The in vitro toxicity of venoms from South Asian Hump-nosed pit vipers (Viperidae: Hypnale)

Research Article

J Venom Res (2011), Vol 2, 17-23

Published online: 08 June 2011

Full Text: (PDF ~1489kb) | ERRATUM-E17 PDF ~487kb (published 18 June 2011) | (PubMed Central Record HTML)

Kalana Maduwage † , Wayne C Hodgson ‡ , Nicki Konstantakopoulos ‡, Margaret A O’Leary §, Indika Gawarammana ¥, Geoffrey K Isbister ‡§¶*

† Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka

‡ Monash Venom Group, Department of Pharmacology, Monash University, Victoria, 3800 Australia

§ Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia

¥ Department of Medicine, Faculty of Medicine, University of Peradeniya, Sri Lanka

¶ Discipline of Clinical Pharmacology, University of Newcastle, New South Wales, Australia

*Correspondence to: Geoffrey Isbister, Email:, Tel: +612 4921 1211, Fax: +612 4921 1870

Received: 02 March 2011, Revised: 24 May 2011, Accepted: 25 May 2011

© Copyright The Authors


Hump-nosed pit vipers (Genus Hypnale) are venomous snakes from South India and Sri Lanka. Envenoming by Hypnale species may cause significant morbidity and is characterized by local envenoming and less commonly coagulopathy and acute renal failure. Currently there are three nominal species of this genus: H. hypnaleH. zara and H. nepa. This study investigates the biochemical and pharmacological properties of the venoms from the three Hypnale species in Sri Lanka. The three Hypnale venoms had similar chromatographic profiles using reverse phase high performance liquid chromatography and fractions with procoagulant activity were identified. Hypnalevenoms had potent cytotoxicity in cultured rat aorta smooth muscle cells with similar IC50 values. The venoms had weak neurotoxic and myotoxic activity in the isolated chick biventer muscle preparation. They had mild procoagulant activity with close MCC 5 values and also phospholipase activity. Locally available polyvalent antivenom did not neutralise any venom effects. The study demonstrates that the three Hypnale venoms are similar and cytotoxicity appears to be the most potent effect, although they have mild procoagulant activity. These findings are consistent with clinical reports.

KEYWORDS: Hump-nosed pit vipers, snake venom, antivenom, Sri Lanka, Hypnale