Cilostazol attenuated prenatal valproic acid-induced behavioural and biochemical deficits in a rat model of autism spectrum disorder

The anti-platelet drug cilostazol enhances heart rate and interrenal steroidogenesis and exerts a scant effect on innate immune responses in zebrafish

RATIONALE

Cilostazol, an anti-platelet phosphodiesterase-3 inhibitor used for the treatment of intermittent claudication, is known for its pleiotropic effects on platelets, endothelial cells and smooth muscle cells. However, how cilostazol impacts the endocrine system and the injury-induced inflammatory processes remains unclear.

METHODS

We used the zebrafish, a simple transparent model that demonstrates rapid development and a strong regenerative ability, to test whether cilostazol influences heart rate, steroidogenesis, and the temporal and dosage effects of cilostazol on innate immune cells during tissue damage and repair.

RESULTS

While dosages of cilostazol from 10 to 100 μM did not induce any noticeable morphological abnormality in the embryonic and larval zebrafish, the heart rate was increased as measured by ImageJ TSA method. Moreover, adrenal/interrenal steroidogenesis in larval zebrafish, analyzed by whole-mount 3β-Hsd enzymatic activity and cortisol ELISA assays, was significantly enhanced. During embryonic fin amputation and regeneration, cilostazol treatments led to a subtle yet significant effect on reducing the aggregation of Mpx-expressing neutrophil at the lesion site, but did not affect the immediate injury-induced recruitment and retention of Mpeg1-expressing macrophages.

CONCLUSIONS

Our results indicate that cilostazol has a significant effect on the heart rate and the growth as well as endocrine function of steroidogenic tissue; with a limited effect on the migration of innate immune cells during tissue damage and repair.

Phosphodiesterase inhibitor, ibudilast alleviates core behavioral and biochemical deficits in the prenatal valproic acid exposure model of autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) is categorized as a neurodevelopmental disorder, presenting with a variety of aetiological and phenotypical features. Ibudilast is known to produce beneficial effects in several neurological disorders including neuropathic pain, multiple sclerosis, etc. by displaying its neuroprotective and anti-inflammatory properties. Here, in our study, the pharmacological outcome of ibudilast administration was investigated in the prenatal valproic acid (VPA)-model of ASD in Wistar rats.

METHODS

Autistic-like symptoms were induced in Wistar male pups of dams administered with Valproic acid (VPA) on embryonic day 12.5. VPA-exposed male pups were administered with two doses of ibudilast (5 and10 mg/kg) and all the groups were evaluated for behavioral parameters like social interaction, spatial memory/learning, anxiety, locomotor activity, and nociceptive threshold. Further, the possible neuroprotective effect of ibudilast was evaluated by assessing oxidative stress, neuroinflammation (IL-1β, TNF-α, IL-6, IL-10) in the hippocampus, % area of Glial fibrillary acidic protein (GFAP)-positive cells and neuronal damage in the cerebellum.

KEY FINDINGS

Treatment with ibudilast significantly attenuated prenatal VPA exposure associated social interaction and spatial learning/memory deficits, anxiety, hyperactivity, and increased nociceptive threshold, and it decreased oxidative stress markers, pro-inflammatory markers (IL-1β, TNF-α, IL-6), and % area of GFAP-positive cells and restored neuronal damage.

CONCLUSIONS

Ibudilast treatment has restored crucial ASD-related behavioural abnormalities, potentially through neuroprotection. Therefore, benefits of ibudilast administration in animal models of ASD suggest that ibudilast may have therapeutic potential in the treatment of ASD.

