Antioxidant, Antidiabetic, and Antiobesity Properties, TC7-Cell Cytotoxicity and Uptake of Achyrocline satureioides (Marcela) Conventional and High Pressure-Assisted Extracts.

Patricia Lema,Adriana Maite Fernández-Fernández,Horacio Heinzen,Ignacio Migues,Alejandra Medrano-Fernandez,Eliane Dumay,Tomás López-Pedemonte,Françoise Lazennec

doi:10.3390/foods10040893

Abstract

The growing incidence of non-communicable diseases makes the search for natural sources of bioactive compounds a priority for such disease prevention/control. Achyrocline satureioides (‘marcela’), a plant rich in polyphenols and native to Brazil, Uruguay, Paraguay, and Argentina, could be used for this purpose. Data on its antidiabetic/antiobesity properties and cellular uptake of bioactive compounds are lacking. The potentiality of non-thermal technologies such as high-hydrostatic pressure (HP) to enhance polyphenol extraction retains attention. Thus, in the present study aqueous and ethanolic marcela extracts with/without assisted-HP processing were chemically characterized and assessed for their in vitro antioxidant capacity, antidiabetic and antiobesity activities, as well as cellular cytotoxicity and uptake on intestinal cell monolayers (TC7-cells, a clone of Caco-2 cells). Aqueous and ethanolic conventional extracts presented different polyphenolic profiles characterized mainly by phenolic acids or flavonoids, respectively, as stated by reverse phase-high-performance liquid chromatography (RP-HPLC) analyses. In general, ethanolic extracts presented the strongest bioactive properties and HP had none or a negative effect on in vitro bioactivities comparing to conventional extracts. TC7-cell viability and cellular uptake demonstrated in conventional and HP-assisted extracts, highlighted the biological effects of marcela bioactive compounds on TC7-cell monolayers. TC7-cell studies showed no HP-induced cytotoxicity. In sum, marcela extracts have great potential as functional ingredients for the prevention/treatment of chronic diseases such as diabetes.

Highlights

The Marcela ethanolic extract (Me) extract in the present study showed greater quercetin content than the marcela aqueous extracts prepared by maceration and ultrasound-assisted extraction reported by Guss et al [26]
We have checked that the deposit of Me extract at the highest concentrations after centrifugation to exclude insoluble compounds displayed similar lactate dehydrogenase (LDH) activity values than that obtained without centrifugation (Figure 3)
The extracts presented high polyphenol content and great antioxidant capacity determined by ABTS and Oxygen radical antioxidant capacity-fluorescein (ORAC-FL) when compared to other medicinal plants, as well as antidiabetic (α-amylase, α-glucosidase and advanced glycation end products (AGEs) formation inhibition capacity) and antiobesity activities

Summary

Introduction

The search for antioxidant, antidiabetic, and antiobesity natural sources is of great importance for their prevention/treatment. Marcela has been studied for its antioxidant, cell cytoprotective effect against oxidants [2], anti-inflammatory, 4.0/). Analgesic, antispasmodic, constipating, sedative, immunomodulatory, antiviral, antiherpetic, choleretic and hepatoprotective actions, whereas partial cytotoxicity in mice and rats has been found for aqueous and ethanolic extracts [3]. Marcela proved to present anti-cancer activity against glioma cell lines (U87, U251 and C6) and to be less cytotoxic to brain cell than gliomas [5]. Marcela extracts are composed of flavonoids such as quercetin, luteolin and 3-O-methylquercetin in their glycosylated and aglycone forms [2], found in both ethanolic [6] and aqueous [2]

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Conclusion