Anti-fibrotic effect of pycnogenol® in a polyhexamethylene guanidine-treated mouse model

Chitosan Nanoparticle-Encapsulated Cordyceps militaris Grown on Germinated Rhynchosia nulubilis Reduces Type II Alveolar Epithelial Cell Apoptosis in PM2.5-Induced Lung Injury

Chitosan nanoparticles (CNPs) were synthesized in this study to enhance the limited bioactivity and stability of Cordyceps militaris grown on germinated Rhynchosia nulubilis (GRC) and effectively deliver it to target tissues. Under optimized conditions, stable encapsulation of GRC was achieved by setting the chitosan (CHI)-to-tripolyphosphate (TPP) ratio to 4:1 and adjusting the pH of TPP to 2, resulting in a zeta potential of +22.77 mV, which indicated excellent stability. As the concentration of GRC increased, the encapsulation efficiency decreased, whereas the loading efficiency increased. Fourier-transform infrared (FT-IR) spectroscopy revealed shifts in the amide I and II bands of CHI from 1659 and 1578 to 1639 cm⁻1, indicating hydrogen bonding and successful encapsulation of GRC encapsulated with CNPs (GCN). X-ray diffraction (XRD) examination revealed the transition of the nanoparticles from a crystalline to an amorphous state, further confirming successful encapsulation. In vivo experiments demonstrated that GCN treatment significantly reduced lung injury scores in fine particulate matter (PM2.5)-exposed mice (p < 0.05) and alleviated lung epithelial barrier damage by restoring the decreased expression of occludin protein (p < 0.05). In addition, GCN decreased the PM2.5-induced upregulation of MMP-9 and COL1A1 mRNA expression levels, preventing extracellular matrix (ECM) degradation and collagen accumulation (p < 0.05). GCN exhibited antioxidant effects by reducing the mRNA expression of nitric oxide synthase (iNOS) and enhancing both the protein and mRNA expression of superoxide dismutase (SOD-1) caused by PM2.5, thereby alleviating oxidative stress (p < 0.05). In A549 cells, GCN significantly reduced PM2.5-induced reactive oxygen species (ROS) production compared with GRC (p < 0.05), with enhanced intracellular uptake confirmed using fluorescence microscopy (p < 0.05). In conclusion, GCN effectively alleviated PM2.5-induced lung damage by attenuating oxidative stress, suppressing apoptosis, and preserving the lung epithelial barrier integrity. These results emphasize its potential as a therapeutic candidate for preventing and treating the lung diseases associated with PM2.5 exposure.

Repeated intratracheal instillation effects of commonly used vehicles in toxicity studies with mice

Intratracheal instillation (ITI) is considered the most pragmatic approach for investigating the potential toxicities of various respiratory exposure materials. Various respiratory exposure materials, including nanomaterials, hazardous air pollutants, fine dust, and household biocides, have raised public health concerns because of limited toxicological information and increasing consumption. Hence, toxicity studies using ITI in laboratory animals are important to accurately assess the human risks associated with these respiratory-exposed materials. However, data to adequately support the study design of ITI toxicity studies, particularly those examining the effects of commonly used vehicles following repeated exposure are insufficient. Therefore, in this study, we examined the effects of 16 types of commonly used vehicles in toxicity studies following 14-day repeated ITI in mice. General health endpoints (mortality, clinical signs, and body weight) were monitored throughout the study period, and terminal endpoints (gross observation, lung weight, bronchoalveolar lavage fluid analysis, and lung histopathological examination) were assessed after terminal sacrifice. Saline and phosphate-buffered saline elicited the least response, whereas corn oil (50 µL) showed the most severe toxicity findings. In addition, several commonly used vehicles, including distilled water, sodium carboxymethyl cellulose, dimethyl sulfoxide, ethanol, Tween 20, and Tween 80, induced mild-to-severe toxicity in the respiratory system. Based on the results of this study, some commonly used vehicles in toxicity studies should be used with caution when the ITI exposure route is considered. These results provide important background information on the effects of vehicles in ITI toxicity studies along with valuable insights for designing toxicity studies using respiratory exposure materials.

The effects of Pycnogenol, a pine bark extract on pulmonary inflammation by Asian sand dust in mice

Asian sand dust (ASD), also called China dust or yellow dust, mainly occurs in East Asia during spring and autumn. Because ASD enters the body mainly through the respiratory system, it can cause respiratory disorders or worsen underlying diseases. Because of this, it has become an important health concern that threatens the well-being of humans and animals. In this study, we investigated the effects of 15 and 30 mg/kg of Pycnogenol (PYC15 and 30 groups), a pine bark extract, on ASD-induced pulmonary inflammation in mice. We evaluated the inflammatory cell counts, inflammatory cytokines, and matrix-metalloproteinase (MMP)-9 expression in animal models. PYC administration significantly decreased inflammatory cell infiltration into lung tissue; this was accompanied by a reduction in the levels of proinflammatory mediators including interleukin (IL)-1β (P < 0.01), IL-6 (P < 0.01) and tumour necrosis factor-α (P < 0.01) in bronchoalveolar lavage fluids of ASD-exposed mice (ASD group). Histological analysis revealed that PYC suppressed ASD-induced pulmonary inflammation. Moreover, PYC suppressed the levels of matrix-metalloproteinase (MMP)-9 in the lung tissue of ASD-exposed mice, indicating that PYC reduced ASD-induced pulmonary inflammation by suppressing MMP-9. Together, these results indicate that PYC as the potential to treat ASD-driven pulmonary inflammation.

Protective Effect of Pycnogenol against Methotrexate-Induced Hepatic, Renal, and Cardiac Toxicity: An In Vivo Study

Methotrexate (MTX) is one of the most commonly used chemotherapies for various types of cancer, including leukemia, breast cancer, hepatocarcinoma, and gastric cancers. However, the efficacy of MTX is frequently limited by serious side effects. Several studies have reported that the cytotoxic effect of MTX is not limited to cancer cells but can also affect normal tissues, leading to prospective damage to many organs. In the present study, we extensively investigated the molecular and microscopic basis of MTX-induced toxicity in different organs (liver, kidney, and heart) and explored the possible protective effect of pycnogenol, a polyphenolic component extracted from the bark of P. pinaster, to attenuate these effects. Biochemical analysis revealed that administration of MTX significantly reduced the function of the liver, kidney, and heart. Histological and immunohistochemical analysis indicated that MTX treatment caused damage to tissues of different organs. Interestingly, administration of pycnogenol (10, 20, and 30 mg/kg) significantly attenuated the deterioration effects of MTX on different organs in a dose-dependent manner, as demonstrated by biochemical and histological analysis. Our results reveal that pycnogenol successfully ameliorated oxidative damage and reduced toxicity, inflammatory response, and histological markers induced by methotrexate treatment. Taken together, this study provides solid evidence for the pharmacological application of pycnogenol to attenuate damage to different organs induced by MTX treatment.