Aqueous extract of some indigenous medicinal plants inhibits glycation at multiple stages and protects erythrocytes from oxidative damage-an in vitro study

Fatty acids characterisation by GC-MS, antiglycation effect at multiple stages and protection of erythrocytes cells from oxidative damage induced by glycation of albumin of Opuntia ficus-indica (L.) Mill seed oil cultivated in Eastern Morocco: Experimental and computational approaches

ETHNOPHARMACOLOGICAL RELEVANCE

Opuntia ficus-indica (L.) Mill is frequently observed in the Moroccan traditional medicinal system, where these approaches are employed to mitigate the onset of diabetes and the subsequent complications it may entail.

AIM OF THE STUDY

The aim of this research was to examine the effectiveness of Opuntia ficus-indica seed oil in preventing diabetic complications. Specifically, the study assessed its ability to counteract glycation at various stages, protected red blood cells from the harmful effects of glycated albumin, and inhibited pancreatic lipase digestive enzymes to understand its potential antihyperglycemic properties. Additionally, the study aimed to identify the chemical components responsible for these effects, evaluate antioxidant and anti-inflammatory properties, and conduct computational investigations such as molecular docking.

MATERIALS AND METHODS

The assessement of Opuntia ficus-indica seed oil antiglycation properties involved co-incubating the extract oil with a bovine serum albumin-glucose glycation model. The study investigated various stages of glycation, incorporating fructosamine (inceptive stage), protein carbonyls (intermediate stage), and AGEs (late stage). Additionally, measurement of β-amyloid aggregation of albumin was performed using Congo red, which is specific to amyloid structures. Additionally, the evaluation of oil's safeguarding effect on erythrocytes against toxicity induced by glycated albumin included the measurement of erythrocyte hemolysis, lipid peroxidation, reduced glutathione. The fatty acid of Opuntia ficus-indica seed oil were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The in vitro evaluation of antihyperglycemic activity involved the use of pancreatic lipase enzyme, while the assessement of antioxidant capability was carried out through the utilization of the ABTS and FRAP methods. The in vitro assessement of the denaturation of albumin activity was also conducted. In conjunction with the experimental outcomes, computational investigations were undertaken, specifically employing ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis. Furthermore, molecular docking was utilized to predict antioxidant and antiglycation mechanisms based on protein targets.

RESULTS

In vitro glycation assays, Opuntia ficus-indica seed oil displayed targeted inhibitory effects at multiple distinct stages. Within erythrocytes, in addition to mitigating hemolysis and lipid peroxidation induced by glycated albumin. GC-MS investigation revealed a richness of fatty acids and the most abundant compounds are Linoleic acid (36.59%), Palmitic acid (20.84%) and Oleic acid (19.33%) respectively. The findings of antioxidant ability showed a remarkable activity on FRAP and ABTS radicals. This oil showed a pronounced inhibitory impact (p < 0.001) on pancreatic lipase enzyme. It also exerted a notibale inhibition of albumin denaturation, in vitro.

CONCLUSION

The identified results were supported by the abundant compounds of fatty acids unveiled through GC-MS analysis, along with the computational investigation and molecular docking.

Glycated LDL generates reactive species that damage cell components, oxidize hemoglobin and alter surface morphology in human erythrocytes

Low-density lipoprotein (LDL) transports cholesterol to various tissues via the blood. Glycation of LDL occurs during hyperglycemic condition which is characterised by persistently high blood glucose level. Circulating erythrocytes can come in direct contact with glycated LDL (G-LDL). The objective of this study was to investigate the effect of G-LDL on human erythrocytes, specifically on hemoglobin, intracellular generation of reactive species and the antioxidant defence system. Isolated erythrocytes were incubated with G-LDL (3 and 6 mg/ml) and native LDL (6 mg/ml) at 37 °C for 24 h. Native LDL and G-LDL untreated erythrocytes were similarly incubated at 37 °C and served as control. G-LDL treatment increased hemolysis compared to control and native LDL-treated erythrocytes. Incubation of erythrocytes with G-LDL led to an increase in protein oxidation and lipid peroxidation while greatly decreasing the total sulfhydryl content. It also significantly enhanced hemoglobin oxidation, heme degradation, and the release of free iron moiety. Treatment with G-LDL led to an appreciable increase in the production of reactive oxygen and nitrogen species. The antioxidant power and activities of major antioxidant enzymes were drastically reduced, while critical membrane-bound enzymes were inhibited. The surface morphology of G-LDL-treated erythrocytes was altered leading to the formation of echinocytes. Importantly, treatment of erythrocytes with native LDL did not significantly affect the above-mentioned parameters and values were similar to the corresponding controls. Thus, G-LDL is cytotoxic to human erythrocytes and causes oxidative damage to cell components. This can reduce the oxygen-transporting ability of blood and also result in red cell senescence and anemia.

