Citrullus colocynthis (Colocynth) Extracts in Therapy: Extraction, Standardization, Antidiabetic and Anticancer Mechanisms, and Toxicity Management - A Comprehensive Review
DOI:
https://doi.org/10.64354/tbadzv89Keywords:
Citrullus colocynthis; Cucurbitacins; Selective extraction; HPLC-MS/MS; Antidiabetic; Anticancer; JAK/STAT3; Toxicity managementAbstract
Citrullus colocynthis (L.) Schrad, known as colocynth or bitter apple, is a perennial species of cucurbit native to dry zones of Africa, Asia and the Mediterranean basin. Bitter gourd is rich in cucurbitacins (highly oxygenated tetracyclic triterpenoids) and its fruit pulp, seeds and leaves have been a subject of continuous study interest due to their marked antidiabetic and anticancer activities. However, the clinical translation of colocynth-derived preparations is hampered by the absence of standardised extraction techniques, the variation in phytochemical profiles between regional accessions, and the short therapeutic window due to cucurbitacin-associated toxicity. This review offers a comprehensive evaluation of selective extraction procedures for the enrichment of cucurbitacins (mainly types B, E, I and their glycosides) from C. colocynthis plant material and evaluation of contemporary analytical quality control platforms like HPLC-UV, HPLC-MS/MS, UPLC-MS/MS and HPTLC techniques which are important for batch-to-batch standardisation. The molecular mechanisms of the antidiabetic action of cucurbitacins are discussed, focusing on the modulation of the AMPK/PI3K/Akt cascade, GLUT4 translocation and GLP-1 stimulation, along with the anticancer pathways including the inhibition of JAK2/STAT3 and the induction of apoptosis by regulation of Bax/Bcl-2 and cell cycle arrest. Finally, the toxicological profile of colocynth preparations is critically discussed and practical options for the mitigation of side effects are given, including dose optimisation, nanoformulation, prodrug derivatisation and co-administration with hepatic-protective drugs. This review intends to connect ethnopharmacological knowledge with evidence-based medicinal development of cucurbitacin-rich colocynth extracts.
References
[1] Dane F, Liu J. Diversity and origin of cultivated and citron type watermelon (Citrullus lanatus). Genet Resour Crop Evol. 2007;54(6):1255–1265.
[2] Si Y, Dane F, Rashotte A, Kang S, Singh NK. Cloning and expression analysis of the Ccrboh gene encoding respiratory burst oxidase in Citrullus colocynthis. J Exp Bot. 2010;61(6):1635–1642.
[3] Hussain AI, Rathore HA, Sattar MZA, Chatha SAS, Sarker SD, Gilani AH. Citrullus colocynthis (L.) Schrad (bitter apple fruit): A review of its phytochemistry, pharmacology, traditional uses and nutritional potential. J Ethnopharmacol. 2014;155(1):54–66.
[4] Marzouk B, Marzouk Z, Décor R, et al. Citrullus colocynthis (L.) Schrad: Chemical composition and biological activities – a review. Afr J Biotechnol. 2010;9(24):6614–6621.
[5] Chen JC, Chiu MH, Nie RL, Cordell GA, Qiu SX. Cucurbitacins and cucurbitane glycosides: structures and biological activities. Nat Prod Rep. 2005;22(3):386–399.
[6] Chung SO, Kim YJ, Park SU. An updated review of cucurbitacins and their biological and pharmacological activities. EXCLI J. 2015;14:562–566.
[7] WHO. Quality control methods for herbal materials. Geneva: World Health Organization; 2011.
[8] Giwa S, Abdullah LC, Adam NM. Investigating Egusi (Citrullus colocynthis L.) seed oil as potential biodiesel feedstock. Energies. 2010;3(7):1472–1483.
[9] Al-Ghaithi F, El-Ridi MR, Adeghate E, Amiri MH. Biochemical effects of Citrullus colocynthis in normal and diabetic rats. Mol Cell Biochem. 2004;261(1):143–149.
[10] Rahbar AR, Nabipour I. The hypolipidemic effect of Citrullus colocynthis on patients with hyperlipidemia. Pak J Biol Sci. 2010;13(24):1202–1207.
