Discovery of antitumor diterpenoids from Casearia graveolens targeting VEGFR-2 to inhibit angiogenesis

Abstract

Eight novel clerodane diterpenoids (1−8) were isolated from the twigs of Casearia graveolens. Their structures were elucidated through comprehensive nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and electronic circular dichroism (ECD) analyses. In addition to structural determination, surface plasmon resonance (SPR) assays were conducted to investigate molecular interactions, revealing that compound 8 exhibited high affinity for vascular endothelial growth factor receptor 2 (VEGFR2), a key regulator of tumor angiogenesis. Subsequent in vivo experiments demonstrated that compound 8 effectively inhibited angiogenesis and displayed significant antitumor activity by suppressing tumor proliferation and metastasis in zebrafish xenograft models. These findings suggest that compound 8 holds promise as an anticancer lead compound targeting VEGFR-2 to obstruct tumor angiogenesis.

Keywords

Clerodane diterpenoids / Casearia graveolens / Surface plasmon resonance / Vascular endothelial growth factor receptor 2 / Antitumor activity / Zebrafish

References

[1] Al-Ostoot FH, Salah S, Khamees HA, et al. Tumor angiogenesis: current challenges and therapeutic opportunities[J]. Cancer Treat Res Commun, 2021, 28: 100422.

[2] Hicklin DJ, Ellis LM. Role of the vascular endothelial growth factor pathway in tumor growth and angiogenesis[J]. J Clin Oncol, 2005, 23(5): 1011-1027.

[3] Liu Y, Li Y, Wang Y, et al. Recent progress on vascular endothelial growth factor receptor inhibitors with dual targeting capabilities for tumor therapy[J]. J Hematol Oncol, 2022, 15(1): 1-28.

[4] Modi SJ, Kulkarni VM. Vascular endothelial growth factor receptor (VEGFR-2)/KDR inhibitors: medicinal chemistry perspective[J]. Med Drug Discov, 2019, 2: 100009.

[5] Kinghorn AD, Carcache De BEJ, Chai HB, et al. Discovery of anticancer agents of diverse natural origin[J]. Pure Appl Chem, 2009, 81(6): 1051-1063.

[6] Newman DJ, Cragg GM. Natural products as sources of new drugs from 1981 to 2014[J]. J Nat Prod, 2016, 79(3): 629-661.

[7] Xia L, Guo Q, Tu P, et al. The genus Casearia: a phytochemical and pharmacological overview[J]. Phytochem Rev, 2015, 14(1): 99-135.

[8] Editorial Committee of the Flora of China, Chinese Academy of Sciences. Flora of China[M]. Beijing Science and Technology Press, 1999, 52(1): 79-80.

[9] Williams RB, Norris A, Miller JS, et al. Cytotoxic clerodane diterpenoids and their hydrolysis products from Casearia nigrescens from the rainforest of Madagascar[J]. J Nat Prod, 2007, 70(2): 206-209.

[10] Ma J, Yang X, Zhang Q, et al. Cytotoxic clerodane diterpenoids from the leaves of Casearia kurzii[J]. Bioorg Chem, 2019, 85: 558-567.

[11] Oberlies NH, Burgess JP, Navarro HA, et al. Novel bioactive clerodane diterpenoids from the leaves and twigs of Casearia sylvestris[J]. J Nat Prod, 2002, 65(2): 95-99.

[12] Oda FB, Crevelin EJ, Crotti AEM, et al. Acidic and hepatic derivatives of bioactive clerodane diterpenes casearins J and O[J]. Fitoterapia, 2019, 137: 104197.

[13] Nguyen HTT, Truong NB, Doan HTM, et al. Cytotoxic clerodane diterpenoids from the leaves of Casearia grewiifolia[J]. J Nat Prod, 2015, 78(11): 2726-2730.

[14] Sai PCV, Hoch JM, Kingston DGI. Structure and stereochemistry of new cytotoxic clerodane diterpenoids from the bark of Casearia lucida from the Madagascar rainforest[J]. J Nat Prod, 2002, 65(2): 100-107.

[15] Hunter MS, Corley DG, Carron CP, et al. Four new clerodane diterpenes from the leaves of Casearia guianensis which inhibit the interaction of leukocyte function antigen 1 with intercellular adhesion molecule 1[J]. J Nat Prod, 1997, 60(9): 894-899.

