The present invention relates to water-soluble extracts
derived from Russian Tarragon, their preparation, fractionation and their use, either
alone or as combinations with further compounds.
The modern civilization especially of the western world
is threatened by a number of diseases related to the rising prosperity. Thus, the
incidences of obesity, cardio-vascular and metabolic diseases, like metabolic syndrome,
increased blood lipids and diabetes type II are increasing dramatically. Especially,
the ingestion of high amounts of simple sugars may lead to high blood concentrations
of glucose and thus, after a longer period of time, to glucose intolerance, metabolic
syndrome and often finally to diabetes type II. Very critical in this context are
the high glucose peaks that occur post-prandial, which can lead to glycoxylation
reactions in the blood and certain tissues, probably followed by secondary diseases.
Additionally, the lack of physical workout and intake of
diets characterized by high fat intake and repeated ingestion of refined foods and
sugars, coupled with low fiber and vegetable intake, along with the natural aging
process, causes a deterioration in the way in which the body metabolizes blood glucose.
When the body cannot properly metabolize blood glucose, a tendency to store glucose
as fat typically occurs. This is one reason levels of body fat increase with age.
On the other hand constantly high blood concentrations of glucose or high post-prandial
glucose peaks can be related to undesirable glycoxylation reactions of blood or
tissue components. Secondarily, a glucose tolerance and/or insulin resistance can
be developed, which may be related to metabolic syndrome and diabetes type 2. Diabetes
is also known to be associated with a variety of other ailments including heart
disease, hypertension, and obesity. There is a known link between insulin resistance
and increased visceral adiposity. Diabetes is also a leading cause of glaucoma and
other conditions related to a decrease in the quality of life.
The object of this invention was thus to provide an extract,
useful for normalizing elevated blood glucose levels under conditions of metabolic
syndrome, pre-diabetes and diabetes Type 2 in animals and humans. Therefore, the
reason for this invention is to prevent or counteract, and treat the general deterioration
of the health status while aging or under the condition of illnesses and/or diseases
related to high blood glucose levels.
The object is solved by an extract, obtainable by
- extracting Russian Tarragon (Artemisia dracunculus) with water or a mixture
of water with up to 20% by volume of a water-miscible solvent. According to the
invention, the application of the disclosed Tarragon extracts and/or combinations
of the said extracts with excipients, supplements, nutrients and alike will normalize
elevated blood glucose levels under conditions of metabolic syndrome, pre-diabetes
and diabetes Type 2 in animals and humans.
Surprisingly, it was found that the oral administration
of the aqueous Russian tarragon extracts showed a change of blood glucose levels
within a well established animal model using a glucose tolerance test, which is
well transferable to human post-prandial lowering of blood glucose that occurs after
meals. The results are clearly improved over the formerly described and existing,
state-of-the-art products containing ethanolic extracts of Tarragon.
Disclosed herein are inter alia orally applicable products
comprising an water-soluble extract of Tarragon, preferably of Russian Tarragon,
fractions, or derivatives thereof without or with formulation constituents and a
method of lowering or normalize elevated blood glucose levels under conditions of
metabolic syndrome, pre-diabetes and diabetes Type 2 in animals and humans comprising
administration of the said products as dietary supplement, food or drink preparation,
or in a pharmaceutical delivery form.
Furthermore, it is an embodiment of this invention to provide
a method and an orally applicable product or combination which will prevent, counteract
and/or treat conditions of metabolic syndrome, pre-diabetes and diabetes Type 2
as well as support weight loss and body fat reduction in animals and humans.
Tarragon (Artemisia dracunculus) and plant extracts of
tarragon are considered as food and generally recognized as safe (GRAS) and can
be administered orally to humans or animals for the purpose of controlling blood
glucose as well as improving glucose tolerance according to US
6,893,627. This patent disclose only an ethanolic plant extract
of freeze-dried fresh plants derived from hydroponically grown Russian Tarragon.
Prior to this patent publication a few scientific papers described the traditional
use of tarragon for diabetes type 2, although they do not differentiate between
French and Russian Tarragon and the kind of preparation was not described either
(e.g. Swantson-Flatt SK, Day C, Flatt PR,
Gould BJ, Baily CJ. Glycemic effects of traditional plants treatments for diabetes:
studies in normal and streptozocin induced diabetic mice. Diabetes Res 1989; 34(2):
132-135).
