Citrus-derived auraptene stimulates angiogenesis by activating the Erk- and PI3K/Akt/eNOS-dependent signaling pathways in human umbilical vein endothelial cells

Monoterpenoids: An upcoming class of therapeutic agents for modulating cancer metastasis

Monoterpenoids, a sub-class of terpenoids, are secondary metabolites frequently extracted from the essential oils of aromatic plants. Their antitumor properties including antiproliferative, apoptotic, antiangiogenic, and antimetastatic effects along with other biological activities have been the subject of extensive study due to their diverse characteristics. In recent years, numerous investigations have been conducted to understand its potential anticancer impacts, specifically focusing on antiproliferative and apoptotic mechanisms. Metastasis, a malignancy hallmark, can exert either protective or destructive influences on tumor cells. Despite this, the potential antimetastatic and antiangiogenic attributes of monoterpenoids need further exploration. This review focuses on specific monoterpenoids, examining their effects on metastasis and relevant signaling pathways. The monoterpenoids exhibit a high level of complexity as natural products that regulate metastatic proteins through various signaling pathways, including phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin, mitogen-activated protein kinase/extracellular signal-regulated kinase/jun N-terminal kinase, nuclear factor kappa B, vascular endothelial growth factor, and epithelial mesenchymal transition process. Additionally, this review delves into the biosynthesis and classification of monoterpenoids, their potential antitumor impacts on cell lines, the plant sources of monoterpenoids, and the current status of limited clinical trials investigating their efficacy against cancer. Moreover, monoterpenoids depict promising potential in preventing cancer metastasis, however, inadequate clinical trials limit their drug usage. State-of-the-art techniques and technologies are being employed to overcome the challenges of utilizing monoterpenoids as an anticancer agent.

The extract of Curcumae Longae Rhizoma suppresses angiogenesis via VEGF-induced PI3K/Akt-eNOS-NO pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Curcumae Longae Rhizoma (CLR) is a safe natural herbal medicine, and which has been widely used for centuries as functional food and health products, but its effects on angiogenesis and related underlying mechanism remain unclear.

AIM OF THE STUDY

The abnormal angiogenesis is closely related with various diseases, and therefore the precise control of angiogenesis is of great importance. The well-known angiogenic factor, vascular endothelial growth factor (VEGF), mediates angiogenesis and induces multiple signalling pathways via binding to VEGF receptor (VEGFR). The attenuation of VEGF-triggered angiogenic-related signalling pathways may relieve various diseases through suppression of angiogenesis. Here, we aimed to elucidate that CLR extract could exert striking anti-angiogenic activities both in vitro and in vivo.

MATERIALS AND METHODS

The viability of human umbilical vascular endothelial cell (HUVEC) was examined by LDH and MTT assays. Migrative and invasive ability of the endothelial cells were independently evaluated by wound healing and transwell assays. The activities of CLR extract on in vitro angiogenesis was tested by tube formation assay. In vivo vascularization was determined by using zebrafish embryo model in the present of CLR extract. Western blotting was applied to determine the phosphorylated levels of VEGFR2, PI3K, AKT and eNOS. Besides, the levels of nitric oxide (NO) and reactive oxygen species (ROS) were separately evaluated by Griess assay and 2'7'-dichlorofluorescein diacetate reaction. In addition, the cell migrative ability of cancer cell was estimated by using cultured human colon carcinoma cells (HT-29 cell line), and immunofluorescence assay was applied to evaluate the effect of CLR extract on nuclear translocation of NF-κB p65 subunit in the VEGF-treated HT-29 cultures.

RESULTS

CLR extract significantly suppressed a series of VEGF-mediated angiogenic responses, including endothelial cell proliferation, migration, invasion, and tube formation. Moreover, CLR extract reduced in vivo sub-intestinal vessel formation in zebrafish embryo model. Mechanistically, the extract of CLR attenuated the VEGF-triggered signalling, as demonstrated by decreased level of phosphorylated VEGFR2 and subsequently inactivated its downstream regulators, e.g. phospho-PI3K, phospho-AKT and phospho-eNOS. The production of NO and formation of ROS were markedly inhibited in HUVECs. Furthermore, CLR extract suppressed cell migration and NF-κB translocation in cultured HT-29 cells.

CONCLUSIONS

These preclinical findings demonstrate that the extract of CLR remarkably attenuates angiogenesis and which has great potential as a natural drug candidate with excellent anti-angiogenic activity.

Auraptene Inhibits Migration and Invasion of Cervical and Ovarian Cancer Cells by Repression of Matrix Metalloproteinasas 2 and 9 Activity

OBJECTIVES

Auraptene, a natural citrus coumarin, found in plants of Rutaceae and Apiaceae families. In this study, we investigated the effects of auraptene on tumor migration, invasion and matrix metalloproteinase (MMP)-2 and -9 enzymes activity.

METHODS

The effects of auraptene on the viability of A2780 and Hela cell lines was evaluated by MTT assay. Wound healing migration assay and Boyden chamber assay were determined the effect of auraptene on migration and cell invasion, respectively. MMP-2 and MMP-9 activities were analyzed by gelatin zymography assay.

RESULTS

Auraptene reduced A2780 cell viability. The results showed that auraptene inhibited in vitro migration and invasion of both cells. Furthermore, cell invasion ability suppressed at 100μM auraptene in Hela cells and at 25, 50μM in A2780 cell line. Gelatin zymography showed that for Hela cell line, auraptene suppressed MMP-2 enzymatic activity in all concentrations and for MMP-9 at a concentration between 12.5 to 100μM in A2780 cell line.

CONCLUSION

Auraptene inhibited migration and invasion of human cervical and ovarian cancer cells in vitro by possibly inhibitory effects on MMP-2 and MMP-9 activity.

PI3K/Akt/mTOR and Ras/Raf/MEK/ERK signaling pathways inhibitors as anticancer agents: Structural and pharmacological perspectives

The protein kinases regulate cellular functions such as transcription, translation, proliferation, growth and survival by the process of phosphorylation. Over activation of signaling pathways play a major role in oncogenesis. The PI3K signaling pathway is dysregulated almost in all cancers due to the amplification, genetic mutation of PI3K gene and the components of the PI3K pathway themselves. Stimulation of the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK pathways enhances growth, survival, and metabolism of cancer cells. Recently, the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK signaling pathways have been identified as promising therapeutic targets for cancer therapy. The kinase inhibitors with enhanced specificity and improved pharmacokinetics have been considered for design and development of anticancer agents. This review focuses primarily on the Ras/Raf/MEK/ERK and PI3K/Akt/mTOR signaling pathways as therapeutic targets of anticancer drugs, their specific and dual inhibitors, structure activity relationships (SARs) and inhibitors under clinical trials.