[16] Meesakul P, Ritthiwigrom T, Cheenpracha S, et al. A new cytotoxic clerodane diterpene from Casearia graveolens twigs[J]. Nat Prod Commun, 2016, 11(1): 13-15.

[17] Li Y, Ma J, Song Z, et al. The antitumor activity and mechanism of a natural diterpenoid from Casearia graveolens[J]. Front Oncol, 2021, 11: 688195.

[18] Liu F, Ma J, Shi Z, et al. Clerodane diterpenoids isolated from the leaves of Casearia graveolens[J]. J Nat Prod, 2020, 83(1): 36-44.

[19] Xu J, Ji F, Sun X, et al. Characterization and biological evaluation of diterpenoids from Casearia graveolens[J]. J Nat Prod, 2015, 78(11): 2648-2656.

[20] Beutler JA, McCall KL, Herbert K, et al. Novel cytotoxic diterpenes from Casearia arborea[J]. J Nat Prod, 2000, 63(5): 657-661.

[21] Whitson EL, Thomas CL, Henrich CJ, et al. Clerodane diterpenes from Casearia arguta that act as synergistic TRAIL sensitizers[J]. J Nat Prod, 2010, 73(12): 2013-2018.

[22] Liang Y, Zhang Q, Yang X, et al. Diterpenoids from the leaves of Casearia kurzii showing cytotoxic activities[J]. Bioorg Chem, 2020, 98: 103741.

[23] Mándi A, Kurtán T. Applications of OR/ECD/VCD to the structure elucidation of natural products[J]. Nat Prod Rep, 2019, 36(6): 889-918.

[24] Li XC, Ferreira D, Ding Y. Determination of absolute configuration of natural products: theoretical calculation of electronic circular dichroism as a tool[J]. Curr Org Chem, 2010, 14(16): 1678-1697.

[25] Lv Y, Wang Y, Zheng X, et al. Reveal the interaction mechanism of five old drugs targeting VEGFR2 through computational simulations[J]. J Mol Graph Model, 2020, 96: 107538.

[26] Al-Abd AM, Alamoudi AJ, Abdel-Naim AB, et al. Anti-angiogenetic agents for the treatment of solid tumors: potential pathways, therapy and current strategies-a review[J]. J Adv Res, 2017, 8(6): 591-605.

[27] Lee D, Yu JS, Ha JW, et al. Antitumor potential of withanolide glycosides from Ashwagandha (Withania somnifera) on apoptosis of human hepatocellular carcinoma cells and tube formation in human umbilical vein endothelial cells[J]. Antioxidants, 2022, 11(9): 1761.

[28] Lee C, Lee JW, Jin Q, et al. Isolation and characterization of dammarane-type saponins from Gynostemma pentaphyllum and their inhibitory effects on IL-6-induced STAT3 activation[J]. J Nat Prod, 2015, 78(5): 971-976.

[29] Morris GM, Huey R, Lindstrom W, et al. AutoDock4 and AutoDockTools4: automated docking with selective receptor flexibility[J]. J Comput Chem, 2009, 30(16): 2785-2791.

[30] Trott O, Olson AJ. AutoDock Vina: improving the speed and accuracy of docking with a new scoring function, efficient optimization, and multithreading[J]. J Comput Chem, 2010, 31(2): 455-461.

[31] Wang S, Zhang Q, Peng M, et al. Design, synthesis, biological evaluation, and preliminary mechanistic study of a novel mitochondrial-targeted xanthone[J]. Molecules, 2023, 28(3): 1016.

[32] Zhang S, Li Y, Li Z, et al. Structure, antitumor activity, and potential antitumor mechanism of a fungus polysaccharide from Fomes officinalis[J]. Carbohydr Polym, 2022, 295: 119794.

[33] Zhao Y, Zhang X, Li Y, et al. A natural xanthone suppresses lung cancer growth and metastasis by targeting STAT3 and FAK signaling pathways[J]. Phytomedicine, 2022, 102: 154118.

Funding

National Natural Science Foundation of China(22077067)

Project of State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University(QJJ(2022)422)

111 Project(B20016)