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ERICKA GARCIA LEITE
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MEMORY B CELL PROFILE IN INDIVIDUALS RECOVERED FROM MILD COVID-19, WITH AND WITHOUT SUBSEQUENT VACCINATION, AFTER REEXPOSURE TO SARS-COV-2 ANTIGENS
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Advisor : TATJANA KEESEN DE SOUZA LIMA CLEMENTE
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Date: Dec 6, 2024
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Time: 14:00
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Show Summary
-
Memory B cells are essential components of the immune system, respon-
sible for ensuring a rapid and specific response upon re-exposure to antigens, playing a
key role in both the response to infection and the protection conferred by vaccination.
However, it is still not fully understood how SARS-CoV-2 infection and vaccination in-
fluence the phenotypic profile of these lymphocytes. Therefore, this study aims to analyze
the response of memory B cells in individuals recovered from mild COVID-19, with and
without subsequent vaccination, after re-exposure to SARS-CoV-2 antigens. Volunteers
were divided into three groups: control (uninfected and unvaccinated, n=9), recovered
non-vaccinated (RNV, n=11), and recovered vaccinated (RV, n=5). Peripheral blood
mononuclear cells (PBMC) from the volunteers were used and later stimulated with
SARS-CoV-2-related peptides (Pool Spike and Pool CoV-2). Flow cytometry was then
used to evaluate the expression of the following molecules: HLA-DR, CD80, CD86, IL-
10, and LAP in both resting and activated memory B cells. In the RNV group, an increase
in HLA-DR expression was observed in resting memory B cells compared to the control
group, suggesting an elevated basal activation state. Meanwhile, the activated memory B
cells from the RNV group showed a lower frequency of HLA-DR and CD80 expression.
However, in the RV group, an increased frequency of CD86 was observed in this cell
population. Regarding IL-10 expression, resting memory B cells showed a lower fre-
quency of IL-10 when compared to the control and RNV groups, whereas no differences
were observed between the groups in the activated memory B cell population. When an-
alyzing LAP expression in both populations of memory B cells, an increase in this mole-
cule was found in the RV group compared to the control and RNV groups. Additionally,
peptide stimulation did not induce phenotypic changes when compared to their respective
controls (culture medium). These results suggest that memory B cells from vaccinated
individuals exhibit a more regulatory phenotypic profile, while those from recovered and
unvaccinated individuals display a more dynamic profile of activation and regulation
among memory populations.
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CECILIA BURLE DE AGUIAR
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Heart Rate Variability Assessment in Post-COVID-19 Patients at a Primary Care Unit in João Pessoa - Paraíba
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Advisor : CAMILLE DE MOURA BALARINI
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Date: Oct 4, 2024
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Time: 08:30
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Show Summary
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The study investigated the impacts of SARS-CoV-2 infection on the autonomic cardiovascular regulation of recovered patients, analyzing heart rate variability (HRV) and
blood pressure parameters at different stages of recovery. The research was conducted at
a Family Health Unit in João Pessoa, Paraíba, including patients who had experienced
varying severities of the disease, with follow-up periods of up to 180 days post-infection.
The Valsalva maneuver was used to assess autonomic function, comparing the results
with a healthy control group. The findings indicated that post-COVID-19 patients showed
significant alterations in HRV parameters, such as decreased SDNN and RMSSD, suggesting an autonomic imbalance characterized by sympathetic dominance and reduced
parasympathetic tone. The abnormal response to the Valsalva maneuver, with an increase
in pNN50 and absence of the expected drop in blood pressure, further supports the presence of prolonged autonomic dysfunction in these individuals. These findings highlight
the need for continuous monitoring of post-COVID-19 patients to promptly identify
changes in autonomic regulation and prevent future complications. HRV assessment
proved to be an effective tool for detecting and tracking dysautonomia in patients after
infection, contributing to clinical management and a better understanding of the disease's
autonomic sequelae.
