Evaluation of Antioxidant, Anti-Inflammatory and Antityrosinase Potential of Extracts from Different Aerial Parts of Rhanterium suaveolens from Tunisia.

The genus Rhanterium (Asteraceae) is a widely distributed medicinal plant throughout western North Africa and some Rhanterium species are used in folk medicine. The aim of research was to investigate methanolic extracts from different parts (flowers, leaves, and stems) of Tunisian Rhanterium suaveolens as potential sources of bioactive products useful for healthy purposes. In particular, were analyzed the phenolic composition of these extracts and their antioxidant, anti-inflammatory, and anti-tyrosinase properties. The phytochemical analyses were performed using standard colorimetric procedures, HPLC-DAD and HPLC-DAD-ESI-MS. Then, several in vitro cell-free assays have been used to estimate the antioxidant/free radical scavenging capability of the extracts. Moreover, in vitro, and in vivo anti-melanogenesis activities of these extracts were tested, respectively, with the tyrosinase inhibition assay and the Zebrafish embryo model. Finally, the anti-inflammatory potential of these extracts in an in vitro model of acute intestinal inflammation in differentiated Caco-2 cells was evaluated. The R. suaveolens extracts under study appeared particularly rich in flavonols and hydroxycinnamic acids and all extracts appeared endowed with good antioxidant/free radical scavenging properties, being the flower extracts slightly more active than the others. Moreover, R. suaveolens flowers extract was able to inhibit in vitro tyrosinase activity and exhibited bleaching effects on the pigmentation of zebrafish embryos. Furthermore, all extracts showed good anti-inflammatory activity in intestinal epithelial cells as demonstrated by the inhibition of TNF-α-induced gene expression of IL-6 and IL-8. R. suaveolens aerial parts may be considered as a potential source of whitening agents, as well as of agents for the treatment of disorders related to oxidative stress and inflammation.

Comparison of Phytochemical Profile and Bioproperties of Methanolic Extracts from Different Parts of Tunisian Rumex roseus.

The genus Rumex (Polygonaceae) is distributed worldwide and the different species belonging to it are used in traditional medicine. The present study aimed at the evaluation of the phytochemical profile and the biochemical properties of methanolic extracts from different parts (roots, stems, and leaves) of Rumex roseus, a wild local Tunisian plant traditionally used as food. The phytochemical analysis on the extracts was performed using standard colorimetric procedures, HPLC-DAD, and HPLC-DAD-ESI-MS; then, several in vitro cell-free assays have been used to estimate their antioxidant/free radical scavenging capability (TAC-PM, DPPH, TEAC, FRAP, ORAC, SOD-like activity, and HOCl-induced albumin degradation). Additionally, anti-inflammatory effect of these extracts was evaluated in an in vitro model of acute intestinal inflammation in differentiated Caco-2 cells. The results showed that the methanolic extracts from stems and, especially, leaves contain substantial amounts of flavones (apigenin and luteolin, together with their derivatives), while the extract from roots is characterized by the presence of tannins and quinic acid derivatives. All the extracts appeared endowed with excellent antioxidant/free radical scavenging properties. In particular, the extract from roots was characterized by a remarkable activity, probably due to its different and peculiar polyphenolic composition. Furthermore, both Rumex roseus roots and stems extracts demonstrated an anti-inflammatory effect in intestinal epithelial cells, reducing TNF-α-induced gene expression of IL-6 and IL-8. In conclusion, R. roseus methanolic extracts have shown to be potential sources of bioactive compounds to be used in the prevention and treatment of pathologies related to oxidative stress and inflammation.

HPLC-DAD Analysis, Antioxidant and Protective Effects of Tunisian Rhanterium suaveolens against Acetamiprid Induced Oxidative Stress on Mice Erythrocytes.

The present study was performed to assess the HPLC-DAD analysis as well as antioxidant and protective effects of Tunisian Rhanterium suaveolens (Rs) against acetamiprid (ACT) induced oxidative stress on mice erythrocytes. The in vitro assays showed that the methanolic extract of Rs has an impressive antioxidant effect proved by testing the total antioxidant and scavenging activities using BCB, DPPH and ABTS assays, respectively. Moreover, qualitative and quantitative analysis using HPLC-DAD revealed the richness of Rs in polyphenols where p-Coumaric, Apigenin-7-glucoside and Ferulic acid were detected as the most abundant polyphenols. In the in vivo experiment, ACT, used as a toxicity model, was given to mice at a dose of 20 mg/kg. The latter was the origin of hemolytic anemia characterized by a significant decrease in red blood cells, hemoglobin and hematocrit levels and an increase in bilirubin, LDH, osmotic fragility, reticulocytes and white blood cells number. Characteristic erythrocyte morphological alterations were also determined as spherocytosis, schistocytosis and dacryocystitis. The oxidative status of ACT-treated mice was also altered manifested by a significant increase in MDA and GSH levels and a decrease in SOD, CAT and GPx activities. When receiving the Rs methanolic extract at a dose of 300 mg/kg, all the parameters cited above were restored in mice. These remarkable corrections could only confirm the important antioxidant effect and the noticeable protective properties that possess Rs owing to its broad range of secondary bioactive metabolites.