Medicinal plants: Their production, phytotherapeuticity, uses and propagation

ROGERTO TOKARSKI

Intituto de Manipulacoes Farmaceuticas Ltda
SHLS 716-Bloco 5 Conjunto B
Lojas 01 a 04 -Salas 101/102
Centro Medico de Brasilia
Brasilia -DF

Introduction

In Brazil phytotherapy is a non-conventional therapy that has received great attention from the Government in the past five years, having proved to be useful for the treatment of many ailments. A large part of the population has access to it, not only due to its low cost, but also because of our Brazilian habit resulting in 90% of the population using tea as a medicine.

We are heading towards a stage in which a medicinal plant is seen as medicine deserving all care and attention. The latter has been shown in the fact that several universities and research centres have acknowledged medicinal plants as auxiliaries in the treatment of, and curing several diseases, and as a solution to many other ailments afflicting the Brazillian community. We see medicinal plants as resources able to produce medicated principles.

It is worthwhile to mention the great transformation seen in the panorama of the infectious diseases after Alexander Flemming discovered a substance produced by a fungus Penicillum notatum which is able to kill bacteria. This substance, known as Penicillin, represented a real progress in therapeutics.

Superior plants which, due to their metabolic activity are able to produce antibiotics, and which are found in Brazil include, among others, Capraria bioflora from which biflorine which is a polycyclic orthoquinone, was isolated. The compound shows an anti-Canadida albicans activity.

Considering that the plant synthesizes its active principles starting from the nutrients in the soil and basic elements, such as carbon dioxide, solar energy and water, we then went into the cultivation of plants which we considered as being important phytotherapeutics and which did not exhibit the required qualities which are necessary for medicines.

In the course of cultivation, the plants were provided with all favourable conditions for their development, thus obtaining as a result, a population of uniform plants regarding the external characters as well as their chemical composition which would guarantee a production of active pharmaceutics.

The following plants have been investigated for their phytotherapeutic properties.

Stevia (Steviare rebaudiance)

The leaves of this plant contain the deterpenic glycosides, stevioside and rebaudioside -A as the main components. These glycosides have found their importance as sweeteners. Thus stevioside and rebaudioside - A are 300 and 400 times as sweet as sucrose, respectively. Presently, the two compounds are widely used in Brazil as non-calorific sweeteners in foodstuffs and medicines. The compounds also posses non-cryogenic activities and are known to be harmless to humans.

Stevia reaudiance

The leaves of this plant contain stevioside and rebaudoside - A, which are diterpenic glycosides as main components. The importance of these glycines were given by the fact that they were sweeteners. Stevioside has up to 300 times the sweetening power of saccharose, and Rebaudoside-A has 400 times the sweetening power of saccharose.

At present there is a great interest in Brazil in the use of these glycines as non-calorific sweeteners, both in foodstuffs and medicine. They also present non-caryogenic activities and are harmless to health.

By using almost 10 kg of good quality dry leaves, we can extract 1 kg of stevioside. This sweetener is recommended to people suffering from diabetes, obesity and those under a hypocalorific regime.

We cultivated this plant in our farms. It can also be found under cultivation in Mato Grosso do Sul, Parana, Santa Catarina and Sao Paulo states.

Besides this sweetener being recommended for hypocalorific regimes we also have in our pharmacies a compound tea in which Stevia is the main plant ingredient and this is also recommended for the same purpose.

Other components of this tea include:

(a) Carqueja Amarga (Baccharis trimera Less), with bitter properties and thus favouring and stimulating digestion.

(b) Chapeu de Cauro (Echinodorus macrophyllus Kunt), from which alkaloids, and other substances have been detected. The plant shows diuretic properties.

(c) Jurubeba (Solanum paniculatum L.), whose active principles are found in the whole plant. It is used for the treatment of jaundice and in maintaining a good functioning of the liver.

Another group of plants are those which are rich in essential oils. One of the representatives of this group is Camomila (Matricaria chamomilla), which is also known as matricaria, margaca das boticas and camomila dos alemaes. Its extract is a blueish liquid which, when exposed to light, first turn green and later on brownish. The essential oil content of the extract varies from 0.15 to 1.35%. Azulene constitutes 0.062 to 0.16% of the crude extract occurring as procamazulene-A (matricina), which during the distillation process successively transforms itself into camazulenogen, and ultimately into camazulene. The amount of azulene in the essential oil fluctuates between 1 and 15%.

