α - Glucosidase inhibitory and antioxidant activities of entada spiralis ridl. (Sintok) stem bark extracts

Entada spiralis Ridl. (Leguminosae), locally known as “Sintok” or “Beluru” is a tropical woody climber that grows widely in Malaysia. It is a valuable and well known plant in herbal medicine due to its various traditional and medicinal applications. Crude extracts were obtained from the stem bark by using petroleum ether, chloroform and methanol as extracting solvents and were then biossayed for their biological potential. The antioxidant and alpha-glucosidase inhibitory activities of the extracts were assessed by using DPPH, ABTS, β-carotene and α-glucosidase inhibitory methods respectively. Qualitative analysis showed the presence of most of the phytochemicals in methanol extract; however, chloroform and petroleum ether extracts contained terpenoid and tannins as their major phytoconstituents respectively. Methanol extract contained the highest amount of total phenolics (42.5 ± 15.85 µg/ml) and flavonoids (28.94 ± 2.93 µg/ml), and showed the most potent α-glucosidase inhibitory activity with IC50 value of 20.67 µg/ml. The same methanol extract exhibited highest β-carotene bleaching inhibition (27% at 1 mg/ml), while methanol and chloroform extracts exhibited good radical scavenging activities dose dependently (IC50 37.29 ± 0.05, 90.84 ± 3.12 µg/ml respectively) against ABTS and DPPH radicals. Bioassay-guided silica gel column chromatography purification of the most active methanol extract afforded 3,4′,5,7- tetrahydroxy flavone (6 mg). The compound displayed promising inhibitory activity against free radicals as well as α-glucosidase enzyme. These results further suggest the traditional medicinal uses of E. spiralis Ridl. stem bark as a therapeutic agent against hyperglycemia

Correlation of FT-IR fingerprint and α-glucosidase inhibitory activity of Salak (Salacca zalacca) fruit extracts utilizing orthogonal partial least square

Salak fruit (Salacca zalacca), commonly known as snake fruit, is used indigenously as food and for medicinal applications in Southeast Asia. This study was conducted to evaluate the α-glucosidase inhibitory activity of salak fruit extracts in correlation to its Fourier transform infrared spectroscopy (FT-IR) fingerprint, utilizing orthogonal partial least square. This calibration model was applied to develop a rapid analytical method tool for quality control of this fruit. A total of 36 extracts prepared with different solvent ratios of ethanol–water (100, 80, 60, 40.20, 0% v/v) and their α-glucosidase inhibitory activities determined. The FT-IR spectra of ethanol–water extracts measured in the region of 400 and 4000 cm−1 at a resolution of 4 cm−1. Multivariate analysis with a combination of orthogonal partial least-squares (OPLS) algorithm was used to correlate the bioactivity of the samples with the FT-IR spectral data. The OPLS biplot model identified several functional groups (C–H, C=O, C–N, N–H, C–O, and C=C) which actively induced α-glucosidase inhibitory activity

Assessment of free radical scavenging and digestive enzyme inhibitory activities of extract, fractions and isolated compounds from Tetracera macrophylla leaves

Tetracera macrophylla is a valuable medicinal plant used traditionally for the treatment of various ailments. The crude ethanol extract was analyzed for its total phenolic and flavonoid contents. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-3-ethylbenzothiazine-6-sulfonic acid (ABTS) were used to examine the free radical scavenging capacity while enzyme inhibitory activity was assessed using α-amylase and α-glucosidase inhibitory methods. The crude extract was found to be rich in both phenolic and flavonoid contents (417.90 and5.86 μg GAE and QUE/mg dry weight, respectively) thus exhibited good radical scavenging activity on DPPH and ABTS radicals (IC50 values of 16.2 and 14.65 μg/mL, respectively). It also showed a promising concentration dependent enzymes inhibitory activity against α-amylase and α-glucosidase with IC50 of 72.17 and 76.16 μg/mL, respectively. Fractionation of active ethanol extract of T. macrophylla leaves through liquid-liquid partitioning yielded fractions Fa, Fb, Fc, and Fd. Among all the fractions, Fb (ethyl acetate fraction) showed the highest phenolic and flavonoid contents (206.34 μg/ GAE and 4.01 μg/ QUE respectively) and was also found to exhibit highest antioxidant and α-glucosidase inhibitory activities. The most active fraction, Fb upon purification yielded five compounds which were characterized and identified through different spectroscopic techniques. FTQ-4 among the compounds exhibited the strongest free radical and enzyme inhibitory activities followed by FTQ-3. All the compounds were isolated from this plant for the first time and found active against free radicals and/or digestive enzymes.These results further suggest the medicinal potential of T. macrophylla leaves as a therapeutic agent against hyperglycemia and free radical associated problems

