**3. Materials and methods**

Alloxan is readily absorbed by beta pancreatic cell, a process that contributes to diabetogenic action. Its absorption also takes place in liver although hepatocytes are more resilient to its

The mechanism of toxic action resides in formation of reactive species of oxygen [45], the alloxan exhibiting increased affinity to substrates containing thiolic groups (reduced glutathione, cysteine, proteins with sulfide groups, enzymes) [46]. The product of alloxan reduction, the dialuric acid, is reoxidized to alloxan, the redox cycle thus formed being responsible for

**Figure 2.** Mechanism of diabetes induction by administration of alloxan [47]. A, Alloxan; AH·, alloxan radical; AH2,

An optimal protection against cytotoxic action of alloxan and dialuric acid is offered by an association between superoxide-dismutase (SOD) and catalase (CAT), in order to completely prevent the redox cycle and consecutively the formation of any reactive oxygen species [48].

Glucose confers complete protection against toxic effects of alloxan both *in vivo* and *in vitro*, by blocking glucokinase inhibition by it and also contributing to maintaining the antioxidant

One of the targets for the reactive oxygen species is the DNA of the pancreatic islet cells. The

The DNA alteration stimulates poly-ADP-ribose, enzyme which contributes to affected DNA repair. In several trials it was stated that glucose administration contributes to counteracting the alloxan cytotoxicity. Such ability is the result not only of glucokinase protection but also of

interaction with glucose carrier GLUT2 resulting in reduced alloxan absorption [51].

, superoxide radical; OH·, hydroxyl radical.

DNA fragmentation occurs in beta cells exposed to alloxan [49, 50].

action compared to beta cells, therefore more protected against its toxicity [44].

**2.1. Mechanism of alloxan toxicity**

226 Adiposity - Epidemiology and Treatment Modalities

dialuric acid; O2·


protection mechanism of the beta cells [49].

releasing superoxide radicals—see **Figure 2** [47].

Diabetes was induced to white Wistar male rats by intraperitoneal administration of extemporaneously prepared alloxan (Sigma-Aldrich) solution, in the dose of 130 mg/kg weight [52]. After 48 hours, glycemia was determined using ACCU-CHEK Active device (Roche Diagnostics GmbH, D-68298 Mannheim, Germany). The blood was harvested from tail veins by vein puncture. The determination was used for the selection of diabetic animals, thus presenting a glycemia over 200 mg/dL.

From the total rat collectivity, a percentage of 66.34% became diabetic with the remaining 33.66% becoming hyperglycemic. Fifteen groups of diabetic animals were designated for experimental research (eight animals/group), being treated as follows:


At the same time, a nondiabetic control group was designated (ND control), treated with distilled water, 1 mL/100 g weight p.o. Administration of tested and reference substances (BRL 37344) continued for 14 days, once daily.

The doses chosen for investigating the metabolic effects of the newly synthesized derivatives were established following previous determinations of acute toxicity which allowed to set the LD50 [53, 54].

At the end of the experiment, the animals were sacrificed and biochemical and enzymatic determinations were performed: glycemia, glucose-6-phosphate dehydrogenase (transforming glucose by pentose-phosphate pathway), glucose–6–phosphatase (catalyzes the hydrolysis of glucose–6–phosphate to glucose and inorganic phosphate), hexokinase (catalyzes the phosphorylation of glucose), total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