Thus, for mildly polar extracted tarragon preparations
an influence on the glucose metabolism was known, but for a water extract of any
variety of Russian Tarragon no positive effect on blood glucose improvement was
described or even demonstrated.
Therefore, the herewith disclosed aqueous Russian Tarragon
extract helps to clear glucose from the blood, reduces post-prandial glucose peaks
and helps reducing undesired glycoxylation reaction with vital molecular body structures
or metabolites in the blood serum or tissues.
Furthermore the invention present very convenient forms
of a Russian Tarragon extracts, which enables many technical feasible applications,
due to its outstanding properties, like complete water solubility that allow all
imaginable beverage formulations. The extraction process is less expensive compared
to solvent extraction, because water can be used as exclusive extraction media.
The manufacturing process is much easier designed as for a solvent extraction, e.g.
with higher ethanol concentrations above 50% V/V. An ethanolic or solvent extraction
bears the disadvantages that lipophilic compounds are extracted in higher concentrations
than using water as extraction media. Thus, the obtained extracts from solvent extraction
are more of pharmaceutical character and efficacy, and additionally it is not completely
water-soluble and not applicable in drinks and beverages and many other dietary
supplement or food products. In addition, the disclosed water extract of Russian
Tarragon can be obtained completely free of the supposing perilous essential oils,
like estragol and methlyeugenol. In addition, it was found that the disclosed extracts
do not have an effect on the basal blood glucose levels, a fact which can be interpreted
as crucial positive safety aspect related to missing of a hypoglycemia status after
oral administration of the said extract by fasting individuals.
The different botanical basic extracts were obtained by
standard laboratory methods but were additionally transferable and could be up-scaled
to technical production. Furthermore, fractionations were obtained by using membrane
filtration and absorption column. Commercially available Russian Tarragon can be
used as raw material for an extraction with water or hydroethanolic extraction solvent.
The raw materials were cultivated on open fields, harvested and gently dried in
a conventional drier commonly used for drying herbs and spices.
Suitable extracts can for example be produced as follows:
1 kg of the raw materials is extracted twice with either 8 L water or 8 L of 20%
ethanol (V/V) at 80°C or 50°C, respectively. After cooling of the eluates
over night, the solutions are filtered through paper filters and the solvent is
evaporated by means of a rotatory evaporator. The obtained dense extracts, were
mixed with 30% of suitable carrier, like maltodextrins, hydrolysed collagen, microcrystalline
cellulose or cellulose derivatives, and dried at 50°C in a drying chamber.
The dried extract is finally ground and sieved for an adjustment of the particle
size. The yield of native extract is about 35% and the analysis shows water contents
of less than 5% and a complete removal of the essential oil (Estragol, Methyleugenol).
The herein disclosed and described water-soluble Russian
Tarragon extracts and products derived therefore help to clear glucose from the
blood, reduce post-prandial glucose peaks and helps reducing undesired glycoxylation
reaction with vital molecular body structures or metabolites in the blood serum
or tissues.
Similarly related, such administration of the said extracts
or products can also be used for the purpose of normalizing blood glucose levels.
The material can be administered as disclosed and described Russian Tarragon extracts
or in combinations with or without further anti-diabetic compounds and for instance
with ergogenic compounds, e.g. creatine and can be administered in a variety of
product forms including capsules, tablets, powdered beverages, bars, gels or drinks.
The invention also relates to the use of water-soluble
plant extracts from Tarragon (Artemisia dracunculus) and ergogenic nutrients (e.g.
creatine and/or carnitine and/or their derivatives) for the enhancement of cellular
glucose uptake into major tissues for the purpose to optimized blood glucose levels,
which involves the supplementary, prophylactic or therapeutic use, in particular
of a water-soluble extract of Russian Tarragon in preferred daily dose of 10 mg
to 20,000 mg. The disclosed tarragon extracts and their combinations of further
favorable components are not restricted to any particular form of application, which
makes them all the more suitable for the different application areas.
