Advances in Research of Pharmacological Effects of Peimine

Tong ZHANG, Yu ZHANG, Yannan LI, Hui XUE, Huiyi LIANG, Yinghua LUO, Chenghao JIN

College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, China

Abstract Peimine is an important effective component of the traditional Chinese medicine Fritillariae Thunbergii Bulbus. It not only has multiple pharmacological activities such as anti-inflammatory, antitussive, analgesic and anti-cerebral ischemia-reperfusion injury, but also can play anti-cancer effects by inhibiting the proliferation of cancer cells, inducing apoptosis of cancer cells, and inhibiting the metastasis and invasion of cancer cells. The present article summarizes and reviews the pharmacological activities and action mechanism of peimine in recent years.

Key words Peimine, Inflammatory response, Cell proliferation, Cell apoptosis

1 Introduction

Traditional Chinese medicine Fritillariae Thunbergii Bulbus is the dry bulb of the Liliaceae plantFritillariathunbergiiMiq., and it has the effects of clearing away heat, resolving phlegm and relieving cough, detoxification, dispersing abscesses and nodules[1]. Peimine mainly comes from Fritillariae Thunbergii Bulbus, Fritillariae Ussuriensis Bulbus, Fritillariae Hupehensis Bulbus, Fritillariae Taipaiensis Bulbus, and Fritillariae Cirrhosae Bulbus,etc.It is an effective ceveratrol base compound and its molecular formula is C27H45NO3[2-3]. In recent years, extensive studies have found that peimine has anti-inflammatory, antitussive, analgesic, anti-cerebral ischemia-reperfusion injury and anti-tumor pharmacological activities, which has attracted the attention of domestic and foreign scholars. In this paper, we summarized and reviewed the pharmacological activities and action mechanism of peimine.

2 Anti-tumor effect

2.1 Inhibiting the proliferation of breast cancer cellsThe proliferation of malignant tumors is closely related to the tumor microenvironment and has become a research hotspot in recent years. The proliferation of malignant tumors is closely associated with the tumor microenvironment and has become a research hotspot in recent years. Related studies indicate that peimine can effectively inhibit the proliferation of breast cancer cells and leukemia cells[4-9]. According to findings of Zhang Yurenetal.[4], peimine can effectively inhibit the proliferation of breast cancer 4T1 cells by interfering with 4T1 breast cancer cells and regulating its tumor inflammatory microenvironment and itsIC50value for 4T1 breast cancer cells at 48 h is 14.7 μmol/L. Chen Haiyanetal.[5]found that peimine can inhibit the proliferation of human breast cancer cells MCF-7/TAM in a concentration-dependent and time-dependent manner. Through the detection of the cell cycle, it was further found that peimine can block the MCF-7/TAM cell cycle in the G1 phase. In addition, at the molecular level, peimine can ultimately induce mitochondrial-dependent apoptosis in MCF-7/TAM cells by down-regulating the expression of the anti-apoptotic protein Bcl-2.

2.2 Inhibiting the proliferation of prostate cancer cellsCalcium (Ca2+) is an important intracellular messenger involved in various cellular processes. Tanetal.[10]found that peimine effectively inhibited the growth of prostate cancer PC-3 cells in a concentration-dependent manner, but had no obvious side effects on normal prostate cells. Their findings also show that peimine can promote Ca2+phosphorylation by regulating calmodulin-dependent protein kinase II (CaMKII) and c-Jun N-terminal kinase (JNK), further inhibiting the growth and invasion of PC-3 cells, and inducing their apoptosis. However, adding 1 μM Ca2+chelating agent BAPTA-AM can offset the increase of intracellular Ca2+concentration. Further experimental results in nude mice showed that peimine inhibited tumor formation through the Ca2+/CaMKII/JNK signaling pathway. In summary, peimine can destroy intracellular calcium homeostasis through the Ca2+/CaMKII/JNK pathway, thereby inhibiting the growth of prostate cancer cells and inducing their apoptosis.

