In vitro antioxidant potential of medicinal plant extracts and their activities against oral bacteria based on Brazilian folk medicine.
OBJECTIVE
This study aims to determine antibacterial activities of Cocos nucifera (husk fiber), Ziziphus joazeiro (inner bark), Caesalpinia pyramidalis (leaves), aqueous extracts and Aristolochia cymbifera (rhizomes) alcoholic extract against Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus mutans and Lactobacillus casei. The antioxidant activity and acute toxicity of these extracts were also evaluated.


METHODS
The plant extracts antibacterial activity was evaluated in vitro and the minimal inhibitory concentration (MIC) was determined by the broth micro-dilution assay. The bacterial killing kinetic was also evaluated for all extracts. In addition, the antibacterial effect of the extracts was tested in vitro on artificial oral biofilms. The acute toxicity of each extract was determined in according to Lorke [Lorke D. A new approach to practical acute toxicity testing. Arch Toxicol 1983;54:275-87] and the antioxidant activity was evaluated by DPPH photometric assay [Mensor LL, Menezes FS, Leitão GG, Reis AS, Santos TC, Coube CS, et al. Screening of Brazilian plants extract for antioxidant activity by the use of DPPH free radical method. Phytother Res 2001;15:127-30].


RESULTS
MIC and the bactericidal concentrations were identical, for each evaluated extract. However, microbes of artificial biofilms were less sensitive to the extracts than the planktonic strains. A. cymbifera extract induced the highest bactericidal effect against all tested bacteria, followed by C. nucifera, Z. joazeiro and C. pyramidalis extracts, respectively. All extracts showed good antioxidant potential, being C. nucifera and C. pyramidalis aqueous extracts the most active ones.


CONCLUSIONS
In conclusion, all oral bacteria tested (planktonic or in artificial biofilms) were more susceptible to, and rapidly killed in presence of A. cymbifera, C. pyramidalis and C. nucifera than Z. joazeiro extracts, respectively. Thus, these extracts may be of great interest for future studies about treatment of oral diseases, considering their potent antioxidant activity and low toxicity.
Alviano
Wagner S
WS
Departamento de Ortodontia, Faculdade de Odontologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Alviano
Daniela S
DS
Diniz
Cláudio G
CG
Antoniolli
Angelo R
AR
Alviano
Celuta S
CS
Farias
Luiz M
LM
Carvalho
Maria Auxiliadora R
MA
Souza
Margareth M G
MM
Bolognese
Ana Maria
AM
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000975:Antioxidants / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy*; D001938:Brazil; D006801:Humans; D008519:Medicine, Traditional; D009059:Mouth Diseases / Q000188:drug therapy*; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use*; D018514:Plant Structures; D010946:Plants, Medicinal; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D010936:Plant Extracts