Lemon grass tea, dried banana pulp lower blood cholesterol, heart disease risk

[XXPANTHAXX]

Fresh lemon grass leaves and dried banana pulp have shown promise as natural agents for lowering blood cholesterol levels and the risk of heart diseases. CHUKWUMA MUANYA reports.

NIGERIAN researchers have successfully used fresh leaves of lemon grass and dried banana pulp to treat hypercholesterolaemia in animal models. Hypercholesterolaemia is a condition in which levels of cholesterol in the blood are higher than normal,

The researchers claim this hypocholesterolaemic effect (lowering of the blood cholesterol levels) can be replicated in human.

Lemongrass (Cymbopogon citrates) belonging to the family Gramineae/Poaceae is a perennial tall grass with rhizomes and densely tufted fibrous roots. The fresh stalks and leaves have green colour and a lemon-like odour. The plant is a native of South India (but present in many parts of the world) growing in dense clumps.

To the French it is citronelle, Potuguese citronela. But in Nigeria the Edos call it eti (thick bush); Efik �k� �t�; Hausa tsauri; Ibibio myoyaka �k�r� (myoyaka of the Europeans); Igbo (Asaba) akw_kw_ (leaf, in general); Igbo (Owerri) �ch�r� ehi (cow's coarse grass); Yoruba ko�ko _ba, kor�ko _ba (lord/king of the grasses), kor�ko �y�nb� (European grass) oko _ba (lord/king of the farm) or t��.

Until now, lemon grass is used in different parts of the world in the treatment of digestive disorders, fevers, menstrual disorder, rheumatism and other joint pains. The essential oil of the plant is used for the treatment of skin diseases.

Traditional medicine practitioners in the Eastern part of Nigeria use the plant's preparation in the form of tincture (solution of plant extract in local alcohol) for treating coronary heart disease and related conditions, such as cardiovascular disorders.

Cholesterol is the major sterol in animal tissues and its amphipathic (a molecule having two different affinities, as a polar end that is attracted to water and a non-polar end that is repelled by it) nature enables it to occur in cell membranes. It is abundant in the brain, liver, adrenal glands and nervous system.

Dietary cholesterol is obtained from animal products. The maximum dietary cholesterol required in a day by an adult is 300 mg. The liver produces sufficient cholesterol (in the absence of enough dietary cholesterol) for all normal body functions. Higher cholesterol levels are found in males and older people. It is carried in the blood in the form of lipoproteins.

High cholesterol in the blood is associated with an increased risk of various disorders, such as coronary heart disease and stroke. These disorders are caused by blood vessels becoming narrowed with fatty deposits (which cholesterol is part of), leading to reduced blood flow (or total blockage of blood flow) to vital organs, like brain. Atherosclerosis is caused by hardening and narrowing of arteries.

Factors that facilitate development of the disorders of hypercholesterolaemia include smoking, lack of proper exercise, emotional stress, diets rich in saturated fatty acids, coffee drinking, diabetes and heredity.

A normal or desirable cholesterol level is less than 200 mg of cholesterol per deciliter of blood. Elevated cholesterol is a level over 240 and is considered to be hypercholesterolemia. Too much cholesterol in the blood has been shown to cause plaque to form inside the blood vessel walls, causing them to thicken and narrow. This change can increase the risk of heart disease and heart attacks.

Studies have shown that anyone with a diet high in saturated fat and cholesterol, is overweight and does not get enough exercise is at a greater risk for developing hypercholesterolemia. In addition, as men and women get older, their cholesterol levels rise. __Hypercholesterolemia can run in families, since heredity partly determines how much cholesterol the body makes.

Cholesterol is divided into two major categories: low-density lipoprotein (LDL), the so-called "bad" cholesterol, and high-density lipoprotein (HDL), the so-called "good" cholesterol.

Diet, exercise, smoking, alcohol, and certain illnesses have been shown to affect the levels of both types of cholesterol. Eating a high fat diet will increase one's level of LDL cholesterol. Exercising and reducing one's weight will both increase HDL cholesterol and lower LDL cholesterol.

Hypercholesterolemia can also be an inherited problem that affects the way the body processes cholesterol. Hypercholesterolemia can also be caused by any disease that raises LDL cholesterol levels, such as diabetes mellitus, kidney disease, liver disease, or hypothyroidism.

Hypercholesterolemia has no obvious symptoms until problems have already developed. Heart disease or a heart attack can be the result of hypercholesterolemia, and symptoms include chest pain and calf pain when walking (due to narrowed or blocked arteries).

A doctor will diagnose hypercholesterolemia by a blood test. The patient will abstain from eating and drinking anything but water for 12 hours before blood is drawn for the test. The blood will be tested to determine the LDL and HDL cholesterol levels, which can only be determined after fasting. A cholesterol level above 240 indicates elevated cholesterol levels and hypercholesterolemia.

Until now, treatment for hypercholesterolemia will involve trying to lower the LDL cholesterol in the blood. A diet high in fiber and low in fat, saturated fat and cholesterol can help lower these levels. The doctor may also recommend the patient lose weight and begin an exercise program.

