FIELD OF THE INVENTION
The present invention relates to a process for preparing herbal medicine. More particularly, the present invention relates to an improved process for preparing Arjuna Ksheerpak.
BACKGROUND OF THE INVENTION
A shift towards a healthy lifestyle has increased the demand for natural products, such as extracts of herbs, vegetables, fruits and other plants. Herbal products are complex mixtures of organic chemicals that may come from any raw or processed part of a plant, including leaves, stems, flowers, roots, and seeds. As herbs are perceived “natural” and therefore safe, there is a growing preference for herbal drugs and traditional medicine over synthetic ones.
Terminalia is one such tree that is extensively used for its various medicinal properties and is mentioned in the Rig Veda. The species of Terminalia that are used in medicine include Terminalia Arjuna, Terminalia Bellerica, and Terminalia Chebula. In traditional ayurvedic medicine, Terminalia Arjuna has been used to balance the three “humors”: kapha, pitta, and vata. It has also been used for asthma, bile duct disorders, scorpion stings, and poisonings.
The bark of Terminalia Arjuna has been used in India for more than 3000 years, primarily as a heart remedy. An Indian physician named Vagbhata has been credited as the first to use this product for heart conditions in the seventh century A.D. According to Ayurveda, the one who takes Arjuna bark with milk, ghee or gur will be relieved from heart diseases, bleeding disorders and chronic fever. Research on Terminalia has been going on since the 1930s, to evaluate and verify its role, if any, in heart disease. Nevertheless, people today use Terminalia Arjuna for disorders of the heart and blood vessels (cardiovascular disease), including heart disease and related chest pain, high blood pressure, and high cholesterol. It is also used as “a water pill,” and for earaches, dysentery, sexually transmitted diseases (STDs), diseases of the urinary tract, and to increase sexual desire.
It has also been found that Terminalia contains ingredients that help stimulate the heart. It might also help the heart by lowering cholesterol and blood pressure. Some researchers have shown that taking Terminalia by mouth with conventional medications improves symptoms in people experiencing chest pain (angina) after a heart attack. Additionally, it has been found that taking Terminalia by mouth with conventional medications for 2 weeks improves symptoms in people with Congestive Heart Failure (CHF).
All the aforementioned health benefits of Terminalia Arjuna can be derived from a unique ayurvedic preparation known as Arjuna Ksheerpak. It is an ayurvedic formulation prepared using the dried bark of Terminalia Arjuna, cow’s milk, water and sugar, which is beneficial for cardiac patients.
The traditional process for preparing Arjuna Ksheerpak, described in Bhaishajya Ratnavali, Chapter 33, Hriday Rog Chikitsa, Verse 11, involves the following steps:
(a) mixing cow’s milk and water in a heating vessel;
(b) mixing powder of a bark of Terminalia Arjuna with water to form a paste;
(c) adding the paste into the heating vessel to form a mixture;
(d) concentrating the mixture by evaporating water;
(e) cooling the mixture;
(f) filtering the mixture and adding sugar to the filtrate.
The traditional process involves heating a mixture of the powdered bark of Terminalia Arjuna, water and cow’s milk in a vessel. However, the solubility of the active components may be low in the milk-water mixture, precluding their efficient extraction into the solution. In the absence of efficient extraction of the actives into the solution, the formulation may not possess optimum efficacy. Further, on heating the mixture for a prolonged period, there is a possibility of the mixture getting charred or destruction of the active components due to temperature spikes. In order to prevent charring and temperature spikes, water has to be added at regular intervals into the heating vessel. Still further, prolonged heating requires careful monitoring of the temperature and water levels by trained personnel. The traditional process may not be amenable to production on an industrial scale. Hence, there is a need for a process to prepare Arjuna Ksheer Pak that is not only efficient at extracting the active components from the powdered bark of Terminalia Arjuna but also compatible with its production on an industrial scale.
Hence it is an objective of the present invention to afford an improved process for preparing Arjuna Ksheerpak that solves the aforestated drawbacks of prior art processes.
It is a further objective of the present invention to afford an improved process for preparing Arjuna Ksheerpak that extracts more extractable herbal components compared to traditional processes.
SUMMARY OF THE INVENTION
The present invention relates to an improved process for preparing Arjuna Ksheerpak containing more extractable herbal components as compared to traditional process.
The inventors of the present invention have developed an improved process for preparing Arjuna Ksheerpak, comprising the steps of:
a. extracting powdered bark of Terminalia arjuna by an extraction solvent to obtain a herbal extract; and
b. concentrating the herbal extract to obtain a concentrated herbal extract;
wherein step a is carried out in a soxhlet apparatus to increase the number of extractable herbal components.