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NOÊMIA NIELLY AMARAL NOGUEIRA
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EVALUATION OF THE IMMUNOMODULATORY EFFECTS OF BD-8, BD-15, AND DIGOXIN MOLECULES IN MYCOBACTERIUM SMEGMATIS INFECTION MODELS
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Advisor : SANDRA RODRIGUES MASCARENHAS
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Date: Sep 18, 2024
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Time: 09:00
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Show Summary
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Cardiotonic steroids are organic compounds that have the
property of inhibiting Na⁺/K⁺-ATPase. It has been described in the literature that
ouabain and digoxin are endogenous molecules capable of interfering with
various aspects of the immune response. Recently, new cardiotonic steroids
were synthesized from digoxin: BD-8 (8-benzylidene digoxin) and BD-15
(15-benzylidene digoxin). However, little is known about the effect of these
compounds on inflammatory and infectious processes. In this context, the aim
of this work is to evaluate the effects of the molecules BD-8, BD-15, and digoxin
in Mycobacterium smegmatis infection models using the murine macrophage
line RAW 264.7. Initially, in vitro susceptibility assays against Mycobacterium
smegmatis were performed. For cell viability studies, the colorimetric MTT
method was used with different concentrations (10 μM, 5 μM, 1 μM, 0.1 μM, and
0.01 μM) at 24, 48, and 72 hours. For the evaluation of the therapeutic effect,
colony-forming unit (CFU) counting was performed in plate assays, where RAW
cells were infected with Mycobacterium smegmatis and treated with the
steroids. For cytokine measurement, the enzyme-linked immunosorbent assay
(ELISA) method was used. Evaluating the Minimum Inhibitory Concentration
(MIC), it was observed that the molecules did not inhibit bacterial growth at
concentrations below 200 μg/mL. In the MTT viability results, it was analyzed
that BD-8 did not show cytotoxic activity at 24 hours but showed cytotoxicity at
10 μM and 5 μM at 48 hours, and at 10 μM, 5 μM, and 1 μM at 72 hours. BD-15
did not show cytotoxic activity at any concentration or time tested and was the
synthetic steroid chosen for the continuation of the experiments. Digoxin did not
show cytotoxic activity at 24 hours, but it did show cytotoxicity at 10 μM and 5
μM at 48 hours, and at 10 μM and 1 μM at 72 hours. Regarding CFU counting,
BD-15 and digoxin reduced the number of CFUs per well at 10 μM in 24 hours
compared to the control. ELISA results showed that IL-6 production increased
by 50% with BD-15 treatment and by 19% with digoxin treatment compared to
the infected control. IL-1β increased by 13% with BD-15 treatment and by 1%
with digoxin treatment compared to the infected control. In TNF-α production,
there was an increase of 104% with BD-15 treatment and an increase of 84%
with digoxin treatment, all compared to the infected control. Thus, this work
contributes to a better understanding of the role of cardiotonic steroids in a
mycobacterial infection model.
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EMMILY FERREIRA DE FARIAS
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EVALUATION OF VASCULAR FUNCTION IN A MURINE MODEL OF ATHEROSCLEROSIS TREATED WITH LIFEPRO, A NUTRACEUTICAL FORMULATION COMPOSED OF LIMOSILACTOBACILLUS FERMENTUM
STRAINS AND POLYPHENOLS
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Date: Aug 28, 2024
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Time: 13:30
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Show Summary
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Atherosclerosis is one of the main cardiovascular diseases.
Hypercholesterolemia has been the primary atherogenic factor in humans, reinforced by
an unregulated diet. Probiotics in association with phenolic compounds have shown
efficacy in reducing lipidemia in animals. The Federal University of Paraíba developed
a new nutraceutical formulation by combining the probiotic Limosilactobacillus
fermentum (strains 139,263,296) with the phenolic compounds quercetin and
resveratrol. The present research aimed to investigate the vascular effects of the
nutraceutical in apolipoprotein E knockout (apoE-/-
) atherosclerotic mice subjected to
an atherogenic diet. Three groups were analyzed: control animals without genetic
modification (wild type, WT); apoE-/- animals that received the vehicle, and apoE-/-
animals that received the nutraceutical for eight weeks. In the end, the animals were
euthanized to evaluate biochemical and inflammatory patterns, lipid deposition, and
vascular reactivity in the aorta artery. The administration of the nutraceutical had a
hypocholesterolemic effect, reducing cholesterol in treated apoE-/- animals (579±46
mg/dL##*) compared to vehicle apoE-/- animals (978±68 mg/dL), but not in relation to
the healthy control group (73±6 mg/dL). There was also a hypoglycemic effect in the
treated group (249±16 mg/dL#) compared to the saline apoE-/- group (300±12 mg/dL*).
