QUALITY CONTROL OF Melissa officinalis COMMERCIALIZED MEDICINAL PRODUCTS BY CAPILLARY ELECTROPHORESIS

ARCE, SILVIA; ACOSTA, GIMENA; LLABOT, JUAN; ALLEMANDI, DANIEL; GOMEZ, MARIA ROXANA

Cordoba

Congreso; 1ª Reunión Internacional de Ciencias Farmacéuticas; 2010

A large percentage of world population, consume regularly infusions and/or crude extracts derived from plant material for the primary health care. The leaves of “lemon balm” (Melissa officinalis L.) are traditionally used in the folk medicine because of their sedative, aromatic, digestive and antispasmodic properties. The European and the British Pharmacopoeia assays for Melissa leaf quality control establish the quantification of total hydroxyccinamic derivatives expressed as rosmarinic acid (RA). This compound is a natural constituent in several herbs belonging Lamiaceae family, therefore was used as a marker compound. By the other hand, “catmint” (Nepeta cataria L.), which is used in gastrointestinal and respiratory hyperactive disorders is a common adulterant of M. officinalis. The aim of this work is to develop a capillary electrophoresis (CE) method for the characterization and quality control of Lamiaceae family herbs in a simple, fast and reliable way, as well as, an approach to detect rapidly M. officinalis adulteration or substitution, particularly by N. cataria in different commercial medicinal samples. Materials and methods The analyzed samples were: infusions (water extracts, 10% w/v) from ground plant material obtained from both M. officinalis cultivated and commercial herbs; tinctures (alcoholic extracts, 10% w/v) both elaborated in our laboratory and commercial. Spray-dried (SDE) and lyophilized extracts (LE) were obtained from the infusions; also, a based Melissa cosmetic product (commercial whitening toothpaste, WT) was investigated. A BÜCHI 290 Mini-spray Dryer at 140 ºC, and a L-A-B5 Rificor equipments were used for drying and lyophilizing the water extracts, respectively. The analyses were performed with a capillary electrophoresis (CE) instrument, Beckman P/ACE MDQ. RA was acquired from Sigma-Aldrich Co. (St. Louis, MO). Results Melissa leaf consists of the dried leaf of Melissa officinalis L. It contains not less than 4.0 per cent of total hydroxycinnamic derivatives expressed as RA of the dried drug. The RA concentration was evaluated according to established in the official assays. In several samples, was found that the RA value did not satisfy that specifications. In these cases, after the botanical analysis, the identity of the mentioned samples was confirmed as N. cataria, which permitted confirm the adulteration and/or substitution of M. officinalis by N. cataria. On the other hand, it was observed that in SDE samples, the RA values were higher than in LE ones, for both Melissa and Nepeta. Respect to tinctures, in those prepared by our group from the cultivated lemon balm the RA value was in accordance with the pharmacopoeias’ requirements. In the case of the commercial ones, the RA value was below than the established in the monographies. With regard to WT sample based on Melissa extract (among others herbs), the presence of RA was not confirmed or was below of the detected by the methodology. The optimal conditions by CE analysis were: BGE sodium tetraborate 20 mM, pH 9.2; hydrodynamic sample injection at 20 Psi during 5 seconds, the applied voltage was 25 kV. The proposed methodology was validated regarding linearity and precision. Conclusions The present CE method represents a useful tool for determination of RA in commercial medicinal samples. The developed technique allows detect in a reliable and fast way the possible adulteration and/or substitution, by Nepeta cataria, of medicinal products labeled as Melissa officinalis. Apparently, the drying process is more favorable than the lyophilization considering RA yielding and operation cost.