In this study, qualitative and quantitative analysis of commercially available food supplements composed of olive leaf extract and herbal tea products containing olive leaf were evaluated by ...High-Performance Thin-Layer Chromatography (HPTLC) and a newly developed and validated High-Performance Liquid Chromatographic (HPLC) method for their quality assessment. In addition, leaves of two varieties of Olea europaea L. (var. europaea and var. sylvestris) grown in Turkey which were assigned as reference plant materials and their chemical compositions were also comparatively analyzed by HPTLC. Then HPTLC fingerprints of reference plant materials were compared to the marketed olive leaf samples. For quantification of oleuropein and luteolin 7-O-glucoside (L7G) contents in the samples, a simple and fast HPLC method was developed and validated. Consequently, in water and hydroalcoholic extracts of O. europaea var. europaea leaves, oleuropein contents were found to be 15.89% (w/w) and 15.84% (w/w), while L7G contents were 0.75% and 1.23%, respectively. For the reference materials, oleuropein in O. europaea L. var. sylvestris leaves was found to be 12.77% (w/w, in water extract) and 12.36%(w/w, in hydroalcoholic extract), while the concentration of L7G was 0.51% (w/w) and 0.83% (w/w) in water and hydroalcoholic extracts, respectively. Qualitative analysis of the commercial products revealed that fraud was detected in three of eight olive leaf herbal tea bag brands and two of ten olive leaf food supplements. These samples were found either devoid of oleuropein or they had different HPTLC fingerprint profiles than the reference samples.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Bioavailability is an important concept when evaluating natural products for their bioactivities. The present study measured the bioavailability of phenolics of Sambucus ebulus (dwarfelder) fruit ...extracts, along with its antioxidant activity after simulated digestion. Total phenolics, phenolic acid, proanthocyanidin and flavonoid content assays were used along with different antioxidant assays such as metal reducing and free radical scavenging activities. High performance thin layer chromatography was used to measure bioactive metabolite of the plant sample, chlorogenic acid. Results indicated that aqueous and methanolic extracts of S. ebulus fruits were affected by simulated human digestion, alterations in antioxidant activity were consistent with the changes in the phenolics. Chlorogenic acid bioavailability rates were calculated as 45.8 and 51.9% for methanolic and aqueous extracts, respectively. Total antioxidant capacity was reduced to 37 ± 0.5 from 82 ± 4 (AAE)/g DE for methanolic extracts after the digestion process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Enzyme inhibitory activities of Nerium oleander L. flower extracts were determined.•N-Hexane extract had better cholinesterase/α-amylase inhibitory activities.•R-H2O/EtOAc extracts had better ...α-glucosidase/tyrosinase inhibitory activities.•β-Sitosterol and oleanolic acid were isolated as active components.•The highest antioxidant capacity values were obtained from EtOAc, EtOH extracts.
Oleander (Nerium oleander L., fam: Apocynaceae) is an evergreen shrub. Although it is known to be poisonous to humans, a large number of utilizations in folk medicine have been reported against diabetes, rheumatic pain and skin diseases. The present study aimed to investigate the cholinesterase inhibitory activities of oleander flower extracts and to isolate the active components responsible for the activity. The antidiabetic and skin care effects were also determined on some key enzymes (α-glucosidase, α-amylase, tyrosinase). The flower extracts obtained with aqueous, polar and apolar organic solvents were evaluated for their phenolic contents and antioxidant capacities. The enzyme inhibitory activities (cholinesterase, α-glucosidase, α-amylase and tyrosinase) were examined by microtiter plate assays. Antioxidant properties were evaluated by DPPH, FRAP and CUPRAC assays. Total phenolic and flavonoid contents were determined using the Folin-Ciocalteu reagent and aluminum chloride, respectively. The structures of the isolates were elucidated by NMR and MS experiments.In the present study, cholinesterase inhibitory activity of the EtOH extract of the olaender flowers was investigated and β-sitosterol and oleanolic acid were isolated as the active components. The less polar extracts (n-hexane) exerted better cholinesterase and α-amylase inhibitory activities than those of the more polar extracts (R-H2O, EtOAc) which had better α-glucosidase and tyrosinase activities. The highest antioxidant capacity values were obtained from EtOAc and EtOH extracts. The EtOH extract was found to contain the highest levels of total phenolic and flavonoid contents. The results suggest that the flowers of oleander could be a potential source for high value phytochemicals for developing novel drug leads.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Since biotransformation processes generally affect the biological activities of phytochemical compounds, bioavailability is one of the primary steps in determining the potency of the activity. ...Previous studies have shown that in vitro antioxidant capacity of phytochemicals cannot completely reflect real health benefits. Clematis species (Ranunculaceae) are used to eliminate the symptoms of many diseases including particularly in the treatment of rheumatic diseases in Turkey, however the number of studies conducted is limited. In the light of this information, the total phytochemical profile of the extract of aerial parts of C. viticella prepared with 80% methanol and the gastrointestinal digestion products and the antioxidant activity profile were evaluated by subjecting them to the in vitro simulation model of the human digestive tract in the study. It was observed that both total phytochemical content and antioxidant activity decreased after simulated human digestion. Moreover, this study was shown potential bioaccessibility and bioavailability of total phenol, phenolic acid, flavonoid, and saponin content found in the aerial parts of Clematis viticella were reduced. Consequently, these indicate that it can result from the complicated interaction of compounds in the plant matrix in an in vitro simulated human digestion.
