PHYTOTHERAPY RESEARCH Phytother. Res. 17, 420 – 421 (2003) Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/ptr.1153 Copyright © 2003 John Wiley & Sons, Ltd. Received 24 September 2001 Accepted 10 December 2001 John Wiley & Sons, Ltd. SHORT COMMUNICATION SHORT COMMUNICATION Trypsin Inhibitory Effect of Wedelolactone and Demethylwedelolactone Wedelolactone Activity Samiulla D. Syed 1 , Mundkinajeddu Deepak 2 , Shivanna Yogisha 1 , Arun P. Chandrashekar 2 , Keerthi A. Muddarachappa 2 , Prashanth D’Souza 1 *, Amit Agarwal 1 and B. V. Venkataraman 3 1 Bioassay Unit, R&D Centre, Natural Remedies Pvt. Ltd, 5B, Veerasandra Indl. Area, Hosur Road, Bangalore 561 229, India 2 Phytochemistry Laboratory, R&D Centre, Natural Remedies Pvt. Ltd, 5B, Veerasandra Indl. Area, Hosur Road, Bangalore 561 229, India 3 Department of Pharmacology, St. Johns’ Medical College, Sarjapur Road, Bangalore 560 034, India Wedelolactone (WL) and demethylwedelolactone (DWL) isolated from Eclipta alba were tested in the trypsin inhibition bioassay (in vitro). Both compounds showed potent activity. IC 50 values of WL and DWL were found to be 2.9 and 3.0 μg/mL respectively. Copyright © 2003 John Wiley & Sons, Ltd. Keywords: Eclipta alba; trypsin inhibition; wedelolactone; demethylwedelolactone. INTRODUCTION Eclipta alba (L) Hassk. (syn: Eclipta prostrata) Asteraceae is a small branched annual herb inhabiting tropical and subtropical regions of the world. It is reported to exhibit hepatoprotective activity (Ma-Ma et al., 1978). WL and DWL were identified as its hepatoprotective principles (Wagner et al., 1986). WL is also a potent 5-LO inhibitor (Wagner and Fessler, 1986). There is considerable evidence to suggest that a variety of disease states are mediated by excessive pro- tease activity. Proteases are involved in malignancy, inflammation, skin disease, pulmonary emphysema etc. Serine proteases such as trypsin and chymotrypsin are involved in glomerulonephritis and pancreatitis (Cannell et al., 1988). In our search for potent protease inhibitors, we have tested WL and DWL for trypsin inhibitory activity. MATERIALS AND METHODS Plant material. The whole plant of Eclipta alba was collected from Bangalore, India. The plant was authen- ticated by our Pharmacognosy Department. Voucher specimen no. BAU/TRY/01 is stored at the Bioassay Unit, R&D Centre, Natural Remedies Pvt. Ltd. Isolation of WL and DWL. This was done according to the method of Wagner et al. (1986). Trypsin inhibition assay. The assay was performed according to the method of Cannell et al. (1988). RESULTS AND DISCUSSION Both WL and DWL showed a potent trypsin inhibition effect (Table 1). Further work on these compounds may suggest the use of these compounds as clinically useful trypsin inhibitors. A trypsin inhibitor such as leupeptin from Streptomyces strains is used topically in burns (Cannell et al., 1988). Hence WL and DWL may be use- ful in burns. Eclipta alba has been shown to exhibit an antiinflammatory effect (Chandra et al., 1987). The observed effect of WL and DWL as trypsin inhibitors may partly explain the antiinflammatory activity of the plant, since trypsin is involved in inflammation. * Correspondence to: Dr P. D’Souza, Bioassay Unit, R&D Centre, Natural Remedies Pvt. Ltd, 5B, Veerasandra Indl. Area, Hosur Road, Bangalore 561 229, India. Table 1. Trypsin inhibitory activity of WL and DWL a IC 50 ( μ g/ml) WL 2.9 DWL 3.0 Ovomucoid from hen egg white b 1.45 a All determinations were done in triplicate. b Reference standard, obtained from M/s. Fluka, USA.