CHAPTER I INTRODUCTION

Utilizing plants for ethnobotany dated back to the records of ancient China, Hindu and Mediterranean civilization. The use of local plants for medicinal purposes has been handed down from generation to generation up to present.

India has kept records of herbal medicines and has succeeded in preserving them despite the test of time and the rapid development of technology. In addition, the safety and efficacy of some plants were established by means of modern testing in the scientific framework.

Herbal medicines have contributed significantly to man’s struggle against diseases
and have been an important component of health care system for the thousands of years. (Romulo, 1989)

However, there is hazard on using these medicinal plants. When they are used to treat certain ailments it should be noted that they come in concentrated amounts which could have toxic effects. The danger of not knowing the correct concentration in concoctions cannot be ignored since they are proven to be fatal. Bioactive compounds are always toxic in high doses and the danger in the practice of uncontrolled use of plants can cause or may worsen if not aggravate illness.

Furthermore, herbal medicines widely used in decoctions and infusions contain certain components other than that of the bioactive compounds which are responsible for their curative properties. Despite their occurrence in small concentrations, these components may have a considerable physiologic activity.

The Philippines is blessed by a wide variety of plants and animals because of its tropical climate. One of the wide varieties of plants includes medicinal plants, which have been studied over the years for their ethnobotanical uses. The government is now putting up regional factories for the mass production of plants which have great potential for curing diseases and are expected to be very useful in the field of medicine. One example is the factory in Cotabato which is manufacturing tablets from lagundi to alleviate cough and asthma.

Through its Traditional Health Program, the Department of Health (DoH) has endorsed 10 plants and herbs that have been clinically proven for their medicinal values to relieve various ailments. These are Akapulko (Cassia alata), Ampalaya (Momordica charantia), Bawang (Allium sativum), Bayabas (Psidium guajava), Lagundi (Vitex negundo), Niyog-niyogan (Quisqualis indica L.), Sambong (Blumea balsamifera), Tsaang Gubat (Ehretia microphylla Lam.), Ulasimang Bato (Peperomia pellucida) and Yerba Buena (Clinopodium douglasii).

There are promising plants that have been showing potentials and drawing interests. One of which is corn, one of the most easily recognizable plants in the world. It is used as a major source of food in many different areas around the globe by a variety of people. In the Philippines, it is one of the most widely propagated crops. Corn Silk is the silky tassel inside the corn husk. It is not considered a food, but it is highly regarded in herbology as a valuable support for the urinary system because of its antidiuretic activity.

Diabetes is one of the top ten diseases in the Philippines. The term diabetes, when not specified, is usually used to refer to Diabetes mellitus, a serious metabolic disorder characterized by defects in the body's use of carbohydrates. It is a serious chronic metabolic disease characterized by an increase in blood sugar levels associated with long term damage and failure of organ functions, especially the eyes, kidneys, nerves, heart and blood vessels. It occurs when the pancreas does not adequately produce insulin, a hormone necessary for the proper utilization of sugar by the body or hen the body cannot properly utilize insulin.

A. Background of the Study
According to the health statistics of DoH, diabetes in the Philippines has been increasing and has affected one out of 25 Filipinos. An estimate of 3.36 million Filipinos is affected by the disease and this number is expected to rise to about eight million in the next 20 years.

The fact that diabetes is still incurable even in the advent of modern equipment and treatment, but when they are faithfully followed, can still relieve the patient of the symptoms of this disease and can reduce the occurrence of complications. Thus, even those who develop diabetes in an early life may, by rigid adherence to treatment, live successfully, comfortably and productively in the late stages of their lives. However, treatment of this disease requires a large amount of money, the cause why the famous “rich man’s disease” notation was attached to the disease.
Corn has been an important crop in the country’s economy. It is widely cultivated and is readily available. Furthermore, corn silk, which cannot be eaten and is not widely used, is considered as waste material so utilizing it will lessen the country’s garbage collection.