Disclosed herein is: (a) a aqueous extract of Russian Tarragon
(Artemisia dracunculus), combinations comprising the said tarragon extract with
formulation agents or constituents, or an extract fraction thereof or a derivative
of the extract thereof; and (b) methods of normalizing elevated blood glucose levels
that may occur under conditions of metabolic syndrome, pre-diabetes and diabetes
Type 2 in animals and humans, whereas the administration of said composition as
dietary supplement, food or drinks preparation, or in pharmaceutical delivery form
is possible.
It is a still further object of the invention to provide
a method and a dietary supplement that achieves these objects when administered
in physiologically acceptable amounts in preferred daily dose of 20 to 5000 mg divided
in several (2-5) servings per day.
Also disclosed herein is: (a) a aqueous extract of Russian
Tarragon (Artemisia dracunculus), combinations comprising the said tarragon extract
with formulation agents or constituents, or an extract fraction thereof or a derivative
of the extract thereof; and (b) methods of losing weight and reducing body fat comprising
administration of said composition.
Accordingly, it is also an object of the invention to provide
a method and a dietary supplement which will promote weight loss and body fat reduction.
Other objectives, advantages and features of the invention
will become apparent from the given detailed description, and from the claims.
The disclosed and described invention is a aqueous extract
of Russian Tarragon (Artemisia dracunculus), combinations comprising the said tarragon
extract with formulation agents or constituents, or an extract fraction thereof
or a derivative of the extract thereof. The administration of the said composition
can also be used for the purpose of enhancing nutrient, e.g. creatine and/or carnitine
transport for purposes of athletic performance and improvement of Body Composition-Index
(BCI) while controlling bodyweight and body fat levels, and therefore improves the
body composition, increases wellness and mental and physical performance during
sports, in illness conditions or are circumstance of special needs.
In preferred embodiments, the Tarragon component is an
extract of Russian Tarragon prepared with water, alcohol or mixtures thereof.
A fraction of the extract is preferably a constituent of
Tarragon selected from the group of carbohydrates, proteins, peptides, and polyphenols.
A further embodiment of the invention is a dietary supplement,
a food, a beverage or a pharmaceutical product comprising the extract of the invention.
It may additional comprise carbohydrates, like dextrose,
maltose, maltodextrin and trehalose, formulation aids, like dissolution enhancer,
binder and other auxiliaries, minerals, like Magnesium and Calcium, trace elements,
like Vanadium, Chromium, Zinc, methylxanthines, like caffeine, theobromine and theophylline,
free amino acids, like taurine, glutamine, citrulline, leucine, glycine, arginine,
alanine, or salts of derivatives thereof, vitamins, like vitamin A, C, E, vitamin
derivatives, herbs and botanical extracts with or without glucose-level-modifying
effect, as well as lactic acid buffering agent, like (sodium) bicarbonate, citrates,
phosphates, carnosine, beta-alanine, and mixtures thereof.
Suitable application form comprises powder, capsules, tablets,
effervescent tablets, powdered beverages, bars, gels or drinks, pharmaceutical delivery
systems.
The product of the invention can be used for regulating,
controlling, normalizing elevated blood glucose levels that may occur under conditions
of metabolic syndrome, pre-diabetes and diabetes Type 2 in animals and humans, for
the prevention and treatment of metabolic diseases, including hyperlipidemia, for
improvement of body-composition index (BCI) and for the reduction of body mass,
and preferable the reduction of body fat in athletes, sport people, elderly people
or overweight and ill patients.
Further embodiment of the invention is the use of tarragon
(Artemisia dracunculus), an extract of Tarragon or a derivative thereof to increase
uptake of ergogenic substances.
Glucose metabolism in humans is often linked to inflammatory
diseases of individual organs. So it is beneficial to find a general antidiabetic
active extract combined with an anti-inflammatoric potential.
A hallmark of inflammation is the secretion of huge amounts
of proinflammatory immune mediators such as prostaglandin E2, and cytokines,
e.g. tumor necrosis factor. Local secretion of cytokines and activation of immunocompetent
cells in the microenvironment are followed by systemic reaction.
Primary human monocytes are a well established cell model
to investigate the effects of compounds and plant extracts on their capability to
inhibit cytokine release.
