scholarly journals Alpha-Glucosidase and Alpha-Amylase Inhibitory Activities of Novel Abietane Diterpenes from Salvia africana-lutea

Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 421 ◽  
Author(s):  
Etsassala ◽  
Badmus ◽  
Waryo ◽  
Marnewick ◽  
Cupido ◽  
...  

The re-investigation of a methanolic extract of Salvia africana-lutea collected from the Cape Floristic Region, South Africa (SA), afforded four new abietane diterpenes, namely 19-acetoxy-12-methoxycarnosic acid (1), 3β-acetoxy-7α-methoxyrosmanol (2), 19-acetoxy-7α-methoxyrosmanol (3), 19-acetoxy-12-methoxy carnosol (4), and two known named clinopodiolides A (5), and B (6), in addition to four known triterpenes, oleanolic, and ursolic acids (7, 8), 11,12-dehydroursolic acid lactone (9) and β-amyrin (10). The chemical structural elucidation of the isolated compounds was determined on the basis of one and two dimensional nuclear magnetic resonance (1D and 2D NMR), high-resolution mass spectrometry (HRMS), ultra violet (UV), fourier transform infrared (IR), in comparison with literature data. The in vitro bio-evaluation against alpha-glucosidase showed strong inhibitory activities of 8, 10, and 7, with the half inhibitory concentration (IC50) values of 11.3 ± 1.0, 17.1 ± 1.0 and 22.9 ± 2.0 µg/mL, respectively, while 7 demonstrated the strongest in vitro alpha-amylase inhibitory activity among the tested compounds with IC50 of 12.5 ± 0.7 µg/mL. Additionally, some of the compounds showed significant antioxidant capacities. In conclusion, the methanolic extract of S. africana-lutea is a rich source of terpenoids, especially abietane diterpenes, with strong antioxidant and anti-diabetic activities that can be helpful to modulate the redox status of the body and could therefore be an excellent candidate for the prevention of the development of diabetes, a disease where oxidase stress plays an important role.

Author(s):  
NANTAPORN DINLAKANONT ◽  
CHANIDA PALANUVEJ ◽  
NIJSIRI RUANGRUNGSI

Objective: Starch metabolizing enzyme inhibitors are able to retard postprandial glucose absorption. This study aimed to investigate the in vitro inhibitory activities of alpha-glucosidase and alpha-amylase of three Malvaceous weeds i.e. Sidaacuta Burm. f., Abutilon indicum (Linn.) Sweet and Malvastrumcoromandelianum (Linn.) Garcke. Methods: The stems, roots and leaves of S. acuta, A. indicum and M. coromandelianum were sequentially extracted in dichloromethane and methanol, respectively. All fractions were tested for the inhibitory activities on yeast alpha-glucosidase, rat intestinal alpha-glucosidase and porcine alpha-amylase. p-Nitrophenyl-α-D-glucopyranoside and 2-chloro-4 nitrophenol-α-D- maltotrioside were used as the substrate for glucosidase and amylase respectively. Results: The dichloromethane fraction of the roots and stems from A. indicum and dichloromethane as well as methanolic fractions of the stems of M. coromandelianum could inhibit yeast alpha-glucosidase compared to 1-deoxynojirimycin with the IC50 of 0.36, 0.45, 0.48, 0.48 and 0.58 mg/ml respectively. A. indicum root methanolic fraction had the highest inhibitory effect on rat alpha-glucosidase activity compared to 1-deoxynojirimycin with the IC50 of 0.08 and 0.11 mg/ml respectively. M. coromandelianum, the dichloromethane fraction of roots and the methanolic fraction of stems, showed the strongest effect on alpha-amylase inhibition compared to acarbose with the IC50 of 0.07, 0.07 and 2.7 mg/ml, respectively. Conclusion: S. acuta, A. indicum and M. coromandelianum dichloromethane and methanolic fractions of the root, stem and leaf parts demonstrated an appreciable inhibitory activity on alpha-amylase from porcine, alpha-glucosidase from Saccharomyces cerevisiae and from rat intestine compared to 1-deoxynojirimycin and acarbose.


