1. Edmaritz Hernández Pagán
RISE
University of Puerto Rico at Cayey
The implementation of Zea mays (corn) in the
diet of Rattus norvegicus (rat) with cataracts to
make a reduction of this problem.

2. Introduction
• Cataract: clouding of eye lens that affects vision
• Free radicals are the major causes of cataract. (R.
Thiagarajan & R. Manikandan, 2013)
• Free radicals produce lens damage by causing membrane
lipid peroxidation, protein inactivation, protein aggregation,
which leads to lens opacification.
• Free radicals: molecules with an odd electron in the
external orbital.

3. • Free radicals are products of the cell’s metabolism and
are inactivated by some mechanisms.
• The problem appears when the organism doesn’t produce
the necessary mechanisms to neutralize the free radicals.

4. • The damage to the biomolecules caused by the free
radicals is involved to problems related to:
Cardiovascular system
Neurologic system
Ocular apparatus
Respiratory apparatus
Kidney
• According to Barry Halliwell, antioxidants are substances
that delays or prevent the oxidation of an oxidable
substrate (biomolecules).
• The antioxidant transfers an electron to a free radical
when they collide, making the free radical nontoxic.

5. • One of the causes for antioxidant deficiency is a diet low
in antioxidants.
• Corn is a great source of the vitamin E antioxidant.
• Vitamin E is an endogen antioxidant.
• Vitamin E or tocopherol is an essential, fat-soluble
nutrient that functions as an antioxidant.

6. • N-methyl-N-nitrosourea (MNU) targets the lens epithelial and
photoreceptor cells, thereby rapidly inducing mature cataract
and retinal degeneration in neonatal and adult rats.

7. Hypothesis:
If there is an implementation of Zea mays (corn) in the diet
of Rattus norvegicus (rat) with cataracts, then it will
produce a reduction of this problem.

8. Research design and methods
Materials:
1. Four 20-days pregnant rats
2. 1,500 mg/kg of MNU
3. Pellet food
4. Corn
5. Tools for the morphologic analysis of the ocular tissue
6. Methacarn (methanol-Carnoy) fixative materials
7. Hematoxyn and eosin (HE) dyes
8. High-resolution digital slide scanner

9. Research design and methods
1. Feed the 20-days pregnant rats with pellet food until
they give birth.
2. Induce MNU (50 mg/kg) to 30 pups.
3. Make an experimental group.
4. Make a control group.
5. Experimental group: pellet food and corn.
6. Control group: pellet food.
7. Six months
8. Examine the retinal morphology.
9. Compare the results.

10. * The experimentation will be made controlling the
following variables:
 Temperature
 Humidity
 Light/dark cycle
 Illumination intensity
 Pathogen-free conditions
 Free access to water
 Pellet diet

11. Morphologic analysis of the ocular tissue
process
1. Fix the eyes of the rats in methacarn.
2. Embed them in paraffin
3. Hematoxylin and eosin (HE)
4. Cut ocular sections.
5. Scan HE-stained slides.
6. Measure the entire length of the retina and the length of the damaged
area, in the HE preparations
* The methodology that will be used follows the methodology of the
article: Mead acid supplementation does not rescue rats from cataract
and retinal degeneration induced by N-methyl-N-nitrosourea. (Yuko
Emoto, Katsuhiko Yoshizawa, 2015)
*The experimental protocol and all animal procedures that will be use in
this study will be approved by the Animal Care and will have all the
necessary animal permits.

12. Expected results
• Reduction of the cataracts
Potential error factor
• If the rats don’t eat the hole given food, the
experiment can have invalid results.

13. Importance:
• There is a great chance of irreversible blind eyes due to
surgery
• Vital for human health and general well-being.
• Inexpensive
• Easy to obtain
• Can be incorporate as dietary habits

14. References
Gritz, C. David. Can cataracts be prevented? Bulletin of the World Health
Organization, 2001,Vol.79, p260-261. 2p.
R. Thiagarajan & R. Manikandan.(2013). Antioxidants and cataract.
Department of Bioengineering, School of Chemical and Biotechnology, SASTRA University,
Thanjavur, India, Department of Animal Health and Management, Alagappa University,
Karaikudi, India.
R.Timm. Rorway Rats.(2005). Retreived from
http://icwdm.org/handbook/rodents/NorwayRats.asp
Varma SD , Chand D , Sharma YR , Kuck JF Jr, Richards RD. Oxidative stress and
cataract formation: role of light and oxygen. Curr Eye Res 1984 ; 3 : 35 – 57.
Y. Emoto, K. Yoshizawa, K. Hamazaki, Y. Kinoshita, M. Yuki, T. Yuri, H.
Kawashima, A. Tsubur. (2015). Mead acid supplementation does not rescue rats from cataract
and Retinal degeneration induced by N-methyl-N-nitrosourea. Kansai Medical University, Japan.

15. Thank you for your
attention!