2.3 Inhibiting the proliferation of leukemia cellsLeukemia, also called blood cancer, is a type of clonal malignant disease in which hematopoietic stem cells are abnormal. Leukemia cells have the same malignant proliferation characteristics as other cancer cells. Zhang Yuetal.[7]found that peimine can inhibit the viability of human acute myeloid leukemia cells KG1-α in a concentration-dependent manner. Besides, flow cytometry found that after peimine treated KG1-α cells for 48 h, the number of cells in the G0/G1phase decreased, while the number of cells in the G2/M phase increased. The above results show that peimine can not only inhibit the proliferation of KG1-α cells, but also promote the cells to enter the division phase, thereby increasing the sensitivity of chemotherapeutics and enhancing the killing effect of chemotherapeutics on tumor cells. The normal oxidation-reduction state in the cell is necessary for its life activities. The massive production of reactive oxygen species (ROS, also oxygen free radicals) in cells or the decline in the function of the antioxidant protection system can lead to an abnormal oxidation-reduction state, causing oxidative injury and even death of cancer cells. According to the study of Qi Yanetal.[8], peimine significantly inhibited the proliferation of human chronic myelogenous leukemia K562 cells in a concentration-dependent manner. In addition, through DCFH2-DA fluorescent probe detection, peimine can induce an increase in the level of ROS in K562 cells and significantly reduce the expression of the antioxidant glutathione (GSH). Furthermore, through DCFH2-DA fluorescent probe detection, it is found that peimine can induce an increase in the level of ROS in K562 cells and significantly reduce the expression of the antioxidant glutathione (GSH). Further pretreatment of K562 cells with ROS scavenger NAC indicates that NAC hindered peimine’s inhibition of K562 cell proliferation. These reveal that peimine can up-regulate the expression of intracellular ROS and down-regulate the expression of GSH, leading to an imbalance of the intracellular oxidation-reduction state, thereby inhibiting the proliferation of K562 cells.

3 Anti-inflammatory effect

Inflammation is a basic pathological process that is mainly defensive response when the body is stimulated. Transforming growth factor-β (TGF-β) is a cytokine that mediates inflammation and can effectively promote inflammation. Inflammation is closely associated with angiogenesis, and vascular endothelial growth factor (VEGF) plays an important role in various inflammations. According to findings of Zhang Yurenetal.[4], peimine has a regulatory effect on the inflammatory microenvironment of 4T1 breast cancer cells, and the relative expression of TGF-β and VEGF mRNA in the peimine treatment group was significantly lower than that of the control group. These reveal that peimine can effectively reduce the relative expression of inflammatory factors and their mRNA, thereby playing the anti-inflammatory effect.

Lipopolysaccharide (LPS) can obviously cause inflammation in the lungs of mice and is an important cause of acute lung injury (ALI). Systemic inflammatory response syndrome (SIRS) is the main pathophysiological process of acute lung injury. Gui Gaixiaetal.[13-16]established a model of induced lung injury through injecting 4 mg/kg of LPS into the trachea of mice and found that LPS can up-regulate the expression of tumor necrosis factor-α (TNF-α) and prostaglandin E2(PGE2). After LPS treatment, it can initiate a series of signal transduction mechanisms, activate a variety of inflammatory cells and effector cells, and release a large number of inflammatory mediators or cytokines. However, peimine treatment can reduce the damage of LPS to alveolar cells and down-regulate the expression of TNF-α and PGE2. Among them, the peimine high dose group has the most significant effect, indicating that peimine can inhibit the release of inflammatory factors.

Acute allergic reactions are diseases caused by mast cells releasing histamine and inducing the release of cytokines such as IL-6, IL-8 and TNF-α in mast cells. These cytokines are regulated by the activated nuclear transcription factor NF-κB, and they play an important role in triggering mast cell-mediated allergic inflammation. Parketal.[18]found that in human mast cells (HMC-1), peimine reduces the expression of IL-6, IL-8 and TNF-α by inducing the expression of NF-κB, and inhibits the release of histamine, and ultimately play an anti-inflammatory effect.

