Preparations based on extracts of St. John's wort are widely marketed for treating
mild to moderately severe depressive disorders and other health conditions such as
anxiety and sleep disorders [1]. Active principles are not yet discovered and flavonols,
based on quercetin aglycone, naphthodianthrones (hypericin and pseudohypericin) and
phloroglucinols such as hyperforin, adhyperforin seems to be related to this action.
Thus, flavonols and naphthodianthrones are polyphenols, quite polar derivatives but
their water solubility is very scarce; phloroglucinols are lipophilic and completely
not water-soluble constituents. In addition, hypericins and hyperforins are not stable
with regard to heat and light [2].
In this study the optimisation of technological and pharmaceutical aspects of dried
commercial extract of St. John's wort were evaluated by the in vivo “Porsolt test“. Solid dosage forms containing β-cyclodextrin and micellear systems
(SDS, ASC-8) were compared in the “Porsolt test“ with the extract alone. The extract
showed the antidepressant activity in the mice after 60 minutes and with the dosage
of 100mg/kg. The same antidepressant activity appeared in 30min with a micellar solution
of SDS 40mM containing the same quantity of extract (100mg/kg), while with micelles
of ASC-8 40 mM the effect appeared at 15min and with a dosage of 30mg/kg. In the case
of colyophilized with β-cyclodextrin the best results were obtained at 30min, administering
60mg/kg of the extract.
Acknowledgements: The financial support of MIUR (PRIN 2004) and Ente Cassa di Risparmio di Firenze is
gratefully acknowledged for financial support.
References: 1. Chatterjee, S.S. et al. (1998), Pharmacopsychiatry 31: 7–15. 2 Bilia A.R. et al. (2001), Int. J. Pharm. 213: 199–208.
