Inventor: MOUSSA FATHI &c
A water-insoluble fullerene is at least partially dissolved in
a biocompatible lipid carrier, especially a fat or an oil such
as butter, olive oil, and liquid paraffin. When administered
to mammals, the fullerene, most preferably [60]fullerene
dissolved in olive oil, scavenges free radicals and prolongs
life span in rats.
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention concerns [60]fullerene and stable
biocompatible compositions comprising [60]fullerene dissolved
in a carrier. The present invention also relates to a method
for increasing the expected lifespan (longevity) of a mammal,
which comprises a step of administering [60]fullerene or a
composition comprising a therapeutically effective amount of
[60]fullerene. The present invention further concerns a method
for preserving a mammal to damages caused by free radicals
using said [60]fullerene or said composition.
2. Description of related art
Free radicals, such as oxygen radicals and other reactive
oxygen/nitrogen/chlorine species (hydroxyl, nitric oxide
radicals), are constantly formed in vivo. Some of these
molecules are physiologically useful, but they can also result
in pathological oxidative stress to cells and tissues.
Endogenous defences include both antioxidants and repairing
systems. However, excess production of free radicals, their
production in inappropriate relative amounts or deficiencies
in endogenous defences can have deleterious effects. Free
radicals can cause oxidative damage to lipids, DNA, bio
molecules, rises in the concentration of intracellular
calcium, as well as activation of proteases, nucleases and
protein kinases. Considerable evidence supports the view that
oxidative damage involving free radicals occurs in most, if
not all, human diseases. Oxidative stress is now recognized as
an important contributor to the development of many human
diseases including liver fibrosis, ischemia-reperfusion,
atherosclerosis, neurodegenerative disease and age-related
cancer as well as to process of ageing. Thus antioxidants and
systems that can protect against oxidative stress are needed
to maintain health. A large body of scientific evidence
supports that oxidative stress is directly responsible for
aging (Aging Cell. 2009, 8(3):258-69) and an array of
neuropathology conditions (Nutrition 2010, 26:595-603.
Neurochem Res. 2007, 32:757-73). The free radical theory of
aging proposes that the organism is unable to repair all of
them and that, with time, unrepaired damages accumulate and
put the organism at risk: in other words, free radicals
provoke aging and death (FEBS Letters 2009, 498: 183-186. J.
Neurochem. 2009, 108:1251-65). Antioxidants are the substances
able to react with free radicals and to protect the body from
the damage caused by these molecules (Ital J Biochem. 2006,
55:263-282). In particular, consumption in excess of some
foods which are rich sources of antioxidants is considered to
promote good health and longevity. It is now believed that the
maintenance of redox balance within the body can forestall
aging and promote good health and longevity.
Due to its 30 carbon double bonds, [60]fullerene
(Buckminsterfullerene, Ceo) is a powerful free radical
scavenger which characterize it as a radical sponge (Science
1991, 254, 1 83- 1185). Biological applications of fullerenes
and derivatives, in particular as antioxidants, have been
extensively reviewed (Bioorg. Med. Chem. 1996, 4: 767- 779.
Eur. J. Med. Chem. 2003, 38: 913-923. Biomedicine &
Pharmacotherapy, 2005, 59: 351-358). Ceo is only soluble in a
limited number of organic solvents, such as toluene, benzene,
chloronaphtalene and dichlorobenzene. Availability of
biocompatible aqueous solutions of Ceo and its derivatives
that are insoluble in water have been major obstacles to
toxicity and in vivo studies of this new family of compounds.
Biological properties of water-insoluble fullerenes are still
misunderstood and to our knowledge there are no certified
toxicology data about them. Most of the fullerenes studied
until now are water-soluble derivatives, since study of
water-insoluble fullerenes, such as pristine Ceo, in
biological medium proves difficult. It is a common practice to
derivatize the fullerene core with substituants such as OH,
COOH, NH2 to increase hydrophilicity (Bioorg. Med. Chem. 1996,
4: 767-779. Eur. J. Med. Chem. 2003, 38: 913-923. Biomedicine
& Pharmacotherapy, 2005, 59: 351-358). Water-soluble Ceo
derivatives have been found to retain in vitro the free
radical scavenger properties of their parent fullerene
molecule, allowing these properties to be exploited in
biological systems. Many patents already exist for a broad
range of biomedical applications and other commercial
applications of water-soluble fullerenes, including anticancer
and anti-HIV therapies, drugs for neurodegenerative diseases,
drug delivery systems, and preparations that retard aging. In
particular, a group of hydrophilic Ceo derivatives,
carboxyfullerenes, were proposed to increase metazoan's
lifespan (U.S. Patent Application 2003/0162837). However,
water-soluble fullerenes are difficult to synthesize and to
purify. Besides, in contrast to pristine Ceo, which is
non-toxic, some C6o-derivatives can be highly toxic (Adv Exp
Med Biol, 2007, 620, 168-80).
