changes that develop over time in normal and obese animals [42],
and has been associated with concurrent decrease in left ventricular
compliance and varying degrees of ventricular hypertrophy [41].
Because the contribution of cardiovascular disease to human
morbidity and mortality is very high in the elderly, much research
in this area has been directed towards determining the role of
specific food components on the development, progression, and
prevention of CVD [4-9]. Our results demonstrate that MGTE
treatment effectively prevents myocardial fibrosis together with
a reduction in blood TG and TC levels. Recently, we demonstrated
that microencapsulated GTE reduced the inflammatory
response by decreasing NO production in murine RAW264.7
cells [43]. It is generally believed that catechin derivatives are
the active components responsible for the beneficial effects of
antioxidant [13] and cardioprotectants [44]. Oxidants are involved
in the pathogenesis of dyslipidemia and CVD [12]. Therefore,
the beneficial effects of antioxidants may be attributed, in part,
to the lowering of oxidant levels. However, bioactive ingredients
including polyphenols are degraded during processing and storage
(temperature, oxygen, and light) and under the conditions
encountered in the gastrointestinal tract (pH, enzyme, and interactions
with other nutrient) [16]. The effectiveness of nutraceutical
products in preventing various diseases depends on preserving
the bioavailability of the bioactive ingredients. It has been reported
that only a small proportion of the ingredients remain available
following oral administration due to insufficient gastric residence
time, low permeability, and/or solubility within the gastrointestinal
tract [45]. In addition, Lambert et al. [46] found that polyphenols
in green tea oxidize readily in beverages and even in the oral
cavity, generating substantial levels of H2O2, which is potentially
cytotoxic. Some bioactives are particularly susceptible to oxidation;
therefore, microencapsulation of bioactives has the ability to
preserve them in certain environments [47]. Lee et al. [48] found
that microencapsulation of GTE with maltodextrin increased
DPPH radical scavenging activities. Reineccius et al. [49] enhanced
the retention of orange oil and prevented the oxidation by using
gum Arabic. In our experiments, the beneficial effect of microencapsulated
GTE was demonstrated by the reduction of serum uric
acid and myocardial fibrosis and the increase in liver catalase
activity compared to non-encapsulated GTE. Thus, the protection
of bioactives from oxidation could be an effective way to utilize
their beneficial effects on human health.
This work compared the ability of GTE and microencapsulated
GTE to ameliorate hypertriglyceridemia and mediate cardiovascular
protection. According to our results, microencapsulated GTE is
more effective at alleviating the cardiovascular risk induced by
high fructose feeding than non-encapsulated GTE.