Gastroprotective Effect and Cytotoxicity of Labdeneamides with Amino Acids

Abstract

Semisynthetic aromatic amides from Araucaria araucana diterpene acids have been shown to display a relevant gastroprotective effect with low cytotoxicity. The aim of this work was to assess the gastroprotective effect of amino acid amides from imbricatolic acid and its 8 (9)-en isomer in the ethanol/HCl-induced gastric lesions model in mice as well as to determine the cytotoxicity of the obtained compounds on the following human cell lines: normal lung fibroblasts (MRC-5), gastric adenocarcinoma (AGS), and liver hepatocellular carcinoma (Hep G2). The diterpenes 15-acetoxyimbricatolic acid, its 8 (9)-en isomer, 15-hydroxyimbricatolic acid, and the 8 (9)-en derivative, bearing a COOH function at C-19, were used as starting compounds. New amides with C-protected amino acids were prepared. The study reports the effect of a single oral administration of either compound 50 min before the induction of gastric lesions by ethanol/HCl. Some 20 amino acid monoamides were obtained. Dose-response experiments on the glycyl derivatives showed that at a single oral dose of 100 mg/kg, the compounds presented an effect comparable to the reference drug lansoprazole at 20 mg/kg and at 50 mg/kg reduced gastric lesions by about 50 %. All derivatives obtained in amounts > 30 mg were compared at a single oral dose of 50 mg/kg. The best gastroprotective effect was observed for the exomethylene derivatives bearing a valine residue at C-19 either with an acetoxy or free hydroxy group at C-15. The tryptophanyl derivative from the acetate belonging to the 8,9-en series presented selective cytotoxicity against hepatocytes. The glycyl amide of 15-acetoxyimbricatolic acid was the most cytotoxic and less selective compound with IC₅₀ values between 47 and 103 µM for the studied cell lines. This is the first report on the obtention of semisynthetic amino acid amides from labdane diterpenes.

Key words

amino acid amides - Araucaria araucana - Araucariaceae - cytotoxicity - gastroprotective effect - labdane diterpenes