[11] Ziyyat A, Legssyer A, Mekhfi H, Dassouli A, Serhrouchni M, Benjelloun W. Phytotherapy of hypertension and diabetes in oriental Morocco. J Ethnopharmacol. 1997;58(1):45–54.
[12] Sadou H, Sabo H, Alma MM, Saadou M, Leger CL. Chemical content of the seeds and physico-chemical characteristics of the seed oils from Citrullus colocynthis. Bull Chem Soc Ethiop. 2007;21(2):323–330.
[13] Benariba N, Djaziri R, Bellakhdar W, et al. Phytochemical screening and free radical scavenging activity of Citrullus colocynthis seeds extracts. Asian Pac J Trop Biomed. 2013;3(1):35–40.
[14] Errajraji A, Ouhdouch F, El-Anssari N. Usage des plantes médicinales dans le traitement du diabète de type 2 au Maroc. Méd Mal Métab. 2010;4(3):301–304.
[15] Nayab D, Ali D, Arshad N, Malik A, Choudhary MI, Ahmed Z. Cucurbitacin glycosides from Citrullus colocynthis. Nat Prod Res. 2006;20(5):409–413.
[16] Yoshikawa M, Morikawa T, Kobayashi H, et al. Bioactive saponins and glycosides. XXVII. Structures of new cucurbitane-type triterpene glycosides from Citrullus colocynthis. Chem Pharm Bull. 2007;55(3):428–434.
[17] Tannin-Spitz T, Grossman S, Dovrat S, Gottlieb HE, Bergman M. Growth inhibitory activity of cucurbitacin glucosides isolated from Citrullus colocynthis on human breast cancer cells. Biochem Pharmacol. 2007;73(1):56–67.
[18] Ayyad SN, Abdel-lateff A, Basaif SA, Shier T. Cucurbitacins-type triterpene with potent activity on mouse embryonic fibroblast from Cucumis prophetarum. Pharmacogn Res. 2011;3(3):189–193.
[19] Cai Y, Fang X, He C, Li P, Xiao F, Wang Y, Chen M. Cucurbitacins: A systematic review of the phytochemistry and anticancer activity. Am J Chin Med. 2015;43(7):1331–1350.
[20] Lang KL, Silva IT, Zimmermann LA, et al. Synthesis and cytotoxic activity evaluation of dihydrocucurbitacin B and cucurbitacin B derivatives. Bioorg Med Chem. 2012;20(10):3016–3023.
[21] Kumar S, Kumar D, Manjusha, Saroha K, Singh N, Vashishta B. Antioxidant and free radical scavenging potential of Citrullus colocynthis (L.) Schrad. methanolic fruit extract. Acta Pharm. 2008;58(2):215–220.
[22] Shawkey AM, Rabeh MA, Abdulall AK, Abdellatif AO. Anticancer activity, phytochemical investigation and molecular docking insights of Citrullus colocynthis (L.) fruits. Sci Rep. 2023;13(1):19918.
[23] Dai J, Mumper RJ. Plant phenolics: extraction, analysis and their antioxidant and anticancer properties. Molecules. 2010;15(10):7313–7352.
[24] Diplocyclos palmatus extraction optimization. J Food Sci Technol. 2018;55(7):2573–2581.
[25] Mustafa A, Turner C. Pressurized liquid extraction as a green approach in food and herbal plants extraction: A review. Anal Chim Acta. 2011;703(1):8–18.
[26] Chemat F, Rombaut N, Sicaire AG, et al. Ultrasound assisted extraction of food and natural products: A review. Ultrason Sonochem. 2017;34:540–560.
[27] Herrero M, Cifuentes A, Ibáñez E. Sub- and supercritical fluid extraction of functional ingredients from different natural sources: A review. Food Chem. 2006;98(1):136–148.
[28] Still WC, Kahn M, Mitra A. Rapid chromatographic technique for preparative separations with moderate resolution. J Org Chem. 1978;43(14):2923–2925.
