Phytochemical, physicochemical, microbiological study and anticholinesterase activity of Ginkgo biloba L. and Bacopa monnieri L. used in phytotherapy

Herbal medicines based on Ginkgo biloba L. and Bacopa monnieri L. are used to improve memory and cognitive function. The quality control and anticholinesterase activity of the herbal medicines prepared from G. biloba and B. monnieri were evaluated which are commercialized in handling pharmacies. Samples of herbal medicines based on G. biloba and B. monnieri were obtained from handling pharmacies in Teresina-PI, submitted to labeling analysis and anticholinesterase activity. The phytochemical study was performed by preliminary prospecting, TLC and HPLC. The tests physicochemical and microbiological analyses were made according to the Pharmacopoeia 2010. It was observed that the labeling, foreign material, disintegration, and microbiological parameters were in accordance with ANVISA standards. The colorimetric tests were uniform in the samples of B. monnieri and variable of G. biloba. The average weight evaluation shows that the G1 and B3 samples have capsular content above that described in the labeling and presented pH values ​​different. Among the thermogravimetric profiles, the mass losses of samples G1 and B3 showed values ​​with high ash content, suggesting adulterations. Phytochemical prospecting showed flavonoids as common secondary metabolites in both species, corroborating with TLC and HPLC analysis, which identified the compounds chlorogenic acid, rutin, myricetin and quercetin. The samples G4, B2 and B5 present metabolites capable of inhibiting the enzyme acetylcholinesterase with IC50 of 0.8540 mg/mL, 0.9650 mg/mL and 1.8221×10-5 mg/mL, respectively. The samples G1 and B3 of G. biloba and B. monnieri, did not obey some parameters of quality control for herbal medicines according to the criteria of the Brazilian Pharmacopeia.