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Alzheimer's disease (AD) affects the elderly and is characterized by progressive neurodegeneration caused by different pathologies. The most significant challenges in treating AD include the inability of medications to reach the brain because of its poor solubility, low bioavailability, and the presence of the blood-brain barrier (BBB). Additionally, current evidence suggests the disruption of BBB plays an important role in the pathogenesis of AD. One of the critical challenges in treating AD is the ineffective treatments and their severe adverse effects. Nanotechnology offers an alternative approach to facilitate the treatment of AD by overcoming the challenges in drug transport across the BBB. Various nanoparticles (NP) loaded with natural products were reported to aid in drug delivery for the treatment of AD. The nano-sized entities of NP are great platforms for incorporating active materials from natural products into formulations that can be delivered effectively to the intended action site without compromising the material's bioactivity. The review highlights the applications of medicinal plants, their derived components, and various nanomedicinebased approaches for the treatment of AD. The combination of medicinal plants and nanotechnology may lead to new theragnostic solutions for the treatment of AD in the future.

Bell’s palsy is characterised by one-sided lower motor neuron impairment of the facial nerve. Even though Bell’s palsy is a peripheral facial nerve palsy, other cranial nerves should be investigated, because they are anatomically interconnected rather than isolated. The study aimed to look for evidence of other cranial nerves being involved in Bell’s palsy. CINAHL, Academic Search Complete, MEDLINE, SPORTDiscus, and Scopus, all of which were updated until May 2021, were used to conduct a comprehensive search. Bell’s palsy research focused on the origins and cause of the condition, regardless of study design, was eligible for inclusion. Animal research, non-English studies, grey literature, studies with no full text available, and those published in non-peer-reviewed journals, were excluded. While 3883 papers were found during the initial search, only 13 were included in the final study. The Joanna Briggs Institute Manual for Evidence Synthesis and Sackett’s standard of evidence was used to assess the validity of the papers that were screened. The most common type was case series (n=5), followed by case-control (n=4), case report (n=3), and cross-sectional (n=1). Most of the articles were categorised as Level-IV (n=8), followed by Level-V (n=3), with only two studies classified as Level-III (n=2) by Sackett’s criteria. The trigeminal and vestibulocochlear nerves are the most involved cranial nerves in Bell’s palsy. The optic, oculomotor, trigeminal, vestibulocochlear, glossopharyngeal, vagus, and hypoglossal nerves are the seven cranial nerves potentially associated with Bell’s palsy

Dementia is a major burden on global health for which there are no effective treatments. The use of noninvasive visual stimulation to ameliorate cognitive deficits is a novel concept that may be applicable for treating dementia. In this study, we investigated the effects of transcorneal electrical stimulation (TES) on memory enhancement using two mouse models, in aged mice and in the 5XFAD model of Alzheimer's disease. After 3 weeks of TES treatment, mice were subjected to Y-maze and Morris water maze tests to assess hippocampal-dependent learning and memory. Immunostaining of the hippocampus of 5XFAD mice was also performed to examine the effects of TES on amyloid plaque pathology. The results showed that TES improved the performance of both aged and 5XFAD mice in memory tests. TES also reduced hippocampal plaque deposition in male, but not female, 5XFAD mice. Moreover, TES significantly reversed the downregulated level of postsynaptic protein 95 in the hippocampus of male 5XFAD mice, suggesting the effects of TES involve a postsynaptic mechanism. Overall, these findings support further investigation of TES as a potential treatment for cognitive dysfunction and mechanistic studies of TES effects in other dementia models.

Depression is a complex heterogeneous brain disorder characterized by a range of symptoms, resulting in psychomotor and cognitive disabilities and suicidal thoughts. Its prevalence has reached an alarming level affecting millions of people globally. Despite advances in current pharmacological treatments, the heterogenicity of clinical response and incidences of adverse effects have shifted research focus to identification of new natural substances with minimal or no adverse effects as therapeutic alternatives. Marine algae-derived extracts and their constituents are considered potential sources of secondary metabolites with diverse beneficial effects. Marine algae with enormous health benefits are emerging as a natural source for discovering new alternative antidepressants. Its medicinal properties exhibited shielding efficacy against neuroinflammation, oxidative stress, and mitochondrial dysfunction, which are indicated to underlie the pathogenesis of many neurological disorders. Marine algae have been found to ameliorate depressive-like symptoms and behaviors in preclinical and clinical studies by restoring monoaminergic neurotransmission, hypothalamic-pituitary-adrenal axis function, neuroplasticity, and continuous neurogenesis in the dentate gyrus of the hippocampus via modulating brain-derived neurotrophic factors and antineuroinflammatory activity. Although antidepressant effects of marine algae have not been validated in comparison with currently available synthetic antidepressants, they have been reported to have effects on the pathophysiology of depression, thus suggesting their potential as novel antidepressants. In this review, we analyzed the currently available research on the potential benefits of marine algae on depression, including their effects on the pathophysiology of depression, potential clinical relevance of their antidepressant effects in preclinical and clinical studies, and the underlying mechanisms of these effects.

Additional file 1: Fig. S1. NMR data assignments. Schematic diagram of the chemical structure of herierin IV (A). Steps involved in the isolation of HE compounds (B). Fig. S2. Visualization of MAPK (A) and IL-17 (B) signalling pathways. Fig. S3. Visualization of TNF (A) and neurotrophin (B) signalling pathways.

Additional file 2: Table S1. 1H and 13C NMR (600 MHz) spectroscopic data for herierin IV (3) in MeOH-d4.

Additional file 1. NMR data assignments. Table S1. 1H and 13C NMR Spectroscopic Data of Adenosine (1). Table S2. 1H and 13C NMR Spectroscopic Data of Herierin III (2).

Peripheral nerve injury represents a huge burden to society. Following peripheral nerve injury, improved behavioral outcome may be the most important evidence of functionality of axonal regeneration after any repair strategy. Nerve-crush injury is a well-established axonotmetic model in experimental regeneration studies to investigate the impact of various pharmacological treatments. Hericium erinaceus is a temperate mushroom but is now being cultivated in tropical Malaysia. In this study, we investigated the activity of aqueous extract of H. erinaceus fresh fruitbodies in promoting functional recovery following an axonotmetic peroneal nerve injury in adult female Sprague-Dawley rats with a long-term view toward the possible use of this mushroom in the treatment of nerve injury. Functional recovery was assessed in the behavioral experiment by walking-track analysis and toe-spreading reflex. The peroneal functional index (PFI) was determined before surgery and after surgery, as the rats showed signs of recovery. Analysis of the PFI indicated that the return of hind-limb function occurred by day 10 to 14 and by day 14 to 17 in the treated and control (nontreated) groups, respectively. Normal toe-spreading in the crushed limb was achieved by day 7 to 10 and day 12 to 17 in the treated and control group, respectively. These results suggest that daily administration of aqueous extract of H. erinaceus fresh firuitbodies has a beneficial effect on the recovery of injured rat peroneal nerve in the early stages of regeneration. The PFI and toe-spreading reflex improved faster in the treated group than in the nontreated group.