[29] Lavie D, Willner D, Merenlender Z. US Patent 5,925,356. Method of isolating cucurbitacin. 1999.
[30] Potterat O, Hamburger M. Concepts and technologies for tracking bioactive compounds from natural product extracts. Planta Med. 2014;80(14):1171–1181.
[31] Zhou Y, Ma Y, Zeng J, et al. Convergence and divergence of bitterness biosynthesis and regulation in Cucurbitaceae. Nat Plants. 2016;2:16183.
[32] Bajcsik S, Stuppner H, Ganzera M. Simultaneous determination of cucurbitacin B, E, I and E-glucoside in plant material and body fluids by HPLC–MS. J Chromatogr B. 2017;1052:128–134.
[33] Zhong YG, Chen WG, Wu J, Yuan S. A new sensitive UPLC-MS/MS method for the determination of cucurbitacin B in rat plasma. RSC Adv. 2022;12(20):12415–12423.
[34] Oliveira AS, Sousa E, Vasconcelos MH, Pinto M. Development and validation of a quantification method for cucurbitacins E and I in rat plasma. J Pharm Biomed Anal. 2019;164:122–130.
[35] Debnath P, Das B, Biswas S, et al. Quality evaluation and quantification of cucurbitacin E in Cucumis sativus L. fruit by a validated HPTLC method. JPC-J Planar Chromatogr. 2021;34:139–146.
[36] Sindhu HA, Afzal M, Shahid I. Pharmacological activities and in-silico studies of bioactive compounds from the methanolic extract of Citrullus colocynthis. Dose-Response. 2023;21(3):15593258231187357.
[37] Abdel-Hassan IA, Abdel-Barry JA, Tariq Mohammeda S. The hypoglycaemic and antihyperglycaemic effect of Citrullus colocynthis fruit aqueous extract in normal and alloxan diabetic rabbits. J Ethnopharmacol. 2000;71(1–2):325–330.
[38] Dallak M, Bashir N, Abbas M, et al. Concomitant down regulation of glycolytic enzymes following the chronic administration of Citrullus colocynthis pulp extract. Am J Biochem Biotechnol. 2009;5(4):153–161.
[39] Barghamdi B, Ghorat F, Asadollahi K, et al. Antidiabetic and antioxidant effects of topically applied Citrullus colocynthis extract in type 2 diabetes. PMC. 2025;12524779.
[40] Hussain AI, et al. Citrullus colocynthis and human health: Transforming nature bitterness to healing medicine. J Ethnopharmacol. 2025.
[41] Hardie DG. AMP-activated protein kinase: an energy sensor that regulates all aspects of cell function. Genes Dev. 2011;25(18):1895–1908.
[42] Sharmila Banu G. Cucurbitacin augments insulin sensitivity and glucose uptake through translocation and activation of GLUT4 in PI3K/AKT signaling pathway. World J Pharm Res. 2017;6(8):1–15.
[43] Kim HJ, Kim BK, Mun EG, Jeong SY, Cha YS. Cucurbitacin B induces hypoglycemic effect in diabetic mice by regulation of AMPK and GLP-1 via bitter taste receptor signaling. Front Pharmacol. 2018;9:1071.
[44] Tan MJ, Ye JM, Turner N, et al. Antidiabetic activities of triterpenoids isolated from bitter melon associated with activation of the AMPK pathway. Chem Biol. 2008;15(3):263–273.
[45] Dalar A, Konczak I. Phenolic contents, antioxidant capacities and inhibitory activities against key enzymes. Food Chem Toxicol. 2013;58:399–407.
[46] Blaskovich MA, Sun J, Cantor A, et al. Discovery of JSI-124 (cucurbitacin I), a selective JAK/STAT3 inhibitor with potent antitumor activity. Cancer Res. 2003;63(6):1270–1279.
[47] Sun J, Blaskovich MA, Jove R, et al. Cucurbitacin Q: a selective STAT3 activation inhibitor with potent antitumor activity. Oncogene. 2005;24(20):3236–3245.
[48] Shawkey AM, et al. Anticancer activity and molecular docking insights of Citrullus colocynthis (L.) fruits. Sci Rep. 2023;13(1):19918.
