Influence of In Vitro Human Digestion Simulation on the Phenolics Contents and Biological Activities of the Aqueous...

Area of Science:

• Phytochemistry
• Pharmacology
• Nutritional Science

Background:

• Oxidative stress is linked to metabolic diseases like diabetes and cardiovascular conditions.
• Secondary plant metabolites, particularly phenolics, are recognized for their antioxidant properties.
• Turkish Cistus species are potential sources of bioactive compounds.

Purpose of the Study:

• To investigate the phenolic profile of Turkish Cistus aqueous extracts.
• To evaluate the antioxidant and antidiabetic potential of these extracts.
• To assess the impact of in vitro digestion on the bioavailability and bioactivity of Cistus phenolics.

Main Methods:

• Aqueous extraction from Turkish Cistus aerial parts.
• In vitro digestion simulation to mimic human digestion.
• Quantification of total phenolics, flavonoids, phenolic acids, and proanthocyanidins.
• High-Performance Thin Layer Chromatography (HPTLC) for marker flavonoids (tiliroside, hyperoside, quercitrin).
• Assays for antioxidant activity (DPPH, ABTS, FRAP).
• In vitro assays for α-amylase, α-glucosidase, and advanced glycation end product (AGE) inhibition.

Main Results:

• Cistus extracts are rich in phenolic compounds with significant antioxidant and antidiabetic enzyme inhibitory activities.
• In vitro digestion reduced the concentration of total phenolics, marker flavonoids, and antioxidant capacity.
• Bioavailable fractions exhibited lower inhibitory effects on α-amylase, α-glucosidase, and AGE formation compared to undigested extracts.

Conclusions:

• Aqueous extracts from Turkish Cistus species possess valuable antioxidant and antidiabetic properties.
• Human digestion significantly diminishes the concentration of bioactive phenolics and overall bioactivity of Cistus extracts.
• The bioavailability of phenolic compounds is a critical factor influencing the therapeutic potential of Cistus in metabolic disease management.