Aqueous preparations of the grass Eleusine indica are used for treating malaria and lung infections. Despite its widespread occurrence and therapeutic potential, little is known about its chemical composition. This study reports a common chemical pattern for aqueous extracts of E. indica samples from four different localities, separated from each other by approximately 75 to 1340 km, in a wide variety of abiotic and biotic factors. High-performance liquid chromatography with diode array detection (HPLC-DAD), ultra-performance liquid chromatography with diode array detection and mass spectrometry (UPLC-DAD-MS/MS), and nuclear magnetic resonance (NMR) were the analytical techniques applied to characterize substances from E. indica, from each locality. Principal component analysis (PCA) confirmed that E. indica specimens came from four different localities. However, all of the four populations showed a common peaks pattern. This is the first chemical profile report of E. indica. Moreover, p-coumaric acid and isoschaftoside were characterized for the first time in this species.

RESUMO: Um extrato aquoso de folhas da espécie medicinal Kalanchoe gastonis-bonnieri (aqui denominado como KGB) foi efetivo como um agente antimicrobiano contra as bactérias da cavidade oral de cães em testes in vitro. Neste estudo, investigou-se o efeito da administração oral tópica de KGB sobre o desenvolvimento do biofilme dental em cães da raça Beagle. Os experimentos foram realizados com um grupo experimental (0,2% de extrato de KGB), um grupo controle negativo (0,9% de solução salina) e um grupo controle positivo (0,12% de gluconato de clorexidina). Cada tratamento foi aplicado no interior da cavidade oral diariamente durante 28 dias. Foram utilizados trinta cães da raça Beagle com características semelhantes e mantidos sob o mesmo manejo e dieta. A medição da placa bacteriana e cálculo dentários foi realizada utilizando-se um método de análise computadorizada. O perfil fenólico do extrato de KGB foi analisado por HPLC-DAD. O extrato de KGB a 0,2% mostrou eficácia no controle da formação de placa bacteriana em comparação com o grupo controle negativo, e de cálculo dentário em relação aos grupos controle negativo e positivo. Uma diferença significativa foi observada entre esses três grupos. Picos atribuídos a flavonoides e ácidos fenólicos foram identificados no cromatograma de HPLC-DAD do extrato de KGB. A presença de tais substâncias pode estar relacionada com a atividade observada. Os resultados demonstram que o tratamento com KGB é eficaz no controle da doença periodontal em cães, fornecendo novas perspectivas sobre as propriedades medicinais desta planta. O extrato de KGB tem uma utilização potencial como um agente suplementar em produtos farmacêuticos para a prevenção da doença periodontal.

ABSTRACT: An aqueous leaf extract of the medicinal species Kalanchoe gastonis-bonnieri (here denominated KGB) has been found to be effective as an antimicrobial agent against canine oral cavity bacteria in in vitro assays. In this study, we investigated the effect of topic oral administration of KGB on the development of dental biofilm in Beagle dogs. The experiments were performed with an experimental group (0.2% of KGB extract), a negative control group (0.9% of saline solution) and a positive control group (0.12% chlorhexidine). Each treatment was sprayed into the oral cavity daily for 28 days. Thirty Beagle dogs with similar characteristics and kept under the same management and diet were used. The measurement of dental plaque and calculus was performed using a computerized analytical method. The phenolic profile of KGB extract was analyzed by HPLC-DAD. KGB extract at 0.2% showed efficacy in controlling the formation of plaque compared to the negative control group, and dental calculus in relation to the negative and positive control groups. A significant difference was observed among these three groups. Peaks attributed to flavonoids and phenolic acids were identified in the HPLC-DAD chromatogram of the KGB extract. The presence of these substances could be related to the activity observed. Our findings demonstrate that treatment with KGB is effective in controlling periodontal disease in dogs, providing new insights into the medicinal properties of this plant. KGB extract has a potential use as a supplemental agent in pharmaceutical products for the prevention of periodontal disease.