Allyl-Containing Sulfides in Garlic Increase Uncoupling Protein Content in Brown Adipose Tissue, and Noradrenaline and Adrenaline Secretion in Rats

Abstract

The effects of garlic supplementation on triglyceride metabolism were investigated by measurements of the degree of thermogenesis in interscapular brown adipose tissue (IBAT), and noradrenaline and adrenaline secretion in rats fed two types of dietary fat. In Experiment 1, rats were given isoenergetic high-fat diets containing either shortening or lard with or without garlic powder supplementation (8 g/kg of diet). After 28 d feeding, body weight, plasma triglyceride levels and the weights of perirenal adipose tissue and epididymal fat pad were significantly lower in rats fed diets supplemented with garlic powder than in those fed diets without garlic powder. The content of mitochondrial protein and uncoupling protein (UCP) in IBAT, and urinary noradrenaline and adrenaline excretion were significantly greater in rats fed a lard diet with garlic powder than in those fed the same diet without garlic. Other than adrenaline secretion, differences due to garlic were significant in rats fed shortening, also. In Experiment 2, the effects of various allyl-containing sulfides present in garlic on noradrenaline and adrenaline secretion were evaluated. Administration of diallyldisulfide, diallyltrisulfide and alliin, organosulfur compounds present in garlic, significantly increased plasma noradrenaline and adrenaline concentrations, whereas the administration of disulfides without allyl residues, diallylmonosulfide and S-allyl-L-cysteine did not increase adrenaline secretion. These results suggest that in rats, allyl-containing sulfides in garlic enhance thermogenesis by increasing UCP content in IBAT, and noradrenaline and adrenaline secretion.

Phytochemicals Having Neuroprotective Properties from Dietary Sources and Medicinal Herbs

“…Beside theses activities, allyl-containing sulfides might activate the pathways related neuroprotection, resulting in the activation of mitochondrial uncoupling proteins. 54 S e v e r a l o t h e r d i e t a r y p h y t o c h e m i c a l s h a v e neuroprotective in nature, such as: Caffeine, a methylxanthine is the most important bioactive constituent of this beverage (coffee) providing neuroprotection ( Figure.I …”

“…Increasing evidence has shown that the neuroprotective effects of the neurotrophic factors are mainly mediated by inhibiting the cell death/apoptosis pathways. 17 54 ; CREB induces the expression of BrainDerived Neurotrophic Factor (BDNF). BDNF is a major neurotrophic factor, which can initiate MAPK/ ERK and PI-3K/Akt pathways, through binding to its tyrosine kinase TrkB receptor and thus activate the downstream molecules which can promote neurogenesis and cell survival.…”

Phytochemicals Having Neuroprotective Properties from Dietary Sources and Medicinal Herbs

“…Beside theses activities, allyl-containing sulfides might activate the pathways related neuroprotection, resulting in the activation of mitochondrial uncoupling proteins. 54 S e v e r a l o t h e r d i e t a r y p h y t o c h e m i c a l s h a v e neuroprotective in nature, such as: Caffeine, a methylxanthine is the most important bioactive constituent of this beverage (coffee) providing neuroprotection ( Figure.I-XI). Other similar xanthine alkaloids found in tea and chocolate are theophylline and theobromine, respectively.…”

“…Ellison activates Transient Receptor Potential (TRP) ion channels in the plasma membrane of neurons, resulting in Ca 2+ influx, which activates neuroprotective kinase cascades via Mitogen-Activated Protein Kinases (MAPK), Camp-Response-Element-Binding protein (CREB) 54 ; CREB induces the expression of BrainDerived Neurotrophic Factor (BDNF). BDNF is a major neurotrophic factor, which can initiate MAPK/ ERK and PI-3K/Akt pathways, through binding to its tyrosine kinase TrkB receptor and thus activate the downstream molecules which can promote neurogenesis and cell survival.…”

“…66 Allyl-containing sulfides might activate other pathways related to stress, resulting in the upregulation of mitochondrial uncoupling proteins. 54 Flavanones, such as hesperetin and its metabolite, 5-nitrohesperetin, have been observed to inhibit oxidantinduced neuronal apoptosis via a mechanism involving the activation/phosphorylation of signalling proteins important in the pro-survival pathways. Capsaicin activates specific Ca 2+ channels (vanilloid receptors).…”