title: Activation of Strychnine-Sensitive Glycine Receptors by Shilajit on Preoptic Hypothalamic Neurons of Juvenile Mice.
abstract: Shilajit, a mineral pitch, has been used in Ayurveda and Siddha system of medicine to treat many human ailments, and is reported to contain at least 85 minerals in ionic form. This study examined the possible mechanism of Shilajit action on preoptic hypothalamic neurons using juvenile mice. The hypothalamic neurons are the key regulator of many hormonal systems. In voltage clamp mode at a holding potential of -60 mV, and under a high chloride pipette solution, Shilajit induced dose-dependent inward current. Shilajit-induced inward currents were reproducible and persisted in the presence of 0.5 μM tetrodotoxin (TTX) suggesting a postsynaptic action of Shilajit on hypothalamic neurons. The currents induced by Shilajit were almost completely blocked by 2 μM strychnine (Stry), a glycine receptor antagonist. In addition, Shilajit-induced inward currents were partially blocked by bicuculline. Under a gramicidin-perforated patch clamp mode, Shilajit induced membrane depolarization on juvenile neurons. These results show that Shilajit affects hypothalamic neuronal activities by activating the Stry-sensitive glycine receptor with α₂/α₂β subunit. Taken together, these results suggest that Shilajit contains some ingredients with possible glycine mimetic activities and might influence hypothalamic neurophysiology through activation of Stry-sensitive glycine receptor-mediated responses on hypothalamic neurons postsynaptically.
authors.affiliation: Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Janardhan Prasad
authors.initials: JP
authors.lastname: Bhattarai
authors.affiliation: Department of Obstetrics and Gynecology, Chonbuk National University Hospital and School of Medicine, Jeonju, 561-756, Republic of Korea.
authors.forename: Dong Hyu
authors.initials: DH
authors.lastname: Cho
authors.affiliation: Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Seong Kyu
authors.initials: SK
authors.lastname: Han
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D008903:Minerals / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D011301:Preoptic Area / Q000187:drug effects* / Q000502:physiology; D018009:Receptors, Glycine / Q000187:drug effects* / Q000502:physiology; D012116:Resins, Plant / Q000494:pharmacology*; D013331:Strychnine / Q000494:pharmacology*
chemical_list: D008903:Minerals; D018009:Receptors, Glycine; D012116:Resins, Plant; C045109:mumie; D013331:Strychnine