Investigation of antihyperglycaemic activity of banana (Musa sp. var. Nanjangud rasa bale) pseudostem in normal and diabetic rats

From sugar binders to diabetes fighters: the lectin saga of antihyperglycemic activity through systematic review and meta-analysis

Introduction

Lectins are carbohydrate-binding proteins that are extremely selective for sugar groups in the other molecules. As a result, they perform a variety of roles in biological processes involving cell, carbohydrate, and protein recognition at the cellular and molecular levels. Because lectins can bind to carbohydrates, they may play a role in determining the rate of carbohydrate digestion. They also bind to some proteins involved in diabetes mellitus (DM) pathophysiology. The present review aims to summarize the efficiency of lectins from different sources as potential antihyperglycemic agents.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were employed for the drafting. In this regard, published scientific articles on the effects of different lectins on blood glucose (BG), glucose tolerance, hormonal effects, carbohydrate-digesting enzymes, oxidative stress, and insulin production process were collected from reputed journals using electronic databases. Furthermore, the toxicity effects of lectins from different sources were collected. A specific keyword search was completed to collect numerous articles with unique experimental designs and significant results. This was followed by the selection of the requisite articles based on the criteria designed by the authors. Data extraction was based on the common research elements included in the articles.

Results and Discussion

Of 13 identified studies, 11 studies were considered after double screening based on the inclusion criteria. All 11 pharmacological investigations were considered for review. Subsequent studies reflected on the pharmacological properties of lectins on the levels of BG, oxidative stress, β-cell proliferation, insulin resistance, inhibition of carbohydrate digesting enzymes, body weight, food and water intake, lipid profile, and other parameters. This review highlights lectins as potential anti-diabetic agents.

Conclusion

However, due to limited research, systematic evaluation is recommended for their development and promotion as effective potential antihyperglycemic agents. The clinical efficacy and safety of lectins against diabetes mellitus must also be evaluated.

In Vitro α-Amylase and α-Glucosidase Inhibitory Potential of Green Banana Powder Extracts

This study investigated the proximate composition and inhibitory potential of hot water and ethanolic extracts of the pulp, peel and whole fruit of green banana (Musa sapientum) on α-amylase and α-glucosidase. Bioactive compounds were identified using GC-MS analysis. In addition, the cytotoxic effect on human gingival fibroblast (hGF) was evaluated using the sulphorhodamine B (SRB) assay. The results showed that the peel of green banana had the highest amount of ash (10.05%), fat (2.83%), protein (3.64%) and total dietary fibre (36.62%). The carbohydrate content of the whole fruit (81.79%) and pulp (81.50%) was higher than that of the peel (71.90%). The moisture content of the pulp (13.08%) was higher than that of the peel (11.58%) and whole fruit (11.30%). The ethanolic green banana peel extract showed a good inhibitory effect of α-amylase and α-glucosidase with the concentration necessary for 50% inhibition (IC50) of 0.512 and 0.100 mg·mL-1, respectively. The α-glucosidase inhibitory effect of the ethanolic green banana peel extract and the hot water green banana peel extract was not significantly different from that of acarbose (IC50 0.108 mg·mL-1). GC-MS analysis of the ethanolic green banana peel extract revealed fatty acids and fatty acid ester (9-octadecenamide (Z), octadecanamide and other compounds). The ethanolic peel extract exhibits a significant noncytotoxicity effect on hGF cells at concentrations ranging from 0.0001 to 1.0 mg·mL-1.

