LC Characterisation of Guaco Medicinal Extracts, Mikania laevigata and M. glomerata, and their Effects on Allergic Pneumonitis

• Published in: Planta medica Vol. 72; no. 8; pp. 679 - 684
• Main Authors: Santos, S.C. dos, Krueger, C.L, Steil, A.A, Kreuger, M.R, Biavatti, M.W, Junior, A.W
• Format: Journal Article
• Language: English
• Published: Germany 01.06.2006
• Subjects: Alveolitis, Extrinsic Allergic - drug therapy; Alveolitis, Extrinsic Allergic - pathology; animal disease models; Animals; asthma; Bronchi - cytology; Bronchi - drug effects; Bronchoalveolar Lavage; chemical constituents of plants; Chromatography, High Pressure Liquid; coumaric acids; coumarins; Disease Models, Animal; Female; high performance liquid chromatography; histopathology; human health; immediate hypersensitivity; medicinal plants; medicinal properties; Mice; Mice, Inbred BALB C; Mikania; Mikania glomerata; Mikania laevigata; Phytotherapy; plant extracts; Plant Extracts - administration & dosage; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; Plant Leaves; pneumonia; quantitative analysis; traditional medicine; Brazil
• ISSN: 0032-0943; 1439-0221
• DOI: 10.1055/s-2006-931577

The leaves of guaco (Mikania glomerata and M. laevigata) are widely used for the treatment of asthma and bronchitis. An LC method for the quantification of coumarin and O-coumaric acid in medicinal extracts was developed and validated for linearity, limit of detection, accuracy, precision, as well as intra- and inter-day variations. Extracts and isolated markers were tested in the mice allergic pneumonitis model and the histopathological profile of the lung tissue was analysed. The values found for coumarin and O-coumaric acid in a fluid extract were 1.53 and 1.69 mg/mL, respectively, for M. glomerata, and 0.96 and 0.38 mg/mL for M. laevigata. The values found for the lyophilised aqueous extract were 0.22 and 0.11 mg/mL of coumarin and O-coumaric acid in M. glomerata and 0.05 and 0.02 mg/mL in M. laevigata, respectively . The analysed samples from the species M. glomerata presented more coumarin and O-coumaric acid than the analogous M. laevigata species. Both coumarin and O-coumaric acid are part of the phytocomplex which is responsible for the therapeutic activity of the guaco species. The lyophilisation process generated some alterations in the extract, in comparison with the fresh aqueous extract, and these extracts did not present anti-inflammatory activity. Comparing the histopathological images of the groups tested, a haemorrhagic profile of lung tissue of animals treated with lyophilised extract, O-coumaric acid and coumarin is observed, but not for the group treated with hydroalcoholic extract. It is probable that some protective effect of the whole extract (lost during the lyophilisation process) blocks the harmful effects of the isolated markers.