Nitidine chloride induces caspase 3/GSDME-dependent pyroptosis by inhibting PI3K/Akt pathway in lung cancer.

BACKGROUND: As the increasing mortality and incidence of lung cancer (LC), there is an urgent need to discover novel treatment agent. In this study, we aimed to investigate the anti-LC effects of nitidine chloride (NC), a small molecular compound extracted from Chinese herbal medicine, while detailing its underlying mechanisms. METHODS: Cell viability was detected by MTT assays and five cell death inhibitors, including ferrostatin-1 (Fer-1), Z-VAD-FMK, necrostatin-1 (Nec-1), disulfiram (DSF) and IM-54 were used to explore the type of cell death induced by NC. The microscopic features of NC-induced pyroptosis were assessed by transmission electron microscopy (TEM) and the pyroptotic-related proteins such as caspase and gasdermin family, were examined by western blot. Network pharmacology was employed to predict the potential mechanisms of NC in lung cancer treatment. CETSA and DARTs were used to determine the activity of NC binding to targeted protein. Xenograft mice model was established to further investigate the inhibitory effect and mechanism of NC against LC. RESULTS: The pyroptosis inhibitor (DSF) and apoptosis inhibitor (Z-VAD-FMK) but not IM-54, necrostatin-1, or Ferrostatin-1 rescued NC-induced cell death. Morphologically, H1688 and A549 cells treated with NC showed notably pyroptotic features, such as cell swelling and large bubbles emerging from the plasma membrane. Gasdermin E (GSDME) rather than GSDMC or GSDMD was cleaved in NC-treated H1688 and A549 cells with an increased cleavage of caspase 3. Combined with network pharmacology and molecule docking, PI3K/Akt signaling axis was predicted and was further verified by CETSA and DARTs assay. In addition, the activation of PI3K is able to rescue the pyroptosis induced by NC in vitro. In xenograft model of LC, NC significantly hindered the transduction of PI3K-AKT pathway, inducing pyroptosis of tumor. CONCLUSION: Our data indicated that NC is a potential therapeutic agent for the treatment of LC via triggering GSDME-dependent pyroptosis.

Zinc supplementation alleviates diabetic peripheral neuropathy by inhibiting oxidative stress and upregulating metallothionein in peripheral nerves of diabetic rats.

We investigated the effect of zinc supplementation on the expression of metallothionein, lipid peroxidation (malondialdehyde, MDA), and poly(ADP-ribose) polymerase-1 (PARP-1) in the sciatic nerve, motor nerve conduction velocity of the left sciatic posterior tibial nerve in streptozotocin (STZ)-induced diabetic rats. Twenty-four male rats were equally divided into four groups. The first group served as untreated controls although the second group received 5 mg/kg/day zinc chloride. The third group was treated with STZ to induce diabetes, and the fourth group was treated with STZ and supplemented with zinc. A gradual but insignificant decline in motor nerve conduction velocity was observed at 2 weeks of induction of diabetes. Zinc supplementation markedly attenuated the decrease in motor nerve conduction velocity at week 8 post-induction of diabetes. Furthermore, the tactile response threshold of diabetic rats receiving normal saline was lower than that of diabetic rats receiving zinc supplementation. Additionally, zinc supplementation accentuated the increase in the mRNA transcript levels of metallothionein but attenuated the increase in the mRNA transcript levels of PARP-1. At week 8 post-induction of diabetes, diabetic rats receiving normal saline had markedly higher MDA contents than diabetic rats receiving zinc supplementation. In conclusion, the present study shows that zinc has a protective effect against diabetes-induced peripheral nerve damage by stimulating metallothionein synthesis and downregulating oxidative stress.

[Effect of puerarin on ADMA-DDAH system in human umbilical vein endothelial cells cultured with oxidized free radical].

OBJECTIVE: To observe the effects of puerarin on activity of dimethylarginine dimethylaminohydrolase (DDAH) in human umbilical vein endothelial cells (HUVECs) cultured with oxidized free radical (OFR), to explore the effect of puerarin on metabolic mechanism of asymmetric dimethylarginine (ADMA). METHODS: HUVECs of the 3rd - 6th passage cultured with modified Jaffe's method were divided into 4 groups, the blank control group cultured with DMEM medium, the OFR group cultured with DMEM medium containing 0.1 mmol of OFR per liter, the puerarin group 1 and 2 cultured with DMEM medium containing 0.1 mmol of OFR per liter as well as 0.5 mg/ml and 1.0 mg/ml of puerarin respectively. After being incubated for 24 h, activity of nitric oxide synthase (NOS), contents of nitric oxide (NO), ADMA, endothelin (ET), and L-citrulline (L-cit) in the supernate were measured, and DDAH protein expression in the lysate was detected by Western blotting. RESULTS: Compared with those in the blank control group, ADMA and ET contents were higher, while the levels of NO and L-cit and the activity of NOS were lower markedly, but the DDAH expression changed insignificantly in the OFR group. These abnormalities were restored significantly in the puerarin groups. CONCLUSION: The increase of ADMA in OFR injured HUVECs was correlated with the reduction of DDAH activity and irrelevant to DDAH expression. Puerarin could promote ADMA metabolism through increasing DDAH activity, and improve NOS activity, thus to reduce the impairing of OFR on endothelial function.