Citation

Maneksh D, Sidharthan A, Kettimuthu K, Kanthakumar P, Lourthuraj AA, Ramachandran A, Subramani S. Indian J. Pharmacol. 2010; 42(3): 178-184.

Copyright

(Copyright © 2010, Medknow Publications)

DOI

10.4103/0253-7613.66843

PMID

unavailable

Abstract

Background and Purpose: A water decoction of the poisonous shrub Cleistanthus collinus is used for suicidal purposes. The mortality rate is 28%. The clinical profile includes distal renal tubular acidosis (DRTA) and respiratory failure. The mechanism of toxicity is unclear.

OBJECTIVES: To demonstrate features of C. collinus toxicity in a rat model and to identify its mechanism(s) of action.

MATERIALS AND METHODS: Rats were anesthetized and the carotid artery was cannulated. Electrocardiogram and respiratory movements were recorded. Either aqueous extract of C. collinus or control solution was administered intraperitoneally. Serial measurements of blood gases, electrolytes and urinary pH were made. Isolated brush border and basolateral membranes from rat kidney were incubated with C. collinus extract and reduction in ATPase activity was assessed. Venous blood samples from human volunteers and rats were incubated with an acetone extract of C. collinus and plasma potassium was estimated as an assay for sodium-potassium pump activity.

RESULTS: The mortality was 100% in tests and 17% in controls. Terminal event in test animals was respiratory arrest. Controls had metabolic acidosis, respiratory compensation , acidic urine and hyperkalemia. Test animals showed respiratory acidosis, alkaline urine and low blood potassium as compared to controls. C. collinus extract inhibited ATPase activity in rat kidney. Plasma K + did not increase in human blood incubated with C. collinus extract.

CONCLUSIONS and Implications: Active principles of C. collinus inhibit proton pumps in the renal brush border, resulting in type I DRTA in rats. There is no inhibition of sodium-potassium pump activity. Test animals develop respiratory acidosis, and the immediate cause of death is respiratory arrest.

Language: en

Keywords

human; suicide; female; male; mortality; article; controlled study; blood sampling; human experiment; unclassified drug; drug mechanism; nonhuman; enzyme activity; placebo; animal experiment; electrocardiogram; animal model; rat; potassium; potassium blood level; respiratory failure; metabolic acidosis; medicinal plant; blood gas analysis; plant extract; hyperkalemia; respiratory acidosis; kidney tubule acidosis; electrolyte balance; aciduria; artery catheterization; adenosine triphosphatase; urine pH; carotid artery; breathing mechanics; adenosine triphosphatase (potassium sodium); basolateral membrane; brush border; cleistanthus collinus; Cleistanthus collinus; Cleistanthus collinus extrat; distal renal tubular acidosis; distal renal tubular acidosis type 1; incubation temperature; proton pump