References

• 1 Luo J, Nordenvall C, Nyren O, Adami H O, Permert J, Ye W. The risk of pancreatic cancer in patients with gastric or duodenal ulcer disease.  Int J Cancer. 2007;  120 368-372
• 2 Bahmanyar S, Ye W, Dickman P W, Nyren O. Long-term risk of gastric cancer by subsite in operated and unoperated patients hospitalized for peptic ulcer.  Am J Gastroenterol. 2007;  102 1185-1191
• 3 Catalano V, Labianca R, Beretta G D, Gatta G, de Braud F, Van Cutsem E. Gastric cancer.  Crit Rev Oncol Hematol. 2009;  71 127-164
• 4 Departamento de Estadísticas e Información de Salud, Ministerio de Salud, Gobierno de Chile .http://deis.minsal.cl/deis/salidas06/causas06.asp?temp=45_64_AMBOS.htm Accessed May 02, 2010
• 5 Rodríguez J A, Bustamante C, Astudillo L, Schmeda-Hirschmann G. Gastroprotective activity of solidagenone on experimentally induced gastric lesions in rats.  J Pharm Pharmacol. 2002;  54 399-404
• 6 Rodríguez J A, Astudillo L, Schmeda-Hirschmann G. Oleanolic acid promotes healing of acetic acid-induced chronic gastric ulcers in rats.  Pharmacol Res. 2003;  48 291-294
• 7 Rodríguez J A, Theoduloz C, Sánchez M, Razmilic I, Schmeda-Hirschmann G. Gastroprotective and ulcer-healing effect of new solidagenone derivatives in human cell cultures.  Life Sci. 2005;  77 2193-2205
• 8 Rodríguez J A, Theoduloz C, Sánchez M, Yáñez T, Razmilic I, Schmeda-Hirschmann G. Gastroprotective activity of a new semi-synthetic solidagenone derivative in mice.  J Pharm Pharmacol. 2005;  57 265-271
• 9 Schmeda-Hirschmann G, Rodríguez J A, Astudillo L. Gastroprotective activity of the diterpene solidagenone and its derivatives on experimentally induced gastric lesions in mice.  J Ethnopharmacol. 2002;  81 111-115
• 10 Schmeda-Hirschmann G, Astudillo L, Sepúlveda B, Rodríguez J A, Theoduloz C, Yáñez T, Palenzuela J A. Gastroprotective effect and cytotoxicity of natural and semisynthetic labdane diterpenes from Araucaria araucana.  Z Naturforsch C. 2005;  60 511-522
• 11 Farina C, Pinza M, Pifferi G. Synthesis and anti-ulcer activity of new derivatives of glycyrrhetic, oleanolic and ursolic acids.  Farmaco. 1998;  53 22-32
• 12 Onoda Y, Magaribuchi T, Tamaki H. Effects of the new anti-ulcer agent 12-sulfodehydroabietic acid monosodium salt on duodenal alkaline secretion in rats.  Arzneimittelforschung. 1990;  40 576-578
• 13 Onoda Y, Takido M, Magaribuchi T, Tamaki H. Effects of 12-sulfodehydroabietic acid monosodium salt (TA-2711), a new anti-ulcer agent, on gastric mucosal lesions induced by necrotizing agents and gastric mucosal defensive factors in rats.  Jpn J Pharmacol. 1990;  52 631-638
• 14 Pearson J P, Roberts N B. Mucosal protective effects of ecabet sodium: pepsin inhibition and interaction with mucus.  Clin Sci. 2001;  100 411-417
• 15 Wada H, Kodato S, Kawamori M, Morikawa T, Nakai H, Takeda M, Saito S, Onoda Y, Tamaki H. Antiulcer activity of dehydroabietic acid derivatives.  Chem Pharm Bull. 1985;  33 1472-1487
• 16 Schmeda-Hirschmann G, Astudillo L, Rodríguez J A, Theoduloz C, Yáñez T. Gastroprotective effect of the Mapuche crude drug Araucaria araucana resin and its main constituents.  J Ethnopharmacol. 2005;  101 271-276
• 17 Izquierdo R, Astudillo L, Rodríguez J A, Theoduloz C, Palenzuela J A, Schmeda-Hirschmann G. Gastroprotective effect and cytotoxicity of labdeneamides.  Planta Med. 2007;  73 310-317
• 18 Sepúlveda B, Astudillo L, Rodríguez J A, Yáñez T, Theoduloz C, Schmeda-Hirschmann G. Gastroprotective and cytotoxic effect of dehydroabietic acid derivatives.  Pharmacol Res. 2005;  2 429-437
• 19 Lee D Y W, He M, Kondaveti L, Liu-Chen L-Y, Ma Z, Wang Y, Chen Y, Li J-G, Beguin C, Carlezon Jr W A, Cohen B. Synthesis and in vitro pharmacological studies of C(4) modified salvinorin A analogues.  Bioorg Med Chem Lett. 2005;  15 4169-4173
• 20 Lee D Y W, He M, Liu-Chen L-Y, Wang Y, Li J-G, Xu W, Ma Z, Carlezon Jr W A, Cohen B. Synthesis and in vitro pharmacological studies of new C(4) modified salvinorin A analogues.  Bioorg Med Chem Lett. 2006;  16 5498-5502
• 21 Yu D, Sakurai Y, Chen C-H, Chang F-R, Huang L, Kashiwada Y, Lee K-H. Anti-AIDS agents 69. Moronic acid and other triterpene derivatives as novel potent anti-HIV agents.  J Med Chem. 2006;  49 5462-5469
• 22 Areche C, Rodríguez J A, Razmilic I, Yañez T, Theoduloz C, Schmeda-Hirschmann G. Gastroprotective and cytotoxic effect of semisynthetic ferruginol derivatives.  J Pharm Pharmacol. 2007;  59 289-300
• 23 Olfert E D, Cross B M, McWilliam A A. Guide to the care and use of experimental animals, Vol. 1. Ottawa; Canadian Council on Animal Care 1993: 213-214
• 24 Rodríguez J A, Haun M. Cytotoxicity of trans-dehydrocrotonin from Croton cajucara (Euphorbiaceae) on V79 cells and hepatocytes.  Planta Med. 1999;  65 522-526
• 25 Parra A, Rivas F, Lopez P E, Garcia-Granados A, Martinez A, Albericio F, Marquez N, Muñoz E. Solution- and solid-phase synthesis and anti-HIV activity of maslinic acid derivatives containing amino acids and peptides.  Bioorg Med Chem. 2009;  17 1139-1145
• 26 Wu F, Yi Y, Sun P, Zhang D. Synthesis, in vitro inhibitory activity towards COX-2 and haemolytic activity of derivatives of Esculentoside A.  Bioorg Med Chem Lett. 2007;  17 6430-6433
• 27 Wei Y, Ma C-M, Hattori M. Synthesis and evaluation of a-seco type triterpenoids for anti-HIV-1 protease activity.  Eur J Med Chem. 2009;  44 4112-4120
• 28 Silva Melo P, Durán N, Hiruma-Lima C A, Souza-Brito A R M, Haun M. Comparison of the gastroprotective effect of a diterpene lactone isolated from Croton cajucara with its synthetic derivatives.  J Ethnopharmacol. 2003;  87 169-174
• 29 Miyagawa T, Ohtsuki T, Koyano T, Kowithayakorn T, Masami I. Cassaine diterpenoid dimers isolated from Erythrophleum succirubrum with TRAIL-resistance overcoming activity.  Tetrahedron Lett. 2009;  50 4658-4662

1 Dedicated to the memory of Prof. Dr. Jaime A. Rodríguez