Pristine C6o has been shown to be more effective as an
antioxidant than certain carboxyfullerenes in Wang, I. et al.,
J. Med. Chem. 1999, 42, 4614-4620. However, Ceo has not been
employed as an active ingredient to develop an in vivo
treating method in this publication. Aqueous suspensions of
Ceo are well known in the art. They are stable for long
periods and can be delivered to cells. A study of
<14>C-labeled C-60 reported that it is possible to form
suspensions of C6o in water that are stable for long periods
(J. Am. Chem. Soc. 1994, 116, 4517-4518). However, the authors
failed to detect the fullerene inside the cells and these
suspensions containing very low concentrations of fullerene
(typically 0.1 mg per ml) were inadequate to perform in vivo
studies, especially toxicity studies. and metabolic fate
investigations ((J. Am. Chem. Soc. 1994, 116, 4517-4518).
Other vectorisation methods include the formation of inclusion
complexes with cyclodextrins, calixarenes, tween-20, micelles,
liposomes, and vesicles; however the Ceo concentrations
reached by such methods are still very low (1 mg/mL at most)
and inadequate to perform in vivo toxicity studies. Further,
these methods present another drawback because they generally
necessitate a preliminary dissolution step of the fullerene in
an organic solvent. Other studies proposed the use of Ceo
nanoparticles suspended in aqueous media to form a colloidal
solution so-called nC60, however such solutions prpved to be
highly toxic because they contain impurities linked to the
oxidation byproducts of the solvents used during their
preparation (Adv Exp Med Biol, 2007, 620, 168-80. Journal of
Nanoscience Letters 2011 , 1 : 62-63). Another method,
disclosed in J. Med. Chem. 2000, 43, 3186-3188 uses
polyvinyl-pyrrolidone to solubilize C6o; however this vehicle
can react with fullerene and the formed complex may cause
harmful effects on mice embryos.
Moussa et al. described in Fullerene Science & Technology
1995, 3, 333-342 that partially micronized Ceo particles can
be incorporated into living human phagocyte cells. C6o was
directly suspended in the culture media and did not exhibit
acute toxicity. Moussa et al. also described in Fullerene
Science & Technology 1996, 4, 21-29 that micronized
particles of water-insoluble fullerenes may be administered to
mice on the form of a biocompatible aqueous suspension
comprising a surfactant (tween 80) and a suspending agent
(carboxym ethyl cellulose) which stabilizes the suspension.
The authors disclosed that C6o is non-toxic, can cross
cellular membranes and accumulates in liver and spleen
(Fullerene Science & Technology 1996, 4: 21-29). The same
group headed by F. Moussa have already used Micronized Ceo
suspensions as free radical scavenger in vivo (Nano Letters
2005, 5: 2578 - 2585). However, the effective doses were very
high (i.e. > 1 g/kg of body-weight) and intra peritoneal
(i. p.) administration was the only route of administration
for such suspensions. The authors also disclosed that Ceo can
solubilize in vivo inside lipid droplets (Nano Letters 2005,
5: 2578 - 2585). This result has been confirmed in vitro by
other authors whom studied [Omicron][beta][omicron] solubility
in vegetable oils (Fullerenes, Nanotubes, and Carbon
Nanostructures, 2007, 15: 311-314. Fullerenes, Nanotubes, and
Carbon Nanostructures, 2007, 15: 331-339). Stable
biocompatible compositions comprising water insoluble
fullerenes dispersed and/or dissolved in a carrier selected
from the group consisting of fats and oils in an amount
ranging from 0.2 to 10 % by weight relative to the total
weight of the composition, preferably from 0.1 to 2 % by
weight, were already proposed by N Gharbi and F Moussa for
preventing damages caused by free radicals (2005/lnternational
Application No. PCT/EP2005/004963). However, in such
compositions the water-insoluble fullerene is not fully
dissolved and their oral absorption was unknown. Further,
large aggregates of the administered fullerene can be filtered
by liver and spleen and confined in their reticulo-endothelial
system (RES) thus altering the diffusion and biodistribution
of Ceo in the whole body. Thus, the in vivo use of
water-insoluble fullerenes as free radical scavengers through
delivery thanks to a non-aqueous carrier is still not
satisfactory.