Enzyme inhibitory and antioxidant investigations of Tetracera macrophylla Vall. and Entada spiralis Ridl. and isolation of active principles

Diabetes is a serious global health problem that affects over 422 million citizens (WHO, 2014). It is characterized by hyperglycemia, (abnormal increase in plasma glucose level) resulting from hydrolysis of starch by pancreatic α- amylase and glucose uptake by intestinal α- glycosidase. Inhibitors of these two enzymes have been suggested to be better candidates in preventing diabetes and its complications. Pancreatic α- amylase is an enzyme that helps in the hydrolysis of starch into maltose prior to absorption.α- glucosidase enzyme catalyses the breakage of disaccharide to glucose, inhibiting these enzymes retards the dietary carbohydrate uptake and supress the postprandial hyperglycemia. Therefore, the most effective strategy of controlling diabetes is to inhibit the actions of these enzymes (Apostollidis & Lee, 2010; Striegel et al., 2015. Additionally Free radicals are considered as a major causative factor of cell damage that degenerate into chronic diseases such type 2 DM, liver problem, stroke and cancers. From ancient times antioxidants from herbal extracts and drinks were utilized and many have been proved to improve antioxidant capacity and therefore prevent cell and tissue damage. Tetracera macrophylla Vall (family: Dilliniacea) is an evergreen climber that widely spreads across Sumatra, Peninsula Malaysia, Bangka and Borneo and some parts of Africa. . It plays an important role in traditional herbal medicine for curing many ailments. Similarly, Entada spiralis Ridl (Family : leguminosae) locally known as Beluru or Sintok is a woody climber that can grow up to 25 m tall, possessing a wide range of ethno medicinal uses. Many species of Entada and Tetracera have been scientifically investigated on several ailments, these plants lacks scientific record to proof their vast medicinal uses, this research therefore aim to investigate the inhibitory capacity of these plants on digestive enzymes and free radicals as many species of the genus have been validated for these activities

In vitro α- glucosidase inhibitory and antioxidant activities of extract, fractions and isolated compounds from Tetracera macrophylla vall leaf

Tetracera macrophylla vall. (Dilleniaceae), has been a neglected species from Tetracera genus despite its usefulness in the traditional herbal medicines. T. macrophylla leaves crude ethanol (95%) extract (ETM) and its different fractions obtained through liquid-liquid partitioning strategy were screened for their total phenolics and flavonoids contents and then investigated using in vitro models for their inhibitory activity on α-glucosidase. Free radical scavenging techniques including 2, 2diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-3-ethylbenzothiazine-6-sulfonic acid (ABTS) were used to examine the antioxidant capacity. ETM was found to be rich in both phenolic and flavonoid contents (417.90 ± 20.16, 5.86 ± 0.51 µg gallic acid (GA) and quercetin (QU) equivalent/mg dry weight) and exhibited good radical scavenging activity on DPPH and ABTS radicals ( 78.00% and 79.0%, respectively). Ethyl acetate fraction exhibited highest phenolic and flavonoid contents (206.34 ± 4.86, 14.01± 1.20 µg GA and QU equivalent/mg dry weight, respectively), and it was also observed to exhibit highest scavenging capacity on DPPH and ABTS radicals viz., 96.73%, 76.51% respectively. Both ETM and ethyl acetate fraction showed a promising and concentration-dependent α-glucosidase inhibitory activity. Bioassay guided silica gel column chromatography purification of ethyl-acetate fraction afforded a triterpenoid (12 mg), and a flavonoid (10 mg) characterized as betullinic acid and 5,7-dihydroxy-8-methoxy flavone based on spectroscopic analysis (IR, NMR). These compounds displayed promising radical scavenging activity against DPPH and ABTS radicals with moderate inhibitory activity on α-glucosidase enzymes