The pharmacological activity of Camomila is attributed to remarkable anticongestion properties of the extract, which are due to the camazulene and alpha-bisabolol present in it.

The Camomila extract also contains a bicyclic acetylenic ether which causes some toxicity as a result of its spasmolitic properties. Its anticongestion action is superior to that of guaiazulene.

Camomila is used as an internal medicine in the form of an infusion, as a digestive bitter tonic and also as an antispasmodic agent. Externally it is used as an anticongestion drug in erythemas created by sunlight, locally applied as a mask.

In cosmetics the extract is used to increase the flaxen, golden, light auburn, or pale yellowish brown colour of hair.

Barbatimao (Straphnodendron barbatimam Martius)

This is a leguminous Brazilian plant which is rich in tannins. Its thick bark contains 18 to 27%, sometimes up to 40% tannin. The high tannin content gives this plant a pharmacological astringent, energetic, healing, hemostatic and antiseptic action, due to the phenolic nature of the tannin.

Barbatimao tea is prepared under a boiling process, and it is used for cleansing and in baths when treating leucorrea, ulcers, wounds and uterine hemorrhage. Manoel da Silva et al., used it at the Assistencial-Brasilia-DF-Brazil teaching hospital to cure proctitis actinic. This non-comparative work was done on 16 patients with 11 of them having an unspecified proctosigmoiditis and 5 patients with actinic proctosigmoiditcs. Those patients, who were diagnosed by means of a biopsy were given a retention enema with Barbatimao tea, without any other additional oral medication. All patients showed a full recovery. Nine of them had lesions limited only to the rectum and seven to the rectum-sigmoide flexure. The patients selected in this study were those who did not respond to the topical treatment with 5-ASB corticoid or those who could not afford to purchase the conventional medicines. The minimum time for the use of the medicine was one month and the maximum 30 months. Two of the patients had to suspend the medication because they developed abdominal colics. There was clinical and endoscopic recision in 50% of the cases; in 6% there was clinical recision and endoscopic improvement and in 19% there was clinical and endoscopic improvement. The unaltered patients consisted of 25% of all those studied.

Given the initial clinical data, there is the possibility to use this new medicine for the treatment of these ailments, the medicine being easy to purchase and it is cheap.

Conditioning of the soil

We should stress the fact that during the conditioning of the soil when cultivating medicinal plants, several measures were taken that increased the productivity of the crop. Thus the following factors have now been established:

· Calcium favours the growing of Alfazema and Aleerim.

· An acidic soil is ideal for the development of Camomila.

· Nitrogenous compounds guarantee the production of alkaloids in the plant.

Collection

We have some basic procedures for the collection of different parts of the plant:

· Roots, stems and tubercle: collected during the autumn, when the plant is adult.

· Bark: collected from the branches during spring, before blossoming.

· Leaves: when the plant is developing the reproduction organs; preference is given to fully developed leaves.

· Flowers: when the floral buds are opening.

Drying

Regarding drying, we were able to verify that the amount of water present in the plants varied according to the tissue and organs, but in general it reached high volumes, as shown below:

Roots - 70 to 75%
Leaves - 60 to 90%
Flowers - over 90%

We were able to reduce these volumes to a percentage close to 5%, thus avoiding undesirable enzymatic reactions and the proliferation of fungi and bacteria, which endanger the stability of the active principles produced by the plant.

Phytotherapeutic forms

In our pharmacies, the pharmaceutical forms we indicate and prepare for the use of medicinal plants ranges from the simple one, a tea, to the one in which we use a fluid extract and dry plant, microcrushed in capsules. We attach importance to the information given to our clients on the fact that when plants are used as medicine, besides containing a large amount of active principles, they should be prepared in the right way, so as not to alter the composition and damage the medicinal fractions. When used as a tea, we stress on the way to prepare it, either by infusion or by boiling, and how to use it.

In obtaining fluid extracts and dyes for pharmaceutical preparations for topical and oral therapy we use suitable extracting solvents which dissolve and carry in them the active principles of the plants. At present consumers prefer the phytotherapeutic which are in the form of capsules. We either put the whole plant or part of it to a microcrushing process, thus obtaining a product which liberates easily its active principles to be absorbed by the body. Capsules are then made from this material.