The inventors of the instant invention have now discovered a
surprising use of [60]fullerene as agent that promotes an
increases in the overall length of the expected lifespan of
mammals.
Compositions comprising [60]fullerene and their use for
preventing damages caused to metazons by free radicals are
disclosed in TN Patent No.TN 2011/327 issued June 30, 2011 to
Moussa et al. which is incorporated herein by reference in its
entirety.
SUM MARY OF THE INVENTION
It is in view of the above problems that the present invention
was developed. The main objective of the invention is to
provide a process or method for extending the longevity of a
mammal, which comprises a step of administering to said mammal
a composition comprising an effective amount of [60]fullerene,
which avoids the drawbacks of the prior art processes, and in
particular : 1- avoids the use of charge transfer complexes,
2-avoids the use of organic solvents, and 3- avoids in situ
aggregation of the administered fullerene. It has now been
discovered by the inventors that the compositions comprising
[60]fullerene dissolved in a suitable carrier selected from
the group consisting of oils and fats proved suitable to
achieve the aforementioned objectives. In particular, not only
they allow [60]fullerene to be administered orally or
intramuscularly or intra peritoneally to prolong the longevity
of mammals but they are at least several times more active
than previous compositions. Thus, a first embodiment of the
instant invention comprises a stable biocompatible composition
comprising (a) a carrier selected from the group consisting of
fats and oils; and (b) [60]fullerene, wherein [60]fullerene is
almost dissolved in said carrier. The embodiment is further
drawn to compositions, in which [60]fullerene is dissolved in
the carrier. Another embodiment of the instant invention is a
method to prolong the longevity of mammals, which comprises a
step of administering to said mammal a stable biocompatible
composition comprising an effective amount of [60]fullerene
dissolved in a carrier selected from the group consisting of
fats and oils. In a preferred embodiment, the invention is
drawn to a method of prolonging the longevity of mammals,
which comprises a step of adding to food or any nutritional
composition a stable composition comprising an effective
amount of [60]fullerene dispersed in a carrier selected from
the group consisting of fats and oils.
Other objects, features and advantages of the present
invention will become apparent from the following detailed
description. It should be understood, however, that the
detailed description and the specific examples, while
indicating specific embodiments of the invention, are given by
way of illustration only, since various changes and
modifications within the spirit and scope of the invention
will become apparent to those skilled in the art from this
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of
the present invention will become readily apparent to those
skilled in the art from a reading of the detailed description
hereafter when considered in conjunction with the accompanying
drawings wherein: - figure 1 is a representation of the growth
rate of rats as a function of time, which were treated or not
with a composition according to the present invention. -
figure 2 shows whole blood Ceo concentrations-time plot (mean
+- S.E. .) following single dose oral administration (4 mg/kg,
n = 3) or single dose intra-peritoneal (ip) bolus injection of
the same dose (n = 3) of Ceo dissolved in olive oil (0.8
mg/ml) (n = 3), figures 3 and 4 show the results of some
biochemical tests for Ceo pre-treated and control rats before
CCI4 administration, and figure 5 represents the survival
percentage of rats (n = 6 per group) orally treated with Ceo
at the age of 10 months (1 ml/ kg of body-weight, weekly until
the end of the second month then every two weeks until the end
of the 7th month, with water, olive oil or Ceo dissolved in
olive oil (0.8 mg/ml)). Table 1 summarizes the mean
pharmacokinetic parameters obtained in rats after oral (n = 3)
or intra-peritoneal (n = 3) administration of Ceo dissolved in
olive oil and table 2 summarizes Ceo concentrations in whole
blood (WB), liver, spleen and brain of rats daily treated with
a single dose of Ceo dissolved in olive oil (4 mg/kg body
weight) by oral (n = 3) or ip route (n = 3).
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED
EMBODIMENTS
Free radicals are constantly formed in vivo. Some of these
molecules are physiologically useful, but they can also result
in pathological oxidative stress to cells and tissues.
