Medicinal plantsthe 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

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

Cataract risk factors

nutritional

deficiences trace metals sunlight smoking radiation

aging diabetes dehydration genetic factors certain drugs

(neuroleptics, steroids)

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

cataractphacoemulsificator needle

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

Cataract - biochemical causes

Aldose reductaseProtein glycation

Oxidative stress

http://www.siskiyoueye.com/images/photos/education/cataracts.jpg

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

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

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

>

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

Currently following species are under research:

Pueraria lobata, Allium cepa, Trigonella foenum-graecum,

Zingiber officinalis, Foeniculum vulgare, Curcuma longa.

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

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

Aldosereductase

GENISTEIN

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

Onion: anti-cataract activity

increases concentration of superoxide dismutase and glutathione peroxidase (antioxidant enzymes)

moderately inhibits aldose reductase.

>

Trigonella foenum-graecum - fenugreek

family: Fabaceae plant part used in medicine: seeds the plant is cultivated worldwide

www.mdidea.com/products/new/new004photogallery.html

Flowerupload.wikimedia.org/wikipedia/commons/thumb/6/6a/Fenugreek-methi-seeds.jpg/707px-Fenugreek-methi-seeds.jpg

Seeds

Fenugreek: anti-cataract activity

decreases malondialdehyde concentration,

increases glutathione levels,

increases antioxidant enzyme activity.

POLYUNSATURATEDLIPIDS

MALONDIALDEHYDE

oxidativestress

lensopacity

fenugreek extract

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

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

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

FlowersSeeds

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

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

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

CURCUMINfree

radicals

Lipid peroxidation

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