tannins and Seizures

Marine plants have been reported to possess various pharmacological properties; however, there have been few reports on their neuropharmacological effects. Terrestrial plants have depressive effects on the central nervous system (CNS) because of their polyphenols which make them effective as anticonvulsants and sleep inducers. We investigated in this study the depressive effects of the polyphenol-rich brown seaweed, Ecklonia cava (EC), on CNS. An EC enzymatic extract (ECEE) showed significant anticonvulsive (>500 mg/kg) and sleep-inducing (>500 mg/kg) effects on the respective mice seizure induced by picrotoxin and on the mice sleep induced by pentobarbital. The phlorotannin-rich fraction (PTRF) from ECEE significantly potentiated the pentobarbital-induced sleep at >50 mg/kg. PTRF had binding activity to the gamma aminobutyric acid type A (GABA(A))-benzodiazepine (BZD) receptors. The sleep-inducing effects of diazepam (DZP, a well-known GABA(A)-BZD agonist), ECEE, and PTRF were completely blocked by flumazenil, a well-known antagonist of GABA(A)-BZD receptors. These results imply that ECEE produced depressive effects on CNS by positive allosteric modulation of its phlorotannins on GABA(A)-BZD receptors like DZP. Our study proposes EC as a candidate for the effective treatment of neuropsychiatric disorders such as anxiety and insomnia.

Topics: Animals; Anticonvulsants; Benzodiazepines; Central Nervous System; Central Nervous System Agents; Enzymes; Male; Mice; Phaeophyceae; Picrotoxin; Plant Extracts; Plants, Edible; Rats; Receptors, GABA-A; Seaweed; Seizures; Sleep; Tannins

Magnistipula butayei subsp. montana (Chrysobalanaceae) is known, in the Great Lakes Region, to possess toxicological properties. In this paper, we investigated the acute toxicity (dose levels 50-1600 mg/kg) of its aqueous extract, administered orally to adult Wistar rats. This study demonstrated that the freeze-dried aqueous extract (5%, w/w) possesses high toxicity. The extract caused hypothermia, neurological disorders, including extensor reflex of maximal convulsive induced-seizures at about 2 h after the administered dose, and death occurred (LD50=370 mg/kg) in a dose dependent manner. Blood parameter evaluation revealed slight variations, but these might not have clinical relevance. Histological examination of internal organs (lungs, liver, heart and kidneys) did not reveal any abnormality in the treated group compared to the control. Therefore, it can be concluded that Magnistipula butayei subsp. montana aqueous extract, given orally, is toxic and that its target is the central nervous system. General phytochemical screening revealed that the plant did not contain significant amounts of products known to be toxic, such as alkaloids or cardioactive glycosides, but only catechic tannins, amino acids, saponins and other aphrogen principles in the three parts of the species (fruit, leave and bark).

Topics: Africa, Central; Animals; Anthocyanins; Body Temperature; Central Nervous System; Chrysobalanaceae; Dose-Response Relationship, Drug; Fruit; Lethal Dose 50; Male; Plant Bark; Plant Extracts; Plant Leaves; Rats; Rats, Wistar; Saponins; Seizures; Tannins

Topics: Acute Disease; Adrenocortical Hyperfunction; Adult; Alopecia; Animals; Antidotes; Asthenia; Colchicine; Coma; Diarrhea; Diuresis; Endometrium; Enzyme Inhibitors; Exchange Transfusion, Whole Blood; Fallopian Tubes; Feeding and Eating Disorders; Female; Hemorrhage; Humans; Leukocytosis; Mice; Mitosis; Myelin Sheath; Neuromuscular Junction; Polyneuropathies; Rats; Seizures; Tannins; Vitamin B Complex; Vomiting

The LD(50) +/- S.E. of tannic acid given orally to albino rats was found to be 2.26+/-0.083 g. per kg. body weight, which is higher than its apparent LD(50) when given per rectum. The immediate cause of death was respiratory failure preceded by convulsions when death occurred early and by hypothermic cachexia when death was delayed. Death was associated with a progressively developing hepatic necrosis and nephritis and a temporary acute gastroenteritis. It was accompanied by loss of weight and edema in many organs, evidence of stimulation of the spleen, adrenal cortex and testes, and atrophy of the thymus. Recovery in survivors was associated with a temporary increase in weight of the spleen and testes and persistence of loss of weight in the adrenal, pyloric stomach, and skin.

Topics: Cachexia; Chemical and Drug Induced Liver Injury; Edema; Gastroenteritis; Hepatitis; Hepatitis A; Hypothermia; Liver Diseases; Nephritis; Pathology; Rats; Research; Seizures; Spleen; Tannins; Toxicology