Abstract
Propolis is a natural resinous and waxy product obtained from honey bee
combs. Although propolis has been now explored globally for its wide range of
chemical constituents and its therapeutic value, the detailed investigation of
pharmacological activities of its key chemical constituents and its analogues is in its
infancy. In this study, a detailed review of the therapeutic potential of propolis and its
isolated key chemical constituents was carried out to provide basic literature data
required for further detailed investigation and discover new therapeutic potential
molecules from propolis. Till now, more than 300 isolated chemical compounds are
reported from worldwide propolis samples that include the presence of various
polyphenols, flavonoids, esters, beta-steroids, aromatic aldehydes, alcohols, etc. Some
specific chemical constituents of propolis, such as pinocembrin, are reported for its
potential neuroprotective action with reduced neurodegeneration in the cerebral cortex
and enhanced cognitive function in Aβ25-35-treated mice. Galangin is also well proven
for acetylcholinesterase enzyme inhibition and AβPP-Selective BACE inhibitor
(ASBI), which may be developed as a new therapeutic agent for Alzheimer's disease.
Caffeic acid phenethyl ester is reported as a moiety isolated from European propolis; it
is present even in the form of a mixture of caffeic acid esters and phenethyl ester for
antibacterial and antifungal properties. In vitro and in vivo evidence suggested that
caffeic acid phenethyl ester has cytotoxic mechanisms, including the activation of
p21protein, p38 MAPK, p53, and JNK kinase activity, inhibition of NF-B, and
increased caspase-3 or 7 activity. Various pharmacological activities are reported for
different propolis extracts, as well as for its constituents that include antioxidant, antiulcer,
anti-cancer, antiviral, anti-microbial, anti-inflammatory, anti-fungal, etc. Propolis
possesses tremendous therapeutic potential, and it is also reported worldwide in various
traditional systems of medicine. In this study, the key chemical constituents,
pharmacological activities, various critical issues in its application in drug delivery, and
pharmacological activities, various critical issues in its application in drug delivery, and
detailed investigation on approaches for formulation development to enhance
biopharmaceutical aspects of propolis have been reviewed.
Keywords: Cytotoxicity, Flavonoids, Neuroprotection, Polyphenols, Propolis.