[49] Thoennissen NH, Iwanski GB, Doan NB, et al. Cucurbitacin B induces apoptosis by inhibition of the JAK/STAT pathway and potentiates antiproliferative effects of gemcitabine. Cancer Res. 2009;69(14):5876–5884.
[50] Sorensen PM, Iacob RE, Fritzsche M, et al. The natural product cucurbitacin E inhibits depolymerization of actin filaments. ACS Chem Biol. 2012;7(9):1502–1508.
[51] Al-Ghazzewi FH, Tester RF. Biopharmaceutical applications of Citrullus colocynthis. J Pharm Pharmacol. 2012;64(9):1219–1228.
[52] Ali MH, et al. Colocynth induced multiorgan toxicity: a case report. PMC. 2025;12522648.
[53] Soufane S, Bouzidi A, Mahdeb N. Acute toxicity study on Citrullus colocynthis fruit methanol extract in rats. J Appl Pharm Sci. 2013;3(6):88–93.
[54] Zamani M, Rahbar A, Zamani P, et al. Citrullus colocynthis (bitter apple) poisoning: a case report. Iran J Toxicol. 2011;5(1–2):559–562.
[55] Patel K, Patel DK. Medicinal importance, pharmacological activities, and analytical aspects of cucurbitacin: A review. J Pharmacogn Phytochem. 2016;5(1):272–276.
[56] Zhang YT, Feng NN, Zhao JH, et al. Cucurbitacin B-loaded lipid nanoparticles for enhanced anticancer activity. J Drug Deliv Sci Technol. 2019;54:101317.
[57] Abenavoli L, Capasso R, Milic N, Capasso F. Milk thistle in liver diseases: past, present, future. Phytother Res. 2010;24(10):1423–1432.
[58] Ojo OA, Ajiboye BO, Ojo AB, et al. Citrullus colocynthis Linn. fruit extract ameliorates cisplatin-induced hepato-renal toxicity in rats. J Complement Integr Med. 2018;15(3):20170086.
[59] Kausar H, Munagala R, Bansal SS, et al. Cucurbitacin B potently suppresses non-small-cell lung cancer growth: Identification of intracellular thiols as critical targets. Cancer Lett. 2013;332(1):35–45.
[60] EMA. Guideline on quality of herbal medicinal products. EMA/HMPC/201116/2005. 2011.
[61] Hopkins AL. Network pharmacology: the next paradigm in drug discovery. Nat Chem Biol. 2008;4(11):682–690.
[62] Efferth T, Koch E. Complex interactions between phytochemicals. Curr Drug Targets. 2011;12(2):159–172.
[63] Hoffola AA, Robi AG, Tefera ZT, et al. Optimization of antioxidant extraction from Citrullus colocynthis seed using response surface methodology. Sci Rep. 2026;16. DOI: 10.1038/s41598-026-35921-8.
[64] Gholami A, Mohkam M, Omidifar N, Mousavi SM, Yousefi K, Hashempur MH, et al. Bioinspired 8-hydroxyquinoline-Fe3O4 nanostructures from Citrullus colocynthis exhibit strong antibacterial, antifungal, and anticancer effects. Sci Rep. 2026;16(1). DOI: 10.1038/s41598-025-34899-z.
[65] Ismael S, et al. Citrullus colocynthis extract ameliorates hypothalamic–pituitary–gonadal axis dysfunction in diabetic rats. Open Vet J. 2026.
[66] Ibrahim R, et al. Investigation of antidiabetic nephropathy properties of Citrullus colocynthis methanol extracts by targeting aldose reductase enzyme: in silico and in vitro studies. In Silico Res Biomed. 2026.
[67] Prenetha R, et al. Anticancer activity of Citrullus colocynthis on PI3K and AKT gene expression in human lung cancer cell lines in vitro. Int J Drug Deliv Technol. 2026.
[68] Singh M, et al. Anti-tumour activity of Citrullus colocynthis against Ehrlich ascites carcinoma-induced solid tumor model in mice. Int J Pharm Sci Drug Res. 2026.
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