The boiling flask of the soxhlet apparatus contains the extraction solvent comprising a mixture of milk and water, wherein milk is present in an amount in the range from 60 to 75% and water is present in an amount in the range from 25 to 40%. In a preferred embodiment, milk and water are present in a ratio of 2:1.
In accordance with an embodiment of the invention, step a comprises heating the extraction solvent in the boiling flask of the soxhlet apparatus for a pre-determined period of time at the boiling point of the extraction solvent. The pre-determined period of time ranges from 1 to 12 h.
In accordance with another embodiment of the invention, the improved process for preparing Arjuna Ksheerpak comprises the steps of:
I. Heating the extraction solvent in the boiling flask at the boiling point of the extraction solvent for a first time period;
II. Allowing the extraction solvent in the boiling flask to stand without heating for a second time period;
III. Heating the extraction solvent in the boiling flask at the boiling point of the extraction solvent for a third time period; and
IV. Allowing the extraction solvent in the boiling flask to stand without heating for a fourth time period to obtain the herbal extract;
wherein heating the extraction solvent in the boiling flask is carried out at the boiling point of the extraction solvent, the first time period and the third time period range from 1 to 12 h, and the second time period and the fourth time period range from 1 to 36 h.
In accordance with an embodiment of the invention, the herbal extract obtained in step a is concentrated in step b by heating in an open vessel at a temperature in the range from 90 to 100 °C, until the moisture content is in the range from 40 to 50%, to obtain the concentrated herbal extract.
In accordance with another embodiment of the invention, the herbal extract obtained in step a is concentrated in step b in a rotary evaporator under vacuum, until the moisture content is in the range from 40 to 50%, to obtain the concentrated herbal extract.
The ratio of milk: water: powdered bark of Terminalia arjuna at the beginning of the extraction process is preferably 10:5:2.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1. High Performance Thin Layer Chromatography (HPTLC) of TAsm and TAaq visualized at 254 nm.
Figure 2. High Performance Thin Layer Chromatography (HPTLC) of TAsm and TAaq visualized at 366 nm.
Figure 3. High Performance Thin Layer Chromatography (HPTLC) of TAsm and TAaq visualized with spray reagent.
DETAILED DESCRIPTION OF THE INVENTION
Discussed below are some representative embodiments of the present invention. The invention in its broader aspects is not limited to the specific details and representative methods. The illustrative examples are described in this section in connection with the embodiments and methods provided. The invention according to its various aspects is particularly pointed out and distinctly claimed in the attached claims read in view of this specification.
It is to be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of two or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
The expression of various quantities in terms of “%” or “% w/w” means the percentage by weight of the total solution or composition unless otherwise specified.
All cited references are incorporated herein by reference in their entireties. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention.
The present invention, in its product and process aspects, is described in detail as follows:
In a first aspect, the present invention relates to an improved process for preparation of Arjuna Ksheerpak involving extraction of powdered bark of Terminalia arjuna using soxhlet apparatus. The bark of Terminalia arjuna, commonly known as Arjun Chaal are washed with water, dried and passed through hammer mill to obtain a coarse powder hereinafter referred to as a powdered bark of Terminalia arjuna.
The improved process for preparing Arjuna Ksheerpak, comprising the steps of:
a. extracting powdered bark of Terminalia arjuna by an extraction solvent to obtain a herbal extract; and
b. concentrating the herbal extract to obtain a concentrated herbal extract;
wherein step a is carried out in a soxhlet apparatus to increase the number of extractable herbal components, thereby improving the efficacy of Arjuna Ksheerpak.
A soxhlet apparatus comprises the following basic parts: boiling flask, an extraction chamber, which has a thimble (the thimble is usually made of a porous material such as a filter paper which allows the flow of the extraction solvent while retaining the solid material), a condenser and a siphon mechanism, which periodically empties the thimble. The powdered bark of Terminalia arjuna is placed in the thimble. The extraction solvent, which is placed in a boiling flask is heated to reflux by a heating element, which is placed below the boiling flask. The term “reflux” used herein refers to the cycle comprising heating the extraction solvent contained in the boiling flask to its boiling point, vaporizing the extraction solvent, condensing the vapours back to the liquid state and into the boiling flask.
