Osteoarthritis (OA) is a degenerative joint disorder characterized by progressive articular cartilage degradation, leading to pain, stiffness, and impaired mobility. This study investigated the anti-osteoarthritic effects of Lindera obtusiloba (LO) leaf extract in primary cultured chondrocytes and a mouse model of destabilization of the medial meniscus (DMM)-induced OA. Mouse primary chondrocytes were treated with IL-1β and various concentrations of LO leaf extract (50–150 μg/mL), and analyzed by RT-PCR, Western blotting, and ELISA. For the in vivo experiments, male C57BL/6 mice underwent DMM surgery and were administered LO leaf extract (50–200 mg/kg/day) for eight weeks, followed by micro-CT, histological, and immunohistochemical analyses. LO leaf extract exhibited no cytotoxicity in chondrocytes. In interleukin-1β-induced inflammatory chondrocytes, LO leaf extract significantly suppressed the expression of OA-associated catabolic factors, including cyclooxygenase-2 (Cox-2), matrix metalloproteinases (MMP3 and MMP13), and phosphorylated nuclear factor-kappa B (NF-κB). It also reduced the production of destructive mediators, such as prostaglandin E₂ (PGE₂) and collagenase, in a dose-dependent manner. In vivo, LO leaf extract-treated mice demonstrated significant reductions in articular cartilage degradation, subchondral bone sclerosis, and the expression of catabolic and inflammatory mediators. Additionally, LO leaf extract administration significantly decreased systemic pro-inflammatory cytokine levels in DMM-induced mice. Collectively, these findings indicate that LO leaf extract attenuates OA progression by suppressing both local and systemic inflammatory responses, supporting its potential as a natural therapeutic agent for the prevention and treatment of OA.

Preventing or reversing Tau hyperphosphorylation and aggregation represent critical objectives in the development of effective therapies for Alzheimer’s disease. The present study investigated the potential of a novel Aronia bioactive fraction—alginic acid nanocomplex (AANCP)—to simultaneously inhibit pathological features of Alzheimer’s disease. Evaluations of Aronia bioactive fraction (ABF) and low-molecular-weight alginic acid (LAA), utilized both individually and as AANCP, were conducted in HEK293-TauP301L and SH-SY5Y-TauP301L cell models of Alzheimer’s disease. Both ABF and LAA reduced the expression of total Tau and Tau phosphorylated at Ser396 in a concentration-dependent manner, with AANCP demonstrating significant synergistic activity of its components. Notably, the optimal AANCP ratio was 1:1 and 1:8 for inhibiting Tau phosphorylation and Tau aggregation, respectively. Mechanistically, AANCP inhibited Tau phosphorylation by upregulating p-Akt (phosphorylated protein kinase B) and p-GSK-3β (phosphorylated glycogen synthase kinase-3 beta), while also enhancing the activity of methylated PP2A, a key Tau phosphatase. Furthermore, AANCP exhibited superior efficacy in inhibiting heparin-induced Tau aggregation compared to the individual components. Analysis of autophagy markers indicated that the nanocomplex enhanced Tau clearance, as shown by increased LC3-II and Beclin-1 levels and reduced p62 levels. These results suggest AANCP as a promising therapeutic candidate that simultaneously reduces Tau phosphorylation and aggregation and facilitates autophagic Tau clearance, offering a potent, synergistic strategy for treating Alzheimer’s disease.

Mild cognitive impairment (MCI) represents an intermediate stage between normal aging and Alzheimer’s disease. This study investigated the neuroprotective effects of a combined extract of Mentha piperita (MP) and Cornus officinalis (CO) (MC) using in vitro and in vivo models. In SK-N-SH cells, pretreatment with MC (50–150 μg/mL) significantly attenuated H₂O₂-induced cellular injury, as evidenced by a reduction in Annexin V-positive cells and an increase in brain-derived neurotrophic factor (BDNF) mRNA expression. Rosmarinic acid and loganin, the marker compounds of MP and CO, alone or combined at a 6:4 ratio, mitigated H₂O₂-induced decreases in cell viability and BDNF mRNA. In the in vivo study, male Sprague–Dawley rats were orally administered MC (50, 100, or 200 mg/kg/day) for 28 days, with phosphatidylserine (50 mg/kg/day) serving as a positive control. MC administration significantly improved cognitive performance in rats with scopolamine-induced memory impairment, as demonstrated by increased step-through latency in the passive avoidance test and reduced escape latency in the Morris water maze. Furthermore, in the probe trial, MC-treated rats spent significantly more time in the target quadrant, indicating enhanced spatial memory retention. Mechanistically, MC restored hippocampal acetylcholine levels and reversed the scopolamine-induced decrease in BDNF and its downstream signaling. Specifically, MC upregulated hippocampal BDNF expression and enhanced the phosphorylation of extracellular signal-regulated kinase (ERK), protein kinase B (AKT), and cAMP response element-binding protein (CREB). In conclusion, these results demonstrate that the MC extract possesses potent neuroprotective and learning- and memory-enhancing effects, highlighting its potential as a therapeutic candidate for managing age-related cognitive decline and MCI.