Crosstalk between Aldosterone and Glycation through Rac-1 Induces Diabetic Nephropathy

Background: Advanced glycation end products (AGEs) interaction with its receptor (RAGE) and aldosterone (Aldo) through the mineralocorticoid receptor (MR) activates Rac-1 and NF-κB independently in diabetic nephropathy (DN). However, the crosstalk of Aldo with AGEs-RAGE is still unresolved. Our study examined the impact of the AGEs-Aldo complex on renal cells and its effect on the RAGE-MR interaction. Methods and results: Glycation of human serum albumin (HSA) (40 mg/mL) with methylglyoxal (10 mM) in the presence of Aldo (100 nM) and aminoguanidine (AG) (100 nM) was performed. Glycation markers such as fructosamine and carbonyl groups and fluorescence of AGEs, pentosidine, and tryptophan followed by protein modification were measured. Renal (HEK-293T) cells were treated with the glycated HSA-Aldo (200 μg/mL) along with FPS-ZM1 and spironolactone antagonists for RAGE and Aldo, respectively, for 24 h. Glycation markers and esRAGE levels were measured. Protein and mRNA levels of RAGE, MR, Rac-1, and NF-κB were estimated. Glycation markers were enhanced with Aldo when albumin was only 14-16% glycated. AGEs-Aldo complex upregulated RAGE, MR, Rac-1 and NF-κB expressions. However, FPS-ZM1 action might have activated the RAGE-independent pathway, further elevating MR, Rac-1, and NF-κB levels. Conclusion: Our study concluded that the presence of Aldo has a significant impact on glycation. In the presence of AGEs-Aldo, RAGE-MR crosstalk exerts inflammatory responses through Rac-1 in DN. Insights into this molecular interplay are crucial for developing novel therapeutic strategies to alleviate DN in the future.

Comparison of Protective Effects of Phenolic Acids on Protein Glycation of BSA Supported by In Vitro and Docking Studies

Several diabetic complications are associated with forming advanced glycation end products (AGEs). Different chemical and natural compounds are able to prevent the development of these products. In this study, glycosylation was induced as a model by incubating bovine serum albumin (BSA) with glucose. Consequently, BSA was treated with glucose and different concentrations (1.25, 2.5, and 5 μM) of syringic acid, gallic acid, ellagic acid, ferulic acid, paracoumaric acid, and caffeic acid for 4 and 6 weeks. Biochemical experiments comprise measurements of fluorescent AGEs, protein carbonyl contents, total thiol, hemolysis tests, and also malondialdehyde (MDA) levels in RBC. These demonstrated the antiglycating mechanism of these phenolic acids. Most of the phenolic acids used in this study reduced MDA levels and protected thiol residues in protein structures. They also inhibited the formation of fluorescent AGEs and RBC lysis, except gallic acid. Moreover, ferulic acid, paracoumaric acid, and caffeic acid proteins significantly prevent carbonylation. Molecular docking and simulation studies showed that ellagic, caffeic, gallic, and syringic acids could interact with lysine and arginine residues in the active site of BSA and stabilize its structure to inhibit the formation of AGEs. Our results suggest that phenolic acid could be used as a potential phytochemical against protein glycation and related diabetic complications.

