Ruscogenin attenuates particulate matter-induced acute lung injury in mice via protecting pulmonary endothelial barrier and inhibiting TLR4 signaling pathway.

The inhalation of particulate matter (PM) is closely related to respiratory damage, including acute lung injury (ALI), characterized by inflammatory fluid edema and disturbed alveolar-capillary permeability. Ruscogenin (RUS), the main active ingredient in the traditional Chinese medicine Ophiopogonis japonicus, has been found to exhibit anti-inflammatory activity and rescue LPS-induced ALI. In this study, we investigated whether and how RUS exerted therapeutic effects on PM-induced ALI. RUS (0.1, 0.3, 1 mg·kg-1·d-1) was orally administered to mice prior to or after intratracheal instillation of PM suspension (50 mg/kg). We showed that RUS administration either prior to or after PM challenge significantly attenuated PM-induced pathological injury, lung edema, vascular leakage and VE-cadherin expression in lung tissue. RUS administration significantly decreased the levels of cytokines IL-6 and IL-1ß, as well as the levels of NO and MPO in both bronchoalveolar lavage fluid (BALF) and serum. RUS administration dose-dependently suppressed the phosphorylation of NF-κB p65 and the expression of TLR4 and MyD88 in lung tissue. Furthermore, TLR4 knockout partly diminished PM-induced lung injury, and abolished the protective effects of RUS in PM-instilled mice. In conclusion, RUS effectively alleviates PM-induced ALI probably by inhibition of vascular leakage and TLR4/MyD88 signaling. TLR4 might be crucial for PM to initiate pulmonary lesion and for RUS to exert efficacy against PM-induced lung injury.

Advances in the antitumor activities and mechanisms of action of steroidal saponins.

The steroidal saponins are one of the saponin types that exist in an unbound state and have various pharmacological activities, such as anticancer, anti-inflammatory, antiviral, antibacterial and nerves-calming properties. Cancer is a growing health problem worldwide. Significant progress has been made to understand the antitumor effects of steroidal saponins in recent years. According to reported findings, steroidal saponins exert various antitumor activities, such as inhibiting proliferation, inducing apoptosis and autophagy, and regulating the tumor microenvironment, through multiple related signaling pathways. This article focuses on the advances in domestic and foreign studies on the antitumor activity and mechanism of actions of steroidal saponins in the last five years to provide a scientific basis and research ideas for further development and clinical application of steroidal saponins.