Plants also used in Brazilian traditional medicine

1. Guarana (Paullinia cupana Kunts)

A native plant from the Amazon region that sometimes might reach ten meters high. Its principal constituent is caffeine and the average content in its seeds is 3 to 5%. This phytotherapeutic plant has several pharmacological actions:

· It stimulates the central nervous system.
· It stimulates the cardiac muscle.
· It relaxes the lean muscle, in particular the bronchial muscles.
· It acts on the kidneys, determining diuresis.

It is indicated to maintain the person awake, to restore mental lucidity in exhausted patients and to increase the respiratory capacity.

2. Espinheria Santa (Maytenus ilicifolia)

The plant is used for patients with high dyspepsia or peptic ulcers.

Trial uses for the protecting effect of the lyophilized extract of the Maytenus licifolia tea against gastric ulcer on mice, which was induced by indometnacine or by the stress obtained when immobilizing mice at a low temperature were carried out. The protecting effect was found to be dose-dependent and the results revealed an antigastric ulcer action.

Doses up to 360 times larger than the ones commonly used by human beings did not bring about any alteration in either biochemical serum or hematologic parameters.

Mice which were treated for as long as two months did not show a reduction in the reproduction capacity and the offsprings developed normally. The reproducing capacity and the offsprings born from females which received the treatment during pregnancy did not show any alteration when compared to the control group.

The clinical toxicology in healthy volunteers that drank Espinheira Santa during 14 days of a double dose of the posology was negative, indicating that the plant is non-toxic to humans. 23 patients who showed a diagnosis of a non-ulcer high dyspepsia, received during 28 days, two capsules of 200 mg each of lyophilized Espinheria Santa tea, equivalent to 2.4 g of dry pulverized plant material per day. As a result the group which took Espinheira santa showed significant improvement in relation to the placebo group, regarding the symptomatology of global dyspepsia and, in particular, of the burning symptoms and pain.

There were no complaints of side-effects produced by Espinhearia Santa.

3. Mentrasto (Ageratum conyzoides L.)

The plant is used for the treatment of arthritis.

In the research programme on medicinal plants, the authors studied the analgesic action of Mentrasto tea in fifty patients with clinical and radiological arthrosis of the knee, the femur, the hands and cervix. A study was undertaken on the daily and nightly spontaneous pain for a whole week.

Regarding pain, there was an improvement in 66% of the patients after the second week. The mobility of the joints improved only in 12% and probably it was a secondary effect in the absence of pain.

The absence of collateral effects, as well as from my personal impression led to the recommendation of Mentrasto as an alternative treatment for pain in arthritis, mainly for people who are financially unable to buy common anti-inflammatory medicines.

4. Quebra Pedra

To show the interest and depth of the study on medicinal plants as phytopharmaceutics, we tested, by means of this work, a new alkaloid obtained from Phylanthus sellowianus, commonly known as Quebra Pedra, used in the treatment of kidney stones.

Alkaloid fractions extracted from the leaves and branches of this plant presented anti-spasmodic effects in different pharmacological models and one of the alkaloid component was found to have formula C₁₅H₂₀N₂O₂.

5. Ricinus communis

The crude seed extract of this plant showed antineoplastic action. The non-oily fraction of the acetone extract of the seeds of R. comunis showed activity on the Walker carcinoma 256 in mice, with a daily dose of 0.3 mg/Kg for 8 days. A significant tumoral inhibition of 65% was seen in relation to the control group.

6. Alipina nutans

The aqueous alcoholic extract of this plant has shown a prolonged hypertensive effect in dogs.

This plant, commonly known as "colonia", is widely used in popular medicines both in the North and North-Eastern parts of Brazil to control hypertension in a form of tea.

With the objectives of verifying the possible hypotensive effect of these concoctions, male does put under anaesthesia by using Sodium pentobarbital (30 mg/kg) were injected with the extract from the leaves of the plant, to which alcohol had been previously eliminated. A decrease in the mean blood pressure was observed, thus showing that the preparation is less powerful than the aqueous alcoholic extract.

With these data we reached the conclusion that scientific experiments cannot only prove the popular use of a plant, but can also identify the more active forms from it, to be used as a phytotherapeutic. Due to the fact that the interest shown by research centres on medicinal plants is recent, we find that most of the medicinal plants have not been scientifically studied, even though they have been widely used by the people for a long period.

Table 1: Examples of medicinal plants available in pharmacies in Brazil

Acknowledgements

I am grateful to FARMACOTECNICA and my country for making it possible to attend this conference. To the organizers of the conference, I express my gratitude for the successful meeting.