Inhibitory effect of gallic acid from Thunbergia mysorensis against α-glucosidase, α-amylase, aldose reductase and their interaction: Inhibition kinetics and molecular simulations

In this exploration, we assessed the antihyperglycaemic properties of methanol extract of flowers of Thunbergia mysorensis (MeT) against α-glucosidase, α-amylase and aldose reductase enzymes for the effective management of postprandial hyperglycemia. Hyperglycemia occurs when the body lacks enough insulin or is unable to correctly utilize it. MeT inhibited both the carbohydrate digestive enzymes (α-glucosidase and α-amylase) and aldose reductase, which are vital for the therapeutic control of postprandial hyperglycaemia. MeT was also found to have significant antioxidant activity. Using several spectroscopic approaches, the primary active component found in MeT was identified as gallic acid. With low Ki values, gallic acid significantly inhibited α-glucosidase (30.86 µg/mL) and α-amylase (6.50 µg/mL). Also, MeT and gallic acid both inhibited aldose reductase effectively, corresponding to an IC50 value of 3.31 and 3.05 µg/mL. Our findings imply that the presence of polyphenol compounds (identified via HPLC analysis) is more likely to be responsible for the antihyperglycaemic role exhibited by MeT via the inhibition of α-glucosidase and the polyol pathway. Further, gallic acid interacted with the key residues of the active sites of α-glucosidase (-6.4 kcal/mol), α-amylase (-5.8 kcal/mol) and aldose reductase (-5.8 kcal/mol) as observed in the protein-ligand docking. It was also predicted that gallic acid was stable inside the binding pockets of the target enzymes during molecular dynamics simulation. Overall, gallic acid derived from MeT via bioassay-guided isolation emerges as a natural antidiabetic drug and can be taken into in vivo and clinical studies shortly.Communicated by Ramaswamy H. Sarma.

Quinoline- and Isoindoline-Integrated Polycyclic Compounds as Antioxidant, and Antidiabetic Agents Targeting the Dual Inhibition of α-Glycosidase and α-Amylase Enzymes

Novel analogs of quinoline and isoindoline containing various heterocycles, such as tetrazole, triazole, pyrazole, and pyridine, were synthesized and characterized using FT-IR, NMR, and mass spectroscopy, and their antioxidant and antidiabetic activities were investigated. The previously synthesized compound 1 was utilized in conjugation with ketone-bearing tetrazole and isoindoline-1,3-dione to synthesize Schiff's bases 2 and 3. Furthermore, hydrazide 1 was treated with aryledines to provide pyrazoles 4a-c. Compound 5 was obtained by treating 1 with potassium thiocyanate, which was then cyclized in a basic solution to afford triazole 6. On the other hand, pyridine derivatives 7a-d and 8a-d were synthesized using 2-(4-acetylphenyl)isoindoline-1,3-dione via a one-pot condensation reaction with aryl aldehydes and active methylene compounds. From the antioxidant and antidiabetic studies, compound 7d showed significant antioxidant activity with an EC50 = 0.65, 0.52, and 0.93 mM in the free radical scavenging assays (DPPH, ABTS, and superoxide anion radicals). It also displayed noteworthy inhibitory activity against both enzymes α-glycosidase (IC50: 0.07 mM) and α-amylase (0.21 mM) compared to acarbose (0.09 mM α-glycosidase and 0.25 mM for α-amylase), and higher than in the other compounds. During in silico assays, compound 7d exhibited favorable binding affinities towards both α-glycosidase (-10.9 kcal/mol) and α-amylase (-9.0 kcal/mol) compared to acarbose (-8.6 kcal/mol for α-glycosidase and -6.0 kcal/mol for α-amylase). The stability of 7d was demonstrated by molecular dynamics simulations and estimations of the binding free energy throughout the simulation session (100 ns).

Screening for potential novel probiotic Levilactobacillus brevis RAMULAB52 with antihyperglycemic property from fermented Carica papaya L

