??? ????? (Phytochemicals)

1
??? ?????(Phytochemicals)

• Yan Zhao (Associate Prof.)
• Department of Nutrition Food Hygiene
• Harbin Medical University

2
Outlines

• Definition ??
• Classification ??
• Physiological effects ?????
• Epidemiological evidence for the protective
  effects ?????????????

3
DefinitionPhytochemicals exist in plant food and
are active components of secondary metabolites
(excluding vitamins). ?????????,????????????????(
?????)????????
4
? ?????????(Secondary metabolites)
? ?????????(Primary metabolites) They mainly
contribute to energy metabolism and to the
structure of the plant cell. ????????,???????????,
??????????????????????? ????????????????????? ????
?,?????????? ?????,??????????????
5
Table1 Classification of phytochemicals and
their main effects
Phytochemicals Biological effects Biological effects Biological effects Biological effects Biological effects Biological effects Biological effects Biological effects Biological effects Biological effects
Phytochemicals A B C D E F G H I J
Carotenoids ? ? ? ?
Phytosterols ? ?
Saponins ? ? ? ?
Glucosinolates ? ? ?
Polyphenols ? ? ? ? ? ? ? ?
Protease-inhibitors ? ?
Monoterpenes ? ?
Phyto-oestrogens ? ?
Sulphides ? ? ? ? ? ? ? ? ?
Phytic acid ? ? ? ?
A anticarcinogenic D antithrombotic G influence of blood pressure J digestive-promoting
B antimicrobial E immunomodulatory H cholesterol lowering effect
C antioxidative F inhibition of inflammation I influence of blood glucose
6
Carotenoids ?????

• Carotenoids are widespread secondary plant
  metabolites in fruits and vegetables. One of
  their main functions is to provide the red and
  yellow color to the plant.
• ?????????????????????????,?????????????????????
  ?

7

• ???(oxygen-free)??a-????? ß-?????????,????ß-????
  ??????????1530,????
  
• ???(oxygen-containing) ???(??????????ß-???)????,
  ????
  

8
Phytosterols ????
Phytosterols are mainly found in plant seeds and
oils. ???????????????????,?ß-???(ß-sitosterol)???
?(stigmasterol)?????(campesterol) ???????????????1
50400mg,?????????5?????????????????????????????,
?????????????????
9
Saponins ??
????????(?????)?????????????
??????????,?????????????????????????????????????
???????? ?????????,?????????????10mg,????
?200mg???
10

• ???????????????????????????,???????????
  ?????????????????,?????????????????????,??????????
  ?

11
Glucosinolates ????

• Glucosinolates are found in all plants
  belonging to the family of Cruciferae.
• ????????????????,?????????????????????????

12
Polyphenols ??

• Polyphenol is used for all substances that are
  made up of phenol derivatives. ?????????????
• ??(Phenolic acid)??????
• ???(Flavonoids)??????(A?B?)????????????????????
• The most commonly found flavonoid is quercetin
  with a daily intake of about 23 mg.
• ???????????,?????????23mg,???????????????,????????
  ??????

13
??????? ?????????(flavones and
flavonols),???????????????????????????? ?????????
???(flavanones and flavanonols),????????? ?????(f
lavanols),????????????(?70)??,????????-3-?? ????
???????(isoflavones and isoflavanones),???????????
????,???????? ?????(biflavonoids),????????,?????
???,??????????
14

• ???????????????????????,????????????????????,?????
  ??????????????
• ???????????????????????????????
• ????????????????,?????????????????????????????????
  ??????????????????????????????????????????????????
  ????

15
Protease inhibitors ??????
Protease inhibitors are ubiquitous in the flora
and are found especially in plant seeds (legumes,
grains). ????????????????,????????????????? ?????
??????????,????????,??????????????????????????????
??
16

• Trypsin inhibitor intake averages about 295 mg
  daily. ??????????????????295mg,??????????????????
  ???????????
• ????????????????????????????,??????????????????

17
Monoterpenes ???

• ??(peppermint)?????(menthol)
• ?????(caraway seeds)?????(carvone)
• ???(citrus oil)??????(limonene)
• The average daily intake of monoterpenes is
  around 150 mg.

18
Phyto-estrogens ?????

• Phytoestrogens are plant components that bind to
  mammalian estrogen receptors and have effects
  similar to those of endogenous estrogens.
• ????????????,???????????????????????????????????

19
Isoflavones and lignans, chemically both
polyphenols, belong to the phytoestrogens.
???(isoflavones)??????????????? ???(lignans)????
?????????
????????????????????????0.1,?????????????????????
101000?? ??????????????????,?????????????????????
20
Sulphides ???
The sulphides among secondary plant metabolites
include all organosulphur compounds of garlic and
other bulbous plants. ????????????????????????????
??????????
21
????????????????

• ????????????????????????????????????,?????????????
  ????
• ?????????30??,????????????,???????????????????????
  ?????,??????????????????,?????????

22
Phytic acid ??
?????????????????????????????????,????????
?????????
23
Physiological effects ?????1. Anticarcinogenic
effects ????

• ???????????????????,????????????????????
• Vegetables and fruits have been shown to be rich
  sources of secondary plant metabolites with the
  potential to prevent human cancers.
• About 30 classes of chemicals have shown
  cancer-preventive effects.
• ?????????????????????,???????CAC????????????????5?
  

24

• 2. Antioxidative effects ?????
• ???????
• ????SOD?GSH-Px?
• ???????????????a-??????Q10?
• ????????????????E????C?
• ???????????????????????????????

25

• ?????????????????????100mg,???????????????????????
  1g,???????????????????????????????????????????????
  ???

26
3. Immunomodulatory effects ??????
?????(?????????) ???(????)
???? ???? ????
27
4. Antimicrobial effects ??????
??? ?? ???? ?????
???? ????????????????
?? ???300ml????????
28
5. Cholesterol-lowering effects ???????
Some individual representatives of the saponins,
phytosterols, sulphides and tocotrienols have
been found to lower serum cholesterol levels in
both animal experiments and in clinical studies.
????????????,?????????????????????????????????????
???? The extent to which cholesterol levels are
reduced depends on the cholesterol and fat
content of the diet. ??????????????????????????
29

• Epidemiological evidence ??????????????????
• A meta-analysis of over 200 epidemiological
  studies gives evidence of the protective effects
  of vegetables and fruits consumed in high
  quantities against different kinds of cancer in
  humans.
• ??????????????????????????????50
• ??(?)??????????????????,?????????/????????????
• ????????????????????????
• ?????????????????????

30

• ????????????????????????(?????????????????)???????
  ??????????????????????????????????????????????????
  ???????????
• Phytochemicals, along with vitamins, minerals,
  trace elements and dietary fibre, are responsible
  for the protective effects of vegetables and
  fruits against cancer and cardiovascular disease.
  ?????????????????????????,????????????????????????
  ???