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Cervical cancer is the fourth leading cancer type and the second most common gynecological malignancy among women worldwide. Silibinin (SB), a chief bioactive natural polyphenolic flavonoid of Silybum marianum L., has been used clinically for its hepatocyte protective effects. It also has anticancer effects via the induction of apoptosis and cell cycle arrest. However, the effects of SB on cervical cancer cells through mitochondrial fission have not been studied. Here, we showed that SB markedly suppressed cervical cell proliferation by inducing G2/M cell cycle arrest via the activation of dynamin-related protein 1 (Drp1), which in turn mediated the mitochondrial fission dysfunction both in vitro and in vivo. SB decreased the ATP content, mitochondrial membrane potential, and mtDNA copy number, as well as reduced the reactive oxygen species levels in cervical cells. Furthermore, SB induced excessive mitochondrial fragmentation and reduced tubule formation. Further study showed that knockdown of Drp1 abolished the SB-induced G2/M cell cycle arrest in cervical cancer cells by inhibiting the mitochondrial fission pathway. More importantly, SB inhibited Hela cell growth in vivo model. In conclusion, we are the first to demonstrate that SB induces cervical cancer cell G2/M cell cycle arrest by activating Drp1-dependent mitochondrial fission dysfunction. This study suggests the strategy of inducing Drp1-dependent mitochondrial fission for cervical cancer prevention and treatment.

Background. Chinese herbal medicines are widely used to lower serum uric acid levels. However, no systemic review summarizes and evaluates their efficacies and the underlying mechanisms of action. Objectives. To evaluate the clinical and experimental evidences for the effectiveness and the potential mechanism of Chinese herbal medicines in lowering serum uric acid levels. Methods. Four electronic databases PubMed, Wed of Science, the Cochrane Library and Embase were used to search for Chinese herbal medicines for their effects in lowering serum uric acid levels, dated from 1 January 2009 to 19 August 2020. For clinical trials, randomized controlled trials (RCTs) were included; and for experimental studies, original articles were included. The methodological quality of RCTs was assessed according to the Cochrane criteria. For clinical trials, a meta-analysis of continuous variables was used to obtain pooled effects. For experimental studies, lists were used to summarize and integrate the mechanisms involved. Results. A total of 10 clinical trials and 184 experimental studies were included. Current data showed that Chinese herbal medicines have promising clinical efficacies in patients with elevated serum uric acid levels (SMD: −1.65, 95% CI: −3.09 to −0.22; p = 0.024). There was no significant difference in serum uric acid levels between Chinese herbal medicine treatments and Western medicine treatments (SMD: −0.13, 95% CI: −0.99 to 0.74; p = 0.772). Experimental studies revealed that the mechanistic signaling pathways involved in the serum uric acid lowering effects include uric acid synthesis, uric acid transport, inflammation, renal fibrosis and oxidative stress. Conclusions. The clinical studies indicate that Chinese herbal medicines lower serum uric acid levels. Further studies with sophisticated research design can further demonstrate the efficacy and safety of these Chinese herbal medicines in lowering serum uric acid levels and reveal a comprehensive picture of the underlying mechanisms of action.