Cellular stress response in Eca-109 cells inhibits apoptosis during early exposure to isorhamnetin

Research progress of Paris polyphylla in the treatment of digestive tract cancers

Cancer has become one of the most important causes of human death. In particular, the 5 year survival rate of patients with digestive tract cancer is low. Although chemotherapy drugs have a certain efficacy, they are highly toxic and prone to chemotherapy resistance. With the advancement of antitumor research, many natural drugs have gradually entered basic clinical research. They have low toxicity, few adverse reactions, and play an important synergistic role in the combined targeted therapy of radiotherapy and chemotherapy. A large number of studies have shown that the active components of Paris polyphylla (PPA), a common natural medicinal plant, can play an antitumor role in a variety of digestive tract cancers. In this paper, the main components of PPA such as polyphyllin, C21 steroids, sterols, and flavonoids, amongst others, are introduced, and the mechanisms of action and research progress of PPA and its active components in the treatment of various digestive tract cancers are reviewed and summarized. The main components of PPA have been thoroughly explored to provide more detailed references and innovative ideas for the further development and utilization of similar natural antitumor drugs.

Isorhamnetin Induces Melanoma Cell Apoptosis via the PI3K/Akt and NF-κB Pathways

Malignant melanoma is characterized by its bad prognosis for aggressiveness, drug resistance, and early metastasis. Isorhamnetin (3′-methoxy-3,4′,5,7-tetrahydroxyflavone; IH) is a natural flavonoid that has been investigated for its antitumor effects in breast cancer, colon cancer, and gastric cancer through inducing cell apoptosis. Given its role in tumor inhibition, no research has been conducted concerning its effect against melanoma. In the present study, we found that IH could significantly inhibit B16F10 cell proliferation and migration and induce B16F10 cell apoptosis. The examination on molecular mechanism revealed that IH could suppress the phosphorylation of Akt and the translocation of NF-κB, which are key factors in apoptosis-related pathways. We also detected that this process was related to the bifunctional 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases 4 (PFKFB4) by PFKFB4 knockdown experiment. In line with in vitro study, we further provided that IH effectively inhibited tumor growth in vivo. Taken together, IH was proven to induce melanoma cell apoptosis in vitro and in vivo, which may serve as a potential agent in malignant melanoma treatment in the future.

Protective Effects of Isorhamnetin on Cardiomyocytes Against Anoxia/Reoxygenation-induced Injury Is Mediated by SIRT1

It has been reported that apoptosis plays a very important role on anoxia/reoxygenation (A/R)-induced injury, and human silent information regulator type 1 (SIRT1) can inhibit the apoptosis of cardiomyocytes. It has been proved that isorhamnetin (IsoRN), 3'-O-methyl-quecetin, can protect the cardiomyocytes, but the mechanism is still not clear. The aim of the study was to explore whether the protective effects of IsoRN on the cardiomyocytes against the A/R-induced injury are mediated by SIRT1. The effects of IsoRN on cardioprotection against A/R injury in neonatal rat cardiomyocytes were monitored by cell viability, the levels of mitochondrial membrane potential (Δψm), apoptosis, and intracellular reactive oxygen species (ROS), the levels of lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and mitochondrial permeability transition pores (mPTP). The effects on protein expression were measured by western blot assay. The results showed that IsoRN can reduce A/R-induced injury by decreasing the level of lactate dehydrogenase and creatine phosphokinase release from the cardiomyocytes, increasing cell viability and expression of SIRT1, reducing the generation of reactive oxygen species, inhibiting opening of mitochondrial permeability transition pores and loss of Δψm and activation of caspase-3, and decreasing the release of cytochrome c, and reducing apoptosis. In addition, sirtinol, a SIRT1 inhibitor, drastically reduced the protective effects of IsoRN on cardioprotective effects in cardiomocytes. In conclusion, we firstly demonstrated that SIRT1 may be involved in the protective effects of IsoRN on cardiomocytes against the A/R-induced injury.

Isorhamnetin inhibits cell proliferation and induces apoptosis in breast cancer via Akt and mitogen‑activated protein kinase kinase signaling pathways

Breast cancer is the most common cause of female cancer-associated mortality. Although treatment options, including chemotherapy, radiotherapy and surgery have led to a decline in the mortality rates associated with breast cancer, drug resistance remains one of the predominant causes for poor prognosis and high recurrence rates. The present study investigated the potential effects of the natural product, isorhamnetin on breast cancer, and examined the effects of isorhamnetin on the Akt/mammalian target of rapamycin (mTOR) and the mitogen-activated protein kinase (MAPK)/MAPK kinase (MEK) signaling cascades, which are two important signaling pathways for endocrine therapy resistance in breast cancer. The results of the present study indicate that isorhamnetin inhibits cell proliferation and induces cell apoptosis. In addition, isorhamnetin was observed to inhibit the Akt/mTOR and the MEK/extracellular signal-regulated kinase phosphorylation cascades. The inhibition of these two signaling pathways was attenuated by the two Akt and MEK1 inhibitors, but not by the nuclear factor-κB inhibitor. Furthermore, epidermal growth factor inhibited the effects of isorhamnetin via activation of the Akt and MEK signaling pathways. These results indicate that isorhamnetin exhibits antitumor effects in breast cancer, which are mediated by the Akt and MEK signaling pathways.

Pharmacological Activities of Sijunzi Decoction Which Are Related to Its Antioxidant Properties

This paper introduces the antioxidant constituents and pharmacological effects of Sijunzi decoction by looking up literatures in recent years. Sijunzi decoction is composed of Ginseng, Atractylodes, Tuckahoe, and Glycyrrhiza. The antioxidant ingredients of Sijunzi decoction include paeonol, dauricine, naringin, and isoliquiritigenin. The study has proved that it possesses wide pharmacological effects of anticardiovascular diseases, antinervous system disease, antidiabetes, antimetabolic syndrome, and antitumor. Research on the antioxidant components of Sijunzi decoction and their targets is a promising study area in the future.