The aqueos Tarragon extract of the invention shows a dose
dependent inhibition of the TNF&agr; release. The strongest inhibition of about
80% at the concentration of 300 µg/ml has been found. This demonstrates a significant
anti-inflammatoric activity.
The following examples are used to explain the invention
in more details without limiting the scope.
Figure 1 shows
the blood sampling scheme for basal blood glucose levels according to example 11.
Figure 2 shows
the basal blood glucose levels AUC (area under the curve) 0 to 180 minutes according
to example 11.
Figure 3 shows
the glucose challenge blood glucose levels AUC (area under the curve) 0 to 180 minutes
according to example 11.
Example 1 (Comparative example)
Preparation of a hydroethanolic extract of Russian Tarragon:
1 kg of the raw material of Russian Tarragon was extracted
twice with 6 L of 60% ethanol (V/V) at 50°C. After cooling of the eluate over
night, the solutions were filtered through paper filters and the solvent evaporated
by means of a rotatory evaporator. The obtained dense extracts was mixed with 30%
of microcrystalline cellulose as suitable carrier, and dried at 50°C in a vacuum
drying chamber. The dried extract was finally ground and sieved for an adjustment
of the particle size. The yield of native extract is about 20% and the analysis
showed water contents of less than 2% and an almost complete removal of the essential
oil (Estragol, Methyleugenol) of less than 3 ppm.
Example 2
Preparation of aqueous extracts of Russian Tarragon:
1 kg of the raw material of Russian Tarragon was extracted
twice with 6 L water at 80°C. After cooling of the eluate over night, the solutions
were separated from the drug by filtration through paper filters and the solvent
evaporated by means of a rotatory evaporator. The obtained dense extracts was mixed
with 30% of maltodextrin as suitable carrier, and dried at 50°C in a vacuum
drying chamber. The dried extract was finally ground and sieved for an adjustment
of the particle size. The yield of native extract is about 32% and the analysis
showed water contents of less than 4% and a complete removal of the essential oil
(Estragol, Methyleugenol).
Example 3:
Fractionation of aqueous extracts of Russian Tarragon by
means of membrane techniques:
300 g extract of example 2, diluted in demineralized water to 20% (w/w), was divided
by ultrafiltration with a middle cut-off of about 100 kDa in two fractions (retentate
and permeate). Separation results in a volume distribution of retentate : permeate
of 1 : 12 respectively a mass distribution of residual dry mass of 1 : 9. The active
principle cumulates in permeate.
Example 4
Fractionation of aqueous extracts of Russian Tarragon by
means of absorption column techniques:
200 g extract analogous to example 2, diluted in demineralized water to 20% (w/w),
was given onto adsorptive resin (Amberlite® XAD7HP). The active priciple remains
in passing aqueous phase, with a yield of about 95%, whereas organic middle-polar
constituents were removed by the column. The active principle cumulates in this
purified aqueous extract.
Example 5
Preparation of tablets
Ingredient
Amount per tablet
Russian Tarragon aqueous extract
225 mg
Zinc (as sulfate, chloride or pyruvate)
15 mg
Calcium phosphate
165 mg
Methylcellulose
150 mg
Stearic acid
24 mg
Magnesium stearate
7 mg
Silicon dioxide
10 mg
TOTAL
596 mg
The recommended daily dose is 3-6 tablets.
Production procedure
- 1. All the active substances and adjuvants are sieved through a sieve with a
mesh size of 1.0 mm.
- 2. The tarragon extract and the excipients are weighed and introduced into a
mixer. The blend is mixed, using schedules as known by galenic qualified staff.
The homogeneity of the mixture is checked visually.
- 3. The tablets are compressed directly from the mixture.
Example 6
Preparation of Soft-Gelatin Capsule
Formulation:
Ingredient
Amount per tablet
Russian Tarragon aqueous extract
350 mg
Medium Chain Triglycerides
125 mg
TOTAL
475 mg
Filled in Soft-Gelatin Capsule. The recommended daily dose
is 3-6 capsules.
Production procedure
- 1. All the active substances, adjuvants, and the diluent are weighed and introduced
into a mixer. The blend is mixed for 15 minutes. The homogeneity of the obtained
paste is checked visually.