If diet and exercise are not enough to lower cholesterol levels, the doctor may prescribe drugs such as cholestyramine (Questran), colestipol (Colestid), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), probucol (Lorelco), gemfibrozil, or niacin.

Medical experts say lowering cholesterol levels is very important to prevent complications such as heart disease and heart attacks. For every one percent reduction in cholesterol level, the risk of heart disease is reduced by two percent.

To prevent hypercholesterolemia, doctors recommend that people should adopt a healthy diet, exercise, quit smoking, maintain a normal weight and have cholesterol levels and weight checked regularly by a doctor. They say people who have a family history of early heart attacks especially should be checked regularly.

But researchers at the Departments of Biochemistry/Biotechnology, Ebonyi State University, Abakaliki Ebonyi State; and Biochemistry, Abia State University, Uturu, have shown that the extract of lemon grass possesses hypocholesterolaemia (lowers blood cholesterol levels) potential.

Agbafor K. N. and Akubugwo E. I. investigated the hypocholesterolaemic effect of ethanolic extract of fresh leaves of Cymbopogon citratus (lemongrass) using albino rats.

The researchers said the leaves of lemon grass are widely used in the Eastern Nigeria to treat various heart disorders. Thus, it is imperative to investigate if this could be based on reduction of blood cholesterol level.

According to the study published recently in African Journal of Biotechnology, hypercholesterolaemia was induced in the animals by feeding with egg yolk fortified diet for 14 days. The plant extract was administered orally to two groups, doses of 200 and 100 mg/kg body weight respectively for seven days. Physical activities, food and water intake and body weight increased before the administration of extract. These parameters, however, decreased after administration of extract.

The elevated cholesterol concentration were significantly (P<05) lowered in the animals given the plant extract. This reduction was found to be dose dependent. The result shows that the extract possesses hypocholestecolaemic potential. This may explain its efficacy in the management of heart diseases.

The study consisted of two segments. In the first segment which lasted 14 days animals were divided into three groups A B C. Animals in group C were five in number while those in group A were 10. the animals in group C were fed the normal rat chow while those in group A, were given diets fortified with egg yolk. Animals in all the groups were allowed free access to food and water. At the end of 14 days, blood was collected from all the animals by cutting the tail vain under mild anaesthesici with diethylether.

In the second stage, which was designed to test the potency of the crude ethanol leaf extract of Lemon grass, animals in group A were divided into two sub groups A1 and A2 with five animals in each sub group. Animal in A2 received 100 mg/kg while those in A1 were given 200 mg/kg of the crude leaf extract. All extracts were all administration was orally dissolved in 0.8 - 1 ml of distilled water. Animals in groups and were given 0.8-1 ml of distilled water orally daily for seven days as place 60. After the seven days period, blood was collected by cutting the tail of all the animals under mild anesthesia.

A general increase in physical activities, food and water intake were observed for all the animals during the feeding experiment. The animal on the high egg yolk diet recorded significant (P � 0.05) weight gains compared to the animals on the normal rat chow. The increase in weight of the animals suggests that they accumulated calories in the form of fats from the egg yolk diet.

This result agrees with the report of Wells et al. (1987), which suggests that accumulation of fats from diets such as egg yolk and liver might increase body weight. This suggestion is further corroborated by the significant increase (P � 0.05) in the serum cholesterol level of animals on the egg yolk diet. This observation tallies with the report of Laakso et al. (1988) that egg yolk supply significant amount of cholesterol to human diet which could be accumulated in the body and may lead to hypercholesterolaemia.

A different picture emerged following the administration of the crude ethanolic extract of fresh leaves of Lemon grass on the animals given the egg yolk diet for seven days. The animals exhibited reduced physical activity and also consumed less food and water compared to the untreated animals. These treated animals also recorded significant (P � 0.05) decreases in weight and lower serum cholesterol levels relative to untreated animals. These reductions in serum cholesterol level were dose dependent. The serum cholesterol level in the animals given the higher dose (200 mg/kg) of lemon grass ethanol extract was almost at par with those of the animals that were never given the egg yolk diet.

The researchers said the mechanism underlying these observations especially the loss of appetite is not clear. They noted: "However, there is evidence of metabolic upset. Studies aimed at understanding these events are going on in our laboratory. The cholesterol-lowering potential of the extract many be ascribed to modification of cholesterol uptake from the intestine, conversion of cholesterol to bile acids and increasing excretion of bile acids by extracts of lemon grass and curcumin plants as reported (National cholesterol Education programme Expert panel, 1988). Our result therefore seems to confirm the anti-hypercholestero laemic potentials of ethanolic extracts of fresh leaves of C. citratus which may explain its use in management of heart disease in ethnomedicine".

Researchers have also examined cholesterol-lowering effect of banana (Musa sapientum) pulp in the rat fed on a cholesterol-containing diet.

