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Essential oil of Lippia alba and its main constituent citral block the excitability of rat sciatic nerves.

Sousa DG, Sousa SD, Silva RE, Silva-Alves KS, Ferreira-da-Silva FW, Kerntopf MR, Menezes IR, Leal-Cardoso JH, Barbosa R - Braz. J. Med. Biol. Res. (2015)

Bottom Line: Peak-to-peak amplitude of the CAP was significantly reduced by 30 µg/mL EOLa and 10 µg/mL citral.Both EOLa and citral showed inhibitory actions at lower concentrations compared with other essential oils and constituents with local anesthetic activity.In conclusion, these data demonstrate that EOLa and citral are promising agents in the development of new drugs with local anesthetic activity.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Fisiofarmacologia das Células Excitáveis, Universidade Regional do Cariri, Crato, CE, Brasil.

ABSTRACT
Lippia alba is empirically used for infusions, teas, macerates, and hydroalcoholic extracts because of its antispasmodic, analgesic, sedative, and anxiolytic effects. Citral is a mixture of trans-geranial and cis-neral and is the main constituent of L. alba essential oil and possesses analgesic, anxiolytic, anticonvulsant, and sedative effects. The present study evaluated the effects of the essential oil of L. alba (EOLa) and citral on compound action potentials (CAPs) in Wistar rat sciatic nerves. Both drugs inhibited CAP in a concentration-dependent manner. The calculated half-maximal inhibitory concentrations (IC50) of peak-to-peak amplitude were 53.2 µg/mL and 35.00 µg/mL (or 230 µM) for EOLa and citral, respectively. Peak-to-peak amplitude of the CAP was significantly reduced by 30 µg/mL EOLa and 10 µg/mL citral. EOLa and citral (at 60 and 30 µg/mL, values close to their respective IC50 for CAP blockade) significantly increased chronaxy and rheobase. The conduction velocity of the first and second CAP components was statistically reduced to ∼86% of control with 10 µg/mL EOLa and ∼90% of control with 3 µg/mL citral. This study showed that EOLa inhibited nerve excitability and this effect can be explained by the presence of citral in its composition. Both EOLa and citral showed inhibitory actions at lower concentrations compared with other essential oils and constituents with local anesthetic activity. In conclusion, these data demonstrate that EOLa and citral are promising agents in the development of new drugs with local anesthetic activity.

No MeSH data available.


Related in: MedlinePlus

Alterations in rheobase (A, B) and chronaxy(C, D) after exposure to essential oil ofLippia alba (EOLa) and citral. *P<0.05, compared to control(ANOVA or paired t-test).
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f02: Alterations in rheobase (A, B) and chronaxy(C, D) after exposure to essential oil ofLippia alba (EOLa) and citral. *P<0.05, compared to control(ANOVA or paired t-test).

Mentions: In view of all the concentrations used, we chose 60 µg/mL EOLa and 30 µg/mL citral(concentration values near to the IC50 for both drugs) to study their effectson nerve excitability (Figure 2). At the end of180 min exposure to EOLa and citral, rheobase was increased to 3.7±0.09 (n=7) and4.6±0.54 V (n=9), respectively. Chronaxy was significantly altered to 61.1±6.80 µs (n=7)and 65.2±5.26 µs (n=9) for 60 µg/mL EOLa and 30 µg/mL citral, respectively compared tocontrols (both, P<0.05, paired t-test). Thus, the presence of EOLaand citral reduced nerve excitability due to the increased values of rheobase andchronaxy, indicating a more potent stimulus with greater duration was required togenerate an action potential (Figure 2).


Essential oil of Lippia alba and its main constituent citral block the excitability of rat sciatic nerves.

Sousa DG, Sousa SD, Silva RE, Silva-Alves KS, Ferreira-da-Silva FW, Kerntopf MR, Menezes IR, Leal-Cardoso JH, Barbosa R - Braz. J. Med. Biol. Res. (2015)

Alterations in rheobase (A, B) and chronaxy(C, D) after exposure to essential oil ofLippia alba (EOLa) and citral. *P<0.05, compared to control(ANOVA or paired t-test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541688&req=5

f02: Alterations in rheobase (A, B) and chronaxy(C, D) after exposure to essential oil ofLippia alba (EOLa) and citral. *P<0.05, compared to control(ANOVA or paired t-test).
Mentions: In view of all the concentrations used, we chose 60 µg/mL EOLa and 30 µg/mL citral(concentration values near to the IC50 for both drugs) to study their effectson nerve excitability (Figure 2). At the end of180 min exposure to EOLa and citral, rheobase was increased to 3.7±0.09 (n=7) and4.6±0.54 V (n=9), respectively. Chronaxy was significantly altered to 61.1±6.80 µs (n=7)and 65.2±5.26 µs (n=9) for 60 µg/mL EOLa and 30 µg/mL citral, respectively compared tocontrols (both, P<0.05, paired t-test). Thus, the presence of EOLaand citral reduced nerve excitability due to the increased values of rheobase andchronaxy, indicating a more potent stimulus with greater duration was required togenerate an action potential (Figure 2).

Bottom Line: Peak-to-peak amplitude of the CAP was significantly reduced by 30 µg/mL EOLa and 10 µg/mL citral.Both EOLa and citral showed inhibitory actions at lower concentrations compared with other essential oils and constituents with local anesthetic activity.In conclusion, these data demonstrate that EOLa and citral are promising agents in the development of new drugs with local anesthetic activity.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Fisiofarmacologia das Células Excitáveis, Universidade Regional do Cariri, Crato, CE, Brasil.

ABSTRACT
Lippia alba is empirically used for infusions, teas, macerates, and hydroalcoholic extracts because of its antispasmodic, analgesic, sedative, and anxiolytic effects. Citral is a mixture of trans-geranial and cis-neral and is the main constituent of L. alba essential oil and possesses analgesic, anxiolytic, anticonvulsant, and sedative effects. The present study evaluated the effects of the essential oil of L. alba (EOLa) and citral on compound action potentials (CAPs) in Wistar rat sciatic nerves. Both drugs inhibited CAP in a concentration-dependent manner. The calculated half-maximal inhibitory concentrations (IC50) of peak-to-peak amplitude were 53.2 µg/mL and 35.00 µg/mL (or 230 µM) for EOLa and citral, respectively. Peak-to-peak amplitude of the CAP was significantly reduced by 30 µg/mL EOLa and 10 µg/mL citral. EOLa and citral (at 60 and 30 µg/mL, values close to their respective IC50 for CAP blockade) significantly increased chronaxy and rheobase. The conduction velocity of the first and second CAP components was statistically reduced to ∼86% of control with 10 µg/mL EOLa and ∼90% of control with 3 µg/mL citral. This study showed that EOLa inhibited nerve excitability and this effect can be explained by the presence of citral in its composition. Both EOLa and citral showed inhibitory actions at lower concentrations compared with other essential oils and constituents with local anesthetic activity. In conclusion, these data demonstrate that EOLa and citral are promising agents in the development of new drugs with local anesthetic activity.

No MeSH data available.


Related in: MedlinePlus