Triglycerides were also reduced in treated animals (211 mg/dL#* vs. apoE-/- saline - 145
mg/dL**). The lipoprotein profile was altered in the vehicle apoE-/- group (HDL -
17±2** vs. WT - 41±2 and LDL - 159±21** vs. WT - 5±0.7); the treatment did not alter
HDL and LDL. On the other hand, VLDL was reduced in the treated group (503±62
mg/dL#*) compared to the saline group (779±46 mg/dL**), not differing from healthy
animals (29±3 mg/dL). The treatment did not influence food intake and weight.
Oxidative stress was higher in the saline apoE-/-group (30±1** vs. WT 13±1) and the
LifePro reduced the concentrations (14±2###). Regarding vascular reactivity, the
vehicle apoE-/- group showed an increase in vasoconstriction to phenylephrine (Rmax:
88±7**) compared to the healthy control group (Rmax: 70±3) and impaired
endothelium-dependent relaxation (apoE-/- vehicle - Rmax: 62±6** and WT-Rmax:
89±5), highlighting endothelial dysfunction in this group. The nutraceutical improved
endothelial dysfunction by reducing vasoconstrictor behavior (apoE-/-
treated - Rmax:
50±3**##) and increasing relaxation to acetylcholine (apoE-/-
treated - Rmax:
107±12##). The treatment restored NO in relaxation and reduced the impact of
oxidative stress in an organ bath. Regarding the inflammatory profile, the cytokines
TNF (18±1** vs. 7±1) and MCP-1 (145±12** vs. 77±8) were higher in the saline
apoE-/- group compared to WT, while IL-6 and IL-10 showed no changes between
groups. The treatment did not modify cytokine levels. Lipid deposition in the aortic arch
was accentuated in saline apoE-/-
(45%±2%**), while treatment (27±2%##) reduced the
plaque percentage by 1.2 times. Thus, we suggest that the treatment proved effective in
a murine model of atherosclerosis.
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EMILLE RAULINO DE BARROS
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Impact of temperature variations on the physiology of the Aedes aegypti mosquito.
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Date: Aug 28, 2024
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Time: 09:00
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Show Summary
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The Aedes aegypti mosquito is the main vector of arboviruses such as dengue, chikungunya
and zika. It is known that climatic variables interfere in the dynamics of the vector, which
can contribute to its population increase, and consequently to the increase in disease
transmission. The present study aimed to analyze the influence of temperature on the
development time of Aedes aegypti mosquitoes. Eggs of Ae. aegypti strain Lapavet-SD were
used, obtained from the colony of the Laboratory of Biotechnology Applied to Parasites and
Vectors of CBiotec-UFPB, which is kept in a BOD greenhouse, under controlled
temperature conditions of 28 ± 2°C, relative humidity of 75 ± 5% and photoperiod of 12
hours of light and dark. For the tests, 180 eggs were used, which were subdivided into six
groups, two of which were subjected to a temperature of 20 ± 2°C, two to a temperature of
28 ± 2°C and the others to 36 ± 2°C. The development time from the egg stage until the
death of the last mosquito was determined by means of survival analysis using the Log-rank
method (Mantel Cox) and the production of nitric oxide (NO) by hemocytes using the Griess
method. The statistical analysis was performed using the GraphPrism 8.0.1 program and P
< 0.05 was considered for significant differences. As a result, it was possible to verify a
significant difference between the development curves in the survival of Aedes aegypti
mosquitoes. At a temperature of 28°C (control group), the average duration of the larval
stage was 7 days, while at 20°C it was 11 days and at 36°C, the larval stage lasted 3 days.