Adolescent swimming exercise following maternal valproic acid treatment improves cognition and reduces stress-related symptoms in offspring mice: Role of sex and brain cytokines

Valproic acid (VPA) treatment during pregnancy is a risk factor for developing autism spectrum disorder, cognitive deficits, and stress-related disorders in children. No effective therapeutic strategies are currently approved to treat or manage core symptoms of autism. Active lifestyles and physical activity are closely associated with health and quality of life during childhood and adulthood. This study aimed to evaluate whether swimming exercise during adolescence can prevent the development of cognitive dysfunction and stress-related disorders in prenatally VPA-exposed mice offspring. Pregnant mice received VPA, afterwards, offspring were subjected to swimming exercise. We assessed neurobehavioral performances and inflammatory cytokines (interleukin-(IL)6, tumor-necrosis-factor-(TNF)α, interferon-(IFN)γ, and IL-17A) in the hippocampus and prefrontal cortex of offspring. Prenatal VPA treatment increased anxiety-and anhedonia-like behavior and decreased social behavior in male and female offspring. Prenatal VPA exposure also increased behavioral despair and reduced working and recognition memory in male offspring. Although prenatal VPA increased hippocampal IL-6 and IFN-γ, and prefrontal IFN-γ and IL-17 in males, it only increased hippocampal TNF-α and IFN-γ in female offspring. Adolescent exercise made VPA-treated male and female offspring resistant to anxiety-and anhedonia-like behavior in adulthood, whereas it only made VPA-exposed male offspring resistant to behavioral despair, social and cognitive deficits in adulthood. Exercise reduced hippocampal IL-6, TNF-α, IFN-γ, and IL-17, and prefrontal IFN-γ and IL-17 in VPA-treated male offspring, whereas it reduced hippocampal TNF-α and IFN-γ in VPA-treated female offspring. This study suggests that adolescent exercise may prevents the development of stress-related symptoms, cognitive deficits, and neuroinflammation in prenatally VPA-exposed offspring mice.

Cilostazol novel neuroprotective mechanism against rotenone-induced Parkinson's disease in rats: Correlation between Nrf2 and HMGB1/TLR4/PI3K/Akt/mTOR signaling

Neuroinflammation induced by activation of the high mobility group box 1/ toll-like receptor 4 (HMGB1/TLR4) axis is one of the principal mechanisms involved in dopaminergic neuronal loss in Parkinson's disease (PD), and its activation exacerbates oxidative stress augmenting neurodegeneration.

AIMS

This study investigated the novel neuroprotective effect of cilostazol on rotenone-intoxicated rats focusing on the HMGB1/TLR4 axis, erythroid-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1), and phosphoinositide 3-kinase (PI3K)/Protein kinase B (Akt)/the mammalian target of rapamycin (mTOR) pathway. The aim is extended to correlate the Nrf2 expression with all assessed parameters as promising therapeutic targets for neuroprotection.

MAIN METHODS

Our experiment was designed as follows: vehicle group, cilostazol group, rotenone group (1.5 mg/kg, s.c), and the rotenone pretreated with cilostazol (50 mg/kg, p.o.) group. Eleven rotenone injections were injected day after day, while cilostazol was administered daily for 21 days.

KEY FINDINGS

Cilostazol significantly improved the neurobehavioral analysis, the histopathological examination, and dopamine levels. Moreover, the immunoreactivity of tyrosine hydroxylase (TH) in substantia nigra pars compacta (SNpc) enhanced. These effects were associated with enhancement of the antioxidant expression of Nrf2 and HO-1 by 1.01 and 1.08-fold, respectively, and repression of HMGB1/TLR4 pathway by 50.2 % and 39.3 %, respectively. Upregulation of the neuro-survival PI3K and Akt expression by 2.26 and 2.69-fold, respectively, and readjusting mTOR overexpression.

SIGNIFICANCE

Cilostazol exerts a novel neuroprotective strategy against rotenone-induced neurodegeneration via activation of Nrf2/HO-1, suppression of HMGB1/TLR4 axis, upregulation of PI3K/Akt besides mTOR inhibition that compels more investigations with different PD models to clarify its precise role.

