Larrea divaricata, better known as chaparral, is a plant widely used in South American folk medicine for its anti-inflammatory properties.. With this in mind, a team of researchers conducted a study on whether an aqueous extract could be used to treat oxidative stress in the submandibular glands of diabetic rats..

Previous studies have shown that L. divaricata contains the antioxidant compound nordihydroguaiaretic acid (NDGA). Other studies have also shown that an aqueous extract of L. divaricata mimics the secretion of the antioxidant enzyme peroxidase in the submandibular glands of healthy rats. The effect of an aqueous extract of L. divaricata on prooxidant and antioxidant homeostasis in the salivary glands of healthy rats.

But researchers from the Argentine University of Buenos Aires and the UCA-CONICET Biomedical Research Institute noted that the effect of an aqueous extract of L. divaricata on homeostasis in submandibular glands exposed to oxidative stress has not yet been studied. The results of their animal study were published in the journal BMC Complementary and Alternative Medicine..

For their study, the researchers divided 40 female Wistar albino rats into two groups.. One of them was a control group, while the other was injected with 60 milligrams per kilogram of streptozoate (STZ), a known oxidative stressor.. STZ has been shown to create an imbalance between the oxidative and antioxidant systems by reducing peroxidase secretion in the submandibular glands.. After 10 days of treatment, blood samples were taken from the veins in the rats' tails to determine the level of glucose.. Those with glucose levels greater than 300 milligrams per milliliter (mg/mL) of blood were selected from the STZ group.

The submandibular glands of both control and STZ rats were incubated with either 500 micrograms per milliliter (? g/ml) of an aqueous extract, or with 1.5? g/ml NDGA.

To obtain an aqueous extract, the researchers dried the leaves of L. divaricata in the air. They then infused 750 milligrams (mg) of dry leaves for 20 minutes with 10 milliliters (mL) of sterilized boiling water.. To quantify the amount of NDGA, the researchers performed high performance liquid chromatography (HPLC). This led to the production of NDGA.

After incubation, the researchers performed analyzes to determine the levels of malondialdehyde, protein carbonyl groups, reactive oxygen species and reactive nitrogen species (RNS), as well as the activity and expression of peroxidase, superoxide dismutase, and inducible nitric oxide synthase in the submandibular glands of rats..

Here, the researchers found that the glands of animals treated with STZ exhibited low peroxidase activity and high superoxide dismutase activity.. Meanwhile, in both control and STZ groups, both aqueous extract and NDGA induced a significant increase in peroxidase activity.. However, the increase in peroxidase from the aqueous extract was higher than that of NDGA.. In addition, they noted that the aqueous extract reduced the levels of malondialdehyde and protein carbonyl groups, and also modulated the levels of reactive oxygen species..

Based on the results of their experiment, the researchers concluded that the aqueous extract of L. divaricata is able to reverse oxidative stress caused by STZ injection into the submandibular glands of rats and can be used as a topical or systemic prophylactic against oxidative stress-induced oral diseases in diabetic patients.

medical-heal. en.