Furthermore, it was found that the average duration of the pupal stage was 3 days in the
control group (28°C), while in the group raised at 20°C it was 7 days and at a temperature
of 36°, 11 days. The duration of the adult stage, in mosquitoes exposed to a temperature of
28°C was 27 days. Mosquitoes raised at a temperature of 20°C, lived 152 days, while at a
temperature of 36°C they survived 19 days. Furthermore, there was no significant difference
in the production of nitric oxide between the control group and the group raised at a
temperature of 20°C. However, nitric oxide levels in the test group (36°C) were high. These
results contribute to the understanding of the relationship between temperature and the
development of the Aedes aegypti mosquito, thus predicting possible changes in its
distribution patterns in relation to climate change.
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JOÃO PAULO CARVALHO DE LIMA
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STUDY OF THE EFFECTS OF CHALCONES ON THE DEVELOPMENT AND IMMUNE SYSTEM OF MOSQUITOES AEDES AEGYPTI L. (DIPTERA: CULICIDAE)
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Date: Aug 23, 2024
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Time: 10:00
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Show Summary
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Responsible for transmitting several arboviruses, such as dengue, zika,
and chikungunya, the Aedes aegypti mosquito is undergoing a process of population
expansion, in part due to the inefficiency of the control methods used. Synthetic
compounds were trained by the scientific community due to their wide biological
applicability. In this sense, the search for new synthetic molecules with insecticidal
activity is of great value. Therefore, the objectives of this study are to evaluate the effect
of chalcones (CH) on the development and immune system in Ae. aegypti, its activity in
silico, and toxicity in Artemia salina (AS). As a methodology, to evaluate insecticidal
activity on Ae. aegypti, concentrations between 2.5 and 1000 ppm were used, and
mortality (Mt) was assessed at 24 and 48 hours. Scanning electron microscopy (SEM)
was used for morphological analysis of eggs upon exposure to CH. For the immunological
analysis of the larvae (L3), nitrite ion (NO2-) concentrations and total hemocyte profile
in the hemolymph pool were evaluated. Control groups were exposed to dechlorinated
water, Tween® 80, and 20 a (2%). The experiments were performed in triplicate. For
statistical analysis, the following were used: ANOVA, Tukey post test, and p<0.05
(GraphPad Prism 8.0). As a result, CH demonstrated conformational stability and lower
binding energy (CHN: -126,547 kcal/mol-1) and CHH: -128,536 kcal/mol-1) when
compared to co-crystallized ligands. In larvicidal activity, there was greater Mt in the 48h
period, shortening the LC50: 10.04 ppm (24h) and 6.84 ppm (48h) for CHH; CHF: 42.01
ppm (24h) and 8.46 ppm (48h); BCH: 195.6 ppm (24h) and 161.8 ppm (48h); and CHN
595.6 ppm (24h) and 553.4 ppm (48h). In the pupicide and adulticide trials, BCH and
CHN had higher Mt in 24h, LC50 = 562.1 and 893.7 ppm and Mt with 550 and 1000 ppm,
respectively. In the hatchability test, there was a reduction in hatchability by 97.4%. In
the SEM analysis, CHH and CHF caused visible damage to the egg exochorium. In
toxicity tests, there was a lower Mt compared to BCH: 4.9±0.6% and CHN: 4.0±0.6%
(24h). The immunological activity mediated by CH demonstrated a quantitative increase
in hemocytes, CHH: 9.6±1.3% (24h) and 10.7±8.8% (48h); ICC: 10.91±1.3% (24h) and
13.7±7.8% (48h); CHN: 10.7±1.5% (24h) and 11.1±7.8% (48h); an increase by BCH:
22.3±1.3% (24h) and 16.4±1.8 % (48h), and an increase in NO2- in all CH (24h:
18.9±0.6% and 48h: 20.9±0.6%). The results highlight CH as molecules with significant
insecticidal and immunomodulatory activity, combined with low toxicity and proven
efficacy in in silico studies. These properties show promise for the development of new
insecticidal agents with potential impacts on public health.