Probiotics are live microorganisms with various health benefits when consumed in appropriate amounts. Fermented foods are a rich source of these beneficial organisms. This study aimed to investigate the probiotic potential of lactic acid bacteria (LAB) isolated from fermented papaya (Carica papaya L.) through in vitro methods. The LAB strains were thoroughly characterized, considering their morphological, physiological, fermentative, biochemical, and molecular properties. The LAB strain's adherence and resistance to gastrointestinal conditions, as well as its antibacterial and antioxidant capabilities, were examined. Moreover, the strains were tested for susceptibility against specific antibiotics, and safety evaluations encompassed the hemolytic assay and DNase activity. The supernatant of the LAB isolate underwent organic acid profiling (LCMS). The primary objective of this study was to assess the inhibitory activity of α-amylase and α-glucosidase enzymes, both in vitro and in silico. Gram-positive strains that were catalase-negative and carbohydrate fermenting were selected for further analysis. The LAB isolate exhibited resistance to acid bile (0.3% and 1%), phenol (0.1% and 0.4%), and simulated gastrointestinal juice (pH 3-8). It demonstrated potent antibacterial and antioxidant abilities and resistance to kanamycin, vancomycin, and methicillin. The LAB strain showed autoaggregation (83%) and adhesion to chicken crop epithelial cells, buccal epithelial cells, and HT-29 cells. Safety assessments indicated no evidence of hemolysis or DNA degradation, confirming the safety of the LAB isolates. The isolate's identity was confirmed using the 16S rRNA sequence. The LAB strain Levilactobacillus brevis RAMULAB52, derived from fermented papaya, exhibited promising probiotic properties. Moreover, the isolate demonstrated significant inhibition of α-amylase (86.97%) and α-glucosidase (75.87%) enzymes. In silico studies uncovered that hydroxycitric acid, one of the organic acids derived from the isolate, interacted with crucial amino acid residues of the target enzymes. Specifically, hydroxycitric acid formed hydrogen bonds with key amino acid residues, such as GLU233 and ASP197 in α-amylase, and ASN241, ARG312, GLU304, SER308, HIS279, PRO309, and PHE311 in α-glucosidase. In conclusion, Levilactobacillus brevis RAMULAB52, isolated from fermented papaya, possesses promising probiotic properties and exhibits potential as an effective remedy for diabetes. Its resistance to gastrointestinal conditions, antibacterial and antioxidant abilities, adhesion to different cell types, and significant inhibition of target enzymes make it a valuable candidate for further research and potential application in the field of probiotics and diabetes management.

B. C, Huligere SS, Khan MS, Alafaleq NO, Ahmad S, Akhter F, Sreepathi N, P. A, Ramu R. Inhibition of carbohydrate hydrolyzing enzymes by a potential probiotic Levilactobacillus brevis RAMULAB49 isolated from fermented Ananas comosus

The research aimed to explore the potential probiotic characteristics of Levilactobacillus brevis RAMULAB49, a strain of lactic acid bacteria (LAB) isolated from fermented pineapple, specifically focusing on its antidiabetic effects. The importance of probiotics in maintaining a balanced gut microbiota and supporting human physiology and metabolism motivated this research. All collected isolates underwent microscopic and biochemical screenings, and those exhibiting Gram-positive characteristics, negative catalase activity, phenol tolerance, gastrointestinal conditions, and adhesion capabilities were selected. Antibiotic susceptibility was assessed, along with safety evaluations encompassing hemolytic and DNase enzyme activity tests. The isolate's antioxidant activity and its ability to inhibit carbohydrate hydrolyzing enzymes were examined. Additionally, organic acid profiling (LC-MS) and in silico studies were conducted on the tested extracts. Levilactobacillus brevis RAMULAB49 demonstrated desired characteristics such as Gram-positive, negative catalase activity, phenol tolerance, gastrointestinal conditions, hydrophobicity (65.71%), and autoaggregation (77.76%). Coaggregation activity against Micrococcus luteus, Pseudomonas aeruginosa, and Salmonella enterica serovar Typhimurium was observed. Molecular characterization revealed significant antioxidant activity in Levilactobacillus brevis RAMULAB49, with ABTS and DPPH inhibition rates of 74.85% and 60.51%, respectively, at a bacterial cell concentration of 109 CFU/mL. The cell-free supernatant exhibited substantial inhibition of α-amylase (56.19%) and α-glucosidase (55.69%) in vitro. In silico studies supported these findings, highlighting the inhibitory effects of specific organic acids such as citric acid, hydroxycitric acid, and malic acid, which displayed higher Pa values compared to other compounds. These outcomes underscore the promising antidiabetic potential of Levilactobacillus brevis RAMULAB49, isolated from fermented pineapple. Its probiotic properties, including antimicrobial activity, autoaggregation, and gastrointestinal conditions, contribute to its potential therapeutic application. The inhibitory effects on α-amylase and α-glucosidase activities further support its anti-diabetic properties. In silico analysis identified specific organic acids that may contribute to the observed antidiabetic effects. Levilactobacillus brevis RAMULAB49, as a probiotic isolate derived from fermented pineapple, holds promise as an agent for managing diabetes. Further investigations should focus on evaluating its efficacy and safety in vivo to consider its potential therapeutic application in diabetes management.