4 Anti-cerebral ischemia-reperfusion injury

Cerebral ischemia reperfusion injury (CIRI) is a complex pathological and physiological process. It is brain tissue injury and related dysfunction caused by blood flow reperfusion after brain tissue ischemia. The neurological function score and the degree of brain tissue injury are the CIRI indicators. The pathogenesis of CIRI is extremely complex and is related to multiple mechanisms such as inflammatory injury, oxidative damage, abnormal apoptosis, calcium overload, and excitatory amino acid toxicity. Duan Jianetal.[19]found that peimine can significantly reduce the neurological function score of rats and significantly improve the pathological injury. Further studies have found that peimine can significantly down-regulate the expression of caspase-9, caspase-3 and Bax in rats with CIRI, and significantly up-regulate the expression of Bcl-2. These reveal that peimine can inhibit the apoptosis of CIRI rats in a dose-dependent manner. In addition, peimine significantly reduced the expression of malondialdehyde (MDA) and lactate dehydrogenase (LDH) in rats with CIRI in a concentration-dependent manner, and increased the expression of superoxide dismutase (SOD), reflecting that peimine can inhibit the oxidative stress in rats with CIRI.

The damaged biological macromolecules and organelles in the cell are mainly eliminated through autophagy. When CIRI occurs, the body will up-regulate the level of autophagy, and LC3 II, as a marker protein of autophagy, is mainly used to reflect the level of autophagy in the body. According to the study of Duan Jianetal.[19], peimine significantly down-regulated the expression of p62, PI3K, AKT and mTOR in rats with CIRI and at the same time up-regulated the expression of LC3 II/LC3 I and beclin 1, proving that peimine can regulate PI3K/Akt/mTOR pathway in rats with CIRI in a dose-dependent manner. Inflammatory factors such as TNF-α and IL-1β play an important role in the occurrence and development of CIRI. When CIRI occurs, TNF-α can promote the secretion of IL-1β, and IL-10 as an anti-inflammatory factor can reduce the inflammatory response, thereby reducing the CIRI symptoms. Guo Sulanetal.[20]found that, compared with wild mice, the expression of TNF-α and IL-1β in the brain homogenate of the cerebral ischemia-reperfusion injury model group mice was significantly increased, and the expression of IL-10 and the expression of autophagy protein LC3 II were significantly reduced. On the contrary, compared with the model group, the expression of TNF-α and IL-1β in the peimine administration group was significantly reduced, and the expression of IL-10 and the expression of autophagy protein LC3 II were significantly increased in a dose-dependent manner. These indicate that peimine has a good protective effect on mouse brain CIRI, and its mechanism may be related to inhibiting inflammation and promoting autophagy.

5 Analgesic effect

According to the records ofChinesePharmacopoeia, Fritillariae Thunbergii Bulbus has the functions of clearing heat, resolving phlegm and relieving cough, detoxification, dispersing abscesses and nodules, and its analgesic pharmacological effects are related to the content of alkaloids in Fritillariae Thunbergii Bulbu[21]. Liang Xiaonanetal.[22]found that voltage-gated sodium channel NaV1.7 is mainly distributed in peripheral sensory neurons and sympathetic ganglion neurons, and is the threshold channel for painful action potentials. It can excite the dorsal root ganglion (DRG) by amplifying slight stimuli below the threshold to transmit pain signals, so NaV1.7 may be a highly effective and specific target for pain treatment. Kan Liandietal.[23]used the human embryonic kidney (HEK) 293 cell line stably transfected with NaV1.7 channel to study the analgesic mechanism of peimine. Experimental data reflected that peimine can not only block NaV1.7 ion channels in a concentration-dependent manner, but also inhibit other sodium ion channels, and ultimately playing the analgesic effect.

6 Conclusions and prospects

Fritillariae Thunbergii Bulbus, bitter in taste and cold in nature, has the functions of clearing heat, resolving phlegm and relieving cough, detoxification, dispersing abscesses and nodules. As the main active alkaloid of Fritillariae Thunbergii Bulbus, peimine has a variety of pharmacological effects and has a wide range of drug development and application prospects. At present, although there have been extensive studies about peimine’s anti-inflammatory effects, the research on its anti-cancer mechanism is still in the preliminary stage. For example, it is not clear how peimine inhibits blood vessel and lymphangiogenesis in the process of tumor invasion and metastasis so as to play its anti-cancer effect. Therefore, it is necessary to conduct more and more in-depth studies on peimine’s anti-cancer effects to explore more and better use values, so as to lay a solid theoretical foundation for cancer treatment and the development of active components of drugs.