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LAYANE DA SILVA LIMA
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VASORELAXANT EFFECT AND MECHANISM OF ACTION OF 4-NITROOXYBUTYL 4-METHYLBENZOATE ON THE VASCULAR FUNCTION OF NORMOTENSIVE RATS
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Date: Jun 11, 2024
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Time: 14:00
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Show Summary
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Organic nitrates are used in the treatment of cardiovascular diseases as they are donors
of nitric oxide. Therefore, this work aimed to investigate the mechanism of action of a
new organic nitrate, 4-methylbenzoate 4-nitrooxybutyl (NIB7) on the vascular function
of the superior mesenteric artery of rats. The protocol was the ex vivo approach, where
the mesenteric artery rings were isolated in an aerated Tyrode nutrient solution with a
carbogenic mixture, using compact organ bath equipment. After stabilization for one
hour, the viability of the rings was checked and the endothelium test was performed.
When the rings were subjected to contraction with phenylephrine (FEN), NIB7 showed
vasorelaxant activity independent of functional endothelium (pD2= 6,328 ± 0,11 n=10;
Emáx= 107,6 ± 3,07 n=10). Relaxation was attenuated when another contracture agent,
60 mM KCl, was used (pD2 = 5,0 ± 0,09 n=7, *p< 0,05). In the presence of L-NAME, a
non-selective NOS inhibitor, there was no difference in the vasorelaxant effect. When
incubating the rings with a NO scavenger (HDX), vasorelaxation was attenuated (pD2 =
5.11 ± 0.08 n=7, *p < 0.05). When inhibiting soluble guanylyl cyclase (GCs) with
ODQ, the effect was also attenuated (pD2= 3.819 ± 0.10 n=7; Emax= 75.83 ± 7.50 n=7,
*p< 0.05). When using 20mM KCl, a potassium efflux modulator, and 3mM TEA, a
nonspecific potassium channel blocker, potency was attenuated (pD2 = 5.525 ± 0.05 n=7
and 5.320 ± 0.05 n=7, respectively, * p<0.05). When investigating potassium-specific
channels, using 1 mM 4-AP (for voltage-operated channels), 1 mM TEA (calcium-sensitive channels), BaCl2 (input rectifying channels), GLIB (ATP-dependent channel),
it was seen that no subtype demonstrated a significant influence on the relaxation
induced by the compound when evaluated in isolation. When the rings were pre-
exposed to a high concentration of NIB7 (100μM) to assess the development of vascular
tolerance, attenuation of potency was observed (pD2= 5.095 ± 0.10 n=6, *p< 0.05).
With this, it was seen that NIB7 is an NO donor, whose effect is independent of the
endothelium. It suggests the involvement of the NO-GCs-PKG pathway, with the
participation of potassium channels, despite not having a specific channel. Finally, the
compound appears to induce tolerance to vasorelaxation in the ex vivo experimental
approach. However, more studies are needed to better clarify this effect.
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CLARA RITTMEYER RUIZ
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Effects of the new organic nitrate 4-nitrooxybutyl 4-chlorobenzoate on the vascular function of the cranial mesenteric artery of normotensive rats.
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Date: Apr 26, 2024
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Time: 14:00
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Show Summary
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Cardiovascular diseases (CVDs) are prevalent and lead the causes of death in the world
population. The pathogenesis of CVDs is related to functional and morphological
changes in the heart and/or blood vessels. Endothelial dysfunction causes increased con-
tractility and vascular resistance, observed in diseases such as atherosclerosis and arteri-
al hypertension. Organic nitrates are nitric oxide (NO) donors and potent vasodilators.
Thus, the research aims to investigate the mechanism of action of a new organic nitrate,
4-nitrooxybutyl 4-chlorobenzoate (NHJB2), on the vascular function of the cranial mes-
enteric artery of normotensive Wistar rats (Rattus norvegicus). The ex vivo experi-
mental protocols were carried out using the compact organ bath equipment (76-00xx
series, Panlab, S.L. Havard Apparatus Spain). Cranial mesenteric artery rings were iso-
lated using aerated Tyrode nutrient solution with a carbogen mixture at a temperature of
37°C. After stabilization for one hour, the viability of the rings was checked and the
endothelium test was performed. Next, pre-contraction was performed with phe-
nylephrine (FEN) and a concentration-response curve was performed using NHJB2 to
evaluate the vasorelaxant effect. NHJB2 was able to evoke a vasorelaxant response in
the absence of endothelium (E-) in rings pre-contracted with FEN (Emax=114.7±4.2;
pD2=6.64 ±0.08). When incubating positive endothelium rings (E+) with L-NAME
(100 μM) the potency (pD2) was attenuated (5.52 ± 0.02), and the Emax (109.0 ± 0.95)
remained the same. Vasorelaxation was attenuated in rings pre-contracted with 60 mM
KCl (pD2=5.18±0.03). In the presence of a NO scavenger - HDX (100 μM)
vasorelaxation was attenuated (Emax=74.05±6.22 and pD2=4.08±0.06). When blocking
soluble guanylyl cyclase (GCs) with ODQ (10 μM), vasorelaxation was also attenuated
(Emax=96.84±10.86 and pD2=3.69±0.06). When incubating the rings with 20 mM KCl
and 3 mM TEA the potency was attenuated (5.35±0.05 and 5,03±0,04, respectively).