The main advantage of using a Soxhlet apparatus is that the extraction solvent always has zero concentration of the extractable herbal components when the solvent first contacts powdered bark of Terminalia Arjuna, leading to their effective extraction. The term “extractable herbal components” used herein refer to the compounds present in the powdered bark of Terminalia arjuna that dissolve in warm water and are responsible for its physiological activity. There is also no need to carefully monitor solvent levels and temperature at regular intervals.
The extraction solvent of the present invention is selected from the group consisting of milk, water and combinations thereof. The term “milk” used herein refers to both milk and colostrum in the form in which it is produced by the mammal or any derivative of whole milk in liquid form. Preferably, the milk used in the present invention has total solid-12% w/w, specific gravity-1.022, milk fat-3.1% w/w, milk Solid Not Fat (SNF) - 9.1% w/w and pH 6.67. Preferably, milk is present in an amount in the range from 60 to 75%, and water is present in an amount in the range from 25 to 40%. In a preferred embodiment, the extraction solvent of the present invention comprises milk and water in a ratio of 2:1. Preferably, the ratio of milk: water: powdered bark of Terminalia arjuna at the beginning of the extraction process is 10:5:2.
The boiling point of pure water is 100 °C, however, the extraction solvent being a mixture of milk and water will have a boiling point slightly above 100 °C. However, a person skilled in the art would be aware of the fact that the boiling point of, the extraction solvent, comprising a water-milk mixture, would depend on the composition of the milk and the altitude at which the refluxing is performed.
As the extraction solvent, i.e. the water-milk mixture is heated up to its boiling point, water vapour travels up a distillation arm, and floods into the extraction chamber housing the thimble containing the powdered bark of Terminalia arjuna. The condenser ensures that water vapour cools, and drips back down into the extraction chamber housing the thimble containing the powdered bark of Terminalia arjuna. The extraction chamber containing the thimble slowly fills with warm water. Some of the desired extractable herbal components dissolve in the warm water. When the extraction chamber is almost full, said chamber is emptied by the siphon mechanism. The water is returned to the boiling flask. The extraction of the extractable herbal components can be monitored by observing the colour of the water being emptied by the siphon mechanism. On complete extraction of the extractable herbal components, the water being emptied by the siphon mechanism appears to be colourless, thereby indicating the completion of the extraction process of step a. The thimble ensures that the rapid motion of water does not transport any powdered bark of Terminalia arjuna into the boiling flask. This cycle may be allowed to repeat many times, over a pre-determined period of time ranging from 1 to 12 h. Preferably, the pre-determined period of time is 12 h.
During each cycle, a portion of the extractable herbal components dissolves in the water. After many cycles the extractable herbal components get concentrated in the extraction solvent in the boiling flask. The soxhlet apparatus may be operated continuously as disclosed above, or in a series of steps as described herein below.
In accordance with another embodiment of the invention, step a of the improved process for preparing Arjuna Ksheerpak comprises the steps of:
I. Heating the extraction solvent in the boiling flask at the boiling point of the extraction solvent for a first time period;
II. Allowing the extraction solvent in the boiling flask to stand without heating for a second time period;
III. Heating the extraction solvent in the boiling flask at the boiling point of the extraction solvent for a third time period; and
IV. Allowing the extraction solvent in the boiling flask to stand without heating for a fourth time period to obtain the herbal extract;
wherein heating the extraction solvent in the boiling flask is carried out at the boiling point of the extraction solvent, the first time period and the third time period range from 1 to 12 h, and the second time period and the fourth time period range from 1 to 36 h. Although the above process describes step a as comprising two alternating heating and non-heating periods, however, step a can be carried out in any number of alternating heating and non-heating periods, having time periods independent of each other.
In step b, the herbal extract is concentrated to obtain a concentrated herbal extract The terms “Arjuna Ksheerpak” and “concentrated herbal extract” essentially mean the same thing and can be used interchangeably. The herbal extract obtained in step a can be concentrated by heating it in an open vessel or in a rotary evaporator under vacuum. Preferably, the herbal extract is heated in an open vessel at a temperature ranging from 90 °C to 100 °C, until the moisture content of the herbal extract is in the range from 40 to 50%, to obtain the concentrated herbal extract. A person skilled in the art would be aware that concentration of herbal extract in a rotary evaporator under vacuum would occur at a lower temperature compared to concentration in an open vessel, due to depression of the boiling point of the extraction solvent under reduced pressure. The concentration of the herbal extract obtained in step a is carried out in a rotary evaporator, until the moisture content of the herbal extract is in the range from 40 to 50%, to obtain the concentrated herbal extract. The non-soluble portion of the powdered bark of Terminalia arjuna remains in the thimble, and is discarded.