- 2. The soft-gel capsule can be filled using standard industrial equipment.
Example 7
Preparation of chewable tablets
For the preparation of the tablets a commercial available
chewable matrix based on Mannitol or Sorbitol, starch (or its derivatives), sweetener,
and other excipients were used.
Formulation:
Ingredient
Amount per tablet
Russian Tarragon aqueous extract
175 mg
Caffeine
75 mg
Chewable matrix
1500 mg
Sodium bicarbonate
50 mg
Flavors
90 mg
Magnesium stearate
25 mg
Silicon dioxide
10 mg
TOTAL
1925 mg
The recommended daily dose is 3-4 chewable tablets.
Production procedure
- 1. All the active substances and adjuvants are sieved through a sieve with a
mesh size of 1.0 mm.
- 2. The Tarragon extract and the excipients are weighed and introduced into a
mixer. The blend is mixed for 30 minutes. The homogeneity of the mixture is checked
visually.
- 3. The tablets are compressed directly from the mixture.
The daily dose is one chewable tablets three times a day.
Example 8
Preparation of effervescent tablets
Formulation:
Ingredient
Amount per tablet
Russian Tarragon aqueous extract
150 mg
Caffeine
75 mg
Anhydrous citric acid
1700 mg
Sodium hydrogen carbonate
1000 mg
Polyethylene glycol 2000
500 mg
Sweetener
70 mg
Orange flavor
90 mg
Magnesium stearate
20 mg
TOTAL
3605 mg
The recommended daily dose is 2-4 effervescent tablets
dissolved each in 300 ml of water.
Production procedure
- 1. All the active substances and adjuvants are sieved through a sieve with a
mesh size of 1.0 mm.
- 2. All ingredients are weighed and introduced into a mixer. The mixture is mixed
using schedules as known by galenic qualified staff. The homogeneity of the mixture
is checked visually.
- 3. The tablets are compressed directly from the mixture.
Example 9
Preparation of nutritional bars
Formula of the bar filling: 1/2 cup Sugar, 5 tb Cornstarch,
3 tb Brown sugar, 1/4 ts Salt, 3 c Milk, 3 Egg yolks,beaten 1 ts Vanilla, 8 oz Chocolatebar,
and 4750 mg Russian tarragon water extract, 25 grams of micronized creatine monohydrate,
1000 mg vitamin blend (e.g. Multi 10, Roche, RDA=200mg), 1200 mg Calcium as Carbonate,
450 mg Magnesium as Carbonate, and 50 mg Zinc as Sulfate.
Production procedure
Combine all but vanilla and chocolate bar in a saucepan.
Stir constantly until mixture boils; boil and stir 1 minute. Remove from heat; add
vanilla and chocolate bar, broken into pieces. Stir until chocolate is completely
melted. Add the Russian Tarragon extracts, creatine, vitamins, and minerals. Pour
into bowl and press plastic wrap directly on surface; cool. Yields about 4 cups
filling or about 10 bars of 100 grams each.
The recommended daily dose is two to four nutritional bars.
Example 10
Preparation of refreshing and energizing powder drink formulation
One serving size of this drink contains:
Russian Tarragon water extract
350 mg
Creatine monohydrate
1500 mg
L-Carnitine L-tartrate
1000 mg
Amino acids (protein hydrolysate)
7.5 g
Carbohydrates (Maltodextrin)
7.5 g
Sweetener
70 mg
Orange flavor
90 mg
Vitamin B1
0.7 mg
Vitamin B2
0.8 mg
Vitamin B6
1 mg
Vitamin B12
0.5 µg
Vitamin C
30 mg
Vitamin E
5 mg
Niacinamide
9 mg
Folsäure
100 µg
Biotin
75 µg
Pantothenic acid
3 mg
Calcium
120 mg
Magnesium
45 mg
Zinc
5 mg
Production procedure
For the production on technical scale the above shown quantities
of the blend should be multi-fold with a factor up to 10000 or even higher to obtain
200 kg+ batches.
- 1 All the active substances and adjuvants are sieved through a sieve with a
mesh size of 1.0 mm.