Thus, we suggest that the vasorelaxant response induced by NHJB2 does not depend on
the presence of the endothelium, it is effected by the mechanism of NO donation and
activation of the NO/GCs pathway and participation of potassium (K+) channels. The
next steps involve investigating K+ channel subtypes and evaluating acute desensitiza-
tion to NHJB2.
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JULIANA TELES DE ANDRADE
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EFFECTS OF KONJAC GLUCOMANNAN (KONJAC MASSA MF®) CONSUMPTION ON THE GLYCEMIC AND LIPID PROFILE OF TYPE 1 DIABETIC MICE
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Advisor : JOSIANE DE CAMPOS CRUZ
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Date: Feb 29, 2024
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Time: 14:00
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Show Summary
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Type 1 diabetes mellitus (T1DM) is a metabolic condition characterized by immune
activation against pancreatic beta cells. Therapies that enhance insulin levels and
sensitivity are vital for individuals with T1DM. Diet, including dietary fibers, emerges as
a promising non-pharmacological intervention for glycemic control. Konjac
glucomannan (KGM) stands out for its hypoglycemic properties in T1DM animal models.
Thus, this study aimed to assess the effects of KGM, in the form of the commercial
product Konjac Massa MF®, on the glycemic and lipid profile of mice with STZ-induced
T1DM. Male C57BL/6J mice, induced to T1DM with STZ, were treated for four weeks
with Konjac Massa MF® (120 mg/kg/day ig). We monitored glycemia, weight gain, and
water and feed consumption during treatment. We also conducted glucose (IPGTT) and
insulin (IPITT) tolerance tests, followed by plasma collection for biochemical analyses
and tissue preservation in 10% formalin for histological analyses. Results showed a
significant reduction in fasting glycemia in diabetic mice treated from the third week
compared to untreated diabetics (245.20 ± 26.91 vs 412.10 ± 25.18mg/dL). However,
there was no significant difference in glucose tolerance between treated and untreated
diabetic groups. The treated group exhibited improved insulin sensitivity (209.90 ± 57.20
vs 378.50 ± 61.97 mg/dL; 60 min: 213.70 ± 48.49 vs 361.00 ± 61.34 mg/dL; 90 min:
197.90 ± 51.85 vs 316.30 ± 60.74 mg/dL; 120 min: 234.50 ± 59.23 vs 318.30 ± 54.78
mg/dL). Treatment also reduced serum alanine aminotransferase (ALT) levels (39.39 ±
6.89 vs 82.83 ± 25.19 nmol/dL), suggesting a potential hepatoprotective effect of KGM.
We conclude that Konjac Massa MF® is a promising therapeutic agent for improving
insulin sensitivity and hepatic function in T1DM models, with no adverse side effects.
Further research is crucial to unravel the protective mechanisms of KGM and determine
its clinical applicability in the management of T1DM and its associated complications.
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JULIANA TELES DE ANDRADE
-
EFFECTS OF KONJAC GLUCOMANNAN (KONJAC MASSA MF®) CONSUMPTION ON THE GLYCEMIC AND LIPID PROFILE OF TYPE 1 DIABETIC MICE
-
Advisor : JOSIANE DE CAMPOS CRUZ
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Date: Feb 29, 2024
-
Time: 14:00
-
Show Summary
-
Type 1 diabetes mellitus (T1DM) is a metabolic condition characterized by immune
activation against pancreatic beta cells. Therapies that enhance insulin levels and
sensitivity are vital for individuals with T1DM. Diet, including dietary fibers, emerges as
a promising non-pharmacological intervention for glycemic control. Konjac
glucomannan (KGM) stands out for its hypoglycemic properties in T1DM animal models.