Since not all diabetic people belong tot the upper class of the society, the proponent had decided to focus her study on the effectiveness of corn silk in reducing blood sugar level. This part which is expected to yield a hypoglycemic preparation using simple methodologies will be employed by the researcher. In doing so, a low cost but effective antidiabetic drug may be made available to meet the common health care needs of the population’s majority.

B. Statement of the Problem
This proposal generally aims to determine the hypoglycemic activity of corn silk (Zea mays) on the blood glucose level of diabetic-induced Swiss mice.
Specifically, it seeks to answer the following questions:
1. How much extract can be obtained from 1.00 kg corn silk?
2. What substances can be found in corn silk extract?
3. Which among the doses (25%, 50%, 75% and 100%) of extracted and decocted corn silk is the most effective in lowering blood glucose level?

C. Objectives
In general, the objective of this investigation is to determine the hypoglycemic activity of corn silk (Zea mays) on the blood glucose level of diabetic-induced Swiss mice.
It specifically has the following objectives:
1. To measure how much extract can be obtained from 1.00 kilogram (kg) corn silk.
2. To identify the substances that can be found in corn silk extract.
3. To determine which among the doses (25%, 50%, 75% and 100%) of the extracted and decocted corn silk is the most effective in lowering the blood glucose level.

D. Hypotheses
Based on the formulated questions above, the researcher had come up with the following hypotheses:
1. Approximately 200 milliliters (200 mL) extract can be obtained from 1.00 kg corn silk.
2. Saponins, triterpenes, flavonoids, tannins, pseudo-tannins, alkaloids, volatile oils and glycosides are the substances in corn silk extract.
3. There are no significant differences on the effect of the different concentrations of the decocted and extracted corn silk on the blood glucose level of the Swiss mice.

E. Scope and Limitation
This project will focus on the hypoglycemic activity of the decocted and extracted corn silk (Zea mays) on the blood glucose level of diabetic-induced Swiss mice. The extract will be obtained from air-dried corn silk using blender. The preparation of the different concentrations of the extracts (25%, 50%, 75% and 100%) will be done in a laboratory. Distilled water will be used as a diluting agent in the preparations of the different concentrations of the corn silk extract.

The test animals in this proposal will be male Swiss mice with significant increase in their blood glucose level, 24 hours after inducing Diabetes mellitus through the use of Alloxan. The test animals will be 25 male Swiss mice randomly selected and divided among five groups. Each group is composed of 5 Swiss mice. The four groups will be used in determining the effective extract concentrations of corn silk while the remaining group will be used for comparative test using the test drug, Normal Saline Solution (NSS). The crude extracts and the test drug will be administered orally in a controlled environment.

The observation period of the diabetes-induced Swiss mice was limited to one day or 24 hour-period.

F. Significance of the Study
This investigation on the hypoglycemic effect of corn silk on the blood glucose level of diabetic-induced Swiss mice will be beneficial to the following:

Country. The discovery of the medicinal uses of indigenous plants such as corn (Zea mays) will greatly help the country’s progress since the utilization of these plants in pharmaceutical preparations will boost our nation’s economy by providing cheaper and more readily available raw materials for drug production. Likewise, it will provide the government with alternative antidiabetic drugs that can be produced locally and exported to other countries. On the other hand, corn silk which is considered as refuse will be employed to produce a new antidiabetic drug, thus this will lessen the some of the country’s garbage problem.

Pharmaceutical Industries. Patronizing drugs from local plants with cheaper active ingredients than imported raw materials will increase the volume of sales of pharmaceutical manufacturers.

Community. The result of this study will inform the people about effective and easily-obtainable medicinal plants and traditional medicines. Also, they will utilize corn silk more optimally for their benefits.

Diabetic Patients. The direct beneficiaries of this research are the diabetes-afflicted patients. Due to the rising cost of commercial antidiabetic drugs, most of them, particularly the patients of low socio-economic status, cannot afford to treat their disease leading to complications and in extreme cases, death. This proposal views the tapping of the curative and antidiabetic properties of corn silk as a home remedy for diabetes will result to lower priced medicine.

Farmers(Agricultural Sector). The discovery of the antidiabetic property of corn silk will give farmers an alternative source of income by propagating this plant and supplying the market with locally-produced raw materials that can be exported to other countries.

