A comparative study of two clerodane diterpenes from Baccharis trimera (Less.) DC. on the influx and mobilization of intracellular calcium in rat cardiomyocytes

• Published in: Phytomedicine (Stuttgart) Vol. 21; no. 8-9; pp. 1021 - 1025
• Main Authors: Garcia, Francisca Adilfa de Oliveira, Tanae, Mirtes Midori, Torres, Luce Maria Brandão, Lapa, Antônio José, de Lima-Landman, Maria Teresa Riggio, Souccar, Caden
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01.07.2014; Urban & Fischer Verlag
• Subjects: Animals; Asteraceae; Baccharis; Baccharis - chemistry; Baccharis trimera; Biological transport; Brazil; Calcium - metabolism; Calcium Channels, L-Type - drug effects; Cardiomyocytes; Cell research; Cells, Cultured; Compositae; Cytoplasm - metabolism; Diterpenes; Diterpenes, Clerodane - chemistry; Diterpenes, Clerodane - isolation & purification; Diterpenes, Clerodane - pharmacology; Health aspects; L-type Ca2+ channels; Medicine, Traditional; Molecular Structure; Myocytes, Cardiac - drug effects; Plant Components, Aerial - chemistry; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Portal Vein - drug effects; Properties; Rats; Rats, Wistar; Terpenes; Brazil; Diterpenes; Cardiomyocytes; Baccharis trimera; L-type Ca2+ channels; L-type Ca(2+) channels
• ISSN: 0944-7113; 1618-095X
• DOI: 10.1016/j.phymed.2014.04.018

Baccharis trimera (Less.) D.C. (Asteraceae) is a medicinal species native to South America and used in Brazilian folk medicine to treat gastrointestinal and liver diseases, kidney disorders and diabetes. The aqueous extract (AE) of the aerial parts of this species presented two mainly constituents: the ent-clerodane diterpene (Fig. 1) and the neo-clerodane diterpene (Fig. 2). The objective of this work was to study their activities on the blockade of Ca2+-induced contractions in KCL-depolarized rat portal vein preparations, and on the influx and mobilization of cytosolic calcium in rat cardiomyocytes by fluorescence measurements. The results showed that both the neo- and the ent-clerodane diterpenes reduced the maximal contractions induced by CaCl2, in KCl depolarized rat portal vein preparations, without modifying the EC50. The data on the concentration of cytosolic calcium ([Ca2+]c) showed that, while the neo-clerodane diterpene stimulates the mobilization of [Ca2+]c in rat cardiomyocytes, this effect was not observed with the ent-clerodane diterpene. On the other hand, the influx of calcium was not altered by the neo-clerodane diterpene, but was reduced in the presence of the ent-clerodane diterpene, indicating that this compound induces a blockade of the voltage-dependent calcium channels.