application of these phytochemicals include low bioavailability, low tissue distribution, fast metabolism, and short half life [104].
The effectiveness of nutraceutical products in preventing disease depends on
preserving the bioavailability of the active ingredients. Novel drug delivery systems
have been developed for the potent plant extracts and their compounds. Nanophytomedicines include polymeric nanoparticles, nanocapsules, liposomes, phytosomes,
nanoemulsions, microspheres, transferosomes, and ethosomes loaded with bioactive
plant extracts. The nanocarriers selected for the phytodrugs should channel the active
entity to the site of action and also should deliver them at a rate directed by the need of
the body. Thus, the intention of the nanosized delivery systems of herbal drugs is to
enhance their activity and overcome the problems associated with plant medicines.
The novel nanoformulated phytodrugs are reported to have remarkable advantages
over conventional formulations of plant actives and extracts and include enhancement of solubility and bioavailability, improved half life, protection from toxicity,
enhancement of pharmacological activity, enhancement of stability, improved tissue
macrophage distribution, sustained delivery, and protection from physical and chemical degradation. This review highlights and summarizes the anticancer potency of
the available nanophytomedicine formulations (see also [105]).
4 Phytochemicals Encapsulated in Polymeric Nanoparticles
4.1 Curcumin
Despite its promising anticancer properties, the extremely low water solubility of
curcumin limits its bioavailability and clinical efficacy; for example, its serum
concentrations and tissue distributions are low and, furthermore, it is rapidly
metabolized and thus has a short half-life [104]. Curcumin has been encapsulated
in liposomes [106, 107], polymeric nanoparticles [108], lipid-based nanoparticles
[109], biodegradable microspheres [110], cyclodextrin [111], and hydrogel [112]
with the aim of overcoming the issues associated with the conventional form of the
drug. Nanoparticles have been used as effective delivery tools to enhance the
tumoricidal activities of anticancer drugs. Such delivery systems offer many
benefits due to their tumor-targeting abilities, internalization efficiencies and,
sometimes, escape from multidrug resistance [113, 114].
Nanoscaled particles with a disk-shaped lipid bilayer stabilized by an apolipoprotein scaffold (curcumin nanodisks, NDs, with <50 nm size) have been used for
encapsulating curcumin. NDs self-assemble in solution upon presentation of the
scaffold protein to a phospholipid vesicle substrate to which an appropriate hydrophobic bioactive agent has been introduced. The incorporation of curcumin into NDs
enhanced growth inhibition of human hepatocellular carcinoma cells (HepG2) and
induced apoptosis in mantle cell lymphoma (Jeko cells) [115, 116]. Natthakitta et al.
reported the development of mucoadhesive curcumin nanospheres. Ethyl cellulose
Phytomedicine-Loaded Polymeric Nanomedicines: Potential Cancer Therapeutics
215
The effectiveness of nutraceutical products in preventing disease depends on
preserving the bioavailability of the active ingredients. Novel drug delivery systems
have been developed for the potent plant extracts and their compounds. Nanophytomedicines include polymeric nanoparticles, nanocapsules, liposomes, phytosomes,
nanoemulsions, microspheres, transferosomes, and ethosomes loaded with bioactive
plant extracts. The nanocarriers selected for the phytodrugs should channel the active
entity to the site of action and also should deliver them at a rate directed by the need of
the body. Thus, the intention of the nanosized delivery systems of herbal drugs is to
enhance their activity and overcome the problems associated with plant medicines.
The novel nanoformulated phytodrugs are reported to have remarkable advantages
over conventional formulations of plant actives and extracts and include enhancement of solubility and bioavailability, improved half life, protection from toxicity,
enhancement of pharmacological activity, enhancement of stability, improved tissue
macrophage distribution, sustained delivery, and protection from physical and chemical degradation. This review highlights and summarizes the anticancer potency of
the available nanophytomedicine formulations (see also [105]).
4 Phytochemicals Encapsulated in Polymeric Nanoparticles
4.1 Curcumin
Despite its promising anticancer properties, the extremely low water solubility of
curcumin limits its bioavailability and clinical efficacy; for example, its serum
concentrations and tissue distributions are low and, furthermore, it is rapidly
metabolized and thus has a short half-life [104]. Curcumin has been encapsulated
in liposomes [106, 107], polymeric nanoparticles [108], lipid-based nanoparticles
[109], biodegradable microspheres [110], cyclodextrin [111], and hydrogel [112]
with the aim of overcoming the issues associated with the conventional form of the
drug. Nanoparticles have been used as effective delivery tools to enhance the
tumoricidal activities of anticancer drugs. Such delivery systems offer many
benefits due to their tumor-targeting abilities, internalization efficiencies and,
sometimes, escape from multidrug resistance [113, 114].
Nanoscaled particles with a disk-shaped lipid bilayer stabilized by an apolipoprotein scaffold (curcumin nanodisks, NDs, with <50 nm size) have been used for
encapsulating curcumin. NDs self-assemble in solution upon presentation of the
scaffold protein to a phospholipid vesicle substrate to which an appropriate hydrophobic bioactive agent has been introduced. The incorporation of curcumin into NDs
enhanced growth inhibition of human hepatocellular carcinoma cells (HepG2) and
induced apoptosis in mantle cell lymphoma (Jeko cells) [115, 116]. Natthakitta et al.
reported the development of mucoadhesive curcumin nanospheres. Ethyl cellulose
Phytomedicine-Loaded Polymeric Nanomedicines: Potential Cancer Therapeutics
215