All spectra showed a similar absorption pattern, with two
bands of maximum absorption around 230 and 290 nm,
with the exception of the peak at 12.15 min, which comprises
a single band of absorption at 282 nm. These data
suggest the predominance of compounds like flavonoids
that normally occurs as secondary metabolites in plants
by the characteristics absorptions of the A and B bands
(Fig. 1).
The crude tamarind extract was found to be rich in sugars
(70.25 ± 8.56 mg/ml), polyphenols (34.02 ± 2.11 nmol/
ml) and flavonoids (35.51 ± 5.61 lg/ml), the later two
being well known antioxidant agents. The assays for quantification
of these components were all performed in triplicate
in three independent extract preparations.
DPPH and superoxide radicals scavenging activities are
present in the extract in a dose-dependent manner, with
Pearson correlation of 0.89 (Fig. 2). The results of
both scavenging activities of the extract were compared
with the reference compound BHT (not shown). BHT presented
61.65% ± 0.3 and 80.29% ± 0.2 of scavenging activities
against DPPH and superoxide, respectively, whereas
the extract, at the concentration of 1 mg/dl, presented
7.31% ± 0.5 and 42.01% ± 3.5 scavenging activities against
DPPH and superoxide, respectively (Fig. 2).
Fe2+/citrate-mediated lipid peroxidation in animal
serum, assessed as TBARS, was inhibited by about 50%
in the presence of 2.5% crude tamarind extract. In the presence
of 5% of the extract the inhibition was almost complete
(Fig. 3).
3.2. Dietary intake and growth rate of hamsters
Table 1 shows food and fluid consumption by the experimental
hamsters; no differences were observed between
groups, but it should be noted that the animals consumed
less tamarind extract than tap water. The animals were
weighed at the beginning and at the end of the treatment.
Similar increases in body weight were observed in all experimental
groups.
3.3. Biochemical parameters of hamsters
AST and ALT serum levels were performed to assess
liver function. As can be observed in Table 2, no alterations
are detected in the animal groups treated with the cholesterol
diet and/or tamarind extract, during 10 weeks, when
compared to the control group (Table 2).