Banca de DEFESA: DANIELE OLIVEIRA SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DANIELE OLIVEIRA SOUZA
DATE: 11/03/2021
TIME: 13:30
LOCAL: Videoconferência
TITLE:
KEY WORDS:
PAGES: 92
BIG AREA: Ciências Humanas
AREA: Psicologia
SUMMARY:

Peripheral nerve injuries are a public health problem. Motor, sensory, autonomic deficits and the development of Neuropathic Pain (DN), resulting from peripheral nerve injuries, can compromise patients' quality of life. After nerve damage, oxidative stress occurs and the release of inflammatory cytokines and allogeneic mediators that induce DR. The occurrence of these problems instigates the search in nature for compounds for the manipulation of new drugs. Lippia alba is a medicinal plant whose essential leaf oil has biological activity in the Peripheral Nervous System (SNP). The aim of this study is to evaluate the effect of treatment with Lippia alba essential oil (OELa) on peripheral neuropathy caused by Chronic Sciatic Nerve Constriction (CCNC) in rats. Thirty Rattus novergicus (Wistar) rats, of both sexes, with body mass varying between 200-250g were used. The animals were divided into the experimental groups: Control treated vehicle (CON), control treated with OELa 100 mg/Kg, p.o. (CON+OELa), group submitted to CCNC treated with vehicle solution (CCNC) and group submitted to CCNC treated with OELa 100 mg/Kg (CCNC+ OELa). The treatment was administered 30 minutes before the CCNC was performed on the animal's right sciatic nerve for 14 consecutive days. The pain hypersensitivity test was performed using the von Frey test and hot plate, 24 hours before CCNC induction (day 0), and on days 5, 7, 9 and 14 after CCNC. On the 14th day after CCNC, the animals were euthanized. Then, dissection of the right and left sciatic nerve was performed to analyze the extracellular record of the Compound Action Potential (PAC). The evaluated parameters of the PAC were: Pico-a-Pico Amplitude (APP), chronaxia, positive amplitude reobase, conduction speed and duration of the 1st and 2nd components of the PAC. The phytochemical analysis of OELa identified a quantitative variation of substances, the major compound of which was citral (geranial with 42.59% and neral with 28.21%). The evaluation of the mechanical sensitivity presented in the CON an average of 20.87s in the reaction time to the stimulus. In the CCNC group, there was an increase of 72.4% in the reaction time to the stimulus on the 5th evaluation day in relation to the CON, followed by a “sustained” reduction from the 7th evaluation day, in 54.65%, 59.34%, 58.8% on evaluation days 7, 9 and 14, respectively in relation to the CON, characterizing mechanical hyperalgesia. The CCNC + OELa group increased the reaction time to mechanical stimulus by 116.79%, 145.4%, 54.56% and 62% on evaluation days 5, 7, 9 and 14, respectively in relation to the CON. In the CON + OELa group, the reaction time to the stimulus increased by 141.2% after the 5th evaluation, showing a greater response on the 7th evaluation day, with an increase of 260%. There was no significant difference in the sensitivity of the thermal stimulus in rats submitted to CCNC and CON group. However, there was a 56.25% increase in reaction time to the stimulus in the CON + OELa group also on the 7th evaluation day, compared to the CON. In the other experimental groups, there was no significant difference. CCNC caused electrophysiological changes in all evaluated parameters. The sciatic nerve excitability in the CCNC group (mean: 2.5 ± 0.14) increased by 27.53%, when reducing the reobase, compared to the CON (mean: 3.38 ± 0.17). Meanwhile, the chronaxia value increased by 54.89% in the CCNC group (76.67 ± 7.4) compared to the CON (49.5 ± 0.34). In the CCNC+OELa group (3.6 ± 0.05), the reobase increased by 39.5%, compared to the CCNC group, the chronaxia (59.7 ± 1.12) in this group did not change. The reobase in the CON + OELa group (4.14 ± 0.18) differed by 16.5% in relation to the CON. In the NE CCNC group (3.15 ± 0.25) the reobase was not changed. The chronaxia for the CON + OELa (68.5 ± 2.7) and NE CCNC (65.2 ± 5.7) groups did not differ from the CON. The APP in the CCNC group decreased 51.62% in relation to the CON. When associated to treatment with OELa (CCNC + OELa) the reduction in APP was 73%. The CON + OELa group reduced the APP by 54.8% compared to the CON. The positive amplitude of the first component in the CCNC group decreased by 52.53% in relation to the CON. In the CCNC + OELa group, it decreased 74.59%. The CON + OELa group also showed a 57% reduction. The second component was not registered in the CCNC group. However, this was preserved when CCNC was associated with treatment with OELa (CCNC + OELa), with an average of 0.3 ± 0.03, n = 6, with a decrease in amplitude of 88.14% in relation to the CON. The CON + OELa group also decreased the amplitude of the second component by 34.78%, with an average of 1.65 ± 0.14, n = 8, in relation to the CON. The NE CCNC group (2.24 ± 010, n = 6) showed no change compared to the CON. Regarding the PAC's conduction speed, the CCNC group showed a 44.73% reduction in the first component of the PAC. Treatment with OELa (CCNC + OELa) reversed this decrease by 102.96%, compared to the CCNC group. The other experimental groups showed no statistical difference, presenting the following averages: CON + OELa: 92.36 ± 5.28, n = 7; NE CCNC: 112.1 ± 14.45, n = 6. In the second component of the PAC, the driving speed was not changed in the CCNC + OELa and CON + OELa groups compared to the CON. The duration of the first component of the PAC increased by 45.21% in the group submitted to CCNC, in relation to the CON. The other groups showed no significant difference compared to the CON. As for the duration of the second component of the PAC, in the CCNC group it was not possible to evaluate, since it was not registered. In the other experimental groups, there was no statistical difference in relation to the CON. PAC behavioral and electrophysiological assessment data show that they are in line, suggesting an anesthetic effect of OELa. Since in the sensitivity assessment there was an increase in the response time to the stimulus and an increase in the reobase in the groups that received treatment with OELa, while in the CCNC group these parameters decreased. However, in the CCNC group, the chronaxia was increased, possibly related to changes in the passive properties of the membrane, resulting from CCNC. It is important to note that there was no change in chronaxia in the groups treated with OELa, suggesting a neuroprotective effect of OELa through neuronal damage, probably due to its antioxidant activity. Another evidence of the neuroprotective effect of OELa is the preservation of the fibers of the second component of the PAC in the CCNC + OELa group, considering that in the CCNC group there was no record of this. This is an important fact, as this phenomenon is probably related to the reduction of neuroinflammation and neuronal damage.

BANKING MEMBERS:
Externo à Instituição - FRANCISCO WALBER FERREIRA DA SILVA - UVA
Presidente - 4363493 - EXPEDITO SILVA DO NASCIMENTO JUNIOR
Externo ao Programa - 1076490 - FERNANDO VAGNER LOBO LADD
Externo à Instituição - JOSÉ HENRIQUE LEAL CARDOSO - UECE
Externa ao Programa - 1733434 - RENATA FIGUEIREDO ANOMAL