Synthesis of 13-β-elemene ester derivatives and evaluation of their antioxidant activity in human umbilical vein endothelial cells

Second generation β-elemene nitric oxide derivatives with reasonable linkers: potential hybrids against malignant brain glioma

Elemene is a second-line broad-spectrum anti-tumour drug that has been used in China for more than two decades. However, its main anti-tumour ingredient, β-elemene, has disadvantages, including excessive lipophilicity and relatively weak anti-tumour efficacy. To improve the anti-tumour activity of β-elemene, based on its minor molecular weight character, we introduced furoxan nitric oxide (NO) donors into the β-elemene structure and designed six series of new generation β-elemene NO donor hybrids. The synthesised compounds could effectively release NO in vitro, displayed significant anti-proliferative effects on U87MG, NCI-H520, and SW620 cell lines. In the orthotopic glioma model, compound Id significantly and continuously suppressed the growth of gliomas in nude mice, and the brain glioma of the treatment group was markedly inhibited (>90%). In short, the structural fusion design of NO donor and β-elemene is a feasible strategy to improve the in vivo anti-tumour activity of β-elemene.

Anti-Tumor Drug Discovery Based on Natural Product β-Elemene: Anti-Tumor Mechanisms and Structural Modification

Natural products are important sources for drug discovery, especially anti-tumor drugs. β-Elemene, the prominent active ingredient extract from the rhizome of Curcuma wenyujin, is a representative natural product with broad anti-tumor activities. The main molecular mechanism of β-elemene is to inhibit tumor growth and proliferation, induce apoptosis, inhibit tumor cell invasion and metastasis, enhance the sensitivity of chemoradiotherapy, regulate the immune system, and reverse multidrug resistance (MDR). Elemene oral emulsion and elemene injection were approved by the China Food and Drug Administration (CFDA) for the treatment of various cancers and bone metastasis in 1994. However, the lipophilicity and low bioavailability limit its application. To discover better β-elemene-derived anti-tumor drugs with satisfying drug-like properties, researchers have modified its structure under the premise of not damaging the basic scaffold structure. In this review, we comprehensively discuss and summarize the potential anti-tumor mechanisms and the progress of structural modifications of β-elemene.

The Antitumor Efficacy of β-Elemene by Changing Tumor Inflammatory Environment and Tumor Microenvironment

Inflammatory mediators and inflammatory cells in the inflammatory microenvironment promote the transformation of normal cells to cancer cells in the early stage of cancer, promote the growth and development of cancer cells, and induce tumor immune escape. The monomeric active ingredient β-elemene is extracted from the traditional Chinese medicine Curcuma wenyujin and has been proven to have good anti-inflammatory and antitumor activities in clinical applications for more than 20 years in China. Recent studies have found that this traditional Chinese medicine plays a vital role in macrophage infiltration and M2 polarization, as well as in regulating immune disorders, and it even regulates the transcription factors NF-κB and STAT3 to alter inflammation, tumorigenesis, and development. In addition, β-elemene regulates not only different inflammatory factors (such as TNF-α, IFN, TGF-β, and IL-6/10) but also oxidative stress in vivo and in vitro. The excellent anti-inflammatory and antitumor effects of β-elemene and its ability to alter the inflammatory microenvironment of tumors have been gradually elaborated. Although the study of monomeric active ingredients in traditional Chinese medicines is insufficient in terms of quality and quantity, the pharmacological effects of more active ingredients of traditional Chinese medicines will be revealed after β-elemene.

Multi-Targeting by β-Elemene and Its Anticancer Properties: A Good Choice for Oncotherapy and Radiochemotherapy Sensitization

Several studies have focused on chemical agents, tailored from natural edible products, used to prevent and treat various diseases. β-elemene is a well-known compound derived from Curcuma wenyujin that possesses a wide spectrum of anticancer properties under preclinical and clinical conditions. Several studies have demonstrated its inhibitory effect both in humans and animals with cancers. Numerous in vivo and in vitro experimental models have revealed that β-elemene can modulate multiple molecular pathways involved in carcinogenesis. In general, (1) β-elemene itself can inhibit and kill tumor cells through a variety of mechanisms, and (2) can synergistically enhance the effect of radiotherapy and/or chemotherapy, (3) also can regulate autoimmune in the treatment of tumors. In this article, we critically focused on the available scientific evidence discussing the use of β-elemene in cancer prevention, and its molecular targets and mechanisms of action in different types of cancer. In addition, we have discussed its sources, chemistry, bioavailability, and future research directions.

β-elemene induced anticancer effect in bladder cancer through upregulation of PTEN and suppression of AKT phosphorylation

Human bladder cancer is one of the most aggressive tumours known and has shown resistance to traditional chemotherapy, which depends heavily on DNA-damaging drugs. β-elemene is one of the least cytotoxic antitumor agents that are extracted from Curcuma aromatica salisb and it exhibits antitumor effects in many carcinomas. β-elemene has attracted the attention of clinicians and scientists worldwide due to its few side effects and limited effect on the bone marrow. However, the antitumor mechanism of β-elemene remains largely unstudied. In the present study, the expression of the AKT serine/threonine kinase (AKT) signaling pathway in bladder cancer and normal bladder tissue was investigated, and the influence of β-elemene on bladder cancer cells and the mechanisms involved were assessed. The results showed that phosphatase and tensin homolog deleted on chromosome ten (PTEN) was downregulated and phosphorylated-AKT (pAKT) was overexpressed in human bladder cancer. β-elemene significantly suppressed the viability of bladder cancer cells, while leaving normal bladder cells unaffected. In addition, there was an increased number of apoptotic bladder cancer cells following β-elemene treatment, and a significant reduction in cell invasion and migration. Subsequent western blot analyses revealed that bladder cancer cells treated with β-elemene had increased PTEN expression and decreased expression of pAKT. Taken together, these results suggest that β-elemene has an antitumor effect in bladder cancer cells through the upregulation of PTEN and suppression of AKT phosphorylation.