Pharmacological characterization of Tibouchina granulosa

Introduction: Tibouchina granulosa ('quaresmeira') is a tree widely distributed in Brazil and commonly used as an ornamental plant. Some species of the genus are used in popular medicine. Personal observations indicate that teas from the leaves present a significant wound healing effect. However, there are no scientific data that support these applications. The aim of this study is to verify the pharmacological properties from T. granulosa in models of antinociception and inflammation.

Methods: Leaves (#37,931 deposited at herbarium of IB/UFRJ) were collected at Cachoeiras de Macacú (RJ/Brazil), dried, triturated and ethanol extract (EE) prepared in a soxhlet apparatus. EE was submitted to a liquid:liquid partition with hexane (H), dichloromethane (D), ethyl acetate (EA). Antinociceptive and anti-inflammatory effects were evaluated by the hot plate [HP,1] and subcutaneous air pouch [SAP,2] models, respectively. Webster mice (20 – 25 g, n = 6 – 8) were orally treated with 10,30,100 mg/kg. Results are presented as AUC(HP) and medium ± DP (SAP). Statistic was done by ANOVA/Newman-Keuls's (*p < 0.05). Protocols for animal use number #ICBDFBC-015 (COBEA/UFRJ/Brazil).

Results: HP: Vehicle = 780; Morphine = 5153; E = 2301, 9281*#, 7139*# AUC; H = 2655, 7676*#, 1425 AUC; D = 5921*, 2307, 4650* AUC; EA = 3321*, 3363*, 4404* AUC to 10,30,100 mg/kg respectively. SAP: leukocyte migration: Vehicle = 2.9 ± 1.5; Carrageenan(C)= 58.6 ± 15.9; C+Dexamethasone = 33.4 ± 17.3*; C + E = 43 ± 3.9*, 48.1 ± 23.1, 46.4 ± 9.8; C + H = 27.7 ± 5.4*, 28.0 ± 3.1*, 25.8 ± 14.9; C + D = 19.7 ± 9.3*, 17.4 ± 7.6*, 29.1 ± 6.9*; C + EA = 34.6 ± 2.9*, 45.8 ± 11.7, 27.3 ± 11* cell x106/mL, to 10,30,100 mg/kg, respectively.

Conclusions: Ethanol extract and fractions have anti-inflammatory and antinociceptive effects that can justify the popular use.

Acknowledgements: Alan Minho (technical support), Instituto Vital Brazil (donation of animals), CAPES, CNPq and FAPERJ (financial support).

Keywords: Tibouchina granulosa, antinociceptive, anti-inflammatory

References:

[1] Sahley TL, Berntson GG. Antinociceptive effects of central and systemic administration of nicotine in the rat. Psychopharmacol 1979; 65: 279 – 283.

[2] Raymundo LJRP et al. Characterization of the anti-inflammatory and antinociceptive activities of the Hypis pectinata (L.) Poit essencial oil. J Ethnopharmacol 2001; 134: 725 – 732.