Phytochemical analysis and anti-inflammatory evaluation of compounds from an aqueous extract of Croton cajucara Benth.

Croton cajucara Benth. is a medicinal plant popularly used in the Brazilian Amazonia, where it is known as sacaca, being consumed as tea, decoction or infusion of the leaves and stem bark. From a decoction of the leaves, a comprehensive phytochemical analysis was developed by liquid chromatography-mass spectrometry. Many compounds were identified for the first time in C. cajucara, such as O-glycosides of kaempferol and quercetin, flavonoid-C-glycosides, tannins and cinnamic acid derivatives. These compounds were fractionated by polarity and assayed for their anti-inflammatory activity, using a model of mice edema, induced by an intraplantar injection of carrageenan. All fractions exhibited anti-inflammatory properties.

Lipoic acid does not improve renal function markers in 5/6 nephrectomy model: possible role of Nrf2 inactivation.

Chronic kidney disease (CKD) progression and complications are associated with increased oxidative stress, as well as with Nrf2 inactivation. Lipoic acid (LA) has been considered an inducer of Nrf2 antioxidant response. We tested whether oral administration of LA provides beneficial effects in experimental CKD in rats. Wistar rats underwent 5/6 nephrectomy (CKD group) or sham laparotomy. Seven days later, CKD group was divided into three subgroups that received: (i) LA continuously in the drinking water (100 mg/kg/day), (ii) LA by gavage every other day (100 mg/kg), or (iii) no LA treatment. LA treatment lasted until day 60. Plasma urea and creatinine, 24 h-proteinuria, glomerulosclerosis, interstitial fibrosis/tubular atrophy, and Nrf2 activation were analyzed. All parameters measured were significantly altered in the untreated CKD group, compared with the sham group, as expected. Oral LA administration, either in the drinking water or by gavage, did not improve significantly any parameter, comparing the treated-groups with the untreated CKD group. These results indicate that oral LA administration for 53 days was ineffective to reactivate Nrf2 in the remnant kidney of uremic rats, likely preventing improvements in biochemical and histopathological markers of renal function.