Medicinal plants - the future in cataract therapy

1. Medicinal plants
the future in cataract therapy
Justyna Petelewicz
Marlena Zagwożdżon
Jerzy Bukowczan
Department of Pharmacognosy and Phytochemistry
School of Pharmacy and Division of Laboratory Medicine
Medical University of Silesia
www.missouriplants.com/Bluealt/Pueraria_lobata_page.html

2. What is cataract?
 Cataract means clouding of the lens in the eye.
 It may inhibit transmission of images
to the retina, leading to vision field reduction.
Normal eye - the lens is clear,
allowing light to focus properly
on the retina.
When cataract occurs, the lens
becomes clouded, causing
light rays to scatter.
www.itmonline.org/arts/cataracts.htm

3. Cataract risk factors
 nutritional
deficiences
 trace metals
 sunlight
 smoking
 radiation
 aging
 diabetes
 dehydration
 genetic factors
 certain drugs
(neuroleptics, steroids)

4. Cataract treatment
 Mild cataract can be compensated
by using corrective lenses.
 More severe cataract is usually treated by
surgery, removing the original lens and
replacing with an artificial lens.
http://www.optyk-inowroclaw.pl/wzrok/wady_wzroku.html
cataract
phacoemulsificator needle

5. Alternative treatment
 Cataract surgery is popular,
but poses many risks for the patient
 Medicinal plants give wide opportunities
for alternative treatment
 Several plant species regulate
cell metabolism in eye lens

6. Cataract - biochemical causes
Aldose reductase
Protein glycation
Oxidative stress
http://www.siskiyoueye.com/images/photos/education/cataracts.jpg

7. Cataract - biochemical causes
Aldose reductase
 reduces sugars
to polyalcohols
 in hyperglycaemia
too much glucose
is reduced to sorbitol
 sorbitol accumulation
causes osmotic stress
and lens opacity
Protein glycation
Oxidative stress

8. Cataract - biochemical causes
Aldose reductase
Protein glycation
 non-enzymatic
reaction between
sugar and free amino
group of proteins
 advanced glycation
end products (AGE)
are produced
 AGE accumulation
decreases lens
transparence
Oxidative stress

9. Cataract - biochemical causes
Aldose reductase
Protein glycation
Oxidative stress
 regular lens proteins
are reduced
 glutathione and
antioxidative enzyme
deficiency, along with
free radicals oxidizes
lens proteins
 oxidized proteins
cause opacity
>

10. Anti-cataract plants - mechanisms of action
 Increased concentration of glutathione (GSH)
and increased activity of antioxidative enzymes:
superoxide dismutase (SOD),
glutathione peroxidase (GPX),
glutathione S-transferase (GST),
catalase
 Inhibition of lipid peroxidation – decreases of
malondialdehyde synthesis reduces cataract progression
 Aldose reductase (AR) inhibition decreases sorbitol lens
acumulation, inhibiting sugar to polyalcohol reduction
 Decrease of protein glycation inhibits lens opacity

11. Currently following species
are under research:
 Pueraria lobata,
 Allium cepa,
 Trigonella foenum-graecum,
 Zingiber officinalis,
 Foeniculum vulgare,
 Curcuma longa.

12. Pueraria lobata - kudzu
 family: Fabaceae
 plant part used in medicine: root
 native to Southeast Asia (China, Japan and Korea)
en.wikipedia.org/wiki/Kudzu
www.salicicola.com/photos/gallery/view/1443/1443
www.mdidea.com/products/herbextract/kudzu/data09.html
Roots
Flowers

13. Kudzu: anti-cataract activity
Active ingredient:
genistein
Mechanism:
– aldose reductase inhibition
– inhibition of glucose-induced
fibronectin and αB-crystallin gene expression.
GLUCOSE (in excess)
SORBITOL
(accumulating)
cataract
Aldose
reductase
GENISTEIN

14. Allium cepa - onion
 family: Liliaceae
 plant part used in medicine: onion extract
 widely cultivated around the world
en.wikipedia.org/wiki/Onion
pl.wikipedia.org/w/index.php?title=Plik:Allium_cepa.jpg&filetimestamp=20070304114730
Bulb
Flowers

15. Onion: anti-cataract activity
 increases concentration of
superoxide dismutase
and glutathione peroxidase
(antioxidant enzymes)
 moderately inhibits aldose reductase.
>

16. Trigonella foenum-graecum - fenugreek
 family: Fabaceae
 plant part used in medicine: seeds
 the plant is cultivated worldwide
www.mdidea.com/products/new/new004photogallery.html
Flower
upload.wikimedia.org/wikipedia/commons/thumb/6/6a/Fenugreek-methi-seeds.jpg/707px-Fenugreek-methi-seeds.jpg
Seeds

17. Fenugreek: anti-cataract activity
 decreases malondialdehyde concentration,
 increases glutathione levels,
 increases antioxidant enzyme activity.
POLYUNSATURATED
LIPIDS
MALONDIALDEHYDE
oxidative
stress
lens
opacity
fenugreek extract

