Environmental enrichment (EE) is a process of brain stimulation by modifying the surroundings, for example, by changing the sensory, social, or physical conditions. Rodents have been used in such experimental strategies through exposure to diverse physical, social, and exploration conditions. The present study conducted an extensive analysis of the existing literature surrounding the impact of EE on dementia rodent models. The review emphasised the two principal aspects that are very closely related to dementia: cognitive function (learning and memory) as well as psychological factors (anxiety-related behaviours such as phobias and unrealistic worries). Also highlighted were the mechanisms involved in the rodent models of dementia showing EE effects. Two search engines, PubMed and Science Direct, were used for data collection using the following keywords: environmental enrichment, dementia, rodent model, cognitive performance, and anxiety-related behaviour. Fifty-five articles were chosen depending on the criteria for inclusion and exclusion. The rodent models with dementia demonstrated improved learning and memory in the form of hampered inflammatory responses, enhanced neuronal plasticity, and sustained neuronal activity. EE housing also prevented memory impairment through the prevention of amyloid beta (Aβ) seeding formation, an early stage of Aβ plaque formation. The rodents subjected to EE were observed to present increased exploratory activity and exert less anxiety-related behaviour, compared to those in standard housing. However, some studies have proposed that EE intervention through exercise would be too mild to counteract the anxiety-related behaviour and risk assessment behaviour deficits in the Alzheimer's disease rodent model. Future studies should be conducted on old-aged rodents and the duration of EE exposure that would elicit the greatest benefits since the existing studies have been conducted on a range of ages and EE durations. In summary, EE had a considerable effect on dementia rodent models, with the most evident being improved cognitive function.
Astaxanthin derived from natural sources has excellent antioxidant and anti-inflammatory effects, and it is currently being widely researched as a neuroprotectant. However, astaxanthin possesses low oral bioavailability, and thus, astaxanthin extract from Haematococcus pluvialis was formulated into a nanoemulsion to improve its bioavailability and administered to Alzheimer's disease (AD)-like rats to study its possible neuroprotective benefits. Astaxanthin nanoemulsion was administered orally once a day for 28 days to streptozotocin (STZ)-induced AD rats at concentrations of 160, 320, and 640 mg/kg of body weight (bw) and subsequently assessed for cognitive function using behavioral assessments. Brain samples were collected for the assessment of AD biomarkers. Astaxanthin nanoemulsion at a dosage of 640 mg/kg bw significantly improved spatial learning, spatial memory, and recognition memory against STZ-AD rats. At 320 and 640 mg/kg bw, astaxanthin nanoemulsion significantly reduced levels of hippocampus synaptosomal amyloid beta and paired-helical fibrillary tau protein while increasing neuron survival. Additionally, astaxanthin nanoemulsion at 640 mg/kg bw significantly increased acetylcholine levels in the hippocampus and cerebellum. Astaxanthin nanoemulsion at all treatment dosages significantly reduced malondialdehyde, a lipid peroxidation product, and neuroinflammatory mediators (GFAP and TNF-α). Astaxanthin nanoemulsion supplementation has the potential to improve cognitive function and synaptic function by lowering amyloid beta and tau levels, as well as preserve neuron integrity by reducing neuroinflammation and lipid peroxidation, indicating that it may be able to treat some of the underlying causes of AD.
Background: Self-learning (SL) is a process in which individuals take the initiative to acquire knowledge with or without the help of others. Knowledge about herbal and dietary supplements (HDS) is important for pharmacists. Unfortunately, there is limited coverage of topics relating to HDS in the pharmacy curricula. The present focus group study applies the Theoretical Domains Framework (TDF) to explore pharmacy students' practices and beliefs regarding SL about HDS (SL-HDS). Methods: Focus group interviews (FGIs) were conducted between April and May 2019 among a sample of undergraduate pharmacy students at a public university (n = 20). Four FGI sessions were conducted, each lasting about 60 to 75 min, and all the sessions were audio-recorded. The interviews were transcribed verbatim and analysed using thematic content analysis. Results: Beliefs about SL-HDS were categorised into 12 domains based on the TDF. Students showed positive attitudes towards SL-HDS and agreed that their involvement in SL-HDS was instrumental in improving their knowledge about various aspects of HDS including indications, adverse effects, and HDS-drug interactions. Various facilitators and barriers influencing students' participation in SL-HDS were uncovered (e.g., access to the internet, time, availability of reference resources). The students demanded to be equipped with critical appraisal skills, as they had limited confidence in assessing literature or information about HDS. Conclusion: This study revealed that the students saw the benefits of SL-HDS. They also perceived that engaging in SL-HDS is compatible with the role of pharmacy students. The findings showed students' readiness and willingness to conduct SL-HDS.