Font: Authored by the author
Legend: The results represent the medium ± standard deviation of 8-10
determinations per treatment, estimated of serum levels of fructosamine.
ANOVA was determined and the letters indicate that there was significant
difference of Tukey-Kramer test, adopting p<0,05.
The diuretic effect of artichoke helps the urea and toxic substances
eliminate, developing a depurative action. One of the antioxidant
compounds present in the artichoke is the vitamin E, which in the human
body is soluble in fat and has an effect on the oxidative stress
involved in aging and complications as diabetes (Lactantius 2002). The
fact that the artichoke is rich in dietetic fibres gives the artichoke
the properti to regulate intestinal activity, contributing to the
control of blood glucose and cholesterol levels [Ceccarelli,, Curadi
& Picciarelli, 2010].
According to [Gebhardt, 1997], the extracts with a higher content of
phenolic derivatives present a higher protection of the liver, as well
as antioxidant activities (they can limit the oxidative stress and
restore the endothelial functions). Probability, the caffeine
derivatives have a role in therapeutic activities of the artichoke when
administered in vitro, but not in isolation. The leaf artichoke
extract is capable not only to increase the bile flow, by reducing the
cholesterol levels, but also to reestablish this flow when it is
inhibited. These effects are performed by luteolin and to a lesser
extent by luteolin-7-o-glucoside, while the chlorogenic acid and
1,5-dicaffeoylquinic are almost inefficient.
The antioxidant activity of flavonoids is obviously linked to its
structure and can be determined by the following factors: The reactivity
as donor agent of hidrogenom or electrons, stability of the formed
flavonyl radical, reactivity against others antioxidants, capacity to
chelate transitions metals, solubility and interaction with membranes.
At the same time, its capacity to kidnap free radicals is directly
linked to its oxidation potential and to the species to be kidnapped,
and the lower oxidation potential of the flavonoids, higher is its
capacity as kidnapper of free radicals [Barreiros, David & Juceni,
2006].
Quercetin actuates normalizing the plasmatic glucose levels, increasing
the content of hepatic glycogen and inducing the enzymes hepatic
glucokinase and hexokinase [Vessal, Hemmati & Vasei, 2003]. The
flavonoid naringenin is known to block the activity of the PI-3K in
adipocytes and thus inhibiting the captivation of glucose. Another 14
flavonoids were investigated as possible inhibitory action on PI-3K,
such as quercetin, luteolin, myricetin, apigenin and diosmetin which
showed any type of inhibition on activity of the PI-3K [Agullo,
Gamet-Payrastre, Manenti,Viala, Remesy, Chap & Payrastre. 1997].
Some authors showed that the quercetin has several effects on glucose
metabolism when administered orally to diabetic animals in a subchronic
treatment. Effects such as the decrease of glycemics levels, increase of
the hepatic hexokinase and glucokinase activity and normalization of the
glucose tolerance curve, in addition to an increase in the number of the
pancreatic islets. The authors linked these effects to the antioxidant
potential that quercetin has and as this consequence, it would be
regenerating pancreatic cells and increasing insulin secretion,
therefore, these actions of the glucose metabolism would be due to the
increased insulin secretion [Vessal, Hemmati & Vasei, 2003].
According to [Salles, da Silva, Taniguthi, Ferreira, da Rocha,
Vilegas., Dias, Pennacchi, Duarte, Rodrigues, Brigagão & Paula. 2020]
the dyslipidemic observed in diabetic animals can be attributed to the
hyperglycemic shown by them. The hypercholesterolemia due to type 2 DM
has been linked to the increase of the atherogenic lipoproteins such as,
low density lipoprotein (LDL) and very low density lipoprotein (VLDL).
However, it has been reported that in type 1 DM, an increase in the
serum concentration of HDL cholesterol may be linked to high or normal
concentrations of the other lipoproteins [Kahri, Groop, Viberti,
Elliot & Taskinen. 1993]. In this case, despite the high levels of
HDL cholesterol, there is no reduction in cardiac risk in these
individuals, since changes in the size, composition and structure of HDL
may be present, compromising their functionality and negatively
interfering with their antiatherogenic properties [Sviridov, Kingwell,
Hoang, Dart & Nestel. 2003].
In our studies, an increase in the concentration of total cholesterol
and triglycerides in the serum of diabetic animals when compared to
non-diabetic animals (Table 1), compatible with the metabolics
alterations observed in diabetes mellitus.
Diabetic animals treated with the artichoke extracts showed serum levels
of total cholesterol and triglycerides significantly lower than
non-treated animals (Table 1).
Table 1 - Evaluation of lipid profile in serum of Wistar rats