Endogenous defences include both antioxidants and repairing
systems. However, excess production of free radicals, their
production in inappropriate relative amounts or deficiencies
in endogenous defences can have deleterious effects. Free
radicals can cause oxidative damage to lipids, DNA, bio
molecules, rises in the concentration of intracellular
calcium, as well as activation of proteases, nucleases and
protein kinases. Considerable evidence supports the view that
oxidative damage involving free radicals occurs in most, if
not all, human diseases. Oxidative stress is now recognized as
an important contributor to the development of many human
diseases including liver fibrosis, ischemia-reperfusion,
atherosclerosis, several neurological disorders and
age-related cancer as well as to process of ageing. Thus
antioxidants and systems that can protect against oxidative
stress are needed to maintain health and prolong the expected
lifespan in metazoans. This has led to attempts to develop
additional antioxidants to supplement the antioxidant defences
of cells as potential therapeutic agents. Diet-derived
antioxidants and a number of small molecules that can scavenge
free radicals as well as super oxide dismutase-mimetics and
chelators of transition metal ions were proposed as potential
therapeutic agents against oxidative stress. Compositions
according to the invention comprising [60]fullerene have been
found to exhibit highly efficient antioxidant properties in
vivo. The fullerene core, i.e. the fullerene skeleton without
lateral substituants, used in the practice of this invention
comprise clustered carbon structures generally spherical in
shape and having a carbon content of 60 carbon atoms.
Typically, [60]fullerene according to the invention is present
in an amount ranging from 0.01 to 0.0.08 % by weight relative
to the total weight of the composition, preferably 0.08 % by
weight. [60]fullerene is preferably dissolved in the carrier,
i.e. the composition can be filtered through a 0.2 pm filter.
The stable, biocompatible compositions according to the
invention comprise a carrier selected from the group
consisting of fats and oils; and [60]fullerene, wherein said
fullerene is mostly dissolved in said carrier. The carrier
used in the present invention is a pharmaceutically acceptable
and biocompatible carrier, selected from the group consisting
of fats and oils. The fat or oil may be any natural or
synthetic fat or oil suitable for administration to a mammal.
They are not particularly restricted inasmuch as they are
components which can be used in pharmaceutical preparations or
in foods. Oils and fats can be hydrogenated or partially
hydrogenated. They are used at a solid, a semisolid, or a
liquid state. Vegetable and animal fats and oils are
preferred, vegetable fats and oils are most preferred. Oils
and fats include, without limitation fatty acid esters, fatty
acids, fatty alcohols and fatty alcohol esters. Synthetic
lipids can also be used. Fatty acids, as defined herein, are
intended to mean aliphatic monocarboxylic acids having a chain
of 4 to 40 carbon atoms, which may be branched or unbranched,
saturated or unsaturated, cyclic or acyclic. Fatty acids may
be natural or synthetic, polyunsaturated, mono-unsaturated or
saturated. Natural fatty acids, which are usually unbranched
and C4-C28 even-numbered, are preferred. Examples of fatty
acids include, but are not limited to, linoleic acid,
arachidonic acid, linolenic acid, gamma-linolenic acid,
caprylic acid, stearic acid, myristic acid, a palmitic acid,
behenic acid, undecylenic acid, oleic acid, an decosahexaenoic
acid (DHA), eicosapentaenoic acid (EPA), isostearic acid,
12-hydroxy-stearic acid. Salts thereof [e.g. alkali metal
salts (sodium salts, potassium salts, etc.), alkaline earth
metal salts (calcium, magnesium salts etc.)] can also be
employed. Fatty acid esters are preferably esters of fatty
acid as defined hereinabove with C-1-C40 aliphatic or aromatic
alcohols, preferably aliphatic, saturated or unsaturated,
straight-chain or branched-chain, cyclic or acyclic. Alcohols
can be polyols, having preferably up to five hydroxyl groups.