The present invention is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those of skill in the art. Unless otherwise noted, all parts, percentages, and ratios reported in the following examples are on a weight basis, and all reagents used in the examples were obtained or are available from the chemical suppliers.
Examples
The following examples illustrate the basic methodology and versatility of the present invention.
Collection of plant material
The bark of Terminalia arjuna L. was collected from Shree Mahavir Jadibooti Ayurved Bhavan, Shivpuri-473551, M.P. (India).
Example 1
Traditionally prepared aqueous extract of Terminalia arjuna L. (TAaq)
The bark of Terminalia arjuna L. was washed with water and dried in air. The dried bark of Terminalia arjuna L. was pulverised using hammer mill and passed through the sieve number# 8 to obtain powdered bark of Terminalia arjuna L. 400 g of powdered bark of Terminalia arjuna L. was taken in a stainless steel vessel. 3.2 L of water were added to the stainless steel vessel to form an extraction solution. The extraction solution was heated at a temperature ranging from 90 to 100 ºC for four hours. Thereafter, the extraction solution was cooled to room temperature and filtered through a nylon cloth having mesh size # 60 to obtain a herbal extract. The herbal extract was concentrated by heating in an open stainless steel vessel at a temperature ranging from 90 to 100 ºC, until the moisture content of the herbal extract was in the range of 40 to 50%, to obtain traditionally prepared aqueous extract of Terminalia arjuna L. (TAaq). Suitable preservative (Sodium Benzoate-0.2%w/w & Potassium Sorbate-0.2%w/w) was added to the traditionally prepared aqueous extract of Terminalia arjuna L. to obtain traditionally prepared aqueous extract of Terminalia arjuna L. with preservative.
Example 2
Improved process for preparing Arjuna Ksheerpak of the present invention involving use of soxhlet apparatus
The bark of Terminalia arjuna L. was washed with water and dried in air. The dried bark of Terminalia arjuna L. was pulverised using hammer mill and passed through the sieve number# 8 to obtain powdered bark of Terminalia arjuna L. 400 g of powdered bark of Terminalia arjuna L. was kept in a thimble of the extraction chamber of a soxhlet apparatus. An extraction solvent comprising a mixture of 1 L of water and 2 L of milk was placed in a boiling flask of the soxhlet apparatus. The extraction solvent was refluxed by heating the extraction solvent in the boiling flask at its boiling point for a period of 6 h followed by allowing the extraction solvent to stand for a period of 18 h without heating. After that, the aforestated step of refluxing by heating the extraction solvent at its boiling point followed by standing without heating was repeated, to obtain the herbal extract. Finally, the herbal extract was taken in a stainless steel open vessel and concentrated by heating at a temperature ranging from 90 to 100 ºC, until the moisture content of the herbal extract was in the range from 40-50%, to obtain the concentrated herbal extract or Arjuna Ksheerpak of the present invention (TAsm).
Example 3
In-vivo evaluation of the cardio-protective efficacy of traditionally prepared aqueous extract of Terminalia arjuna L. (TAaq) and Arjuna Ksheerpak of the present invention involving use of soxhlet apparatus (TAsm) in isoproterenol-induced myocardial necrosis in rats
The present study compared the cardio-protective action of traditionally prepared aqueous extract of Terminalia arjuna L. (TAaq, prepared according to Example 1) and Arjuna Ksheerpak of the present invention involving use of soxhlet apparatus (TAsm, prepared according to Example 2) using plasma creatine kinase (CK) and plasma lactate dehydrogenase (LDH) as cardiac injury biomarkers.
Isoproterenol [1-(3, 4- dihydroxyphenyl)-2-isopropylamino ethanol hydrochloride)] (ISO), is a synthetic catecholamine and ß-adrenergic agonist which causes severe oxidative stress in the myocardium, resulting in infarct-like necrosis of the heart muscle.
In the present study, rats (Wistar male rats) were randomly divided into four groups with six rats each. Control rats were fed normal saline (1.0 mL/kg/ body weight) daily for 15 days. Traditionally prepared aqueous extract of Terminalia arjuna L. (TAaq, 250 mg/kg/body weight) and Arjuna Ksheerpak of the present invention involving use of soxhlet apparatus (TAsm,150 mg/kg/body weight) were administered orally daily for 15 days. After 15 days, rats were administered two doses of isoproterenol (85 mg/kg/body weight), 24 hours apart, and blood was withdrawn in heparinised tube after 24 hours of second dose.
The plasma creatine kinase (CK) level was 779.5±53.0 pg/mL in the group of rats administered TAaq and 770.8±57.4 pg/mL in the group of rats administered TAsm, whereas it was 934.1±33.1 pg/mL, p<0.001, in the control group.