- 2. The aqueous Russian Tarragon extract, creatine monohydrate and creatine pyruavte,
amino acids, maltodextrin, and the other components are weighed and introduced into
a mixer. The mixture is mixed for 45 minutes. The homogeneity of the mixture is
checked visually.
- 3. The powder tablets are filled in powder bottles directly from the mixture.
A daily dose is twice of the single dosage shown above.
This drink powder needs to be stirred in about 400 ml of water prior use.
Example 11
Investigation on the Russian Tarragon extracts in an animal
model
Animal model for a Glucose challenge test
A common way of testing for an effect of extracts or new
chemical entities on blood glucose levels is the glucose challenge test (Verspohl,
E. J.: Recommended testing in diabetes research. Planta Med 68 (7): 581-90, 2002)
in which rats are given the extract, control, or a known antidiabetic substance
with (challenge) and without (basal) an intraperitoneal (i.p.) dose of glucose.
The extracts are given orally 30 min. before the glucose challenge. Blood samples
are taken sublingual at time points 0, 15, 30, 60, and 120 minutes for the glucose
challenge or 0, 30, 60, 120, and 180 minutes for basal blood glucose levels. This
sampling scheme ensures to monitor both effects of extracts on basal blood glucose
levels over a longer time period and the blood glucose levels after glucose challenge
closely enough.
Figure 1 shows
the blood sampling scheme for basal blood glucose levels.
Both extracts (Russian Tarragon extracts according to example
1 and 2; 6 mg/kg, p.o.), control, glyburide (known antidiabetic drug, 18 mg/kg,
p.o.) and sitagliptin (known antidiabetic drug, 100 mg/kg, p.o.) contained 0.5%
propylene glycol as a solubilizer and were administered orally via gavage.
Animals
Male non-fasted Wistar rats weighing 250-300 g were purchased
from Harlan (Indianapolis, IN, U.S.A). The non-fasted condition was chosen to account
for a more physiological situation, but increases variability of blood glucose levels.
Rats were housed in cages of 2 at 20 ± 1 °C in a 12-h light/dark cycle.
Tap water and food pellets were available ad libitum. Groups of 6 rats were randomly
assigned to the 12 different treatment groups. All experiments were carried out
in a quiet room between 9:00 a.m. and 2:00 p.m. All animals were housed and all
experiments performed according to the policies and guidelines of the Institutional
Animal Care and Use Committee (IACUC) of the University of Florida, Gainesville,
U.S.A.
Drugs
Glyburide (Sigma-Aldrich, St. Louis, U.S.A) was used as
a known antidiabetic drug and has been used in a dose of 18 mg/kg according to literature
sources (Subash Babu et al., 2007; Verspohl et al., 2005). It was diluted to 18mg/5
ml with water (Millipore quality) containing 0.5% propylene glycol (Sigma-Aldrich).
Sitagliptin was used as a known antidiabetic drug and has been used in the daily
recommended dose of 100 mg/kg according to recommendation of the manufacturer Merck
& Co. Russian Tarragon extracts were prepared by dissolving the various extracts
(Russian Tarragon extracts according to example 1 (ethanolic) and 2 (water), 6 mg/kg
each); in 5 ml deionized water with 0.5% propylene glycol to form a suspension.
All solutions were prepared freshly on test days. All animals were brought to the
testing room at least 30 minutes prior to testing and remained in the same room
throughout the test. Animals were orally treated with control (vehicle), glyburide
(18 mg/kg), sitagliptin (100 mg/kg), or the extracts. Glucose (Sigma-Aldrich) was
dissolved (using sonication) in 0.9% saline solution in a concentration of 2 g/5
mL and given i.p. 30 minutes after the oral treatment.
Blood glucose evaluation
Blood was drawn at the appropriate time points from the
sublingual vein after a short halothane anesthesia and stored at 4 °C with
addition of heparin. Samples were centrifuged at 8600 rpm for 10 minutes. The supernatant
plasma was taken and analyzed using an autoanalyzer (Merck, Darmstadt). Analytical
plasma controls and matrix blanks were used to guarantee accurate results within
the specified limits.
Statistics and calculations
Both percent and AUC data were analyzed by one-way ANOVA
and Student-Newman-Keuls Multiple Comparison Test using Graphpad 4.0 Software, San
Diego, USA. The AUC (area under the curve) was calculated using the trapezoidal
rule without extensions beyond the last time point measured.