Researchers. This investigation can be used as a basis on the search for other indigenous plant that will be of help in the development of herbal drug industries.

G. Definition of Terms
For a clearer understanding of this proposal, the following terms will be defined as they are used in the context of this paper:
Biological activity. The activity of compounds on specified test organisms. In this investigation, test organisms or species that will be used are the Swiss mice. (Cantoria, 1994)

Bioactive Compounds. These are substances present on plants that when use in high doses can cause or worsen ailments. (Cantoria, 1994)

Control (negative). The solution (NSS) which will be given to the test organisms in which the corn silk extract was not added.

Crude. It is the raw or natural condition of an extract.

Diabetes. A serious metabolic disorder characterized by an increase in blood sugar level associated with long term damage and failure of organ functions. It is the disorder of glucose metabolism that results from an absolute or relative lack of insulin or when the body does not respond to insulin. (Jambora, 2006)

Efficacy. The power to produce an effect or capable of producing an intended effect.

Ethnobotany. This is the study of compounds that were isolated from the extract and exhibit physiologic properties in the field of medicine and pharmacology.

Extraction. it is the process that involves separation of medicinally active portions of plants from inactive components by using selective solvents in standard extraction procedures.

Insulin. A hormone secreted by the islets of Langerhans in the pancreas which helps the body use sugar and other carbohydrates. When there is an increase in blood sugar level, the condition is referred as hyperglycemia. On the other hand, the condition wherein the blood sugar level is lower than normal is called hypoglycemia.

Zea mays Linne. It is the scientific name of corn which is the origin of the silk, the test drug in this investigation.

H. Review of Related Literature (RRL)
Vegetables as Potential Hypoglycemic Agents

Vegetables are among the numerous plants tried for the treatment of Diabetes mellitus. In recent years, considerable amount of work has been carried out for possible beneficial use, such plants are bitter gourd (Momordica charantia) and ivy gourd (Coccinia indica). Majority of these studies have documented that the fruit of bitter gourd and the leaves of ivy gourd when administered orally have beneficial effect.

Origin and Distribution of Corn

For western civilization, the story of corn began in 1492 when Columbus's men discovered this new grain in Cuba. An American native, it was exported to Europe rather than being imported, as were other major grains.
Botanical Description

Corn is a very coarse, erect and tall grass 1.5 to 2 meters in height. The stem is solid, with center soft and spongy. The leaves are numerous and close together, 30 to 100 centimeters long, and 2 to 10 centimeters wide, linear lanceolate. Male inflourescence is erect and terminal; female inflourescence, on the axils of the leaves, cylindric and large. The individual fruit (grain) is roundish or reniform, compressed, smooth, shining, yellow, white, reddish or even purplish-black. (Quisumbing, 1978)

Constituents

Nadkarni reports that the “corn silk” contains mazenic acid (2 per cent), fixed oil, resin, sugar, mucilage and salts. Sayre adds albuminoids and phlobaphene. (Quisumbing, 1978)

It contains fatty acid 2.5%,volatile oil 0.12%,gum 3.8%,resin 2.7%,saponins 3.18%,alkaloids 0.05%, silicon, B vitamins, and moderate amounts of iron, zinc, potassium, calcium, magnesium and phosphorus. Others including allantoin, anthocyanins, calcium, cryptoxanthin, glycoproteins, plant acids, potassium, saponins, sugars, vitamin C, vitamin K , flavonoids, chlorogenic acid, saponins, volatile oil, fixed oil, resin, sugars, phytosterols, allantoin, tannin, resin, sterols, minerals.

Nutrition

Most vitamins and minerals are present in at least small amounts but a solely corn-based diet provides inadequate niacin for human health, leading to deficiency diseases such as pellagra. Yellow corn has higher vitamin A content than white corn. One 77g ear of yellow corn provides 11 percent RDA thiamin, 3g protein, and 85 calories.