Thus, this study aimed to assess the effects of KGM, in the form of the commercial
product Konjac Massa MF®, on the glycemic and lipid profile of mice with STZ-induced
T1DM. Male C57BL/6J mice, induced to T1DM with STZ, were treated for four weeks
with Konjac Massa MF® (120 mg/kg/day ig). We monitored glycemia, weight gain, and
water and feed consumption during treatment. We also conducted glucose (IPGTT) and
insulin (IPITT) tolerance tests, followed by plasma collection for biochemical analyses
and tissue preservation in 10% formalin for histological analyses. Results showed a
significant reduction in fasting glycemia in diabetic mice treated from the third week
compared to untreated diabetics (245.20 ± 26.91 vs 412.10 ± 25.18mg/dL). However,
there was no significant difference in glucose tolerance between treated and untreated
diabetic groups. The treated group exhibited improved insulin sensitivity (209.90 ± 57.20
vs 378.50 ± 61.97 mg/dL; 60 min: 213.70 ± 48.49 vs 361.00 ± 61.34 mg/dL; 90 min:
197.90 ± 51.85 vs 316.30 ± 60.74 mg/dL; 120 min: 234.50 ± 59.23 vs 318.30 ± 54.78
mg/dL). Treatment also reduced serum alanine aminotransferase (ALT) levels (39.39 ±
6.89 vs 82.83 ± 25.19 nmol/dL), suggesting a potential hepatoprotective effect of KGM.
We conclude that Konjac Massa MF® is a promising therapeutic agent for improving
insulin sensitivity and hepatic function in T1DM models, with no adverse side effects.
Further research is crucial to unravel the protective mechanisms of KGM and determine
its clinical applicability in the management of T1DM and its associated complications.
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DEYSE CRISTINA MADRUGA CARVALHO
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AVALIAÇÃO DA ATIVIDADE ANTIVIRAL DA OUABAÍNA CONTRA O ZIKA
VÍRUS EM MODELOS IN VITRO, IN VIVO E IN SILICO
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Date: Feb 29, 2024
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Time: 13:30
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Show Summary
-
Ouabain, a cardiotonic steroid known as Na+ /K+ -ATPase inhibitor, has been
described as an immunomodulatory substance by our group. In addition, the
antiviral activity of ouabain has been reported in several studies. Zika virus (ZIKV)
is an emerging arbovirus associated with neurological disorders. Currently, there
are no vaccines or antivirals available to treat the disease caused by ZIKV. Then,
this work aimed to evaluate the anti-ZIKV activity of ouabain in vitro, in silico and
in vivo. Initially, Vero cells were used to determine the non-toxic concentrations
of ouabain and then, the antiviral activity was evaluated in this cell type. Ouabain
presented a dose-dependent inhibitory effect against ZIKV, mainly when added
post infection. The reduction of infectious virus was accompanied by a decrease
in ZIKV RNA levels, suggesting that the mechanism of ZIKV inhibition by ouabain
occurred at the replication step. To evaluate the activity of ouabain in a more
clinical approach in relation to ZIKV infection, an in vitro model of human neural
progenitor stem cells (NS/PCs) and an animal model of Congenital Zika Virus
Syndrome (SCZ) were performed. In NS/PCs, ouabain reduced ZIKV infection in
this cell type and blocked the impairment of neurogenesis triggered by the virus.
Additionally, in an animal model of SCZ, ouabain protected the fetus from
microcephaly triggered by the infection. This is might related to the ability of
ouabain to inhibit the virus in yolk sac microglial progenitors. In addition to
antiviral activity, ouabain was able to reduce the pro-inflammatory cytokine IL-1β
in the placenta, demonstrating its anti-inflammatory potential in this model.