Evaluation of flavonoids from banana pseudostem and flower (quercetin and catechin) as potent inhibitors of α-glucosidase: An in silico perspective

The amelioration of postprandial hyperglycemia in diabetic conditions could be accomplished by the inhibition of α-glucosidases, a set of intestinal carbohydrate digestive enzymes responsible for starch hydrolysis and its absorption. The ethnopharmacological profile of banana depicts the usage of different plant parts in conventional medicinal formulations. The antidiabetic studies of the plant have demonstrated their ability to inhibit α-glucosidase. Besides, our research group has reported the α-glucosidase inhibitory potential of the banana pseudostem and flower extracts in previous studies. In this study, we deliberate on the specific phytoconstituents of banana pseudostem and flower to evaluate their antidiabetic effects through an in silico perspective for the α-glucosidase inhibition. In this context, several phytoconstituents of banana pseudostem and flower identified through GC-MS analysis were retrieved from chemical databases. These phytochemicals were virtually screened through the molecular docking simulation process, from which only two flavonoids (catechin and quercetin) were selected based on their binding affinity and extent of interaction with the α-glucosidase target protein. The lower binding affinities of catechin and quercetin in comparison with that of acarbose as a control proved their binding efficiency with the target protein. In addition, acarbose showed subservient molecular interaction, forming an unfavourable acceptor-acceptor bond. The molecular dynamics simulations also depicted the effective binding and stability of the complexes formed with catechin and quercetin, in comparison with that of acarbose. Further, PASS analysis, druglikeliness, and pharmacokinetic assessments showed that both catechin and quercetin edge over acarbose in terms of drug-score and pharmacokinetic properties. With the positive results obtained from contemporary strategies, the two flavonoids from banana pseudostem and flower might be established as a considerable phototherapeutic approach to inhibit α-glucosidase. Communicated by Ramaswamy H. Sarma.

Bacteriocins from lactic acid bacteria and their potential clinical applications

Bacteriocins are ribosomally synthesized antimicrobial peptides that have long been used in the food industry. Being a highly diverse and heterogeneous group of molecules the classification is ever-evolving. Their production is widespread among bacteria; nevertheless, their biosynthesis and mode of action remain fairly similar. With the advances in drug resistance mechanisms, it is important to look for alternatives to conventional approaches. Therefore, the advantages of bacteriocin over antibiotics need to be considered to provide a scientific basis for their use. Particularly in the last decade, intensive studies look at their potential as next-generation therapeutics against drug-resistant bacteria. Bacteriocins from lactic acid bacteria are being tested as controlling agents for bacterial and viral infections; they can inhibit biofilm synthesis and have potential as contraceptives. Bioengineered peptides have shown enhanced activity and thereby indicate the lack of knowledge we possess regarding these bacteriocins. In this review, we have listed various Gram-positive LAB bacteriocins with their synthesis and mechanism of action. Recent developments in screening and purification technologies have been analyzed with an emphasis on their potential clinical applications. Although extensive research has been done to identify multifunctional bacteriocins, it is important to focus on the mechanism of action of these peptides to get them from bench to bedside.

