Background: Lung fibrosis is characterized by fibroblast proliferation and the deposition of collagens. Curcumin, a polyphenol antioxidant from the spice tumeric, has been shown to effectively counteract fibroblast proliferation and reducing inflammation and fibrotic progression in animal models of bleomycin-induced lung injury. However, there is little mechanistic insight in the biological activity of curcumin. Here, we study the effects of curcumin on the expression and activity of cathepsins which have been implicated in the development of fibrotic lung diseases. Methods: We investigated the effects of curcumin administration to bleomycin stimulated C57BL/6 mice and human fetal lung fibroblasts (HFL-1) on the expression of cathepsins K and L which have been implicated in matrix degradation, TGF-β1 modulation, and apoptosis. Lung tissues were evaluated for their contents of cathepsins K and L, collagen, and TGF-β1. HFL-1 cells were used to investigate the effects of curcumin and cathepsin inhibition on cell proliferation, migration, apoptosis, and the expression of cathepsins K and L and TGF-β1. Results: Collagen deposition in lungs was decreased by 17-28% after curcumin treatment which was accompanied by increased expression levels of cathepsins L (25%-39%) and K (41%-76%) and a 30% decrease in TGF-β1 expression. Moreover, Tunel staining of lung tissue revealed a 33-41% increase in apoptotic cells after curcumin treatment. These in vivo data correlated well with data obtained from the human fibroblast line, HFL-1. Here, cathepsin K and L expression increased 190% and 240%, respectively, in the presence of curcumin and the expression of TGF-β1 decreased by 34%. Furthermore, curcumin significantly decreased cell proliferation and migration and increased the expression of surrogate markers of apoptosis. In contrast, these curcumin effects were partly reversed by a potent cathepsin inhibitor. Conclusion: This study demonstrates that curcumin increases the expression of cathepsins K and L in lung which an effect on lung fibroblast cell behavior such as proliferation, migration and apoptosis rates and on the expression of TGF-β1 in mouse lung and HFL-1 cells. These results suggest that cathepsin-inducing drugs such as curcumin may be beneficial in the treatment of lung fibrosis.

The global rise in aging populations has made healthy longevity a critical priority in medical research. 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG), the primary bioactive component of Polygonum multiflorum Thunb. (commonly known as Fallopia multiflora Thunb., He shou wu, Fo-ti, or Polygoni multiflori radix), has emerged as a promising agent for combating aging and age-related diseases. This systematic review evaluates the anti-aging properties of TSG and its protective effects against age-related pathologies. The current evidence demonstrates that TSG exhibits comprehensive anti-aging effects, including lifespan extension, neuroprotection (e.g., ameliorating Alzheimer’s and Parkinson’s diseases), cardiovascular protection (e.g., reducing atherosclerosis and hypertension), delay of gonadal aging, reduction in bone loss (e.g., mitigating osteoporosis), and promotion of hair regrowth. Mechanistically, TSG alleviates oxidative stress, inflammation, and apoptosis while enhancing mitophagy, mitochondrial function telomerase activity, and epigenetic regulation. These multi-target actions align with the holistic principles of traditional Chinese medicine, highlighting TSG’s potential as a multifaceted anti-aging agent. However, further research is required to establish standardized quantitative systems for evaluating TSG’s efficacy, paving the way for its broader clinical application in promoting healthy aging.

Rheumatoid arthritis (RA) is a chronic autoimmunity illness, mainly featured with synovitis of the joint. The specificity of ferroptosis is disparate in different diseases, and the mechanism of ferroptosis in RA has some uncertainty yet. Therefore, the mechanism of ferroptosis was deeply observed in RA patients and animal models. In this paper, plasma of RA patients, the tumor necrosis factor‐alpha‐induced human synovial fibroblasts, and an animal model of arthritis induced by collagen were applied to initially inquire about the therapeutic effect of ferroptosis. For the RA patients, ELISA detected protein expression of glutathione (GSH), GPX4, Nrf2, Keap‐1, and ferritin. In cell experiments, erastin or fer‐1 regulated the invasion of human synovial fibroblast cells, mitochondrial membrane potential, reactive oxygen species (ROS) expression, marker protein, and so on. For the animal experiments, 32 Sprague–Dawley male rats were randomly separated into four groups with a collagen‐induced RA model for 14 days and administered with erastin or fer‐1 for 35 days. The expressions of GSH, GPX4, Nrf2, and Keap‐1 were lower, and the ferritin was higher in RA patients, and the expressions of these proteins varied significantly after disease remission. In addition, ferroptosis inactivation also reduced the proliferation and migration ability, mitochondrial membrane potential, and ROS in cells. We discovered unexpectedly that activation of ferroptosis meaningfully forbore the foot swelling in animals with CIA, reduced arthritis scores, destruction of bone, and articular synovitis, and also decreased the high expression of inflammatory factors in plasma. There is a nonlinear relationship between human disease manifestations and animal model pathology. Ferroptosis regulating in RA for humans or animals may produce different effects.