Anti-inflammatory and antihistaminic activity of triterpenoids isolated from Bursera cuneata (Schldl.) Engl.

AIM OF THE STUDY: To isolate compounds with anti-inflammatory activity from Bursera cuneata by a bioassay-guided fractionation. MATERIALS AND METHODS: Three extracts of different polarities were elaborated by maceration. These extracts were assayed for their inhibitory effects on phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induced edema in mice. The dichloromethane extract was subjected to activity guided fractionation using successive chromatographic procedures. Additionally, the levels of histamine were determined in the ear samples obtained from the TPA assay, which were determined by high-performance liquid chromatography (HPLC). Effect of moronic Acid on RAW 264.7 stimulated with LPS was evaluated for NO and TNF secretion. RESULTS: The dichloromethane extract had the highest anti-inflammatory effect (89.1 ±â€¯2.2% inhibition) over that of the hexane (53.3 ±â€¯1.2%) and methanolic (77.4 ±â€¯1.8%) extracts at a dose of 0.1 mg/ear. The FS-3 fraction, obtained from the dichloromethane extract, comprised triterpenes ß-sitosterol (1), α-amyrin (2), moronic acid (3), and ursolic acid (4), and all the compounds showed significant activity in comparison with that of indomethacin (41.5 ±â€¯0.6%) at 0.1 mg/mouse ear. However, moronic acid displayed the highest inhibitory effect (68.1 ±â€¯1.3%). Additionally, levels of histamine were determined by HPLC in the treated tissues. moronic acid was the most active (73.3 ±â€¯1.1%, indomethacin 33.8 ±â€¯0.8%). The bio-guided isolation resulted in the identification of moronic acid as the principal anti-inflammatory and antihistaminic compound present in B. cuneata. To confirm a general anti-inflammatory effect, moronic acid was evaluated on the activation of RAW 264.7 cell stimulated with LPS. At 30 and 15 mg/mL a significant reduction of ON was observed (36% and 28% respectively) but had no significant effect on TNFα production. CONCLUSIONS: Our study showed that the organic extracts and isolated compounds from the aerial parts of B. cuneata had topical anti-inflammatory and antihistaminic activities in vivo, but in vitro only modified the production of ON in RAW cells. The results of this study validated the use of B. cuneata in folk medicine for the treatment of inflammatory diseases.

Isolation of jacaranone, a sedative constituent extracted from the flowers of the Mexican tree Ternstroemia pringlei.

ETHNOPHARMACOLOGICAL RELEVANCE: Ternstroemia pringlei represents one of the most widely employed and commercially exploited medicinal plant in Mexico, used popularly as a tranquilizer and for the treatment of insomnia. AIM OF THE STUDY: To investigate the sedative constituents of the plant through a bio-guided fractionation of extracts derived from calyx and fruits. MATERIALS AND METHODS: Crude extracts with different polarities (CHCl(3), AcOEt, MeOH, aqueous) were prepared and subjected to chromatographic fractionation, leading to the isolation of the sedative compound (1) from the MeOH crude extract. The identity of 1 was unequivocally established by means of 1D and 2D NMR spectroscopic analysis. The sleeping time induced by sodium pentobarbital and the elevated plus-maze models were performed on mice to determine the sedative and anxiolytic activities, respectively. Bioactivity was also investigated though in vitro GABA release experiments using mice brain slices. RESULTS: The sedative compound was established as jacaranone (1), and its effect was clearly demonstrated through a dose-dependent response analysis (ED(50) = 25 mg/kg mouse weight). When tested in the elevated plus-maze model, none of the extracts from Ternstroemia pringlei displayed anxiolytic activity. GABA release experiments showed that the MeOH and aqueous crude extracts released this neurotransmitter at a ratio of 217 and 179 pmol/g protein, respectively, evidencing the presence of other bioactive constituents in the extracts apart of 1, whose activity was absent in this model. CONCLUSIONS: Although 1 has been isolated and identified in a number of plant species, this is the first time that its sedative effect has been demonstrated. No previous record exists of other sedative compounds having been isolated from Ternstroemia pringlei.