2021 ◽  
pp. 1-3
Author(s):  
Srinivasan S ◽  
Rayar A

Biologically active polyphenol, D-catechin was isolated from Decalepis hamiltonii and characterized by IR, 1 H- NMR 13C- NMR and evaluation of its in-vitro α-amylase and α-glucosidase inhibition activities. Bioactive compounds are deposited in many parts of the plants, such as in roots, stems, leaves, flowers, fruits and seeds. They protect the plants from diseases and contribute aroma, color and flavor. Inhibitors 𝛼 - amylase and 𝛼-glucosidase delay the breaking down of carbohydrates in the small intestine and lower the postprandial blood glucose excursion. Methanolic extract showed the greater % inhibition of the alpha glucosidase enzyme compared to D-catechin. The herbal extracts produced a slightly weak alpha glucosidase enzyme inhibition when compared with alpha amylase.


2020 ◽  
Vol 19 (6) ◽  
pp. 1209-1214
Author(s):  
Temitayo Esther Adeyeoluwa ◽  
Fatai Oladunni Balogun ◽  
Anofi Omotayo Tom Ashafa

Purpose: To assess the individual and synergistic inhibitory activities of five (5) tropical spices, viz, Zingiber officinale Rosc., Xylopia aethiopica (Dun.) A. Rich, Piper guineense Schum & Thonn, Myristica fragrans Houtt. and Allium sativum L. against glucose hydrolysing enzymes.Methods: In vitro assessment of the alpha-amylase and alpha-glucosidase inhibitory activities of cold water, hot water, ethanol and aqueous-ethanol extracts of each of the five spices and their combination was investigated using enzymatic protocols. Acarbose was used as the standard.Results: Only four extracts showed strong inhibition against alpha-glucosidase and weak inhibition against alpha-amylase. Going by their half-maximal inhibitory concentrations (IC50), the combined spices exhibited the best concurrent inhibitory activity against both hydrolysing enzymes (665.83 ± 27.50 μg/mL for alpha-glucosidase) and (1166.86 ± 14.70 μg/mL for alpha-amylase).Conclusion: The findings from this study demonstrate the enhanced antihyperglycemic potentials of the combined spices compared to the individual spices for the management of diabetes. Keywords: Hyperglycemia, Diabetes, Alpha-amylase, Alpha-glucosidase, Zingiber officinale, Xylopia aethiopica, Piper guineense, Myristica fragrans, Allium sativum, Spices


Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1149
Author(s):  
Ninon G. E. R. Etsassala ◽  
Jelili A. Badmus ◽  
Jeanine L. Marnewick ◽  
Emmanuel I. Iwuoha ◽  
Felix Nchu ◽  
...  

