Protective effects of paeonol against cognitive impairment in lung diseases.

Pulmonary inflammation may lead to neuroinflammation resulting in neurological dysfunction, and it is associated with a variety of acute and chronic lung diseases. Paeonol is a herbal phenolic compound with anti-inflammatory and anti-oxidative properties. The aim of this study is to understand the beneficial effects of paeonol on cognitive impairment, pulmonary inflammation and its underlying mechanisms. Pulmonary inflammation-associated cognitive deficit was observed in TNFα-stimulated mice, and paeonol mitigated the cognitive impairment by reducing the expressions of interleukin (IL)-1ß, IL-6, and NOD-like receptor family pyrin domain-containing 3 (NLRP3) in hippocampus. Moreover, elevated plasma miR-34c-5p in lung-inflamed mice was also reduced by paeonol. Pulmonary inflammation induced by intratracheal instillation of TNFα in mice resulted in immune cells infiltration in bronchoalveolar lavage fluid, pulmonary edema, and acute fibrosis, and these inflammatory responses were alleviated by paeonol orally. In MH-S alveolar macrophages, tumor necrosis factor (TNF) α- and phorbol myristate acetate (PMA)-induced inflammasome activation was ameliorated by paeonol. In addition, the expressions of antioxidants were elevated by paeonol, and reactive oxygen species production was reduced. In this study, paeonol demonstrates protective effects against cognitive deficits and pulmonary inflammation by exerting anti-inflammatory and anti-oxidative properties, suggesting a powerful benefit as a potential therapeutic agent.

Fisetin inhibits cell migration via inducing HO-1 and reducing MMPs expression in breast cancer cell lines.

Metastasis is commonly seen in advanced stage of cancers, and matrix metalloproteinases (MMPs) are commonly up-regulated and have been identified as critical regulators. In this present study, a flavonoid, fisetin, which can be found in diverse foods, is investigated for its ability to inhibit cell motility, and the underlying mechanism is also studied in breast cancer cells (4T1 and JC cells). We have revealed that fisetin increased HO-1 mRNA and protein expressions. Besides, fisetin also elevated Nrf2 expression in nuclear fraction. By silencing Nrf2, fisetin-induced HO-1 expression was abrogated, suggested that HO-1 expression was mediated by up-regulation of the transcription factor Nrf2. In addition, we also found that fisetin decreased MMP-2 and MMP-9 enzyme activity and gene expression in both protein and mRNA levels. Moreover, by administration of HO-1 inhibitors, tin protoporphyrin and zinc protoporphyrin, fisetin-reduced MMP-2 and MMP-9 expressions were reversed. Furthermore, transfection of siRNA against HO-1 and Nrf2 also abolished MMP-2 and MMP-9 reduction exerted by fisetin. These findings suggest that fisetin-mediated MMP-2 and MMP-9 reduction is regulated by HO-1 through Nrf2. Therefore, fisetin may be useful as a potential therapeutic agent for the treatment of metastatic breast cancer.

Inhibition of estrogen receptor reduces connexin 43 expression in breast cancers.

Connexins are widely supported as tumor suppressors due to their downregulation in cancers, nevertheless, more recent evidence suggests roles for connexins in facilitating tumor progression in later stages, including metastasis. One of the key factors regulating the expression, modification, stability, and localization of connexins is hormone receptors in hormone-dependent cancers. It is reasonable to consider that hormones/hormone receptors may modulate connexins expression and play critical roles in the cellular control of connexins during breast cancer progression. In estrogen receptor (ER)-positive breast cancers, tamoxifen and fulvestrant are widely used therapeutic agents and are considered to alter ER signaling. In this present study, we investigated the effects of fulvestrant and tamoxifen in Cx43 expression, and we also explored the role of Cx43 in ER-positive breast cancer migration and the relationship between Cx43 and ER. The involvement of estrogen/ER in Cx43 modulation was further verified by administering tyrosine kinase inhibitors and chemotherapeutic agents. We found that inhibition of ER promoted the binding of E3 ligase Nedd4 to Cx43, leading to Cx43 ubiquitination. Furthermore, inhibition of ER by fulvestrant and tamoxifen phosphorylated p38 MAPK, and inhibition of Rac, MKK3/6, and p38 reversed fulvestrant-reduced Cx43 expression. These findings suggest that Cx43 expression which may positively regulate cell migration is ER-dependent in ER-positive breast cancer cells.