According to the study published in the British Journal of Nutrition, the pulp of banana fruit (Musa sapientum) was examined for its cholesterol-lowering effect with male rats fed on a diet containing lard (50 g/kg) and cholesterol (5 g/kg).

The researchers wrote: "Freeze-dried banana pulp showed a marked cholesterol-lowering effect when incorporated into a diet at the level of 300 or 500 g/kg, while the banana pulp dried in a hot-air current (65�) did not. Starch and tannin prepared from banana pulp were not responsible for the cholesterol-lowering effect. The results also suggest that banana lipids did not affect the concentration of serum cholesterol. Feeding of dopamine, n-epinephrine and serotonin tended to raise the concentration of serum cholesterol. Thus, all the substances tested which were thought to be susceptible to influence by hot-air drying were unlikely to be responsible for the hypocholesterolaemic effect.

"However, both soluble and insoluble fibres fractionated from banana pulp had a cholesterol-lowering effect, with the exception of cellulose. It was assumed that a browning reaction undergone during hot-air drying might be related to the disappearance of the hypocholesterolaemic effect of banana pulp dried in a hot-air current. The results obtained support the conclusion that soluble and insoluble components of dietary fibre participate in the hypocholesterolaemic effect of banana pulp".

To treat typhoid, researchers recommend that lemon grass leaf or is boiled in two litres of water for 30 - 40 minutes with 25 whole limes, two grape fruits, two unripe papaw fruits, and two unripe pineapples, cut garlic and the bark of Alstonia boonei (alstonia, cheesewood, pattern wood or stool wood in English; egbu in Igbo; and awun in Yoruba).

However, to make an infusion for malaria, pour a cup of boiling water over the lemon grass, let it stand for five minutes, strain it, and drink it.

"Lemon grass is usually used in the form of infusion or herbal tea, four ounces of grass or one bag of tea to one pint of boiling water. It is an excellent stomachic (serves to tone the stomach, improving its function and increasing appetite) to children; of much use in typhoid fevers; given with black pepper it is useful in disordered menstruation and in the congestive and neuralgic forms of dysmenorrhoea (cramps or painful menstruation). It is carminative (a medicinal drug with antispasmodic activity that is used against cramps of the digestive problems) and tonic to the intestinal mucous membrane, useful in ing and diarrhoea," says a homeopath, Dr. Osmond Onyeka of the National Association of Physicians of Natural Medicine (NAPNM).

Phytochemical analysis indicates that lemon grass, contains about 4 per cent of volatile oil. Its volatile oil is 65 per cent citrol, 12 per cent myrcene, and 23 per cent sundry oils. It contains hydrocarbons; myrcene (12-25 per cent), limonene, dipentene (monoterpenes) - alcohol; linalol, geraniol, nerol, citronellol (monoterpenols) (5 percent) - farnesol (12.8 per cent) (sesquiterpenols) - ketones: methylheptenone - aldehydes (60-80 per cent): citral, citronella, farmesal. The most active constituent is citral, which accounts for 70 per cent - 85 per cent of the oil's volume.

According to The Useful Plants of Tropical West Africa by H. M. Burkill, lemon grass has general benefits. It calms nervous exhaustion, stress related conditions. It is also good for acne, athlete's foot, colitis, excessive perspiration, fevers, gastro-enteritis, headaches, indigestion, infectious disease, insect repellent (fleas, lice, ticks), muscle tone, muscular pain, open pores, pediculosis, poor circulation, scabies, slack tissue, tissue toner.

Indeed, lemon grass oil has been known to be a very powerful antiseptic and bactericide, and laboratory trials have provided scientific confirmation of its benefits.

An insulin-like material, according to Encyclopaedia of Useful Plants of Tropical West African has been isolated from the plant value of 440 units orally, or 880 units subcutaneously, per gm. Leaf-wax has been shown to contain a ketone named cymbopogone and an alcohol cymbogonol. A trace of alkaloid is detected in the leaves, and an unnamed one in the rhizome.

The report reads: "Leaf and root contain traces of hydrogen cyanide. Miscellaneous other principles have been reported. The whole plant has a strong fragrant smell. It is often burnt in houses, either green or dry, to dispel mosquitoes. In the early days of the rubber plantation industry in Malaysia it was commonly planted near to labourers' quarters in the belief that it would keep away anopheles (malaria-carrying) mosquitoes, a hope not borne out. It has been planted in West Africa in tsetse fly areas as a control to discourage flies breeding.

"In most areas in Nigeria the leaves are used in infusion to make a tea-form beverage. This infusion is taken as a febrifuge, sudorfic and dyspeptic, and put into hot baths for fumigation. Leaves boiled with guava leaves are taken in Nigeria for cough. Leaf and rhizome infusions are considered pectoral and good for colds, flu, pneumonia, cough and consumption, as well as for fever. It is also applied to the forehead to relieve headache.

The rhizomes are used as toothpicks, chew-sticks and to rub on teeth for cleansing in West Africa. Their use as chew-sticks is said to assuage toothache. A tisane of the root is given to children to relieve cough, and a decoction is considered febrifugal".