Inhibitory Effect of Polyphenols from the Whole Green Jackfruit Flour against α-Glucosidase, α-Amylase, Aldose Reductase and Glycation at Multiple Stages and Their Interaction: Inhibition Kinetics and Molecular Simulations

For the first time, α-glucosidase, α-amylase, aldose reductase, and glycation at multiple stages inhibitory assays were used to explore the antidiabetic potential of whole unripe jackfruit (peel with pulp, flake, and seed). Two polyphenols (phenolic acids) with strong antihyperglycaemic activity were isolated from the methanol extract of whole jackfruit flour (MJ) using activity-guided repeated fractionation on a silica gel column chromatography. The bioactive compounds isolated were identified as 3-(3,4-Dihydroxyphenyl)-2-propenoic acid (caffeic acid: CA) and 4-Hydroxy-3,5-dimethoxybenzoic acid (syringic acid: SA) after various physicochemical and spectroscopic investigations. CA (IC50: 8.0 and 26.90 µg/mL) and SA (IC50: 7.5 and 25.25 µg/mL) were identified to inhibit α-glucosidase and α-amylase in a competitive manner with low Ki values. In vitro glycation experiments further revealed that MJ and its components inhibited each stage of protein glycation as well as the generation of intermediate chemicals. Furthermore, CA (IC50: 3.10) and SA (IC50: 3.0 µg/mL) inhibited aldose reductase effectively in a non-competitive manner, respectively. The binding affinity of these substances towards the enzymes examined has been proposed by molecular docking and molecular dynamics simulation studies, which may explain their inhibitory activities. The found potential of MJ in antihyperglycaemic activity via inhibition of α-glucosidase and in antidiabetic action via inhibition of the polyol pathway and protein glycation is more likely to be related to the presence of the phenolic compounds, according to our findings.

Kluai Hin (Musa sapientum Linn.) peel as a source of functional polyphenols identified by HPLC-ESI-QTOF-MS and its potential antidiabetic function

To date, information on the polyphenolic composition of Kluai Hin banana peel and pulp and the potential antidiabetic activity of its major active compounds is limited. This study aimed to identify polyphenols in extracts of fresh and freeze-dried Kluai Hin banana peel and pulp (methanol:water; M:W, 80:20 for flavonoids and acetone:water:acetic acid; A:W:A, 50:49:1 for phenolic acids) by RP-HPLC-DAD and HPLC-ESI-QTOF-MS. Additionally, inhibition of α-amylase and α-glucosidase activities was investigated with crude extracts from Kluai Hin banana peel and pulp, and compared with its major polyphenols ((+)-catechin, (-)-epicatechin and gallic acid) and the antidiabetic drug acarbose. (-)-Gallocatechin was the most abundant polyphenol and was detected in all fresh and freeze-dried pulp and peel extracts by RP-HPLC-DAD. Furthermore, unidentified polyphenol peaks of Kluai Hin were further explored by HPLC-ESI-QTOF-MS. The A:W:A fresh peel extract contained more total phenolic content (811.56 mg GAE/100 g) than the freeze-dried peel (565.03 mg GAE/100 g). A:W:A extraction of the fresh and freeze-dried peel of exhibited IC₅₀ values for α-amylase activity 2.66 ± 0.07 mg/ml and 2.97 ± 0.00 mg/ml, respectively, but its inhibitory activity was lower than acarbose (IC₅₀ = 0.25 ± 0.01 mg/ml). Peel extracts inhibited α-glucosidase activity, whereas pulp extracts had no effect. In addition, all standards, except gallocatechin, activated α-amylase activity, while, gallocatechin inhibited α-glucosidase activity better than acarbose. Therefore, we propose a further investigation into the use of Kluai Hin banana peel as a potential functional food for the management of postprandial glycaemic response to reduce diabetes risk and in the management of diabetes with a commercial drug.

