The effects of aqueous extracts and hydro-alcoholic extract (HAE), and of a dichloromethane fraction (MG1) obtained from the HAE of Mikania glomerata leaves on isolated respiratory and vascular smooth muscle have been investigated. Aqueousextracts and HAE induced a significant inhibition on the histamine contractions on the isolated guinea-pig trachea. HAE extract induced a concentration-dependent relaxation on guinea-pig trachea pre-contracted with histamine (IC50 0.34 (0.29-0.39) mg mL(-1)), acetylcholine (IC50 0.72 (0.67-0.77) mg mL(-1)) or K+ (IC50 1.41 (1.18-1.64) mg mL(-1)) and on isolated human bronchi precontracted with K+ (IC50 0.34 (0.26-0.42) mg mL(-1)). The dichloromethane fraction induced a concentration dependent relaxation in guinea-pig trachea precontracted with K+ (IC50 0.017 (0.012-0.022) mg mL(-1)). The dichloromethane fraction had also a small vasodilator effect on the isolated mesenteric vascular bed and on the isolated rat aorta, and a significant reduction of the oedema induced by subplantar injections of Bothropsjararaca venom in mice. When tested on plasmid DNA, MG1 did not damage the DNA. Chromatographic analysis showed the presence of 11.4% w/w coumarin in MG1. The results supported the indication of M. glomerata products for the treatment of respiratory diseases where bronchoconstriction is present.

Arachis retusaKrapov. et W. C. Gregory et Valls is endemic in the West-central region of Brazil, occurring in areas endangered by human actions. The establishment of in vitro preservation methods for wild species of Arachis is an alternative to seed banks for germplasm storage, multiplication and distribution. The risk of genetic changes induced by tissue culture and the monitoring of the genetic stability of the biological material before, during and after storage must be considered in the context of conservation. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) fingerprinting were used to evaluate the genetic stability of in vitro plants originated from cotyledons and embryo axes of A. retusa. Cotyledons originated shoots through direct organogenesis and embryo axes displayed multishoot formation induced by 110 mmol/L and 8.8 mmol/L BAP, respectively. Ninety genomic regions (loci) generated from RAPD and 372 from AFLP analyses were evaluated. All amplified fragments detected by both techniques in plants derived from the two explant types were monomorphic. The results indicate that the recovered shoots are genetically stable at the assessed genomic regions. Key words: amplified fragment length polymorphism; Arachis retusa; in vitro preservation; micropropagation; random amplified polymorphic DNA; somaclonal variation. Gagliardi RF, Hanai LR, Pacheco G, Oliveira CA, Carneiro LA, Valls JFM, Mansur E, Vieira MLC (2007). Assessment of genetic stability among in vitro plants of Arachis retusa using RAPD and AFLP markers for germplasm preservation.

Somatic embryogenesis was induced from seed explants of Arachis archeri, A. porphyrocalix (Section Erectoides) and A. appressipila (Section Procumbentes) in response to 6-benzylaminopurine (BAP). Embryo axes first developed into single shoots in response to 4.4 lM BAP. Friable embryogenic calluses were produced from the hypocotyl region of these explants in response to different BAP concentrations. Embryonic leaflets also gave rise to friable calluses, but somatic embryos were only observed in explants of A. archeri and A. appressipila. Histological analyses revealed the presence of heart-shaped, torpedo and cotyledonary stages embryos, both as isolated and fused structures. A low frequency of embryo-to-plant conversion was achieved by inducing shoot development on medium solidified with 0.5% phytagel and supplemented with 1.5% or 3% sucrose. Rooting was induced on MS supplemented with indole-3-acetic acid (IAA).

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