para avaliação de sua atividade citotóxica e antimicrobiana, a fração cromatográfica F3 e os flavonoides 1 (quercetina 3-O-α-L-ramnopiranosil-(1→6)-β-D-glucopiranosídeo) (rutina) e flavonoide 2 (quercetina 3-O-α-L-ramnopiranosil-(1→6)-β-D-galactopiranosídeo) foram isolados das folhas de A. arvense. A fração 3 e os flavonoides não apresentaram atividade antibacteriana. Nenhuma atividade citotóxica foi observada para a fração F3 e para os flavonoides, quando avaliados contra as células tumorais em teste. Entretanto, e considerando a atividade antifúngica, o flavonóide 1 apresentou valor de concentração inibitória mínima (CIM) de 0,5 mg/mL, enquanto o flavonóide 2, CIM de 0,25 mg/mL contra as cepas selvagem e mutante de Trichophyton rubrum, demonstrando, pela primeira vez, que os flavonoides isolados possuem atividade antifúngica, o que valida a mesma atividade para A. arvense.