Effect of seabuckthorn seed protein and its arginine-enriched peptides on combating memory impairment in mice

Cerebral blood flow regulation is essential for normal brain function. In this Review, Kisler and colleagues examine the cellular and molecular mechanisms that underlie cerebral blood flow regulation at the arteriole and capillary level, and how neurovascular dysfunction contributes to neurodegenerative disorders such as Alzheimer disease.

L-Arginine (Arg) is synthesised from glutamine, glutamate, and proline via the intestinal-renal axis in humans and most other mammals (including pigs, sheep and rats). Arg degradation occurs via multiple pathways that are initiated by arginase, nitric-oxide synthase, Arg:glycine amidinotransferase, and Arg decarboxylase. These pathways produce nitric oxide, polyamines, proline, glutamate, creatine, and agmatine with each having enormous biological importance. Arg is also required for the detoxification of ammonia, which is an extremely toxic substance for the central nervous system. There is compelling evidence that Arg regulates interorgan metabolism of energy substrates and the function of multiple organs. The results of both experimental and clinical studies indicate that Arg is a nutritionally essential amino acid (AA) for spermatogenesis, embryonic survival, fetal and neonatal growth, as well as maintenance of vascular tone and hemodynamics. Moreover, a growing body of evidence clearly indicates that dietary supplementation or intravenous administration of Arg is beneficial in improving reproductive, cardiovascular, pulmonary, renal, gastrointestinal, liver and immune functions, as well as facilitating wound healing, enhancing insulin sensitivity, and maintaining tissue integrity. Additionally, Arg or L-citrulline may provide novel and effective therapies for obesity, diabetes, and the metabolic syndrome. The effect of Arg in treating many developmental and health problems is unique among AAs, and offers great promise for improved health and wellbeing of humans and animals.

ETHNOPHARMACOLOGICAL CONTEXT: This review explores the medicinal and therapeutic applications of Sea buckthorn (Hippophae rhamnoides L.) in curtailing different types of acute as well as chronic maladies. The plant is being used in different parts of the world for its nutritional and medicinal properties. Sea buckthorn based preparations have been extensively exploited in folklore treatment of slow digestion, stomach malfunctioning, cardiovascular problems, liver injury, tendon and ligament injuries, skin diseases and ulcers. In the recent years, medicinal and pharmacological activities of Sea buckthorn have been well investigated using various in vitro and in vivo models as well as limited clinical trials. Sea buckthorn has been scientifically analyzed and many of its traditional uses have been established using several biochemical and pharmacological studies. Various pharmacological activities such as cytoprotective, anti-stress, immunomodulatory, hepatoprotective, radioprotective, anti-atherogenic, anti-tumor, anti-microbial and tissue regeneration have been reported. It is clear that Sea buckthorn is an important plant because of its immense medicinal and therapeutic potential. However, several knowledge gaps identified in this paper would give impetus to new academic and R&D activities especially for the development of Sea buckthorn based herbal medicine and nutraceuticals. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.