Examples of fatty acid esters include, but are not limited to,
triglycerides i.e. tri-esters of glycerol with fatty acids
cited above, sterids i.e. esters of sterols with fatty acids
cited above, the group consisting of the lower alkyl esters
thereof (preferably methyl, propyl, butyl, isopropyl and
hexyl), 1 ,2- or 1 ,3-diglycerides, 1- or 2-monoglycerides,
polyglycolysed glycerides such as sucrose fatty acid esters,
polyglyceryl fatty acid esters, propylene glycol fatty acid
esters. Specific examples of fatty acid esters are
octyldodecyl behenate; isocetyl behenate; isocetyl lactate;
isostearyl lactate; linoleyl lactate; oleyl lactate;
isostearyl octanoate, isocetyl octanoate, decyl oleate,
isocetyl isotearate, isocetyl laurate; isocetyl stearate;
isodecyl octanoate; isodecyl oleate; isononyl isononanoate;
isostearyl palmitate; myristyl isostearate; octyl
isononanoate; 2-ethylhexyl isononanoate; octyl isostearate;
octyldodecyl erucate; isopropyl palmitates, 2-ethylhexyl
palmitate, 2- octyldecyl palmitate, branched alkyl myristates
such as isopropyl myristate, t-butyl myristate, 2-octyldodecyl
myristate, hexyl isostearate, butyl isostearate, isobutyl
stearate, hexyl laurate, 2-hexyldecyl laurate, propylene
glycol monostearate and distearate. Examples of giycerides
(fatty acid esters) include, without limitation, triolein,
trilinolein, tripalmitin, tristearin, trimyristin, and
triarachidonin. Examples of sterids (fatty acid esters)
include, without limitation, cholesteryl oleate, cholesteryl
linoleate, cholesteryl myristate, cholesteryl palmitate,
cholesteryl arachidate. Examples of fatty alcohols include,
without limitation, cetyl alcohol, stearyl alcohol, lauryl
alcohol, myristyl alcohol, palmityl alcohol, behenyl alcohol,
hexadecyl alcohol, oleic alcohol, isostearyl alcohol,
cetostearyl alcohol. They can be used as esters with C4-C40
dicarboxylic, tricarboxylic or tetracarboxylic acids. Oils may
be natural oils such as vegetable oils and animal oils
(composed predominantly of triglycerides), or mineral oils
such as silicon oils, fluorinated oils. Liquid paraffin can
also be used. Examples of natural oil include, but are not
limited to, oils from plant sources, such as corn oil, wheat
germ oil, soybean oil, rice bran oil, rapeseed oil, canola
oil, sesame oil, palm (kernel) oil, olive oil, camellia oil,
peanut oil, coconut oil, sunflower oil, peanut oil, orange
oil, evening primrose oil, borage oil, blackcurrant seed oil,
cottonseed oil, beaver oil, pineapple oil, safflower oil,
copra oil, oils found in coffee, and animal oils such as
turtle oil, fish oil, cod-liver oil. Fats may be mineral fats
or natural fats such as vegetable fats and animal fats.
Petrolatum, paraffin can also be used. Examples of natural fat
include, but are not limited to, butter, cocoa butter,
theobroma, peanut butter, lard, beef fat, chicken fat, horse
fat, lanolin and lanolin derivatives. Oils and fats can be
polyunsaturated such as corn, soybean, safflower oils, or
saturated, such as palm, coconut oils and butter, or mono-
unsaturated, such as olive oil and canola oil. Other suitable
carriers according to the invention are diisopropyl sebacate;
diisopropyl adipate; diisostearyl adipate; octyldodecyl
stearoyl stearate; pentaerythrityl tetra-isononanoate;
pentaerythrityl tetraisostearate; triisopropyl citrate;
triisostearyl citrate; and trioctyldodecyl citrate. Preferred
carriers according to the invention are butter, cocoa butter,
peanut butter, olive oil, soybean oil, cod-liver oil and
liquid paraffin. As defined above, carriers may be used each
alone or in a combination of two or more species.
[60]fullerene is dissolved in the carrier, depending on the
nature of the carrier. Some carriers are able to dissolve
substantial amounts of water- insoluble fullerenes (several mg
/ g of carrier). In one embodiment, at least 0.8 mg of
fullerene is dissolved per ml of the carrier (the carrier
being a liquid). As an example, it is possible to dissolve a
total weight up to 1 mg of C60 per g of olive or soybean oil
in less than one week. The compositions according to the
invention may be pharmaceutical compositions comprising the
fullerene in a therapeutically effective amount. Preferably,
said fullerene can protect against biologically reactive
radical species, which means chemicals that are free radicals
or contribute to the generation of free radicals. Generally,
the biologically reactive radical species are generated from
O2 or H2O2. Thus, the invention also concerns a method to
prolong the longevity of a mammal, which comprises a step of
administering to said mammal a stable biocompatible
composition as defined hereinabove. [60]fullerene, when
dissolved in the carriers of the present invention, can be
administered to mammals and this compound is well absorbed by
said mammals. Generally, the said fullerene is administered in
an amount of at least 0.1 mg/kg of body weight per day.