Cilostazol as adjunctive therapy in treatment of children with autism spectrum disorders: a double-blind and placebo-controlled randomized trial

We aimed to evaluate cilostazol therapeutic effects on aberrant behaviors of autism spectrum disorder (ASD) children and its safety profile in a double-blind, randomized clinical trial. Sixty-six children with confirmed ASD were allocated to receive either daily 50-mg cilostazol (increased to 100 mg/day after 2 weeks) or matched placebo in addition to risperidone. The Aberrant Behavior Checklist-Community Edition (ABC-C) scale and a checklist of probable adverse effects were used to assess the behavioral outcomes and safety profile at weeks 0, 5, and 10 of the study. Sixty-one participants, with comparable baseline characteristics, completed the trial. Unlike other ABC-C subscales, repeated-measures analysis showed significant effect for time × treatment interaction in the hyperactivity subscale ( P = 0.047; partial eta squared = 0.06). We used the median value for the baseline score hyperactivity subscale [median (interquartile range) = 31 (24-37)] to stratify participants to higher hyperactivity and lower hyperactivity subgroups and found that only participants with higher hyperactivity benefit from cilostazol adjunctive therapy ( P = 0.028; partial eta squared = 0.14). Cilostazol could be considered as a safe agent with beneficial effects on hyperactivity in children with ASD and higher levels of hyperactivity.

Protective Effect of Nimodipine Against Valproic-acid Induced Biochemical and Behavioral Phenotypes of Autism

OBJECTIVE

Present study was designed to investigate behavioral and biochemical role of nimodipine in prenatal valproic acid (Pre-VPA) induced autism in rats.

METHODS

Valproic acid was utilized to induce autistic phenotypes in Wistar rats. The rats were assessed for social behavior. Hippocampus and prefrontal cortex (PFC) were utilized for various biochemical assessments, whereas cerebellum was used to assess blood brain barrier (BBB) permeability.

RESULTS

Pre-VPA rats showed reduction social interaction. Pre-VPA administration were decreased PFC levels of interleukin- 10 (IL-10), and glutathione along with hippocampus cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF). Also, the animals have shown increase in PFC levels of IL-6, tumor necrosis factor-α, thiobarbituric acid reactive substance, Evans blue leakage and water content. Nimodipine countered Pre-VPA administered reduction in social interaction, CREB, BDNF, inflammation, oxidative stress, BBB permeability.

CONCLUSION

Pre-VPA has induced autistic phenotype, which were attenuated by nimodipine in rats. Nimodipine and other calcium channel blockers should further investigate to check the management of autism.

Influence of Prenatal Drug Exposure, Maternal Inflammation, and Parental Aging on the Development of Autism Spectrum Disorder

Autism spectrum disorder (ASD) affects reciprocal social interaction and produces abnormal repetitive, restrictive behaviors and interests. The diverse causes of ASD are divided into genetic alterations and environmental risks. The prevalence of ASD has been rising for several decades, which might be related to environmental risks as it is difficult to consider that the prevalence of genetic disorders related to ASD would increase suddenly. The latter includes (1) exposure to medications, such as valproic acid (VPA) and selective serotonin reuptake inhibitors (SSRIs) (2), maternal complications during pregnancy, including infection and hypertensive disorders of pregnancy, and (3) high parental age. Epidemiological studies have indicated a pathogenetic role of prenatal exposure to VPA and maternal inflammation in the development of ASD. VPA is considered to exert its deleterious effects on the fetal brain through several distinct mechanisms, such as alterations of γ-aminobutyric acid signaling, the inhibition of histone deacetylase, the disruption of folic acid metabolism, and the activation of mammalian target of rapamycin. Maternal inflammation that is caused by different stimuli converges on a higher load of proinflammatory cytokines in the fetal brain. Rodent models of maternal exposure to SSRIs generate ASD-like behavior in offspring, but clinical correlations with these preclinical findings are inconclusive. Hypertensive disorders of pregnancy and advanced parental age increase the risk of ASD in humans, but the mechanisms have been poorly investigated in animal models. Evidence of the mechanisms by which environmental factors are related to ASD is discussed, which may contribute to the development of preventive and therapeutic interventions for ASD.