Likewise, the Lactate Dehydrogenase level was 225.6±19.2 ng/mL, p<0.001, in the group of rats administered TAaq and 216.9±19.5 ng/mL, p<0.001, in the group of rats administered TAsm.
The decreased levels of both plasma creatine kinase (CK) and lactate dehydrogenase in the groups of rats administered TAaq and TAsm compared to control show that TAaq and TAsm have cardioprotective action, and the action is enhanced in case of TAsm.
Example 4
High Performance Thin Layer Chromatography (HPTLC) of traditionally prepared aqueous extract of Terminalia arjuna L. (TAaq) and Arjuna Ksheerpak of the present invention involving use of soxhlet apparatus (TAsm)
The toluene soluble concentrated extract of TAaq (5gm) and TAsm (5gm) was spotted in the form of bands with a Camag micro litre syringe on precoated silica gel aluminium plate 60F254 (0.2 mm thickness; E. Merck, Darmstad, Germany) using a Camag Linomat V (CAMAG, Muttenz, Switzerland). The plates were developed using mobile phase consisting of chloroform and methanol, in the ratio of 95:5. For visualisation, spots on the developed TLC plates were exposed to UV light (254 nm [Figure 1] and 366 nm [Figure 2]). Finally, the plates were sprayed with anisaldehyde-sulphuric acid followed by drying the plates in an oven at 105 ºC for 5 min and visualized in white light (Figure 3).
Based on the various visualizations (Figures 1, 2 and 3), it was concluded that the number of spots in case of TAsm, were more compared to that in case of TAaq. Hence, more therapeutic compounds, which will be ultimately responsible for therapeutic activity of product, are extracted through soxhlet extraction method of the present invention compared to traditional method.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

We claim:
1. An improved process for preparing Arjuna Ksheerpak, comprising the steps of:
a. extracting powdered bark of Terminalia arjuna by an extraction solvent to obtain a herbal extract; and
b. concentrating the herbal extract to obtain a concentrated herbal extract;
wherein step a is carried out in a soxhlet apparatus to increase the number of extractable herbal components.
2. The improved process for preparing Arjuna Ksheerpak, as claimed in claim 1, wherein a boiling flask of the soxhlet apparatus contains the extraction solvent comprising a mixture of milk and water, wherein milk is present in an amount in the range from 60 to 75 % and water is present in an amount in the range from 25 to 40%.
3. The improved process for preparing Arjuna Ksheerpak, as claimed in claim 2, wherein the ratio of milk: water is 2:1.
4. The improved process for preparing Arjuna Ksheerpak, as claimed in claims 2 and 3, wherein step a comprises heating the extraction solvent in the boiling flask of the soxhlet apparatus for a pre-determined period of time at the boiling point of the extraction solvent to obtain the herbal extract.
5. The improved process for preparing Arjuna Ksheerpak as claimed in claim 4, wherein the pre-determined period of time ranges from 1 to 12 h.
6. The improved process for preparing Arjuna Ksheerpak as claimed in claims 2 and 3, wherein step a comprises the steps of:
I. Heating the extraction solvent in the boiling flask at the boiling point of the extraction solvent for a first time period;
II. Allowing the extraction solvent in the boiling flask to stand without heating for a second time period;
III. Heating the extraction solvent in the boiling flask at the boiling point of the extraction solvent for a third time period; and
IV. Allowing the extraction solvent in the boiling flask to stand without heating for a fourth time period to obtain the herbal extract;
wherein heating the extraction solvent in the boiling flask is carried out at the boiling point of the extraction solvent, the first time period and the third time period range from 1 to 12 h, and the second time period and the fourth time period range from 1 to 36 h.
7. The improved process for preparing Arjuna Ksheerpak as claimed in claims 1 to 6, wherein the herbal extract obtained in step a is concentrated in step b by heating in an open vessel at a temperature in the range from 90 to 100 °C, until the moisture content is in the range from 40 to 50%, to obtain the concentrated herbal extract.
8. The improved process for preparing Arjuna Ksheerpak as claimed in claims 1 to 6, wherein the herbal extract obtained in step a is concentrated in step b in a rotary evaporator under vacuum, until the moisture content is in the range from 40 to 50%, to obtain the concentrated herbal extract.
9. The improved process for preparing Arjuna Ksheerpak as claimed in claims 2 and 3, wherein the ratio of milk: water: powdered bark of Terminalia arjuna is preferably 10:5:2.