According to the method of the invention, the inventive
compositions may be administered orally, intramuscularly,
subcutaneously, intra dermally or intra peritoneally, rectally
by suppositories or sublingually. For oral ingestion by a
mammal to be treated, the carrier is preferably an edible
carrier. In at least one embodiment, said composition is
administered in a pure form. In another embodiment, it is
administered in the form of an emulsion in water. In another
embodiment the fullerene is administered as a labile
C6o-derivative derivative that can deliver Ceo after
administration. The compositions of the instant invention can
be in any liquid or solid conventional pharmaceutical
formulation. The carrier enables the fullerene to be
formulated as tablets, pills, dragees, capsules, liposome,
pomade, ointment, cream , lotion, emulsions, gels, syrups,
slurries and the like. The compositions of the present
invention are preferably presented for oral administration to
mammals in unit dosage forms, such as tablets, capsules, and
oral solutions, containing suitable quantities of
[60]fullerene. The compositions may be sterilized and/or may
contain some adjuvants such as preservatives, stabilizers,
acidity regulators, natural or synthetic flavour, anti-foaming
agents, viscosity- control agents, emulsifiers, salts for
varying the osmotic pressure and/or other buffers. In
addition, compositions may contain other pharmaceutically
active agents. The level of free radicals and reactive oxygen
species in mammal cells decreases following treatment as
compared to the level of reactive oxygen species in a cell
that has not been contacted with a composition according to
the invention. Indeed, [60]fullerene according to the
invention can act as antioxidant and supplement the
antioxidant defences of cells. That means they inhibit
oxidation or inhibit reactions promoted by reactive oxygen
species. Physiologically relevant reactive oxygen species,
which contribute to the generation of free radicals, include
hydrogen peroxide, super oxide anion, and the like. The
protective method of the invention reduces cell damage and
death, and thus generally maintains the health of treated
mammals. Further, the inventors discovered that [60]fullerene
administered as biocompatible composition as described herein
-1) can be absorbed after oral administration (Figure 2); -2)
they can react inside the liver with vitamin A (retinol) and
esters thereof following a Diels-Alder-like reaction without
any toxic effect (New J Chem, 1998, 989-992) ; -3) they are
eliminated through the bile ducts (Nano Letters 2005, 5 (12):
2578 - 2585); and -4) despite the large amounts administered,
no acute or sub-acute toxicity could be observed in mice and
rats. No behaviour or growth disorder could be observed in
treated animals either, which can be seen on figure 1. The
latter shows growth rate of three groups (n = 6) of rats which
received weekly per os 1 ml of olive oil containing 0.8 mg of
Ceo or 1 ml of olive oil only or 1 ml of water only. The in
vivo new properties of [60]fullerene are due to fullerenes
themselves and/or to the fullerene-retinol and
fullerene-retinyl ester adducts formed after administration
inside the liver. Also disclosed herein is a method for
preparing a composition according to the present invention,
comprising a carrier and particles of [60]fullerene. Said
method comprises the steps of: - (a) Charging a milling vessel
with the fullerene, the carrier and balls, said milling vessel
and balls being made out of any biocompatible metal or
polymer; - (b) Agitating the mixture resulting from step (a)
until a homogeneous dissolution is obtained; and - (c)
Sterilizing the composition resulting from step (b) by
filtration. Direct mechanical milling in the carrier presents
the advantages to accelerate the dissolution. Said method
comprises the steps of: - (a) Charging a milling vessel with
the fullerene, the fat or oil and balls, said milling vessel
and balls being made out of any biocompatible metal or
polymer; - (b) Agitating the mixture resulting from step (a)
until complete homogenization of the solution; - (c) Agitating
.the composition resulting from step (b) until complete
dissolution of the fullerene; and - (d) Sterilizing by
filtration the composition resulting from step (c). Other than
in the operating examples, or where otherwise indicated, all
numbers expressing quantities of ingredients, reaction
conditions, and so forth used in the specification and claims
are to be understood as being modified in all instances by the
term "about." Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the following
specification and attached claims are approximations that may
vary depending upon the desired properties sought to be
obtained by the present disclosure. At the very least, and not
as an attempt to limit the application of the doctrine of
equivalents to the scope of the claims, each numerical
parameter should be construed in light of the number of
significant digits and ordinary rounding approaches.
Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the disclosure are
approximations, the numerical values set forth in the specific
examples are reported as precisely as possible. Any numerical
value, however, inherently contain certain errors necessarily
resulting from the standard deviation found in their
respective testing measurements. The invention is further
illustrated by the examples described below. These examples
are meant to illustrate the i nvention and are not to be
interpreted as limiting the scope of the invention.