Phytochemical profile and free radical scavenging activity of Entada spiralis stem bark

Entada spiralis Ridl. (family leguminosae) is a woody climber known to possess a wide range of ethnomedicinal properties. This study reports the phytochemical components of different extracts and its free radical scavenging activity. Both polar and non polar extracts were screened for their phytoconstituents. Free radical scavenging activity was measured using 2,2 diphenyl-picrlhydrazyl (DPPH). Phytoconstituents of these extracts were observed in decreasing order from MeOH > CHCl3 > Et2O. All the extracts showed radical scavenging activity in a concentration dependent manner. Percentage inhibitory activity of MeOH was observed to be higher (77.83 ± 0.64 ) than CHCl3 and Et2O extracts (48.76 ± 1.24, 20.27 ± 4.05 respectivel

Evaluation of the enzyme inhibitory and antioxidant activities of Entada spiralis stem bark and isolation of the active constituents

Digestive enzymes and free radical inhibitors are used to prevent complications resulting from diabetes. Entada spiralis (family Leguminosae), which is a well-known medicinal plant in herbal medicine due to its various traditional and medicinal applications, was studied. Crude extracts were successively obtained from the stem bark using petroleum ether, chloroform and methanol as extracting solvents. The antioxidant activity of all the extracts, fractions and isolated compounds were estimated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene and 2,2′-azinobis(-3-ethylbenzothiazine-6-sulfonic acid) (ABTS) assays, while digestive enzymes inhibitory activity was assessed using α-amylase and α-glucosidase inhibitory methods. Structure elucidation of pure compounds was achieved through different spectroscopic analysis methods. Fractionation and purification of the most active methanol extract resulted in the isolation of a ferulic ester namely; (e)-hexyl 3-(4-hydroxy-3-methoxyphenyl) acrylate (FEQ-2) together with five known phenolic constituents, identified as kaempferol (FEQ-3), 5,4′-dihydroxy-3,7,3′-trimethoxyflavone (FEQ-2), gallic acid (FEQ-5), (+)-catechin (FEQ-7) and (−)-epicatechin (FEQ-8). FEQ-5 exhibited the strongest antioxidant and enzyme inhibitory activities followed by FEQ-3 and FEQ-4. FEQ-2 also displayed potent free radical scavenging activity with IC50 values of 13.79 ± 2.13 (DPPH) and 4.69 ± 1.25 (ABTS) µg/mL, respectively. All other compounds were found active either against free radicals or digestive enzymes

<i>Hystrix Brachyura</i> Bezoar Characterization, Antioxidant Activity Screening, and Anticancer Activity on Melanoma Cells (A375): A Preliminary Study

Porcupine bezoars (PBs) are masses of undigested calcareous concretions formed within the gastrointestinal tract. There are undocumented claims that PBs have antioxidant activity and can treat cancers. However, limited scientific study has been carried out to verify these traditional claims. Hence, this study was conducted to characterize the chemical profile and validate the antioxidant and anticancer activity against melanoma cells (A375). PB extract was initially subjected to Fourier-transform infrared spectroscopy (FTIR), gas chromatography&#8315;mass spectrometry (GCMS), total phenolic content (TPC), and total flavonoid content (TFC) analyses. The bioautography of antioxidant assays, namely 2,2&#8242;-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazy (DPPH), and &#946;-carotene was performed. An in vitro A375 cell viability assay, apoptosis assay, cell cycle arrest assay, and gene expression assay were carried out as well. The experimental finding revealed 5,10-diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo[1,2-a:1&#8242;,2&#8242;-d]pyrazine, ursodeoxycholic acid, and cholest-5-en-3-ol (3 beta)-, carbonochloridate are major compounds detected in PB extract. PB extract has low phenolic content, viz. 698.7 &#177; 0.93 (&#181;g GAE/5 mg dry weight). The bioautography antioxidant assays revealed a potent antioxidant effect (ABTS &gt; DPPH &gt; &#946;-carotene), with free radical scavenging activity. Furthermore, PB extract exhibited dose- and time-dependent inhibition of cancer activity on A375 cells due to the exhibition of apoptosis via an intrinsic pathway