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Experimental Myasthenia Gravis‐like Neuromuscular Impairment with Cleisthanthus collinus Leaf Extract Administration in Rat
Author(s) -
Nanda Kumar N. V.,
Vijayalakshmi K. M.
Publication year - 1996
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/(sici)1099-1573(199603)10:2<121::aid-ptr783>3.0.co;2-a
Subject(s) - myasthenia gravis , neuromuscular junction , neuromuscular blockade , stimulation , repetitive nerve stimulation , medicine , acetylcholine receptor , curare , blockade , tibialis anterior muscle , motor nerve , endocrinology , anesthesia , pharmacology , skeletal muscle , biology , anatomy , receptor , neuroscience
Intraperitoneal administration of a sublethal dose (120 mg/kg body wt) of Cleistanthus collinus aqueous leaf extract (CCLE) was found to induce a neuromuscular disorder like myasthenia gravis in rats after 45 min. The neuromuscular junction (NMJ) blockade was analysed in vivo in the sciatic nerve–anterior tibialis muscle prpearation. The pattern of nerve evoked compound muscle action potentials (NCMAP) at various frequencies of supramaximal electrical stimulation from single to 100 Hz were recorded. Administration of CCLE showed a sequential decremental response in NCMAP resembling the established EMG patterns of myasthenia gravis (MG). The diagnostic tests, namely a transient improvement and repair of the decremental response in NCAMPs after administration of 4‐aminopyridine (1 mg/kg), a characteristic decrement in the 4th or 5th potential on lower frequencies of stimulation, an increased sensitivity to d‐tubocurarine (120 μg/kg) and with least or marginal effect on CMAPs on direct muscle stimulation suggested an MG‐like neuromuscular disorder which occurs due to ACh receptor blockade. Further, with prior administration of antisnake venon serum (AVS) — an antiserum factor for krait alpha bungarotoxin, the NCMAP decremental response in both control and in CCLE administered rats was rectified transiently and also delayed the onset of NMJ blockade. It is suggested that the prolonged and irreversible effect of the leaf extract, unlike the reversible effect of curare, confers a sustained NMJ blockade required for inducing a MG‐like condition.