Calystegia soldanella (L) Roem. et Schult (Convolvulaceae), a representative halophyte and endemic plant, is found on coastal sand dunes and foredunes where the environmental stresses are significant. These plants are perennial vine herbs with ubiquitous distribution in the coastal dune areas of South Korea, East Asia, Europe, and the Pacific (31). This plant has long been used as an edible and medicinal herb to cure rheumatic arthritis, sore throat, dropsy, and scurvy (32). Some studies have shown that this plant species exhibits various biological activities. Another species, C. japonica, which has been used as a traditional medicine to treat urination problems, fever, or diarrhea in Chinese and oriental herb medicine (33,34). Moreover, C. soldanella has been shown to exhibit a number of biological activities, including anti-inflammatory, antiviral, antifungal, anticancer, and analgesic properties, and more specifically, inhibition of protein tyrosine phosphate 1B (PTP1B) (35–42). Methanol extracts of C. soldanella decreased NO production, iNOS protein, and mRNA expression in LPS-activated Raw 264.7 cells (35). Water extracts of C. soldanella induced anti-inflammatory and analgesic effects in mice (36). Alkyl p-coumarates of an n-hexane fraction from a C. soldanella extract inhibited PTP1B activity in vitro (37). Resin glycosides from C. soldanella, calysolins V-IX, X-XIII, and XIV-XVII, induced antiviral activity against the herpes simplex virus type 1 (HSV-1) (39–41,43–46). An active fraction of Ipomoea carnea subsp. fistulosa (Convulvulaceae) induced antifungal activity in Colletotrichum gloeosporioides and Cladosporium cucumerinum (42).
Active components from C. soldanella are nortropane alkaloids, anthocyanin, coumaric acids, and flavonoids (47–50). Moreover, chloroform extracts showed both cytotoxic activities [ED50 2 μg/ml in UISO (squamous cell cervix carcinoma); ED50 7 μg/ml in KB (nasopharyngeal carcinoma)] and antibacterial (MIC 14.7 μg/ml in Bacillus subtilis) (43,44). Methanol extract also exhibited potential cytotoxicity against A549 lung (IC50 8.0 μg/ml) and Col2 colon (IC50 27.4 μg/ml) cancer cells (38). However, studies of the anticancer effect of C. soldanella have not been extensive focused on cytotoxicity. To find active components with anticancer activity, this study investigated the cytotoxic activity of crude extract and four solvent-partitioned fractions of C. soldanella in HepG2 human
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44. Gaspar EMM. Soldanelline B-The first acylated nonlinear tetrasaccharide macrolactone from the European Convolvulaceae Calystegia soldanella. Eur J Org Chem. 2001;2001:369–373. doi: 10.1002/1099-0690(200101)2001:2<369::AID-EJOC369>3.0.CO;2-7. [Cross Ref]
45. Takigawa A, Setoguchi H, Okawa M, Kinjo J, Miyashita H, Yokomizo K, Yoshimitsu H, Nohara T, Ono M. Identification and characterization of component organic and glycosidic acids of crude resin glycoside fraction from Calystegia soldanella. Chem Pharm Bull (Tokyo) 2011;59:1163–1168. doi: 10.1248/cpb.59.1163. [PubMed] [Cross Ref]
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47. Asano N, Yokoyama K, Sakurai M, Ikeda K, Kizu H, Kato A, Arisawa M, Höke D, Dräger B, Watson AA, et al. Dihydroxynortropane alkaloids from calystegine-producing plants. Phytochemistry. 2001;57:721–726. doi: 10.1016/S0031-9422(01)00131-5. [PubMed] [Cross Ref]
48. Tatsuzawa F, Mikanagi Y, Saito N. Flower anthocyanins of Calystegia in Japan. Biochem Syst Ecol. 2004;32:1235–1238. doi: 10.1016/j.bse.2004.05.008. [Cross Ref]
49. Tori M, Ohara Y, Nakashima K, Sono M. Caffeic and coumaric acid esters from Calystegia soldanella. Fitoterapia. 2000;71:353–359. doi: 10.1016/S0367-326X(99)00174-4. [PubMed] [Cross Ref]50. Ahn NR, Ko JM, Cha HC. Comparison of flavonoid profiles between leaves and stems of Calystegia soldanella and Calystegia japonica. Am J Plant Sci. 2012;3:1073–1076. doi: 10.4236/ajps.2012.38128.[Cross Ref] carcinoma cells. Furthermore, the 85% aqueous methanol (aq. MeOH) fraction, which exhibited the greatest cytotoxic effect, was evaluated for cell cycle distribution and the expression of several cell cycle checkpoint proteins.