Diabetes mellitus (DM) is one of the most dangerous metabolic diseases with a high rate of mortality worldwide. It is well known that insulin resistance and deficiency in insulin production from pancreatic β-cells are the main characteristics of DM. Due to the detrimental side effects of the current treatment, there is a considerable need to develop new effective antidiabetic drugs, especially alpha-glucosidase and alpha-amylase inhibitors with lesser adverse effects. These inhibitors are known to be directly involved in the delay of carbohydrate digestion, resulting in a reduction of glucose absorption rate and, consequently, reducing the postprandial rise of plasma glucose, which can reduce the risk of long-term diabetes complications. Furthermore, natural products are well-known sources for the discovery of new bioactive compounds that can serve as scaffolds for drug discovery, including that of new antidiabetic drugs. The phytochemical investigation of Salvia aurita collected from Hogobach Pass, Eastern Cape Province, South Africa (SA), yielded four known abietane diterpenes namely carnosol (1), rosmanol (2), 7-methoxyrosmanol (3), 12-methoxycarnosic acid (4), and one flavonoid named 4,7-dimethylapigenin (5). Structural characterization of these isolated compounds was conducted using 1 and 2D NMR, in comparison with reported spectroscopic data. These compounds are reported for the first time from S. aurita. The biological evaluation of the isolated compound against alpha-glucosidase exhibited strong inhibitory activities for 3 and 2 with the half maximal inhibitory concentration (IC50) values of 4.2 ± 0.7 and 16.4 ± 1.1 µg/mL respectively, while 4 and 1 demonstrated strong alpha-amylase inhibitory activity amongst the isolated compounds with IC50 values of 16.2 ± 0.3 and 19.8 ± 1.4 µg/mL. Molecular docking analysis confirms the strong inhibitory activity of 3 against alpha-glucosidase. Additionally, excellent antioxidant capacities were displayed by 2, 1, and 3, respectively, with oxygen radical absorbance capacity (ORAC) (25.79 ± 0.01; 23.96 ± 0.01; 23.94 ± 0.02) mM Trolox equivalent (TE)/g; 1 and 2 as ferric-ion reducing antioxidant power (FRAP) (3.92 ± 0.002; 1.52 ± 0.002) mM ascorbic acid equivalent (AAE)/g; 5 and 2 as Trolox equivalent absorbance capacity (TEAC) (3.19 ± 0.003; 2.06 ± 0.003) mM TE/g. The methanolic extract of S. aurita is a rich source of abietane diterpenes with excellent antioxidant and antidiabetic activities that can be useful to modulate oxidative stress and might possibly be excellent candidates for the management of diabetes. This is the first scientific report on the phytochemical isolation and biological evaluation of the alpha-glucosidase and alpha-amylase inhibitory activities of Salvia aurita.


Author(s):  
Ninon G.E.R Etsassala ◽  
Jelili A. Badmus ◽  
Jeanine L. Marnewick ◽  
Felix Nchu ◽  
Ahmed A. Hussein

Diabetes mellitus (DM) is one of the most dangerous metabolic diseases with high rate of mortality worldwide. It is well known that insulin resistance and deficiency in insulin production from pancreatic β-cells are the main characteristic of DM. Due to the detrimental side effects of the current treatment, there is a considerable need to develop new effective antidiabetic drugs, especially alpha-glucosidase and alpha-amylase inhibitors with lesser adverse effects. These inhibitors are known to be directly involved in the delay of carbohydrate digestion, resulting in a reduction of glucose absorption rate and consequently reduce the post-prandial raise of plasma glucose, which can reduce the risk of long-term diabetes complications. Hence, natural products are well-known sources for the discovery of new scaffold for drugs discovery, including new antidiabetic drugs. The phytochemical investigation of Salvia aurita collected from Hogobach pass, Eastern Cape, South Africa (SA), yielded four known abietane diterpenes namely carnosol (1), rosmanol (2), 7-methoxyrosmanol (3), 12-methoxycarnosic acid (4) and one flavonoid named 4,7-dimethylapigenin (5). Structural characterization of these isolated compounds was conducted using 1 and 2D NMR, in comparison with reported spectroscopic data. These compounds are reported for the first time from S. aurita. The biological evaluation of the isolated compound against alpha-glucosidase exhibited strong inhibitory activities for 3 and 2 with IC50 values of 4.2 ± 0.7 and 16.4 ± 1.1 µg/mL respectively, while 4 and 1 demonstrated strong alpha-amylase inhibitory activity amongst the isolated compounds with IC50 of 16.2 ± 0.3 and 19.8 ± 1.4 µg/mL. Molecular docking analysis confirms strong inhibitory activity of 3 against alpha-glucosidase. Additionally, excellent antioxidant capacities were displayed by 2, 1 and 3 respectively as ORAC (25789.9 ± 10.5; 23961.8 ± 14.1; 23939.3 ± 2.4) µM TE/g; 1 and 2 as FRAP (3917.8 ± 2.1; 1522.3 ± 0.9) µM AAE/g; 5 and 2 as TEAC (3190.4 ± 2.8; 2055.0 ± 2.6) µM TE/g. The methanolic extract of S. aurita is a rich source of abietane diterpenes with excellent antioxidant and anti-diabetic activities that can be useful to modulate oxidative stress, and might possibly be excellent candidates for the management of diabetes. This is the first scientific report on the phytochemical isolation and biological evaluation of alpha-glucosidase and alpha-amylase inhibitory activities of Salvia aurita.


