22 Allyl Sulfur Phytochemicals Flashcards
Allyl Sulfides
unique organosulfur compounds class of phytochemical
Allyl sulphides are found in?
Allium vegetables allicaeae family of plants - garlic - onion - leeks - scallions - chives
Allium sulfides reputation in what kind of old medicine
folklare medicine
Old uses for garlic
ancient remedy for:
- intestinal disorders, respiratory infections, skin diseases, wounds, symptoms of aging
used to treat wounds in world war 2
- applied directly to wound to inhibit infection
Key in the phytochemistry of garlic
sulfer
- responsible for odour
- primary parent of sulfer containing compound ALLIN
Sulfur compounds in Garlic
water soluble 20%
- after alcohol fermentation
- formed from parent compound “gamma-glutamyl cysteine”
lipid soluble 80%
- most related to health benefits
- formed from alliin
Water soluble sulfur compounds in garlic
formed from parent compound: gamma glumly cysteine
1) SAC (S-allyl cysteine)
2) SAMC (S-allylmercapto cysteine)
others as well
Lipid soluble sulfur compounds in garlic
Formed from parent compound: Alliin
converted to: Allicin
1) DAS
2) DADS
3) DATS
4) Ajoene
and others
Allinase
separate from alliin in the plant
comes in to contact - crushing, chewing
converts alliin to allicin within 6 seconds
- very fast
like glucosinolate and myrosinases
Effect of heat on garlic
Decrease garlic’s odour
- thought to be reduction in alines activity
- less allicin produced
- less key sulfur-compounds produced (DAS, DADS, DATS, Ajeone)
How to limit the effect of heat on allinase
Chop or crush
- let stand for 10mins
What will denature allinase
heat and gastric acid
Why is fresh garlic not susceptible to gastric acid?
Chewing allows allinase to act on alliin to make allicin
- supplements broken down in stomach before enzymatic activity takes place
Allyl sulphide health benefits
- antimicrobial / immunity
- cancer
- CVD
- lipid soluble products of allicin breakdown most studied
Anti-micrbial / immunity effects of allicin breakdown products
historically used as an antibiotic
- DAS and DADS dose dependent decrease proliferation of H pylori (Gastric ulcers)
- Topical Ajoene
- treatment of dermatitis - Surpress fungal growth
- allicin protects against Candida Albicans
Allicin breakdown products
Cancer Effects: nitrosamine formation
Garlic suppress formation of N-nitroso compounds (NOC)
- potential carcinogens
- need nitrite for synthesis
Allium compounds increase formation of nitrosothiols
- takes up available nitrite
- minimizes nitrite for NOC synthesis
End result - Decrease carcinogenic NOC
Cancer cell growth inhibited by?
DADS
also SAC but not as effective
- also inhibit cancer cell proliferation
Allyl Sulfur compounds from garlic on Phase I and II enzymes
Increase activity of phase II GST (glutathione-S-transferase)
minimal effect on Phase I (cytochrome p450 enzymes)
- decrease cancer risk
Garlic on CVD
- reduction in TGs, total and LDL cholesterol
- little effect on HDL cholesterol
evidence not consistent, health claim not yet approved
ADME
absorption
distribution
metabolism
excretion
Garlic compounds knowledge of bioavailability
detection in blood and urine is unnoticed
- breakdown products in breathe reveals some information about bioavailability
Garlic and supplements
one of the most popular
- bioavailability of garlic in supplemental form shows limitations
- gastric acid denatures alliinase
Possible way to protect garlic supplements from gastric acid?
acid resistant coating
- enteric coating
- cellulose of polyacrylic acid esters
- readily dissolve at neutral pH
Garlic supplements are standardized for..?
allicin potential
- amount of allicin formed when crushed tablets are added to water