In vitro and in silico studies of fluorinated 2,3-disubstituted thiazolidinone-pyrazoles as potential α-amylase inhibitors and antioxidant agents

As part of our effort to identify potent α-amylase inhibitors, in the present study, a novel series of fluorinated thiazolidinone-pyrazole hybrid molecules were prepared by the condensation of 3-(aryl/benzyloxyaryl)-pyrazole-4-carbaldehydes with fluorinated 2,3-disubstituted thiazolidin-4-ones. The structures of the newly synthesized compounds were confirmed by infrared, ¹ H nuclear magnetic resonance (NMR), ¹³ C NMR, and liquid chromatography-mass spectrometry data. All the compounds were screened for their α-amylase inhibitory and free radical scavenging activities by DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS methods. Among the tested compounds, compound 8g emerged as a promising α-amylase inhibitor with IC₅₀  = 0.76 ± 1.23 µM, and it was found to be more potent than the standard drug acarbose (IC₅₀  = 0.86 ± 0.81 μM). Compounds 8b and 8g showed strong free radical scavenging activity compared to the standard butylated hydroxyl anisole. The kinetic study of compound 8g revealed the reversible, classical competitive inhibition mode on the α-amylase enzyme. Molecular docking and dynamic simulations studies were performed for the most potent compound 8g, which displayed remarkable hydrogen bonding with the α-amylase protein (PDB ID: 1DHK).

Targeting Imd pathway receptor in Drosophila melanogaster and repurposing of phyto-inhibitors: structural modulation and molecular dynamics

Dysbiosis is a major cause of disease in an individual, generally initiated in the gastrointestinal tract. The gut, also known as the second brain, constitutes a major role in immune signaling. To study the immunity cascade, the Drosophila model was considered targeting the Imd pathway receptor (2F2L) located in the midgut. This receptor further initiates the immune signaling mechanism influenced by bacteria. To inhibit the Imd pathway, the crystal structure of Imd with PDB: 2F2L was considered for the screening of suitable ligand/inhibitor. In light of our previous studies, repurposing of anti-diabetic ligands from the banana plant namely lupeol (LUP), stigmasterol (STI), β-sitosterol (BST) and umbelliferone (UMB) were screened. This study identifies the potential inhibitor along with the tracheal toxin (TCT), a major peptidoglycan constituent of microbes. The molecular docking and molecular dynamics simulation of complexes 2F2L-MLD, 2F2L- CAP, 2F2L-LUP, 2F2L-BST, 2F2L-STI and 2F2L-UMB elucidates the intermolecular interaction into the inhibitory property of ligands. The results of this study infer LUP and UMB as better ligands with high stability and functionality among the screened candidates. This study provides insights into the dysbiosis and its amelioration by plant-derived molecules. The identified drugs (LUP & UMB) will probably act as an inhibitor against microbial dysbiosis and other related pathogenesis (diabetes and diabetic neuropathy). Further, this study will widen avenues in fly biology research and which could be used as a therapeutic model in the rapid, reliable and reproducible screening of phytobiologics in complementary and alternative medicine for various lifestyle associated complications.Communicated by Ramaswamy H. Sarma.

Tucumã (Astrocaryum aculeatum) extract: phytochemical characterization, acute and subacute oral toxicity studies in Wistar rats

Natural products are often used by the population to treat and/or prevent several disorders. Tucumã is an Amazonian fruit widely consumed by local population and no in vivo toxicity studies regarding its safety are available in the literature to date. Therefore, the phytochemical characterization, acute and repeated dose 28-day oral toxicities of crude extract of tucumã's pulp (CETP) in Wistar rats were evaluated. For the CETP preparation, tucumã pulp was crushed and placed into sealed amber glass jars containing absolute ethanol solution for extraction. CETP phytochemical analyses evidenced the presence of carotenoids, flavonoids, unsaturated and satured fatty acids, and triterpenes. In the acute toxicity, female rats from the test group were treated with CETP at single dose of 2000 mg/kg. For the repeated dose toxicity, CETP was administered to male and female rats at doses of 200, 400 and 600 mg/kg, for 28 days. Body weight was recorded during the experiment and blood, liver and kidney were collected for further analysis. No mortality or toxicity signs were observed during the studies. CETP was classified as safe (category 5, OECD guide), in acute toxicity. In repeated dose study was observed alterations in some biochemical parameters, as well as in oxidative damage and enzymatic activity. Histopathological findings showed renal damage in male rats at higher dose. The data obtained suggest that CETP did not induced toxicity after exposure to a single or repeated doses in female rats. However, in males may be considered safe when given repeatedly in low doses.