EXAMPLES
General considerations
C60 (Purity: 99.98 %) was purchased from Term USA (Fort Bragg,
CA, USA). Its characterization and its purity were assessed by
HPLC, UV, C-NMR, and Mass Spectrometry. No impurity could be
observed. It was used without further purification as well as
after sublimation. All the other reagents were analytical
grade and were purchased from Sigma (St Louis, MO). Animals
received human care and the study protocols complied with
general guidelines for the care and use of laboratory animals.
Male Wistar rats (Charles River, France) were housed by groups
of 3 in polypropylene cages at constant temperature (22
[deg.]C) and humidity (60 %) and with a 12 h light/dark cycle,
and fed a standard diet ad libitum. All rats were allowed to
acclimate to this facility for at least one week before being
used in the experiments. At the end of the experiment, body
weights were determined and the animals were sacrificed under
the same conditions by bleeding through the thoracic aorta
after sodium pentobarbital (1.0 mL/kg of body weight)
anaesthesia.
Biochemical tests, Cso determinations and statistics were
processed as previously described in Nano Letters 2005, 5
(12): 2578 - 2585.
Example 1 : Direct dissolution of [60]fullerene in a
vegetable oil
In the stainless steel milling vessels of a Pulverisette 7
(Fritsch, Idar- Oberstein, Germany) or a similar device, add 8
mg of [60]fullerene and 10 mL of olive oil or 10 g of butter
and 6 stainless steel balls (8 mm of diameter) (the milling
vessels and the balls can be made out of any biocompatible
metal or polymer such as stainless steel, tempered chrome
steel, silicon nitride, corundum, tungsten carbide, agate,
oxide of zirconium etc). Agitate the mixture during several
hours (at 600 rpm for instance) until complete dissolution.
The resulting homogenous solution or paste is then ready for
use for oral administration or by any route of administration
after appropriate sterilization. Sterilization may be achieved
by filtration under vacuum (pore size: 0.2 [mu][eta][iota]).
The sterilized composition is stable for at least 1 month. It
is also possible to dissolve water- insoluble fullerenes in
natural or mineral oils without stirring however the
dissolution may be time consuming (up to several days at room
temperature). Therefore, the former protocol is preferred. The
fullerene concentration in compositions according to the
invention can be determined by HPLC after adequate dilution in
mobile phase as described previously (J. Chromatogr. B 1997,
696: 153-159).
Example 2: Pharmacokinetics and biodistribution of an oily
solution after oral and intra-peritoneal administration in
rats.
Pharmacokinetic studies were carried out with male Wistar rats
(weighing 200 - 220 g). Rats were housed in individual cages
and maintained in an air-conditioned room (22-25 [deg.]C) on a
12 h light/dark cycle with water and food available. The rats
were acclimated for 7 days and they were fasted overnight but
with access to water, before treatment.
Under general anesthesia, a catheter was introduced into the
rat right jugular vein, positioned subcutaneously with the tip
in the inter-scapular region. The prepared rats were then
allowed to recover for 24 h, and the blood catheters were
flushed with 0.9 % NaCI solution containing 20 l U/ml of
heparin to avoid possible clot obstruction. Before Ceo
administration, the rats were fasted overnight but with access
to water. The same single dose of Ceo (4 mg/kg) was delivered
orally, by a gavages needle, or intra-peritoneally to two
groups of three rats. Blood (0.20 ml) was withdrawn via the
canular prior to dosing (f = 0) and at 15, 30, 60 min and then
at 2, 4, 8, 10, 12, 24 and 48 h post-dosing. Antithrombin
heparin (20 lU/ml) was added in each blood sample. After each
blood collection 0.20 ml of sterile 0.9 % NaCI solution were
injected to the animal, to avoid hypovolemia. The rats were
sacrificed 48 h after eo administration for organ collection
(livers, spleens, and brains).
It was now discovered by the inventors that: -1) Soluble Ceo
is absorbed and eliminated after either intraperitoneal or
oral administrations. Table 1 represents the main
pharmacokinetic parameters; 2- the maximal concentrations
(Cmax) are reached 4 and 8 hours after i.p. and oral
administrations, respectively (Fig. 2); 3- the maximal
concentration after i.p. administration (1.47 +- 0.15 pg/ml)
is higher than that after oral administration (0.52 +- 0.16
Mg/ml). Consequently, the area under the curve (AUC) is about
5 times larger when Ceo is administered by i.p. route as
compared to oral route. Although these results do not allow
determining the bioavailability of Ceo, they clearly show that
a non-negligible % of the orally administered dose is absorbed
as compared to the i.p. administered one (Fig. 2); and -3) the
fullerene is well distributed in the whole body, in particular
it can cross the brain barrier (table 2).
