Short communication Phytochemical and pharmacological studies on Orthosiphon stamineus Benth. (Lamiaceae) hydroalcoholic extracts Neli-Kinga Olah a, *, Laura Radu b , Cristina Mogos ¸an c , Daniela Hanganu c , Simion Gocan d a SC PLANTEXTRAKT SRL, 3462-Radaia, Cluj, Romania b SC NORTHWOOD BOTANICAL SRL, L. Pasteur street 75, 3400-Cluj-Napoca, Romania c Faculty of Pharmacy, ‘‘Iuliu Hat ¸ieganu’’ University of Medicine and Pharmacy, I. Creanga street 15, 3400-Cluj-Napoca, Romania d Faculty of Chemistry, ‘‘Babes ¸-Bolyai’’ University, Arany J. street 11, 3400-Cluj-Napoca, Romania Received 17 October 2002; received in revised form 21 March 2003; accepted 21 March 2003 Abstract The main components of Orthosiphon stamineus Benth. leaves and extracts are the pharmacologically active polyphenols: the polymethoxylated flavonoids and the caffeic acid derivatives. Two tinctures, having different alcohol concentration, were studied from phytochemical and pharmacological point of view. The main polyphenols were identified and quantitatively determined by HPLC. Comparison of the retention parameters and UV  /Vis spectra of standards and those of the separated compounds performed the identification of caffeic-, cichoric- and rosmarinic acids, respectively, of sinesetine and eupatorine. The quantitative determination was performed by external standard method. The diuretic, saluretic and uricosuric actions of the studied tinctures were compared by experiments on rats. # 2003 Elsevier Science B.V. All rights reserved. Keywords: Orthosiphon stamineus Benth.; Hydroalcoholic extracts; Tinctures; Polyphenols; Caffeic acid derivatives; Polymethoxylated flavonoids; HPLC; Qualitative and quantitative determination; Diuretic action; Saluretic action; Uricosuric action 1. Introduction The most important components of Orthosiphon stamineus Benth. leaves are the polyphenols: the polymethoxylated flavonoids: sinesetine (IV), eu- patorine (V), etc. and the caffeic acid derivatives: rosmarinic acid (III), cichoric acid (II), caffeic acid (I), etc. The polyphenols from O. stamineus Benth. leaves were studied by different chromatographic and spectral methods: TLC [1], HPLC  /UV  /Vis spectrometry [1  /4], HPLC-NMR [5], UV  /Vis spectrometry [4]. This paper presents a HPLC method for identi- fication and quantitative determination of main polyphenols (I  /V) from two different O. stami- neus Benth. tinctures and a comparison of the pharmacological action of these tinctures. * Corresponding author. E-mail address: neliolah@yahoo.com (N.-K. Olah). Journal of Pharmaceutical and Biomedical Analysis 33 (2003) 117  /123 www.elsevier.com/locate/jpba 0731-7085/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0731-7085(03)00227-9