Results and discussion
Basal blood glucose levels
One-way ANOVA statistical analysis followed by Student-Newman-Keuls
posthoc test revealed a significant effect on basal blood glucose levels for the
known antidiabetic glyburide and sitagliptin but no effect for the Russian Tarragon
extracts 1 and 2. The percent data better reflects the change in blood glucose levels
as there was significant variability between the treatment groups. The percent AUC
(figure 2) better reflects the change over
time for blood glucose levels than the time point comparison and should be used
for final interpretation of the data. The time point comparison was not significant
for any of the extracts, whereas glyburide and sitagliptin lowered the basal blood
glucose levels significantly. The finding of no effect of the extracts of the basal
blood glucose levels can be interpreted as crucial positive safety aspect related
to missing of a hypoglycemia status after oral administration of the said extract
by fasting individuals.
Figures 2 shows
the effect of glyburide, sitapliptin and the extracts on basal blood glucose levels
expressed in percent AUC (top) and percent of time point zero minutes (a-e), displayed
is Mean ± S.E.M, n=5-6 per treatment group
(* p<0.05 vs. control, ** p<0.01 vs. control, ***
p<0.001 vs. control).
3.2 Glucose challenge blood glucose levels
The statistical analysis using a one-way ANOVA test followed
by Student-Newman-Keuls multiple comparison concluded that glyburide, sitagliptin,
and extract 2 (water) had a significant effect on lowering the blood glucose levels
following the i.p. glucose challenge. Extract 1 (60% ethanolic) lowered the blood
glucose level as well, but did not reach significance in this animal test. The AUC
comparison (figure 3) more accurately reflects
the influence over time of glyburide, sitagliptin and the extracts.
Figures 3 shows
the effect of glyburide, sitagliptin, and the extracts on glucose challenge blood
glucose levels expressed in percent AUC (top) and percent of time point zero minutes
(a-e), displayed is Mean ± S.E.M, n=5-6 per treatment group, (* p<0.05
vs. control, ** p<0.01 vs. control).
The Student-Newman-Keuls multiple comparison allows for
pair wise comparisons (also called range or multiple-step statistics) as it has
different critical values for each pair wise comparison depending on the difference
of the means. This method presents with a higher power compared to the Tukey's Test
(a one-step procedure), which uses only one critical value for pair wise comparisons
without adjusting for the difference in means. Both tests are used as post-hoc tests
to compare more than two treatment means (if only two treatments are compared, the
Student t-test would be the appropriate test to be used).
The comparison of the single time points in this experimental
setting (5 treatment groups and physiological non-fasted animals) presents with
the problem of significant variation that might mask a potential blood glucose lowering
effect. This variability can be accounted for in part by comparing the percent change
in blood glucose levels over time in relation to the initial levels at time point
zero. This has been done but data is not shown here. In order to compensate for
inter-day variability, the percent change in the AUC can best represent the influence
of glyburide, sitagliptin and the extracts on blood glucose levels.
In conclusion, these results show an effect on blood glucose
levels after glucose challenge for the known antidiabetic drugs glyburide, sitagliptin,
for the evaluated extracts 1 and 2, although extract 1 (ethanolic) did not reach
significance in the performed test.
Example 12
Reducing TNF-a release
Human primary monocytes were prepared from buffy coats
of healthy human blood donors following a standardized procedure. Cells were seeded
in 24-well-plates for ELISA measurements.
Monocytic cell treatment and measurement of TNFalpha
Monocytes were stimulated with LPS (10ng/ml) at 37 °C
and 5 % CO2 for 24 h. The extracts were added 30 min before LPS treatment
to test if they can prevent the LPS-induced effects. The following concentrations
were tested: 50, 100, 300, 400, and 500 µg/ml. After 24 h, supernatants were
removed, centrifugated and investigated for TNFalpha concentrations in ELISAs/EIAs
using manufactorer's protocol (Biotrend, Germany; Immunotools, Germany).
The results demonstrate a clear dose depending inhibition
of the TNF-alpha release, which is related to an anti-inflammatory activity. IC50
value is about 120 µg per ml.