Purification, structural elucidation, antioxidant capacity and neuroprotective potential of the main polyphenolic compounds contained in Achyrocline satureioides (Lam) D.C. (Compositae).

Achyrocline satureioides (Lam) D.C (Compositae) is a native medicinal plant of South America traditionally utilized for its anti-inflammatory, sedative and anti-atherosclerotic properties among others. Neuroprotective effects have been reported in vivo and could be associated to its elevated content of flavonoid aglycones. In the present study we performed the isolation and structure elucidation of the major individual flavonoids of A. satureioides along with the in vitro characterization of their individual antioxidant and neuroprotective properties in order to see their putative relevance for treating neurodegeneration. Exact mass, HPLC-MS/MS and 1H NMR identified dicaffeoyl quinic acid isomers, quercetin, luteolin, isoquercitrin, and 3-O-methylquercetin as the mayor polyphenols. Flavonoids intrinsic redox properties were evaluated in the presence of the endogenous antioxidants GSH and Ascorbate. Density Functional Theory (DFT) molecular modeling and electron density studies showed a theoretical basis for their different redox properties. Finally, in vitro neuroprotective effect of each isolated flavonoid was evaluated against hydrogen peroxide-induced toxicity in a primary neuronal culture paradigm. Our results showed that quercetin was more efficacious than luteolin and isoquercitrin, while 3-O-methylquercetin was unable to afford neuroprotection significantly. This was in accordance with the susceptibility of each flavonoid to be oxidized and to react with GSH. Overall our results shed light on chemical and molecular mechanisms underlying bioactive actions of A. satureioides main flavonoids that could contribute to its neuroprotective effects and support the positive association between the consumption of A. satureioides as a natural dietary source of polyphenols, and beneficial health effect.

Achyrocline alata potentiates repair of skin full thickness excision in mice.

Plants of the Asteraceae family have been traditionally used as medicinal plants. The species Achyrocline satureioides and Achyrocline alata present anti-inflammatory properties and great chemical similarity. However, no study has been performed to evaluate the influence of these plants on skin wound healing in vivo. Here, we have assessed the effect of these plants extracts on skin wound healing in mice. Mice were randomly arranged into three groups (n = 10), an injury was performed on the dorsal area of the animals, which received the following topical treatment: group 1, control (ointment base); group 2, A. satureioides extract; group 3, A. alata extract. The solution for treatment was prepared as 10% (w/w) concentration. The wound area was measured on days 1, 4, 9, 15 and 17 after treatment and tissues of local lesion were collected on the ninth day for histological analysis. A. alata was more effective since it induced earlier wound closure associated with decreasing initial inflammatory response, faster reepithelialization and collagen remodeling. A. satureioides improved the collagen renovation, but induced slower closure, which may be due to different concentrations of phenolic compounds among the plants here studied. Both plants did not alter the ultrastructural characteristics of cells in the healing process. In conclusion, our findings suggest the potent wound healing capacity of A. alata extracts, as demonstrated by more efficient and faster induction of wound closure. We believe this plant is a potential wound healing treatment for humans and further studies are necessary to assess its clinical practice.

Optimization and technological development strategies of an antimicrobial extract from Achyrocline alata assisted by statistical design.

Achyrocline alata, known as Jateí-ka-há, is traditionally used to treat several health problems, including inflammations and infections. This study aimed to optimize an active extract against Streptococcus mutans, the main bacteria that causes caries. The extract was developed using an accelerated solvent extraction and chemometric calculations. Factorial design and response surface methodologies were used to determine the most important variables, such as active compound selectivity. The standardized extraction recovered 99% of the four main compounds, gnaphaliin, helipyrone, obtusifolin and lepidissipyrone, which represent 44% of the extract. The optimized extract of A. alata has a MIC of 62.5 µg/mL against S. mutans and could be used in mouth care products.