Chrysanthellum americanum L. (Vatke) is a medicinal plant from the Compositae family used in west-African traditional medicine, known for its flavonoid and saponin richness and for its strong antioxidant potential. In the present study, we assessed the effects of Chrysanthellum americanum polyphenolic extract in the psychological stress-induced rat model of irritable bowel syndrome (IBS), a chronic functional digestive tract disorder marked by immune and inflammatory-related disturbances of central nervous and peripheral intestinal systems, which is often associated with mood disorders including depression and anxiety. Consequently, memory impairment, anxiety and depression behavioral indicators, and cerebral oxidative stress biomarker dynamics were evaluated in a multifactorial heterotypic stress-exposed IBS rats after 6-day gavage with polyphenolic C. americanum extract (100 mg/kg body weight). Y-maze, elevated plus maze, and forced swimming tests were used for assessing behavioral responses. Administration of the extract exhibited significant anxiolytic and antidepressant-like effects coupled with significantly increased temporal lobe antioxidant enzyme specific activity (superoxide dismutase and glutathione peroxidase) and decreased malondialdehyde levels, a well-known lipid peroxidation marker. Furthermore, linear regression statistical analyses showed significant correlations between the oxidative stress parameters and behavioral tests. In conclusion, our results suggest that the administration of Chrysanthellum americanum polyphenolic extract could ameliorate mood and cognitive disturbances related to stress-induced in an IBS rat model. This could be also related to cerebral oxidative stress status attenuation.

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Background and objectives: Oxidative stress and inflammation have been implicated in the etiology of irritable bowel syndrome (IBS), a common gastrointestinal functional disease. This study aimed to further characterize the contention-stress rat model by exploring a possible correlation between oxidative stress markers measured in brain tissues with behavioral components of the aforementioned model. Thus, it is hereby proposed a possible IBS animal model relevant to pharmacological and complementary medicine studies. Materials and Methods: Wild-type male Wistar rats (n = 5/group) were chronically exposed to 6-hour/day contention, consisting of isolating the animals in small, vital space-granting plastic devices, for seven consecutive days. Following contention exposure, temporal lobes were extracted and subjected to biochemical analyses to assess oxidative stress-status parameters. Results: Our results show increased brain oxidative stress in contention-stress rat model: decreased superoxide dismutase and glutathione peroxidase activities and increased malondialdehyde production in the IBS group, as compared to the control group. Furthermore, the biochemical ratios which are used to evaluate the effectiveness of an antioxidant system on oxidative stress could be described in this model. Conclusions: The correlations between the behavioral patterns and biochemical oxidative stress features could suggest that this may be a complex model, which can successfully mimic IBS symptomatology further providing evidence of a strong connection between the digestive system, enteric nervous system, and the central nervous system.

Background and objectives: The hormone oxytocin (OXT) has already been reported in both human and animal studies for its promising therapeutic potential in autism spectrum disorder (ASD), but the comparative effectiveness of various administration routes, whether central or peripheral has been insufficiently studied. In the present study, we examined the effects of intranasal (IN) vs. intraperitoneal (IP) oxytocin in a valproic-acid (VPA) autistic rat model, focusing on cognitive and mood behavioral disturbances, gastrointestinal transit and central oxidative stress status. Materials and Methods: VPA prenatally-exposed rats (500 mg/kg; age 90 days) in small groups of 5 (n = 20 total) were given OXT by IP injection (10 mg/kg) for 8 days consecutively or by an adapted IN pipetting protocol (12 IU/kg, 20 μL/day) for 4 consecutive days. Behavioral tests were performed during the last three days of OXT treatment, and OXT was administrated 20 minutes before each behavioral testing for each rat. Biochemical determination of oxidative stress markers in the temporal area included superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA). A brief quantitative assessment of fecal discharge over a period of 24 hours was performed at the end of the OXT treatment to determine differences in intestinal transit. Results: OXT improved behavioral and oxidative stress status in both routes of administration, but IN treatment had significantly better outcome in improving short-term memory, alleviating depressive manifestations and mitigating lipid peroxidation in the temporal lobes. Significant correlations were also found between behavioral parameters and oxidative stress status in rats after OXT administration. The quantitative evaluation of the gastrointestinal (GI) transit indicated lower fecal pellet counts in the VPA group and homogenous average values for the control and both OXT treated groups. Conclusions: The data from the present study suggest OXT IN administration to be more efficient than IP injections in alleviating autistic cognitive and mood dysfunctions in a VPA-induced rat model. OXT effects on the cognitive and mood behavior of autistic rats may be associated with its effects on oxidative stress. Additionally, present results provide preliminary evidence that OXT may have a balancing effect on gastrointestinal motility.

The neurohormone oxytocin is known to exert a special function in the regulation of social relationships throughout vertebrate taxa. Recently it has been discovered that not only within-species, but in certain cases, between-species social bonds are also mediated by the same hormone, e.g. in case of the dog�human relationship. However, despite the exponential growth of findings at the behavioural level, there are still a lot of controversies on the biochemical assessment of oxytocin in canine samples. Thus, in the current study we replicate previous findings of canine serum oxytocin increase following a positive dog�human interaction. We provide a detailed description of both the immunoassay method used as well as the behavioural protocol (including crucial time-parameters). This will serve as a base for further studies that both our group as well as others in the field will conduct.