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The genus Salvia is regarded as an important medicinal plant and also as spice worldwide. Current report might be counted as one of the first investigations to reveal the enzyme inhibitory and antiglycation activities, together with phenolic and antioxidant profiles of 80% methanolic extract prepared from the aerial parts of S.virgata (SVM). Furthermore, the bioavailability parameters of major phenolic compounds in SVM were evaluated. An in vitro human digestion simulation model composed of both gastric and intestinal phases was used for this purpose. Total phenolic, phenolic acid and flavonoid components of each of these phases were calculated in order to assess the phenolic profile of the samples. In addition, quantitative analysis of major bioactive compounds (rutin and rosmarinic acid), before and after the simulation, was practiced by employing High Performance Thin Layer Chromatography (HPTLC) system. Moreover, the potential of non-digested (ND) and bioavailable (IN) phases on the inhibition of diabetes-related enzymes (α-amylase and α-glucosidase) was determined. Also, the inhibitory effect of the samples on the advanced glycation end products (AGEs), formed due to hyperglycemia, was detected. In addition, cholinesterase enzyme inhibition activity of both ND and IN samples was determined. Since, the role of oxidative stress on diabetes and neurodegenerative diseases is well-known, the antioxidant potential of the samples was also estimated by different methods: DPPH and DMPD tests for free radical scavenging activity, FRAP and CUPRAC tests for metal reducing activity and total antioxidant capacity test, as well. The results showed that total phenolic contents, antioxidant potential and diabetes-related and cholinesterase enzymes inhibition of the bioavailable phase were lower than non-digested sample. Besides, in vitro human digestion simulation system had a declining influence on the concentrations of the major bioactive metabolites (rutin and rosmarinic acid).

The genus Hypericum has been utilized in traditional medicine in several parts of the world since ancient times. The utmost activities have been associated with the natural pharmaceuticals prepared from Hypericum species due to their unique chemical profile. In the present study, Hypericum olympicum L. extracts before and after being processing in an in vitro simulated digestion system were submitted to in vitro anti-diabetic assays, i.e., α-glucosidase and α-amylase inhibition assays and antiglycation assay. The formation of advanced glycation end products (AGEs) is one of the most precursor molecules for the complications of diabetes mellitus. In oxidative stress conditions, reactive oxygen species (ROS) and AGEs production increase significantly inside the cells. Furthermore, mechanistically different antioxidant assays, including free radical scavenging and metal-reducing activities, and the total antioxidant capacity assay were conducted. Major flavonoid glycosides (rutin, hyperoside and isoquercitrin) and the main phenolic acid (chlorogenic acid) in the extracts and their bioaccessibilities were also determined by high performance thin layer chromatography (HPTLC). The results indicated that amounts of all phenolic compounds analyzed in this study increased throughout in vitro simulated gastric system in comparison with non-digested fraction. Moreover, the results demonstrated that anti-diabetic activity and antioxidant capacity of the extract increased remarkably following the simulation process.

Sideritis trojana Bornm. is an endemic plant in Turkey, which is widely consumed as refreshing herbal tea, and used in traditional medicine. This study was designed to elucidate the effect of extraction methods including infusion, decoction, ultrasonic assisted and chemical extraction on phenolic profile, enzyme inhibition and antioxidant capacity. Alpha amylase and alpha glucosidase enzymes were tooled for assessing the antidiabetic activity, while HPLC-DAD method was used for the analysis of phenolic compounds. Besides, different methods were applied to the samples to understand their antioxidant activity. Results indicated that there is no considerable difference between infusion and decoction forms of S. trojana in terms parameters mentioned above. The chemical extraction method provided the highest phenolic content and antioxidant activity. In conclusion, S. trojana can be assumed as a good source of phenolic compounds with considerable antioxidant activity and enzyme inhibition capacity. © 2018 South African Association of Botanists

The hexane, chloroform, ethyl acetate, water, and n-butanol extracts of Arcethobium oxycedri (DC.) M. Bieb. (Santalaceae) were evaluated for their inhibitory effects against acetyl-(AChE) and butyrylcholinesterase (BChE), related to Alzheimer's disease at 200 mu g/mL using microplate assays. Since oxidative stress contributes much to neurodegeneration, antioxidative effect of the extracts was determined in metal-chelating and ferric-reducing antioxidant power (FRAP) test systems as well as antiradical effect against 2,2-diphenyl-1picrylhydrazyl (DPPH). Total phenol and flavonoid contents of the extracts were calculated spectrophotometrically. Our findings indicated that the EtOAc extract, the richest one in total phenol and flavonoid amount (455.22 +/- 4.35 and 194.45 mg/g extract, respectively) displayed the highest cholinesterase inhibition (45.37 +/- 1.23% for AChE and 94.74 +/- 2.43% for BChE at 200 mu g/mL). Fractionation of the EtOAc led to isolation of (+)-catechin as the major compound. Catechin exerted remarkable antioxidant effect, whereas it did not cause cholinesterase inhibition. Therefore, the EtOAc extract deserves further investigation for its high BChE inhibition. (c) 2018 SAAB. Published by Elsevier B.V. All rights reserved.