1. Presented to
SIR TANVEER KHAN
Presented by
ZAINAB JAVED
MPhil Pharmacognosy
THE UNIVERSITY OF LAHORE

2. What are lignans and Neolignans
 What are their sources
 Role of lignans and neolignans in plants and
human body


3. PHYTOESTROGENS
(substances found in plants
having estrogen like activities)
COUMESTANS
ISOFLAVONES

4.  In
1936, Haworth defined lignans as
“Phenylpropanoid dimers consisting
of two phenyl propane units (C6C3)
linked by their central C8 carbon.”

5. Phenylpropane unit
Lignan

6.  In
1972, Gottileib defined neolignan as
“Phenylpropanoid dimers consisting
of two phenylpropane units (C6C3)
linked in a manner other than C8-C8'
linkage”

8.  Widely

distributed in plants.
Usually occur in
root, stem, bark, fruits and seed parts
of plant.

9. FLAX SEEDS:
1.


Secoisolariciresinol Diglucoside (SDG)
1 ounce of flaxseed contains 85mg of
lignans

13.  Sesamin
1
ounce of sesame seeds contain 11
mg of lignans

16.  Secoisolariciresinol

17.  Larisiresinol

18. SOURCES
LIGNANS
Wheat
7-hydroxymatairesinol
Corn
7-hydroxymatairesinol
Strawberry
Pinoresinol
Pea
Pinoresinol
Broccoli
Larisiresinol

19. Plant lignans
Intestinal
bacteria
Mammalian lignans or Enterolignans
(enterolactone, enterodiol)

20. Narrow distribution
 Isolated from magnoliales and piperales.
 Neolignans isolated from stem bark of Magnolia
obovata are
 Magnolol
 Honokiol
 4-methoxyhonokiol
 Obovatol
 Neolignan isolated from stem of Piper kadsura
 Kadsurenone


22.  Participate
in defensive mechanism
against pathogens due to its antiviral, anti-bacterial and anti-fungal
properties.

23.  Steroidal
hormone mainly present in females
but also in men.
 Mainly secreted by ovaries, minute quantity
by adrenal cortex.
 3 forms: estradiol, estrone, estriol.
 Synthesized from cholesterol and transported
by albumin and globulin in plasma.
 Role in maturation of sperms in males.

24.  Promote
cellular
proliferation
and
tissue
growth.
 Contribute to development of secondary
sexual
characters
(hair
distribution, voice, body shape)
 Increases osteoblastic activity and thus its
lack lead to osteoporosis.
 Increases fat deposition in subcutaneous
tissues
 Causes the skin to develop a texture that is
soft and smooth

25.  Estrogens
bind with estrogen receptors and
form hormone-receptor complex which in turn
binds with DNA and induces transcription of
mRNA.
 2 types of estrogen receptors
1. ER-α (uterus, heart, liver, kidneys)
2. ER-β (ovaries, other tissues)

26.  ESTROGEN
RECEPTOR – DEPENDENT
ACTIVITIES:

Phytoestrogens bind to estrogen receptors and
either
 Mimic the estrogenic effects (low dose)
 Antagonizes the estrogenic effects(high dose)
 Anti-estrogenic activity is important in
prevention of cancer.

27.  Estrogens
contribute to cause breast cancer
by stimulating the proliferation of breast
cells.

28.  High
blood levels of enterolactone are
associated with a lower incidence of breast
cancer.
 The new study, published in EUROPEAN
JOURNAL OF CANCER PREVENTION reports
that women with high plasma level of
enterolactone was associated with 58%
reduction in breast cancer risk.
 34%
in breast cancer cell growth after giving
SDG daily for 30 days.

30. A
new study from SWEDEN concluded that
diet rich in lignans could reduce the risk of
prostate cancer risk by 26%
 The
in-vitro study from NEWZEALAND report
that enterolactone may prevent spread of
prostate cancer by regulating genes which
produce important effects on apoptosis of
prostate cancer cells.

31.  In
a case-control study of lignans and
endometrial cancer, U.S. women with the
highest intakes of plant lignans had the lowest
risk of endometrial and ovarian cancer, but
the reduction in risk was statistically
significant in postmenopausal women only.

32. 
Enterolactone
helps
with
estrogen
balance, researchers have found that it is a safe
and natural alternative to help buffer the hormonal
fluctuations during menopause. This in turn helps
to alleviate the accompanying symptoms of hot
flashes and night sweats.

33. 
ANTI-OXIDANT EFFECT
Lignans exhibit very strong antioxidant
properties, thus it can protect the body
from the effects of oxidation which can
lead to a series of chronic diseases.

34.  Increased
blood levels of enterolactone
have been shown to reduce oxidation of
blood lipids and reduce risk of heart
disease by offering antioxidant and antiinflammatory protection.

35. TESTOSTERONE
INHIBIT
5-alpha reductase
DHT
(DIHYDROTESTOSTERONE)
INHIBIT
HAIR LOSS AND ACNE

36. 
Lignans
suppresses
the
integration of proviral DNA into
cellular genome.

37. 
ANTI-MICROBIAL EFFECT
 Anti-bacterial effect
 Anti-fungal effect

INHIBITION OF PLATELET ACTIVTING
FACTOR
 Kadsurenone antagonizes the activity
of PAF

38.  Honokiol
and magnolol have been evaluated
as antioxidants. These neolignans protected
mitochondrial respiratory chain enzyme
activity against NADPH-induced per oxidative
stress and protected red cells against
oxidative haemolysis.

39.  Magnolol
has
depressant and
effects.
showed
antianxiety reduced