Neuroprotective Effect of Ulva Lactuca Extract Against Cognitive Deficits and Anxiety Like Behaviour in Rats

Abstract

Background and Aim Chronic stress is the type of stress which results in remarkable changes in the structure and function of many central nervous system sites. It affects brain areas involved in anxiety and affective disorder, such as the hippocampus and prefrontal cortex and play major role in chronic stress neurobiological disorder. Chronic Unpredictable Stress (CUS) is characterized by the release of stress mediators, like glucocorticoids and adrenaline from which stress mediator allows the body stability function through stressor arrangement. There is high degree of Comorbidities of depression and anxiety. The marine drug under investigation Ulva lactuca extractis having anti-inflammatory, anti-oxidant and antimicrobial activity. We aimed to investigate the neuroprotective action of Ulva lactuca extract against Chronic unpredictable stress induced cognitive deficits and anxiety like behaviour in rats. Material and Methods Wistar rats (female) weighing between 200-250g were divided into seven groups each consisting of six animals: Group 1: Normal control (NC), Group 2: Sham Control (SC), Group 3: Disease Control (CUS), Group 4: Disease Control with Escitalopram, 5mg/kg, oral, Group 5: Ulva lactuca extract group (150 mg/kg), Group 6: Ulva lactuca extract group (250 mg/kg) , Group 7: Ulva lactuca extract group (350 mg/kg). Treatment group animals were administered with the investigational drug from day 0. On 8 th day, the CUS procedure was initiatedin each group except the sham group. Sham rats were housed separately for the same time frame and were handled daily in the housing room for 30 seconds, but they were not stressed. Finally, animals were tested for neurobehavioral parameters namely Elevated plus Maze (EPM), Open Field Test (OFT), Locomotor activity, Morris water maze. Biochemical estimations included Biogenic amine Neurotransmitter parameters (Dopamine, Serotonin) and Oxidative stress Parameters (SOD, Catalyse, Reduced Glutathione, MDA Activity). Histopathological examination was performed at the end. Results: In our study, we found out that Ulva lactuca extract treatment showed neuroprotective and neurorestorative activity in neurobehavioral parameters. All the treatment groups showed improved results in all the neurobehavioral tests, by increase in the open arm entries and %OTR in elevated plus maze test, increase in the centre square entries in open field test, decrease in latency to find hidden platform in Morris water maze, increase in sucrose preference in comparison to Disease control group. The antioxidant property of Ulva lactuca extract was proved by significant improvement in MDA, SOD, Catalase and reduced Glutathione levels in treatment groups in comparison to disease control groups. Similarly, the anti-inflammatory property was exhibited by significant improvement in IL- 1beta and NGF-beta levels in treatment groups. The histopathological examination revealed neuroprotection in treatment groups. Specifically, Ulva lactuca extract250 mg/kg treatment group of animals showed significant improvement in all the parameters as compared to other doses of Ulva Lactuca extract. Conclusion: In conclusion, our data suggests that the neuroprotective and preventive activity of Ulva lactuca extract against CUS induced cognitive deficits and anxiety like behaviour in rats. This may be due to its antioxidant, anti-inflammatory and improvement in biogenic amine levels which is confirmed by improvement in neurobehavioral parameters. Out of the three dose of Ulva lactuca extract, the dose of 250mg/kg dose showed better neuroprotective action and can be tested further for confirmatory studies.