Antihyperglycemic and hypoglycemic activity of Mayan plant foods in rodent models

Bixa orellana (Bixaceae) seeds as a potential source of bioactive compounds for modulating postprandial hyperglycemia

BACKGROUND

α-Amylase (α-AMY) and α-glucosidase (α-GLU) inhibitors are important for controlling postprandial hyperglycemia (PHG). Bixa orellana (annatto) reported inhibitory activity against these enzymes because of its bioactive compound content. However, an understanding of its inhibitory mechanisms and metabolic profile is necessary to establish its therapeutic potential. The present study aimed to elucidate the inhibitory mechanisms of B. orellana extract (BOE) on α-AMY and α-GLU, identify and quantify its bioactive compounds using metabolomics (untargeted and targeted) analyses, and evaluate their interactions through in silico approaches.

RESULTS

BOE exhibited IC50 values of 37.75 and 47.06 mg mL-1 for α-AMY and α-GLU, respectively, indicating mixed and competitive inhibition types. Thirty-six putative compounds were identified by untargeted metabolomics, mainly fatty acids (dethiobiotin, occidentalol, palmitic acid, norbixin, among others). The most significant biosynthetic pathways included secondary metabolites (unclassified), unsaturated fatty acids, phenylpropanoids and flavonoid metabolism. Eighteen compounds were identified and quantified by the targeted analysis, such as l-phenylalanine, gallic acid, protocatechuic acid and naringenin. In silico studies highlighted xanthoangelol, norbixin, myricetin and 26-hydroxybrassinolide as key compounds with the highest binding affinities to enzyme active sites.

CONCLUSION

BOE effectively inhibited α-AMY and α-GLU, with gallic acid, naringenin, xanthoangelol, norbixin and 26-hydroxybrassinolide identified as key bioactive contributors. These findings provide molecular evidence of the inhibitory mechanisms of BOE and support its potential for PHG management and diabetes control. © 2024 Society of Chemical Industry.

Identification of bioactive compounds in Brassica oleracea var. capitata L. with enzyme-inhibitory activity against postprandial hyperglycemia

Postprandial hyperglycemia is a hallmark of diabetes, and inhibition of key carbohydrate digestion enzymes such as α-amylase (α-AMY) and α-glucosidase (α-GLU) is an effective therapeutic target. A potential unexplored source of inhibitory compounds of these enzymes is Brassica oleracea var. capitata L (BOCE). This study explored the in vitro inhibition mechanism of BOCE and studied in silico the interaction of its compounds identified and quantified by UPLC-QTOF-MS on α-AMY and α-GLU. BOCE demonstrated IC50 values of 3.08 mg/mL for α-AMY and 22.63 mg/mL for α-GLU, indicating competitive and mixed-type inhibitions, respectively. Untargeted metabolomics identified 21 compounds, primarily phenolic acids such as t-cinnamic, sinapic, and caffeoylquinic acid. In the targeted analysis, 11 compounds were quantified, mainly phenolic acids. The most impactful biosynthetic pathways identified were phenylpropanoids and brassinosteroids. In silico analysis revealed that for α-AMY and α-GLU, castasterone and 26-hydroxybrassinolide displayed the lowest binding free energies with specific hydrogen bond patterns to catalytic residues in the binding site, respectively. B. oleracea is a promising source of compounds with the ability to modulate key enzymes related to hyperglycemia. Specifically, compounds such as castasterone and 26-hydroxybrassinolide show potential against α-AMY and α-GLU inhibition, offering a novel approach to diabetes.

Mechanistic in vitro study of the effect of Cucurbita moschata (Cucurbitaceae) on carbohydrate digestive enzymes

Diabetes is marked by postprandial hyperglycemia (PHG), an abnormal rise in blood glucose after meals. A key therapeutic goal to reduce PHG is the inhibition of α-amylase (αAM) and α-glucosidase (αGL), enzymes that break down carbohydrates into sugars. Cucurbita moschata has been shown to inhibit both enzymes. However, its inhibition mechanism has not been explored. This study investigated the in vitro inhibition mechanisms of αAM and αGL and conducted a metabolomic analysis of C. moschata (edible part) water-extract (CME), aiming to preliminarily identify its bioactive compounds (BCs). The inhibitory mechanisms were determined using Lineweaver-Burk plots. The BCs were identified and quantified using HPLC-QTOF-MS, employing both targeted and untargeted metabolomic approaches. CME had a significant higher effect (p < 0.05) on αAM activity than against αGL with IC50 of 28.99 and 698.42 mg/mL, respectively. The extract showed mixed and uncompetitive type inhibitions on αAM and αGL, respectively. The lowest inhibition constant (Ki) was 47.68 mg/mL on αAM activity at 20 mg/mL. Untargeted metabolic profiling by UPLC-MS-ESI-QTOF putatively identified 30 compounds in CME, such as amino acids, vitamins, phytohormones, fatty acids, cucurbitacins and phenolic acids, and flavonoids. Functional analysis of CME identified significant pathways, including pantothenate and CoA biosynthesis and phenylpropanoids, among others. The targeted analysis by UPLC-MS-ESI-QqQ allowed us to identify 12 compounds, with l-phenylalanine, p-hydroxybenzoic, and p-coumaric acid as majors. This study demonstrated the inhibitory potential of CME on αAM and αGL activities, which may be attributed to its metabolites. Thus, this plant represents a valuable source of BC against PHG. Practical Application: The research highlights that Cucurbita moschata has significant potential in managing postprandial hyperglycemia in diabetic patients by inhibiting enzymes like α-amylase and α-glucosidase. In addition, the identification of its compounds emphasizes its importance as a source of bioactive compounds. Therefore, C. moschata could be effectively utilized in the development of nutraceuticals or as an ingredient in functional foods specifically designed for postprandial hyperglycemia management. Thus, integrating C. moschata as part of the daily diet could offer patients with diabetes a natural alternative to control their blood glucose levels after eating.

