Introduction Prolonged exposure to air polluted with airborne fine particulate matter (PM2.5) can increase respiratory disease risk. Astragaloside IV (AS-IV) is one of the main bioactive substances in the traditional Chinese medicinal herb, Astragalus membranaceus Bunge. AS-IV has numerous pharmacological properties; whereas there are few reports on the prevention of PM2.5-induced lung injury by AS-IV through modulation of the autophagic pathway. This study aimed to investigate the protective effects and the underlying mechanisms of AS-IV in PM2.5-induced lung injury rats and rat alveolar macrophages (NR8383 cells). Methods The pneumotoxicity model was established by intratracheal injection of PM2.5 in rats, and PM2.5 challenge in NR8383 cells. The severity of lung injury was evaluated by wet weight to dry weight ratio and McGuigan pathology scoring. Inflammatory factors and oxidative stress were detected through ELISA. The expressions of p-PI3K, p-Akt, and p-mTOR proteins were analyzed by immunohistochemistry. Immunofluorescence and transmission electron microscopy were used to detect autophagosomes. The expressions of autophagy marker protein (LC3B and p62), PI3K/Akt/mTOR signaling and NF-κB translocation were detected by Western blot in lung tissue and NR8383 cells. Results After PM2.5 stimulation, rats showed severe inflammation and oxidative stress, along with inhibition of autophagy in lung tissue. AS-IV not only decreased pulmonary inflammation and oxidative stress by inhibiting nuclear factor kappa B translocation, but also regulated autophagy by inhibiting PI3K/Akt/mTOR signaling. After treatment with 3-methyladenine (a classic PI3K inhibitor, blocking the formation of autophagosomes), the protective effect of AS-IV on PM2.5-induced lung injury was further strengthened. In parallel, using Western blot, immunohistochemistry, and transmission electron microscopy, we demonstrated that AS-IV restore autophagic flux mainly through regulating the degradation of autophagosomes rather than suppressing the formation in vivo and in vitro. Conclusion Our data indicated that AS-IV protects from PM2.5-induced lung injury in vivo and in vitro by inhibiting the PI3K/Akt/mTOR pathway to regulate autophagy and inflammation.

Gastrointestinal symptoms and liver injury are common in patients with coronavirus disease 2019 (COVID‐19). However, profiles of different pharmaceutical interventions used are relatively underexplored. Chinese herbal medicine (CHM) has been increasingly used for patients with COVID‐19, but the efficacy of CHM used in COVID‐19 on gastrointestinal symptoms and liver functions has not been well studied with definitive results based on the updated studies. The present study aimed at testing the efficacy of CHM on digestive symptoms and liver function (primary outcomes), the aggravation of COVID‐19, and the time to viral assay conversion (secondary outcomes), among patients with COVID‐19, compared with standard pharmacotherapy. The literature search was undertaken in 11 electronic databases from December 1, 2019 up to November 8, 2020. Appraisal of the evidence was conducted with Cochrane risk of bias tool or Newcastle Ottawa Scale. A random‐effects model or subgroup analysis was conducted when significant heterogeneity was identified in the meta‐analysis. The certainty of the evidence was assessed with the grading of recommendations assessment, development, and evaluation approach. Forty‐eight included trials involving 4,704 participants were included. Meta‐analyses favored CHM plus standard pharmacotherapy for COVID‐19 on reducing the aggravation of COVID‐19 and the time to viral assay conversion compared with standard pharmacotherapy. However, the present CHM as a complementary therapy for treating COVID‐19 may not be beneficial for improving most gastrointestinal symptoms and liver function based on the current evidence. More well‐conducted trials are warranted to confirm the potential efficacy of CHM furtherly.

BackgroundCellular immune responses including lymphocyte functions and immune effector cells are critical for the control of coronavirus infection. Chinese herbal medicine (CHM) potentially has a therapeutic effect for treatment of coronavirus disease 2019 (COVID-19). Nevertheless, there are limited clinical practice suggestions on immunogenicity of the CHM against SARS-CoV-2. To assess the effect of oral CHM on immunogenicity and whether oral CHM improves the clinical parameters through the immunity profile during COVID-19, we performed the present study.MethodsFor this systematic review and meta-analysis, 11 databases were searched for relevant studies assessing oral CHM for COVID-19 on November 20, 2020 (updated March 9, 2021). Primary outcomes mainly included immunity profiles. Secondary outcomes included all-cause mortality; the remission time of fever, cough, chest tightness, and fatigue. The random effect was used to estimate the heterogeneity of the studies. Summary relative risks, weight mean difference and standardized mean difference were measured with 95% confidence intervals. Modified Jadad scale and Newcastle-Ottawa Scale were used to assess the risk of bias of randomized controlled trials (RCTs) and observational studies, respectively. The certainty of evidence was evaluated using the GRADE approach.ResultsWe analyzed findings from 3,145 patients in 30 eligible studies. Compared with routine treatment, oral CHM, as an adjuvant medicine, improved lymphocyte counts, CD4+, and CD4+/CD8+ ratio with low quality of evidence; improved CD3+ with moderate quality of evidence; and reduced TNF-α with low certainty of evidence. Besides, oral CHM, as an adjuvant medicine reduced the time to clinical symptoms remission with a lower risk of all-cause mortality, compared with routine treatment alone.ConclusionCHM may be recommended as an adjuvant immunotherapy for disease modification and symptom relief in COVID-19 treatment. However, large RCTs objectively assessing the efficacy of CHM on immune responses in COVID-19 are needed to confirm our findings.

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