Jamun (Syzygium cumini (L.) Skeels) Seed: A Review on Nutritional Profile, Functional Food Properties, Health-Promoting Applications, and Safety Aspects

Jamun (Syzygium cumini L. Skeels) is highly perishable with a very short shelf life, hence, jamun fruit is either consumed fresh as soon as it is harvested or converted to value-added products such as jam, wine, juice, and jellies. The processing of jamun fruit generates a large quantity of seeds as the primary waste. Jamun seeds are a rich source of macronutrients such as carbohydrates, proteins, lipids, minerals, and vitamins, thus making them an important ingredient in the food industry. The valorization of underutilized, nutritionally rich byproducts of the food processing industry has been providing new ways for unlocking their potential in the functional food industry or therapeutic food formulations. This review presents a detailed nutritional profile of jamun seeds and its potent application in the food industry as a possible functional ingredient. Along with its beneficial nutritional profile, the review also throws light upon the safety aspects associated with jamun seed consumption along with its acceptable daily intake. Safety and toxicity studies have motivated researchers and industrialists to search for possible applications in the food industry. Jamun seeds with array of nutritional benefits can be an important functional ingredient; however, further extensive research is necessary to find suitable levels of application of jamun seed in food products for harnessing its nutritional potential without affecting the products’ sensory palatability.

Function of selected natural antidiabetic compounds with potential against cancer via modulation of the PI3K/AKT/mTOR cascade

Diabetes mellitus (DM) is a metabolic disorder with growing global incidence, as 387 million people were diagnosed in 2014 with an expected projection of 642 million in 2040. Several complications are associated with DM including heart attack, stroke, kidney failure, blindness, and cancer. The latter is the second leading cause of death worldwide accounting for one in every six deaths, with liver, pancreas, and endometrium cancers are the most abundant among patients with diabetes. Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway plays a vital role in developing a wide array of pathological disorders, among them diabetes and cancer. Natural secondary metabolites that counteract the deleterious effects of reactive oxygen species (ROS) and modulate PI3K/Akt/mTOR pathway could be a promising approach in cancer therapy. Here, 717 medicinal plants with antidiabetic activities were highlighted along with 357 bioactive compounds responsible for the antidiabetic activity. Also, 43 individual plant compounds with potential antidiabetic activities against cancer via the modulation of PI3K/Akt/mTOR cascade were identified. Taken together, the available data give an insight of the potential of repurposing medicinal plants and/or the individual secondary metabolites with antidiabetic activities for cancer therapy.

Medicinal plants utilized in Thai Traditional Medicine for diabetes treatment: Ethnobotanical surveys, scientific evidence and phytochemicals

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes mellitus remains the most lethal metabolic disease of contemporaneous times and despite the therapeutic arsenal currently available, research on new antidiabetic agents remains a priority. In recent years, the revitalization of Thai Traditional Medicine (TTM) became a clear priority for the Thai government, and many efforts have been undertaken to accelerate research on herbal medicines and their use in medical services in various hospitals. Additionally, and particularly in rural areas, treatment of diabetes and associated symptomatology frequently relies on herbal preparations recommended by practitioners of TTM. In the current work, medicinal plants used in Thailand for treating diabetes, as well as their hypoglycaemic pharmacological evidences and potential therapeutic use for diabetes-related complications were reviewed.

MATERIALS AND METHODS

Ethnopharmacological information on the plant materials used in TTM for diabetes treatment was collected through literature search in a range of scientific databases using the search terms: diabetes, folk medicine, Thailand medicinal plants, traditional medicine. Information regarding scientific evidence on the antidiabetic effects of surveyed species was obtained considering not only the most common taxonomic designation, but also taxonomic synonyms, and including the keywords 'diabetes' and 'hypoglycaemic effect'.

RESULTS

A total of 183 species known to be used for diabetes management in TTM were reviewed, with 30% of them still lacking experimental evidences to support claims regarding the mechanisms and phytochemicals underlying their antidiabetic properties. Moreover, a total of 46 bioactives displaying effective antidiabetic effects have been isolated from 24 species, their underlying mechanism(s) of action being fully or partially disclosed.

CONCLUSIONS

We deliver the most extensive survey dealing with the ethnomedicinal knowledge of Thai medicinal plants utilized on diabetes management. We are certain that the current review will spark further research on Thai plants for the development of new standardized phytomedicines through drug discovery programmes.