The effect of a plant extract enriched in stigmasterol and β-sitosterol on glycaemic status and glucose metabolism in alloxan-induced diabetic rats

Banana is an extensively cultivated plant worldwide, mainly for its fruit, while its ancillary product, the banana pseudostem, is consumed as a vegetable and is highly recommended for diabetics in the traditional Indian medicine system. The present study was aimed at elucidating the mechanism of antihyperglycaemia exerted by the ethanol extract of banana pseudostem (EE) and its isolated compounds viz., stigmasterol (C1) and β-sitosterol (C2), in an alloxan-induced diabetic rat model. Diabetic rats which were administered with C1, C2 and EE (100 and 200 mg per kg b. wt.) for 4 weeks showed reduced levels of fasting blood glucose and reversal of abnormalities in serum/urine protein, urea and creatinine in diabetic rats compared to the diabetic control group of rats. Diabetic symptoms such as polyphagia, polydipsia, polyuria, urine glucose and reduced body weight were ameliorated in the diabetic group of rats fed with EE, C1 and C2 (100 mg per kg b. wt., once daily) for 28 days. The levels of insulin and Hb were also increased, while the HbA1c level was reduced. The altered activities of hepatic marker enzymes viz., aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP); glycolytic enzyme (hexokinase); shunt enzyme (glucose-6-phosphate dehydrogenase); gluconeogenic enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase and lactate dehydrogenase) and pyruvate kinase were significantly reverted to normal levels by the administration of EE, C1 and C2. In addition, increased levels of hepatic glycogen and glycogen synthase and the corresponding decrease of glycogen phosphorylase activity in diabetic rats illustrated the antihyperglycaemic potential of EE and its components. The histological observations revealed a marked regeneration of the β-cells in the drug treated diabetic rats. These findings suggest that EE might exert its antidiabetic potential in the presence of C1 and C2, attributable to the enhanced glycolytic activity, besides increasing the hepatic glucose utilization in diabetic rats by stimulating insulin secretion from the remnant β-cells.

Plant-Based Beverages as Good Sources of Free and Glycosidic Plant Sterols

To address the ever-growing group of health-conscious consumers, more and more nutritional and health claims are being used on food products. Nevertheless, only very few food constituents, including plant sterols, have been appointed an approved health claim (European Commission and Food and Drugs Administration). Plant sterols are part of those limited lists of approved compounds for their cholesterol-lowering properties but have been praised for their anti-inflammatory and anti-carcinogenic properties as well. Despite this indisputable reputation, direct quantitative data is still lacking for naturally present (conjugated) plant sterols in beverages. This study aimed to fill this gap by applying a validated extraction and UPLC-MS/MS detection method to a diverse range of everyday plant-based beverages. β-sitosterol-β-d-glucoside (BSSG) showed to be by far the most abundant sterol in all beverages studied, with concentrations up to 60-90 mg per 100 mL in plant-based milk alternatives and fresh fruit juices. Ergosterol (provitamin D₂) could be found in beers (0.8-6.1 µg per 100 mL, from the yeast) and occasionally in juices (17-29 µg per 100 mL). Overall, the results demonstrated that the concentrations of water-soluble sterol conjugates have been underestimated significantly and that specific plant-based beverages can be good, low-fat sources of these plant sterols.

Assessment of Nutritional Quality and Global Antioxidant Response of Banana (Musa sp. CV. Nanjangud Rasa Bale) Pseudostem and Flower

BACKGROUND

The assessment of the nutritional composition and phytochemical screening of banana pseudostem (PB) and flower (FB) advocate this nonconventional food source for routine consumption, considering its various health benefits.