Therapeutic Potential of Brassica oleracea and Raphanus sativus Aqueous Extracts on a Prediabetic Rat Model

Type 2 diabetes (T2D) is a serious health problem, and its prevalence is expected to increase worldwide in the years ahead. Cruciferous vegetables such as Brassica oleracea var. capitata L. (green cabbage) and Raphanus sativus L. (radish) have therapeutic properties that can be used to support the treatment of T2D. This study evaluated the effect of B. oleracea (BAE) and R. sativus (RAE) aqueous extracts on zoometric parameters, glycemic profiles, and pancreas and liver in prediabetic rats induced by a high-sucrose diet (HSD). BAE and RAE were administered to male HSD-induced Wistar rats (n = 35) at 5 and 10 mg/kg doses for 5 weeks. Zoometric and biochemical changes were measured, and then the pancreas and liver histological preparations were analyzed to observe the protective effect. BAE decreased feed intake and weight gain. Both extracts decreased fasting glucose and insulin levels compared with control (not treated), although not significantly (P > .05). The extracts significantly (P < .05) reduced homeostatic model assessment for insulin resistance, homeostasis model assessment of β-cell function, and glucose intolerance, similar to metformin control. In addition, minor damage occurred in the pancreas and liver. The results indicated that BAE and RAE decreased weight gain, improved glucose regulation, and protected the pancreas and liver in HSD rats. Therefore, they have multiple therapeutical properties and may be helpful in the prevention of T2D.

Phytochemicals and their Potential Mechanisms against Insulin Resistance

Insulin's inception dates back to 1921 and was unveiled through a momentous revelation. Diabetes is a dangerous, long-term disease in which the body fails to generate enough insulin or utilize the insulin it creates adequately. This causes hyperglycemia, a state of high blood sugar levels, which can even put a person into a coma if not managed. Activation of the insulin receptor corresponds to two crucial metabolic functions, i.e., uptake of glucose and storage of glycogen. Type 2 diabetes mellitus (T2DM) exists as one of the most challenging medical conditions in the 21st century. The sedentary lifestyle and declining quality of food products have contributed to the rapid development of metabolic disorders. Hence, there is an urgent need to lay some reliable, significant molecules and modalities of treatment to combat and manage this epidemic. In this review, we have made an attempt to identify and enlist the major phytoconstituents along with the associated sources and existing mechanisms against insulin resistance. The conducted study may offer potential sustainable solutions for developing and formulating scientifically validated molecules and phytoconstituents as formulations for the management of this metabolic disorder.

Cabbage (Brassica oleracea var. capitata): A food with functional properties aimed to type 2 diabetes prevention and management

Type 2 diabetes mellitus (T2DM) is increasing the prevalence worldwide at an alarming rate, becoming a serious public health problem that mainly affects developing countries. Functional food research is currently of great interest because it contributes to developing nutritional therapy strategies for T2DM prevention and treatment. Bioactive compounds identified in some plant foods contribute to human health by mechanisms of action that exert biological effects on metabolic pathways involved in the development of T2DM. Hence, vegetables with high bioactive compounds content may be a source of functional value for the control of T2DM. Cabbages varieties (Brassica oleracea var. capitata) such as green (GCB), white (WCB), and red (RCB) are foods consumed (raw or cooked) and cultivated in different regions of the world. Scientific evidence shows that cabbage has multi-target effects on glucose homeostatic regulation due to its high content of bioactive compounds. It has also been shown to decrease damage to organs affected by T2DM complications, such as the liver and kidney. Additionally, it could contribute as a preventive by attenuating problems underlying the development of T2DM as oxidative stress and obesity. This review highlights the functional properties of cabbage varieties involved in glucose regulation and the main mechanisms of the action exerted by their bioactive compounds. In conclusion, cabbage is a valuable food that can be employed as part of nutritional therapy or functional ingredient aimed at the prevention and treatment of T2DM.