In Vitro Antioxidant and Antidiabetic Potentials of Syzygium caryophyllatum L. Alston

Syzygium caryophyllatum L. Alston (Family: Myrtaceae, Sinhala: Heendan) is a red-listed plant that has been used in traditional medicine in Sri Lanka for the treatment of diabetes, but it is yet to be exploited for its potential uses as a functional food or a source of supplements. The present study focused on the evaluation of antidiabetic property of S. caryophyllatum fruits and leaves assessing antioxidant, antiglycation, and antiamylase activities and functional mineral element composition. The crude extracts (CR) of leaves and fruits were fractionated into hexane (Hex) ethyl acetate (EA) and aqueous (AQ) and evaluated for bioactivities along with the crude extracts. The isolated fraction (C₃) of Hex fraction of fruit showed significantly high (p < 0.05) antiamylase activity with IC₅₀ value 2.27 ± 1.81 μg/mL where the Hex fraction of fruits exhibited the IC₅₀ value as 47.20 ± 0.3 μg/mL which was higher than acarbose (IC₅₀: 87.96 ± 1.43 μg/mL). The EA fraction of leaves showed highest values for DPPH radical scavenging activity, ferric reducing antioxidant power, and oxygen radical absorbance capacity. Significantly high (p < 0.05) ABTS radical scavenging activity and iron chelating activity were observed in Hex fraction of fruit. The composition of volatiles in leaf oil was studied with GC-MS, and 58 compounds were identified. Inductively coupled plasma-mass spectrometry data revealed the presence of biologically significant trace elements such as Fe, Zn, Mg, Cu, Se, and Sr in leaves and fruits. It is concluded that the Hex fraction of S. caryophyllatum fruits will be a good source for the formulation of supplements for diabetic management with further evaluation of potency and efficacy.

Antirhea borbonica Aqueous Extract Protects Albumin and Erythrocytes from Glycoxidative Damages

Diabetes constitutes a major health problem associated with severe complications. In hyperglycemic conditions, chronically increased oxidation and glycation of circulating components lead to advanced glycation end-products (AGEs) formation, a key contributor in diabetes complication progression. In line with literature documenting the beneficial properties of herbal teas, this study evaluates the antioxidant/glycant properties of Antirhea borbonica (Ab). Ab aqueous extract effects were tested on human albumin or erythrocytes submitted to methyl glyoxal-mediated glycoxidative damages. By using mass spectrometry, Ab aqueous extracts revealed to be rich in polyphenols. All tested biomarkers of oxidation and glycation, such as AGE, ketoamine, oxidized thiol groups, were decreased in albumin when glycated in the presence of Ab aqueous extract. Ab extract preserve erythrocyte from methylglyoxal (MGO)-induced damages in terms of restored membrane deformability, reduced oxidative stress and eryptosis phenomenon. Antioxidant capacities of Ab extract on erythrocytes were retrieved in vivo in zebrafish previously infused with MGO. These results bring new evidences on the deleterious impacts of glycation on albumin and erythrocyte in diabetes. Furthermore, it reveals antioxidant and antiglycant properties of Ab that could be used for the dietary modulation of oxidative stress and glycation in hyperglycemic situations.

Characteristics and bioactive properties of mannooligosaccharides derived from agro-waste mannans

Mannooligosaccharides (MOS) were derived using Aspergillus oryzae β-mannanase (ManAo) from different mannan-rich agro-wastes, palm kernel cake (PKC), guar gum and copra meal (CM). Guar gum (GG) released higher amount of MOS (56.31% w/w) from which purification of mannobiose (0.68 mg) and mannotriose (1.26 mg) was demonstrated using size-exclusion chromatography. FTIR analysis of mannan hydrolysates showed characteristic peaks in 1200-900 cm^-1 region indicating the presence of MOS. ¹H &¹³C NMR spectra showed presence of anomeric sugar forms of MOS in different mannan hydrolysates. MOS from locust bean gum and guar gum had both α- and β-anomers while PKC and CM had only α-anomer. Growth promotional activities of different MOS were demonstrated using two probiotic Lactobacilli. Besides, enzymatically derived MOS also showed metal (Fe²⁺) chelating and anti-oxidant activities, wherein best anti-glycating agent was evaluated as MOS from PKC. PKC derived MOS showed highest cytotoxicity (74.19%) against human colon adenocarcinoma cell line (Caco-2). This study demonstrated the prebiotic potential of agro-waste derived MOS and possibility of their utilization as a functional food ingredient.