OBJECTIVES

The aim is to assess the proximate nutrient composition, fatty acids, minerals, amino acid profile, and global antioxidant response (GAR) of PB and FB.

METHODS

Standard analytical procedures were used to determine the nutritional quality and GAR of PB and FB.

RESULTS

The chemical analysis illustrated that functional profile (water holding capacity, oil holding capacity, swelling power, and solubility), and proximate (ash, moisture, protein, fat, dietary fiber, and carbohydrate) contents were substantially high in FB than PB. With a well-proportionate amino acid profile, PB (0.56) and FB (0.54) comprised of a high ratio of essential to nonessential amino acids than those of FAO/WHO requirement (0.38). The mineral analysis revealed that PB and FB were rich in macro and micro minerals in the order K > Ca > Mg > P > Na and K > Mg > Na > Ca > P, respectively. Linoleic acid was found to be the major component in PB and FB. Besides, total antioxidant activity conducted for PB and FB by GAR method, measuring both bio-accessible and insoluble fractions, revealed that the soluble fraction fared better than the chemical extracts.

CONCLUSION

The results revealed high nutritional qualities of the byproducts of banana and the low cost of its production promotes their use as a prospective nonconventional food resource with high nutraceutical value.

SUMMARY

AOAC: Association of Analytical CommunitiesFAO/WHO: Food and Agriculture Organization of the United Nations/World health organization Abbreviations Used: Banana flower was more potent than banana pseudostem in terms of its nutritional quality and total antioxidant capacity affirming their usefulness (of both the secondary products) in the pharmaceutical sector as a nutritional supplement due to the health-related properties of dietary fibre and associated bioactive compounds.

Investigation of Antihyperglycaemic Activity of Banana (Musa sp. Var. Nanjangud rasa bale) Flower in Normal and Diabetic Rats

BACKGROUND

The vital enzymes of starch digestion and absorption are intestinal α-glucosidases and their inhibition improves postprandial hyperglycaemia, constituting an effective mode of therapy in diabetes.

OBJECTIVES

The present study was designed to assess the inhibitory potential of ethanol extract of banana flower (EF) on mammalian α-glucosidases and its pharmacological effects on postprandial hyperglycaemia in normal and alloxan-induced diabetic rats.

MATERIALS AND METHODS

EF was evaluated for its inhibitory potential and mode of inhibition on mammalian α-glucosidases. Further, the role of EF and its constituents Umbelliferone (C1) and Lupeol (C2) on glucose uptake using isolated rat hemi-diaphragm and insulinotropic activity using RINm5F (rat insulinoma) cell lines were determined. The phytocomponents in EF were also evaluated using GC-MS.

RESULTS

EF illustrated a dose-dependent inhibition for rat intestinal sucrase, maltase and p-nitrophenyl-α-D-glucopyranoside (pNPG) hydrolysis (IC50 values: 18.76±0.22, 25.54±0.10 and 76.42±1.12 µg/ml, respectively) and the mode of inhibition was non-competitive with low Ki values. Oral administration (100-200 mg/kg b.wt.) of EF significantly improved the maltose/glucose-induced postprandial hyperglycaemia in normal and alloxan-induced diabetic rats. EF, C1 and C2 exhibited stimulation of glucose uptake and a dose-dependent glucose-induced insulin secretion at both 4.5 and 16.7 mM glucose concentrations. Further, GC-MS analysis revealed significant levels of steroids (25.61%), diazoprogesterone (21.31%), sesquiterpene (11.78%) and other phytocomponents.

CONCLUSION

EF inhibited α-glucosidases besides promoting glucose uptake and insulin secretion, resulting in antihyperglycaemic effect determining EF as a potent anti-diabetic agent.Abbreviations used: mg/dl: milligramsper deciliter, mM: millimolar, b.wt.: body weight.