Maize (Zea mays L.), or corn, was grown commercially in over 150 countries in 2003. Worldwide combined production was 638 million metric tons harvested from 143 million hectares. The major producers of maize in 2003 were the United States, China, Brazil, Mexico, Argentina and France. Maize is grown primarily for its kernel, which is largely refined into products used in a wide range of food, medical, and industrial goods.

Maize is used as a raw material for the manufacture of starch, the majority of which is converted by a complex refining process into sweeteners, syrups and fermentation products, including ethanol. Maize oil is extracted from the germ of the maize kernel. In the United States and Canada, only a small proportion of the whole kernel is consumed by humans, while refined maize products, sweeteners, starch, and oil are abundant in processed foods such as breakfast cereals, dairy goods, and chewing gum.

Uses

A variety of herbal remedies are prepared from different parts of the corn plant, a very soothing and relaxing diuretic action is possessed by the corn silk. Traditionally, this part of the plant has been also used as an effective remedy for the treatment of acute inflammation and chronic physical irritation present in the urino-genital system of patients; these include problems including cystitis, disorders such as urethritis and cases of prostatitis in men. Bladder infections and urinary tract infection in children are disorders which especially benefit from treatment using the corn silk - this remedy is very useful in both cases. A strong antiseptic and ameliorative action is present in the corn silk, at the same time, the remedy is used in removing toxins from the body, in the treatment of congestion and catarrh, in the reduction of deposits and irritants from the kidneys and urinary bladder - the detoxification power of the corn silk is extremely valuable in a variety of ways for different patients. The remedial action of the corn silk has been effectively used in the removal of urinary stones and accumulated gravel in the urinary tract, it is also used extensively where chronic bladder irritation and physical bladder weakening have led the to the development of a frequent need for urination and perhaps to the display of sudden bedwetting behavior by the patient.
The urinary system responds very well to the corn silk as a remedial measure partly due to the presence of significant amounts of the essential mineral potassium in the corn silk, and also due to its diuretic action - the corn silk can therefore serve as a general remedy for the majority of problems likely to affect the urinary system. The flow of urine, and the elimination of toxins is increased by the corn silk remedy, the herbal remedy also relaxes and soothes the muscular lining of the urinary tubules and the muscular urinary bladder itself, this action helps in relieving any physical irritation in the bladder and improves the condition of the patient. The remedies made from corn silk work by alleviating the irritation at the site or localized area in those cases where a chronic irritation affects the urinary bladder and the urethral walls leading to the frequent urination, the corn silk also acts locally on prostate disorders which give rise to an inability to pass urine properly.
Topical problems and skin irritations as well as inflammation can also be treated effectively and benefit from the corn silk's healing and soothing abilities - as an external or topical treatment, the corn silk is also excellent for rapidly healing wounds and all types of ulcers affecting the skin.

Corn silk is also used in the medical system of China, where problems such as internal fluid retention and jaundice are treated using the corn silk.
The lowering of elevated blood pressure may also be made possible by taking corn silk as the remedy tends to reduce the retention of fluid in all tissues of the body, at the same time, the corn silk also helps in the quick detoxification and rapid elimination of all accumulated toxins and metabolic wastes in the body - due to this, the remedy aids in relieving the symptoms of gout and disorders associated with arthritis. As a remedy, it is considered to have a thorough but gentle detoxifying effect on the body.
Preparation

Some herbalists say that cornsilk is best used when fresh, but it is also available in dried form. Cornsilk can be collected from the female flower or from corn cobs. In addition, cornsilk is available commercially in powdered and capsule form and as an extract. Cornsilk is usually brewed as a tea, a beverage that is said to be soothing.
Cornsilk tea or infusion can be made by pouring 1 cup (240 ml) of boiling water over 2 tsp (2.5 g) of dried cornsilk. The mixture is covered and steeped for 10-15 minutes. The tea should be consumed three times daily.
In addition, a tincture of 1 tsp (3-6 ml) of cornsilk can be taken three times daily. Tincture can be purchased over the counter, or made at home by mixing the herb with water or alcohol at a ratio of 1:5 or 1:10.
Corn silk is also available in capsule form. The usual dosage for 400-mg capsules is two capsules. These are taken with meals three times daily.