Metabolites ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Petr G. Lokhov ◽  
Dmitry L. Maslov ◽  
Steven Lichtenberg ◽  
Oxana P. Trifonova ◽  
Elena E. Balashova

A laboratory-developed test (LDT) is a type of in vitro diagnostic test that is developed and used within a single laboratory. The holistic metabolomic LDT integrating the currently available data on human metabolic pathways, changes in the concentrations of low-molecular-weight compounds in the human blood during diseases and other conditions, and their prevalent location in the body was developed. That is, the LDT uses all of the accumulated metabolic data relevant for disease diagnosis and high-resolution mass spectrometry with data processing by in-house software. In this study, the LDT was applied to diagnose early-stage Parkinson’s disease (PD), which currently lacks available laboratory tests. The use of the LDT for blood plasma samples confirmed its ability for such diagnostics with 73% accuracy. The diagnosis was based on relevant data, such as the detection of overrepresented metabolite sets associated with PD and other neurodegenerative diseases. Additionally, the ability of the LDT to detect normal composition of low-molecular-weight compounds in blood was demonstrated, thus providing a definition of healthy at the molecular level. This LDT approach as a screening tool can be used for the further widespread testing for other diseases, since ‘omics’ tests, to which the metabolomic LDT belongs, cover a variety of them.


Author(s):  
Jirawat Riyaphan ◽  
Chien-Hung Jhong ◽  
May-Jwan Tsai ◽  
Der-Nan Lee ◽  
Max K. Leong ◽  
...  

The inhibition of alpha-glucosidase and alpha-amylase is one of clinic strategies for remedy the type II diabetes. Herbal medicines are reported to alleviate hyperglycemia. However, the constituents from those sources whether are targeted to the alpha-glucosidase and alpha-amylase still unexplored. This study attempted to select the compounds for efficacy of hypoglycemia via cellular and mouse levels. The results illustrated that the cytotoxicity in all tested compounds at various concentrations except the concentration of 16-hydroxy-cleroda-3,13-dine-16,15-olide (HCD) at 30 µM were not significant difference (p > 0.05) when compared with the untreated control. Acarbose (reference drug), Antroquinonol, Catechin, Quercetin, Actinodaphnine, Curcumin, HCD, Docosanol, Tetracosanol, Berberine, and Rutin could effectively inhibit the alpha-glucosidase activity of Caco-2 cells when compared with the control (maltose). The compounds (Curcumin, HCD, Tetracosanol, Antroquinonol, Berberine, Catechin, Actinodaphnine, and Rutin) could reduce blood sugar level at 30 min in tested mice. The effects of tested compounds on area under curve (AUC) were significant (p < 0.05) among Acarbose, Tetracosanol, Antroquinonol, Catechin, Actinodaphnine, and Rutin along with Berberine and Quercetin. In in vitro (alpha-glucosidase) with in vivo (alpha-amylase) experiments suggest that bioactive compounds can be a potential inhibitor candidate of alpha-glucosidase and alpha-amylase for the alleviation of type II diabetes.


Author(s):  
Subhrajyoti Roy ◽  
Somit Dutta ◽  
Tapas Kumar Chaudhuri

AbstractTheTheResults indicated that 70% methanolic extract of


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