CONFIRMATORY IN-VIVO ELECTRODIAGNOSTIC AND ELECTROMYOGRAPHIC STUDIES FOR NEUROMUSCULAR JUNCTIONAL BLOCKING ACTION OF CLEISTANTHUS-COLLINUS LEAF EXTRACT IN RAT

Detailed electromyographic and electrodiagnostic studies were made on sciatic nerve-anterior tibialis muscle preparations in rat in vivo for the first time to confirm the neuromuscular junctional (NMJ) blocking action of Cleistanthus collinus leaf extract (CCLE) and the transient reversal of NMJ blockade by neostigmine. A sublethal dose of 175 mg d ry leaf powder/kg body weight of rat caused NMJ blockade confirmed by a decremental response in nerve evoked compound muscle action potentia ls (NCMAPs). The study suggests the action of the toxic plant extract on acetylcholine (ACh) receptor sites. Muscle evoked compound muscle a ction potentials (MCMAPs) showed negligible decremental response sugge sting the action at the NMJ level only and not on muscle excitation an d contractility. The CCLE poisoning revealed a specific diagnostic EMG pattern which might be of help to clinicians in diagnosing Cleistanth us poisoning. The studies confirm that the leaf extract contains a pro ven and promising new NMJ blocker.