18. Zingiber officinalis - ginger
 family: Zingiberaceae
 plant part used in medicine: rhizome
 ginger cultivation began in South Asia and
spread to East Africa and the Caribbean
www.travelblog.org/Photos/3163690
www.homeopathyandmore.com/forum/viewtopic.php?t=121
Rhizome
Flowers

19. Ginger: anti-cataract activity
 decreases non-enzymatic
protein glycation
 reduces malondialdehyde concentration.
GLUCOSE (in excess)
+
Protein with free NH2 group
AGE
(advanced glycation
end-products)
increased
lens opacity
free radicals
ginger rhizome extract

20. Foeniculum vulgare - Fennel
 family: Apiaceae
 plant part used in medicine: seed oil
 indigenous to the Mediterranean,
widely naturalised in many parts of the world
psychotropia.co/?attachment_id=3609
upload.wikimedia.org/wikipedia/commons/thumb/6/65/Fennel_seed.jpg/220px-Fennel_seed.jpg
Flowers
Seeds

21. Fennel: anti-cataract activity
 Active ingredient: trans-anethole
 Mechanism of action:
- inhibits aldose reductase,
- increases glutathione (GSH) concentration,
catalase and superoxide dismutase (SOD) activity,
- increases soluble protein content in lens.
PROTEIN
(reduced)
soluble
PROTEIN
(oxidized)
insoluble
free radicals
GSH, SOD, catalase,
induced by
ANETHOLE

22. Curcuma longa - Turmeric
 family: Zingiberaceae
 plant part used in medicine: rhizome
 grows wild in the forests of
South and Southeast Asia.
www.raksaherbs.com/product/Curcuma-Longa-capsule/Curcuma-Longa-capsule-P0096.html
www.inriodulce.com/links/ginger.html
en.wikipedia.org/wiki/Turmeric
Flowers Rhizomes

23. Turmeric: anti-cataract activity
 Active ingredient: curcumin
 Mechanism of action:
- increases superoxide dismutase and
glutathione peroxidase activity,
- inhibits aldose reductase,
- decreases lipid peroxidation.
Fatty acids
Malondialdehyde
lens opacity
CURCUMIN
free
radicals
Lipid
peroxidation

24. Thank you!
References:
• Dharmananda S. – CATARACTS: prevention and Treatment-with Reference to Chinese Medicine
• Ángel Guzmán, Ricardo O. Guerrero - Inhibition of aldose reductase by herbs extracts and natural substances and
their role in prevention of cataracts
• Patel DK, Prasad SK, Kumar R, Hemalatha S. – Cataract: A major secondary complication of diabetes, its
epidemiology and an overview on major medicinal plants screened for anticataract activity
• R. Manikandana, R. Thiagarajana, S. Beulaja, S. Chindhud, K. Mariammale, G. Sudhandiranc, M. Arumugama -
Anti-cataractogenic effect of curcumin and aminoguanidine against selenium-induced oxidative stress in the eye lens
of Wistar rat pups: An in vitro study using isolated lens
• N. Halder, S. Joshi, S.K. Gupta - Lens aldose reductase inhibiting potential of some indigenous plants.
• Ramar Manikandan, Raman Thiagarajan, Sivagnanam Beulaja, Ganapasam Sudhandiran, Munuswamy Arumugam -
Curcumin prevents free radical-mediated cataractogenesis through modulations in lens calcium
• Vandana Dongare, Chaitanya Kulkarni, Manish Kondawar, Chandrakant Magdumb, Vivek Haldavnekar, Akalpita
Arvindekar - Inhibition of aldose reductase and anti-cataract action of trans-anethole isolated from Foeniculum
vulgare Mill. fruits
• Young Sook Kim, Nan Hee Kim, Dong Ho Jung, Dae Sik Jang, Yun Mi Lee, Jong Min Kim, Jin Sook Kim - Genistein
inhibits aldose reductase activity and high glucose-induced TGF-β2 expression in human lens epithelial cells
• V. Vats, S.P. Yadav, N.R. Biswas, J.K. Grover - Anti-cataract activity of Pterocarpus marsupium bark and Trigonella
foenum-graecum seeds extract in alloxan diabetic rats
• Suresh Kumar Gupta, Vivekananthan Kalaiselvan,. Pharm, Sushma Srivastava, Rohit Saxena, Shyam Sunder
Agrawal - Inhibitory Effect of Trigonella Foenum-Graecum on Galactose Induced Cataracts in a Rat Model; in vitro
and in vivo Studies
• Suresh K. Gupta & Vivekananthan Kalaiselvan & Sushma Srivastava & Rohit Saxena & Shyam S. Agrawal -
Trigonella foenum-graecum (Fenugreek) Protects Against Selenite-Induced Oxidative Stress in Experimental
Cataractogenesis
• Megha Saraswat, Palla Suryanarayana, Paduru Yadagiri Reddy, Madhoosudan A. Patil, Nagalla Balakrishna,
Geereddy Bhanuprakash Reddy - Antiglycating potential of Zingiber officinalis and delay of diabetic cataract in rats
• Manish Kumar, Talever Singh, Javed Ali and L.K Tyagi - In Vitro Anticataract Activity of Zingiber officinale on Goat
Lenses