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Current
Bioactive Compounds
Current Bioactive Compounds
Volume 3, Number 4, December 2007
Contents
Review Articles
Photosensitizer Nanoparticles for Photodynamic Therapy
Pp. 239-251
Toru Oba
[Abstract]
Natural Product Photoantimicrobials Pp. 252-261
M. Wainwright
[Abstract]
Innovative Drug Delivery Systems for the Administration
of Natural Compounds Pp. 262-277
Donatella Paolino, Donato Cosco, Felisa Cilurzo and Massimo
Fresta
[Abstract]
Obesity: Overview & Management Pp. 278-290
Kalpana Bhandari and Shipra Srivastava
[Abstract]
Myostimulating Effect of the Aqueous Extract of Khaya
senegalensis (Desr) A. Juss. (Meliaceae) in Isolated
Taenia caeci Contractile Activity Pp. 291-294
A. Souza, J. Aka Kadjo, J.C. Abo Kouakou, Y. Datte-Jacques,
F.Traoré and B. M’Batchi
[Abstract]
Bioactive Compounds
Anti-Cancer/Anti-Tumor Pp. 295-301
Anti-Inflammatory Pp. 302
Anti-Malarial Pp. 303
Anti-Microbial Pp. 304-307
Anti-Viral Pp. 307-308
Central Nervous System Related Pp. 309
Enzyme Inhibition Pp. 310-311
Anti-Obesity Pp. 312-313
Other Activities Pp. 314
Abstracts
[Back to top]
Photosensitizer Nanoparticles for Photodynamic Therapy
Toru Oba
Photodynamic therapy (PDT) is an emerging treatment modality
for cancer as well as non-cancer diseases. PDT involves administration
of a photosensitizer in targeted tissues and photogeneration
of cytotoxic reactive oxygen species that destroys tumor cells.
Much effort has been paid to disperse hydrophobic photosensitizers
molecularly in water, since self-aggregation of photosensitizers
significantly reduces singlet oxygen yield. The self-aggregation
and the particle formation have, however, been revaluated
and extended in terms of passive tumor cell targeting and
ongoing nanotechnology. Upon systemic administration, nanoparticles
are preferentially taken up by tumor tissues due to EPR effect
(Enhanced Permeability and Retention Effect). To improve therapeutic
efficacy and suppress side effects, a variety of approaches
has been explored by using photosensitizer nanoparticles such
as dendrimers, quantum dots, liposomes, polymer micelles,
peptide-conjugates, and hydrogel nanoparticles. Control of
the size, surface property, and amphiphilicity are key factors
in optimizing the nano-PDT-agents. In this article, the author
will review recent progress in this growing field, including
our approaches, from the viewpoint of supramolecular chemistry
and nanotechnology. Future subjects will also be discussed.
[Back to top]
Natural Product Photoantimicrobials
M. Wainwright
In the past 20 years, photosensitisers have found a niche
in the photodynamic treatment of accessible tumours (PDT).
Most of the therapeutics involved in this approach are porphyrin-based
natural products or derivatives. However, there is a range
of other photodynamic agents derived from natural sources
– either via direct extraction/purification, or via
semisynthesis - currently being trialled both for anticancer
PDT and the related antimicrobial application, covering areas
such as wound disinfection and blood product sterilisation.
The following review covers the advances made in the potential
photoantimicrobial application of natural product photosensitisers
and their derivatives.
[Back to top]
Innovative Drug Delivery Systems for the Administration of
Natural Compounds
Donatella Paolino, Donato Cosco, Felisa Cilurzo and Massimo
Fresta
The use of natural compounds has recently been reconsidered
in modern clinical practice. A further advancement of these
compounds is represented by the possibility of using innovative
drug delivery systems that can improve the biopharmaceutical
features of the delivered compounds. This review examines
the recent developments in the field of delivery of natural
drugs belonging to several therapeutic classes. In particular,
the examined therapeutic classes are: antitumoral drugs, i.e.
paclitaxel, doxorubicin, tea catechins and hypericin; anti-infective
drugs, i.e. Melaleuca alternifolia and Artemisia arborescens
L.; and antinflammatory/antioxidant drugs, i.e. cannabinoids
and glycyrrhizinates used for topical application. In this
review we highlight the utility of a suitable drug delivery
system to improve the biopharmaceutical aspects of these drugs.
The examined carriers are: vesicular carriers (liposomes,
Ethosomes® ultradeformable
liposomes), nano- and microparticles, innovative gels, microemulsions.
[Back to top]
Obesity: Overview & Management
Kalpana Bhandari and Shipra Srivastava
Obesity and its comorbid conditions are increasing with an
alarming rate throughout the world. The high incidence of
obesity and scarcity of effective and reliable treatment have
fuelled the development of anti-obesity drugs for many years.
Different pharmacological approaches rely on four main lines
of action- i) control of energy intake through modification
of appetite; ii) control of energy expenditure through thermogenesis;
iii) control of fat absorption in the gut through lipase inhibitors
and iv) other pharmacological approaches. While many drugs
have been introduced for the treatment of obesity, only two
have so far been approved by the FDA for long term treatment
- orlistat, which acts to prevent dietary fat absorption and
sibutramine, which seems to affect both arms of energy balance
equation i.e. energy intake as well as energy expenditure.
However side effects have limited their use and both the medications
have failed to gain a large market. A high proportion of current
research is also centered on peptidic control of appetite
and the modulation of signals from the adipose tissue. Hunger
and satiety signals such as ghrelin, obestatin, peptide YY,
the CB1 receptor antagonists such as rimonabant, CP-946,598,
highly specific 5-HT2c
receptor agonist such as APD356, pancreatic lipase
inhibitor e.g. cetilistat (ATL-962) and GT389-255 are potentially
attractive therapeutic strategies for treatment of obesity.
Also, better understanding of human genetics can make an invaluable
contribution to the study of human obesity, pointing toward
more targeted and effective therapies. In addition to the
analysis of current treatment strategies, this review also
focuses on the areas of potentially high productivity in the
future.
[Back to top]
Myostimulating Effect of the Aqueous Extract of
Khaya senegalensis (Desr) A. Juss. (Meliaceae) in
Isolated Taenia caeci Contractile Activity
A. Souza, J. Aka Kadjo, J.C. Abo Kouakou, Y. Datte-Jacques,
F. Traoré and B. M’Batchi
The effects of the aqueous extract of Khaya senegalenis
(Desr) A. Juss. (Meliaceae) (EAKS) were evaluated on the contractile
activity of the guinea-pig Taenia coli. EAKS in a
range of concentrations from 10-8mg/ml
to 10-2mg/ml induced an increase
of the spontaneous rhythmic contractions and of basal muscular
tone, in a concentration-dependent manner (EC50:
6.10-4 mg/ml). With 10-2mg/ml
of the extract, maximal stimulation was obtained. The effects
of EAKS were comparable to those induced by acetylcholine
(ACh). Moreover, the cholinoceptor antagonist, atropine, applied
at a concentration of 10-6
mg/ml inhibited the stimulating effects of ACh. However, atropine
did not inhibit the myostimulant action induced by EAKS. In
calcium-free solution containing EDTA, a bivalent chelator,
at a concentration of 10-3
mM, EAKS had no effect on the guinea-pig isolated Taenia
coli. In the same conditions, ACh induced an increase
of basal muscular tone. In conclusion, EAKS exerted a stimulating
effect in the intestinal smooth muscle. Cholinergic mechanisms
may not be involved. The myostimulating action of EAKS could
be due to a mobilization of bivalent, mainly calcium flux.
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