Finally, we performed a molecular docking procedure followed by molecular
dynamics simulations to predict the interaction between ouabain and the main
drug targets in ZIKV proteome (NS3 Helicase, NS5 Mtase and NS5 RdRp). Our
in silico data demonstrated a conformational stability and favorable binding free
energy of ouabain in the biding sites of the NS5-RdRp and NS3-helicase proteins,
suggesting inhibition of these viral proteins by this steroid.Together, these data
demonstrate the antiviral action of ouabain in ZIKV infection, revealing this
substance as a potential compound for the treatment of infection caused by this
virus. In this way, this study contributes to highlighting the effectiveness of
cardiotonic steroids as promising antiviral agents, in addition to generating more
understanding about the biological functions of ouabain.
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CLENIA DE OLIVEIRA CAVALCANTI
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EVALUATION OF THE ANTI-INFLAMMATORY ACTIVITY OF SODIUM NITRITE AND 2-NITRATE-1,3-DIBUTOXYPROPANE (NDBP) IN EXPERIMENTAL ATHEROSCLEROSIS.
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Date: Jan 26, 2024
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Time: 08:30
-
Show Summary
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Ischemic heart disease and stroke are among the
leading causes of death in the world and maintains a close relationship with atherosclerosis, a
chronic inflammatory disease of the vascular system characterized by intense activity
innate and adaptive immunology. In the atherogenic process, a reduction in
bioavailability of nitric oxide (NO) and increase in reactive oxygen species
(ROS). In this sense, an improved understanding of new therapeutic alternatives
to improve the bioavailability of NO are necessary, which includes studies on
new classes of NO-donating drugs and the nitrate-nitrite-NO pathway. The objective of
study was to evaluate the anti-inflammatory activity of sodium nitrite (NaNO2) and 2-nitrate-
1,3-dibutoxypropane (NDBP) in a model of acute inflammation and atherosclerosis
experimental. Acute inflammation: C57BL/6 (controls) and ApoE-/- mice were
treated with NaNO2 (dose 0.1mmoL/kg) or NDBP (dose 40mg/kg) for three days. One
hour after the last day of treatment, the animals were stimulated with zymosan
(2mg/mL) in order to induce inflammation in the peritoneum. After 4 hours, peritoneal fluid
was collected and used to count total and differential cells by microscopy
optics and for quantification of cytokines (IL-6, IL-10, TNF-α and MCP-1) by Elisa.
Chronic inflammation: ApoE-/- mice, upon reaching 8 weeks of age, received
Western atherogenic diet for 12 weeks and their controls received a standard diet to
rodents. During the last 3 weeks they received NaNO2 by gavage
(0.1mmoL/kg/day), NDBP (40mg/kg) or saline. At the end of the treatment, the
blood collection for analysis of lipid profile, lipid peroxidation, plasma nitrite and
cytokines (IL-6, IL-10, TNF-α and MCP-1) and aortas were removed and processed for
histological evaluation of atherosclerotic plaque deposition (oil red staining),
production of ROS (labeling with dihydroethide - DHE) and NO (labeling with
diaminofluorescein - DAF). Data were expressed as mean ± standard error of
mean and statistical comparisons were made by ANOVA, followed by post hoc
Tuckey, considering p<0.05. In the peritonitis model, zymosan, as expected,
induced an increase in cell migration and levels of pro-inflammatory cytokines in the peritoneum.NaNO2 treatment was able to reduce the total number of cells to
peritoneal cavity, by reducing polymorphonuclear migration in mice
C57BL/6 and Apoe-/- mice reduced plasma levels of the cytokines IL-10,
TNF-α and MCP-1. NDBP increased cell migration in both lineages. At the
experimental atherosclerosis model, treatment with NaNO2 reduced the deposition of
atherosclerotic plaque, plasma MCP-1 levels, systemic and intracellular oxidative stress
situ in the aorta, independent of changes in NO levels, plasma nitrite and profile
lipid. NDBP differed from NaNO2 only in MCP-1 levels, increasing this
cytokine in plasma. These results suggest that NaNO2 has an anti-inflammatory effect
in a model of acute and chronic inflammation, being able to reduce plaque deposition
atherosclerosis by mechanisms involving the reduction of oxidative stress and MCP-1. AND
that NDBP has a dual effect, with pro-inflammatory action in a model of
peritonitis and antiatherogenic action.
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