Example 3: Ceo-induced protection of the liver against
acute toxicity of carbon tetrachloride (CCU) in rats
Carbon tetrachloride is a classical hepatotoxicant that causes
rapid liver damage progressing from steatosis to centrilobular
necrosis. CCU intoxication in rodents is an important model
for elucidation of the mechanism of action of hepatotoxic
effects such as fatty degeneration, fibrosis, hepatocellular
death, and carcinogenicity. These effects are consistent with
the known induced metabolic activation of CCI4 to reactive
intermediates, including CCI3" and CCI02' free radicals, and
mobilization of intracellular calcium. Kupffer cells (liver
resident macrophages) participate in the mechanism of toxicity
of CCI4 in vivo by release of chemoattractants for neutrophils
and a series of chemical mediators (cytokines). Both
expression and synthesis of these cytokines are mainly
modulated through redox-sensitive reactions. Further,
involvement of reactive oxygen species and lipid peroxydation
products can be demonstrated in other fundamental events of
hepatic fibrogenosis, like activation of hepatic stellate
cells (HSC: liver resident nonparenchymal cells also referred
to as fat-storing or perisinusoidal cells, lipocytes and Ito
cells). In a previous work, the effects of C60-pretreatments
on acute carbon tetrachloride intoxication in rats, a
classical model for studying free-radical-mediated liver
injury was reported. The results obtained by the authors
leaded by F Moussa (Nano Letters 2005, 5 (12), 2578 - 2585)
showed that aqueous C6o suspensions not only have no acute or
subacute toxicity in rodents but they also protect their
livers in a dose-dependent manner against free-radical damage.
The most effective dose of C6o reported in the latter paper
was about 2.5 g/kg of body-weight and was administered
intra-peritoneally and the better protection was obtained at
day 14 after administration. It was now discovered by the
inventors that the fullerene is about 100 times more active it
is administered in solution than in suspension, and the effect
is more rapid (24 hours after administration) as compared to
the results published previously in the same experimental
model (Nano Letters 2005, 5: 2578 - 2585).
Example 4: Ceo prolongs the longevity in rats without
chronic toxicity
The rats were housed one per cage and acclimated for 14 days,
before dosing. Three groups of 10 rats ( 10 months old,
weighing 495 +- 31 g) were administered daily for one week,
then weekly until the end of the second month and then every
two weeks until the end of the 7th month, by gavages with 1 ml
of water or olive oil or Ceo dissolved in olive oil (0.8
mg/ml), respectively. The rats were weighed before each
dosing. Routine observations following official
recommendations (EC Commission Directive 2004/73/EC of 29
April 2004 Adapting to Technical Progress for the Twenty-Ninth
Time Council Directive 67/548/EEC on the Approximation of the
Laws, Regulations and Administrative Provisions Relating to
the Classification, Packaging and Labeling of Dangerous
Substances. O.J. No. L1522004) were made on all animals inside
and outside the cage once a day throughout the study for signs
of departure from normal activity, morbidity and mortality.
This experiment was initiated after observing that Ceo is
absorbed through oral administration. To study the chronic
toxicity of Ceo we designed a protocol according to the
general guidelines of US food and drug administration (Chronic
Toxicity Studies with Rodents in Toxicological Principles for
the Safety Assessment of Food Ingredients. Redbook 2000,
revised July 2007, Chapter IV.C.5.a. IV.C.5.a.) with some
modifications. It was now discovered by the inventors that
oral administration of Ceo increases significantly the
longevity of rats (Fig. 5). At 25 months after the beginning
of the treatment, the % of survival is equal to 25 %, 67 % and
100 % for the rats treated with water, olive oil or
C6o-dissolved in olive oil, respectively (Fig. 5). At 37
months, after the beginning of the treatment, this percentage
is always equal to 100 % for the rats treated with
C6o-dissolved in olive oil, 17 % for the rats treated with
olive oil, and 0 % for the rats treated with water (Fig. 5).
The increase of the expected lifespan reported herein has
never been reported for any other substance, to our knowledge.