22 Allyl Sulfur Phytochemicals

Question 1

Allyl Sulfides

Answer 1

unique organosulfur compounds
class of phytochemical

Question 2

Allyl sulphides are found in?

Answer 2

Allium vegetables 
allicaeae family of plants
- garlic
- onion
- leeks
- scallions
- chives

Question 3

Allium sulfides reputation in what kind of old medicine

Answer 3

folklare medicine

Question 4

Old uses for garlic

Answer 4

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

Question 5

Key in the phytochemistry of garlic

Answer 5

sulfer

• responsible for odour
• primary parent of sulfer containing compound ALLIN

Question 6

Sulfur compounds in Garlic

Answer 6

water soluble 20%

• after alcohol fermentation
• formed from parent compound “gamma-glutamyl cysteine”

lipid soluble 80%

• most related to health benefits
• formed from alliin

Question 7

Water soluble sulfur compounds in garlic

Answer 7

formed from parent compound: gamma glumly cysteine

1) SAC (S-allyl cysteine)
2) SAMC (S-allylmercapto cysteine)
others as well

Question 8

Lipid soluble sulfur compounds in garlic

Answer 8

Formed from parent compound: Alliin
converted to: Allicin

1) DAS
2) DADS
3) DATS
4) Ajoene
and others

Question 9

Allinase

Answer 9

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

Question 10

Effect of heat on garlic

Answer 10

Decrease garlic’s odour

• thought to be reduction in alines activity
• less allicin produced
• less key sulfur-compounds produced (DAS, DADS, DATS, Ajeone)

Question 11

How to limit the effect of heat on allinase

Answer 11

Chop or crush

- let stand for 10mins

Question 12

What will denature allinase

Answer 12

heat and gastric acid

Question 13

Why is fresh garlic not susceptible to gastric acid?

Answer 13

Chewing allows allinase to act on alliin to make allicin

- supplements broken down in stomach before enzymatic activity takes place

Question 14

Allyl sulphide health benefits

Answer 14

1. antimicrobial / immunity
2. cancer
3. CVD

• lipid soluble products of allicin breakdown most studied

Question 15

Anti-micrbial / immunity effects of allicin breakdown products

Answer 15

historically used as an antibiotic

1. DAS and DADS dose dependent decrease proliferation of H pylori (Gastric ulcers)
2. Topical Ajoene
   - treatment of dermatitis
3. Surpress fungal growth
   - allicin protects against Candida Albicans

Question 16

Allicin breakdown products

Cancer Effects: nitrosamine formation

Answer 16

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

Question 17

Cancer cell growth inhibited by?

Answer 17

DADS
also SAC but not as effective

• also inhibit cancer cell proliferation

Question 18

Allyl Sulfur compounds from garlic on Phase I and II enzymes

Answer 18

Increase activity of phase II GST (glutathione-S-transferase)

minimal effect on Phase I (cytochrome p450 enzymes)

• decrease cancer risk

Question 19

Garlic on CVD

Answer 19

• reduction in TGs, total and LDL cholesterol
• little effect on HDL cholesterol

evidence not consistent, health claim not yet approved

Question 20

ADME

Answer 20

absorption
distribution
metabolism
excretion

Question 21

Garlic compounds knowledge of bioavailability

Answer 21

detection in blood and urine is unnoticed

- breakdown products in breathe reveals some information about bioavailability

Question 22

Garlic and supplements

Answer 22

one of the most popular

• bioavailability of garlic in supplemental form shows limitations
• gastric acid denatures alliinase

Question 23

Possible way to protect garlic supplements from gastric acid?

Answer 23

acid resistant coating

• enteric coating
• cellulose of polyacrylic acid esters
• readily dissolve at neutral pH

Question 24

Garlic supplements are standardized for..?

Answer 24

allicin potential

- amount of allicin formed when crushed tablets are added to water

Question 25

Activity of garlic supplement will depend on ..?

Answer 25

lipid vs water soluble compounds

Question 26

What medication should garlic not be used with?

Answer 26

HIV medication

- garlic causes stimulation of p450 enzymes which metabolize the drug