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•All Scutellaria species mainly S. hastifolia displayed marked total antioxidant capacity.•S. hastifolia MeOH extract significantly inhibited LOX enzyme at 5mg/mL.•A new cornoside derivative ...phenylethanoid glycoside was isolated from S. hastifolia.
This study was designed to evaluate the phenolic profiles and antioxidant potentials of different solvent extracts of four Scutellaria L. (Lamiaceae) taxa, S. hastifolia, S. velenovskyi, S. albida ssp. albida and S. orientalis ssp. pinnatifida, which are used in traditional medicines for various purposes. Among the investigated species, S. hastifolia was selected for further biological and phytochemical studies according to the results of preliminary screening assays. Phytochemical studies on S. hastifolia yielded a new phenylethanoid glycoside (hastifolioside) together with 16 known metabolites. The structures of the compounds were established on the basis of spectroscopic analyses. The antioxidant potentials and the antiinflammatory activities of the crude extracts of S. hastifolia as well as the isolates were evaluated through DPPH radical scavenging capability, linoleic acid lipid peroxidation inhibition and soybean LOX inhibition assays.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The acute and the subacute (15 days) hypoglycaemic and antihyperglycaemic effect of the two different doses (250, 500
mg/kg) of the aqueous extract from the leaves of
Vitis vinifera L. were evaluated ...in this study. The aqueous extract was further fractionated through successive solvent extractions and the acute effect of different doses of its subfractions, 25
mg/kg for ethylacetate fraction, 80
mg/kg for
n-butanol fraction and 375
mg/kg for remaining aqueous fraction were investigated using normal, glucose-hyperglycaemic and streptozotocin-induced diabetic rats. Blood glucose levels were measured according to the glucose oxidase method. Tolbutamide was used as a reference drug at a dose of 100
mg/kg. The antioxidant activity of the test samples was studied in the liver, kidney and heart tissues of diabetic rats by measuring malondialdehyde (MDA) and glutathion (GSH) levels. All results were compared to the diabetic control groups. The results showed that EtOAc Fr. was rich in polyphenolics and possessed a significant antihyperglycaemic and antioxidant activity equipotent with the reference hypoglycaemic agent (tolbutamide), when evaluated in diabetic rats.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In Turkish folk medicine, tea prepared from the crushed seeds of
Aesculus hippocastanum L. was used to pass kidney stone and against stomach ache, while a fraction of seed was swallowed to alleviate ...hemorrhoid symptoms.
Escin mixture prohibited the adverse effects of oxidative stress and showed a protective effect on the liver architecture both in standard pellet diet (SPD) and high-fat diet (HFD) consumed male mice. The present results indicate that
Aesculus hippocastanum increase the antioxidative defense system of the body and prevent HFD-induced lipid peroxidation in male mice.
Seeds of
Aesculus hippocastanum L. have long been used in European phytotherapy to treat inflammatory and vascular problems. In Turkish folk medicine, tea prepared from the crushed seeds was used to pass kidney stone and against stomach ache, while a fraction of seed was swallowed to alleviate hemorroids symptoms.
In order to evaluate the in vivo effects of escin mixture from
Aesculus hippocastanum seed on the blood and tissue antioxidant defense systems in standard pellet diet (SPD) and in high-fat diet (HFD) consumed male mice.
Escin mixture was obtained from the ethanol extract of seeds. Escin mixture was administered orally to male mice fed either standard pellet diet (SPD) or high-fat diet (HFD) at 100
mg/kg doses daily for 5 weeks and the tissue (liver, kidney and heart) and blood samples were collected at the end of experimental period. The effect of escin mixture on the plasma antioxidant activity; blood and tissue malondialdehyde (MDA) and reduced glutathione (GSH) levels; erythrocyte and tissue superoxide dismutase (SOD) and catalase activity (CAT) in SPD and HFD consumed animals were experimentally studied.
Escin mixture prohibited the adverse effects of oxidative stress and showed a protective effect on the liver architecture both in SPD and HFD consumed male mice. Escin mixture prohibited the adverse effects of oxidative stress and showed a protective effect on the liver architecture both in SPD and HFD consumed male mice. Combined administration of high-fat diet with escin mixture decreased blood (
p
<
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p
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0.01), kidney (
p
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0.05), and heart (
p
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0.05) of MDA, liver SOD (
p
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0.01) and CAT (
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0.05) levels and increased blood (
p
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0.01) and liver GSH (
p
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0.001) levels in mice.
The present results indicate that
Aesculus hippocastanum increase the antioxidative defense system of the body and prevent HFD-induced lipid peroxidation in male mice.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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