The most common neurodegenerative diseases (NDDs), such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), are the seventh leading cause of mortality and morbidity in developed countries. Clinical observations of NDD patients are characterized by a progressive loss of neurons in the brain along with memory decline. The common pathological hallmarks of NDDs include oxidative stress, the dysregulation of calcium, protein aggregation, a defective protein clearance system, mitochondrial dysfunction, neuroinflammation, neuronal apoptosis, and damage to cholinergic neurons. Therefore, managing this pathology requires screening drugs with different pathological targets, and suitable drugs for slowing the progression or prevention of NDDs remain to be discovered. Among the pharmacological strategies used to manage NDDs, natural drugs represent a promising therapeutic strategy. This review discusses the neuroprotective potential of seaweed and its bioactive compounds, and safety issues, which may provide several beneficial insights that warrant further investigation.

The whitening effect of reducing skin pigmentation is one of the most important goals of cosmetics. The purpose of this study was to determine whether Catalpa ovata extract and its fractions have potential as natural skin-lightening agents. Initially, we screened various fractions of Catalpa ovata extract using an in vitro antioxidant assay. Then, the inhibitory effects of C. ovata extract and its fraction on melanogenesis and the related mechanisms were investigated in B16F1 melanoma cells. The results showed that the ethyl acetate fraction (EF) from C. ovata extract markedly inhibited melanin synthesis in a dose-dependent manner at non-toxic concentrations. Furthermore, EF downregulated both the protein and mRNA levels of tyrosinase, which is a specific enzyme that catalyzes the conversion of tyrosine into melanin. We also found that EF decreased the microphthalmia-associated transcription factor (MITF) at the protein and mRNA levels. EF increased the phosphorylation of ERK and suppressed the phosphorylation of JNK and p38 in ɑ-MSH-induced B16F1 cells. These results indicate that EF can regulate the MAPK pathway. In addition, EF has an anti-melanogenic effect via the downregulation of intracellular cyclic-AMP (cAMP). Nineteen major compounds of EF were identified using LC-MS/MS. Taken together, these results suggest that EF may be a potential anti-melanogenic agent for use in skin-whitening cosmetics and in topical treatments for hyperpigmentation disorders.

Background/Objectives: Neuroinflammatory mechanisms, primarily mediated by activated microglia, play a key role in the progression of conditions such as mild cognitive impairment associated with Alzheimer’s disease. Rubus occidentalis (R. occidentalis), a black-fruited raspberry native to North America, is reported to possess antimicrobial, antidiabetic, and anticancer properties. This study investigated the neuroprotective and anti-neuroinflammatory effects of a 100% ethanol extract from premature R. occidentalis fruits (ROE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and a scopolamine-induced amnesic mouse model. Methods: C57BL/6N mice were orally administered ROE (100 or 200 mg/kg/b.w.) and donepezil (DNZ, 5 mg/kg) for 9 days and intraperitoneally injected with scopolamine (2 mg/kg/b.w.) for two days. Spatial learning and cognitive function were assessed using the Y-maze and Morris water maze tests. Protein and mRNA levels were examined both in vitro and in vivo through Western blotting and RT-PCR analysis. Results: In vitro, ROE improved cell viability and reduced nitric oxide overproduction in LPS-stimulated BV-2 cells, attenuated LPS-induced phosphorylation and degradation of IκB-α (thereby limiting NF-κB p65 nuclear translocation), and suppressed phosphorylation of MAPK signaling components. In vivo, ROE administration enhanced spatial learning and memory in scopolamine-treated C57BL/6N mice, increased hippocampal levels of brain-derived neurotrophic factor (BDNF) and phosphorylated CREB, and reduced the expression of iNOS and COX-2. Conclusions: Collectively, these results suggest that ROE possesses neuroprotective properties mediated by inhibition of NF-κB and MAPK signaling, promotion of CREB/BDNF pathways, and amelioration of neuroinflammation and cognitive deficits. Thus, ROE may represent a promising therapeutic candidate for neuroinflammatory disorders.