Antiglycation and antioxidant activity of four Iranian medical plant extracts

Objective

Diabetes mellitus (DM) is the most common metabolic disorder that defined by chronic hyperglycemia for the deficiency in insulin secretion or resistance. Hyperglycemia could induce non-enzymatic glycation of proteins. It has been suggested that some traditional plants can improve blood glucose and inhibit glycation process. This work evaluates and compares the anti-glycation activities of four Iranian plant extracts in vitro.

Methods

The methanolic extract of “Fumaria officinalis, Stachys lavandulifolia, Salvia hydrangea and Rosa Damascene” was prepared in three different concentrations. Phenolic, flavonoids content and antioxidant activity were evaluated. The multistage glycation markers-fructosamines (early stage), protein carbonyls (intermediate stage) and β aggregation of albumin were investigated in the bovine serum albumin (BSA)/ glucose systemt.

Results

All plants showed the high potency of scavenging free radicals and glycation inhibition in the following order: Fumaria officinalis> Rosa Damascene> Stachys lavandulifolia > Salvia hydrangea. There was a significant correlation between antioxidant and anti-glycation activity. Also, the antioxidant and anti-glycation capacity of extracts correlated with total phenolic and flavonoids content.

Conclusion

Our findings demonstrated that the studied plants are good sources of anti-glycation and antioxidant compounds and, these properties can primarily attributable to phenolics, particularly flavonoids.

Attenuation of glycation-induced multiple protein modifications by Indian antidiabetic plant extracts

CONTEXT

Protein glycation is the major contributing factor in the development of diabetic complications. The antiglycation potential of medicinal plants provides a promising opportunity as complementary interventions for complications.

OBJECTIVE

To investigate the antiglycation potential of 19 medicinal plants extracts using albumin by estimating different indicators: (1) glycation (early and late), (2) albumin oxidation, and (3) amyloid aggregation.

MATERIALS AND METHODS

The effect of aqueous plant extracts (1% w/v) on protein glycation was assessed by incubating albumin (10 mg/mL) with fructose (250 mM) for 4 days. Degree of protein glycation in the absence and presence of plant extracts was assessed by estimating fructosamine, advanced glycation end products (AGEs), carbonyls, free thiol group and β-amyloid aggregation.

RESULTS

Petroselinum crispum, Boerhavia diffusa, Terminalia chebula, Swertia chirayita and Glycyrrhiza glabra showed significant antiglycating activity. P. crispum and A. barbadensis inhibited the carbonyl stress and protected the thiol group from oxidative damage. There was significant correlation between protein thiols and amyloid inhibition (R = -.69, p < .001).

CONCLUSION

P. crispum, B. diffusa and T. chebula had the most potent antiglycation activity. These plant exerted noticeable antiglycation activity at different glycation modifications of albumin. These findings are important for identifying plants with potential to combat diabetic complications.

Therapeutic effect of Linum usitatissimum L. in STZ-nicotinamide induced diabetic nephropathy via inhibition of AGE's and oxidative stress

The present study was aimed to evaluate the potential of petroleum ether and hydro-alcoholic extract of Linum usitatissimum (FPE and FHE) in STZ-nicotinamide induced diabetic nephropathy. GC-MS analysis of FPE revealed the presence of different fatty acids, heterocyclic compounds etc. Moreover, chromatography of FHE isolated Secoisolariciresinol diglycoside. After 30 days of STZ-administration, 100, 200 and 400 mg/kg of FPE and FHE were administered for 45 days. FPE and FHE produced significant attenuation in the glycemic status, renal parameter, lipid profile and level of antioxidant enzymes proving efficacy in diabetic nephropathy. Moreover, FPE and FHE produced significant reduction in the formation of AGEs in kidney. The results indicated that via amelioration oxidative stress and formation of AGEs, FPE and FHE produced significant nephroprotective effect in STZ- induced diabetic nephropathy in rats.

Efficacy of Natural Compounds in Neurodegenerative Disorders

Neurodegenerative disorders represent clusters of serious diseases that results in progressive deterioration of normal structure and physiology of central nervous system. Pathophysiology of Alzheimer's, Parkinson's or other neurodegenerative disorders involves multifaceted permutation of genetic and environmental factors. Combinations of lifestyle modification linked with environmental factor jointly or alone represent the largest share of cases of these disorders. Etiology of such neuronal degeneration involves manifestation of toxic reaction in the form of functional anomalies leading to dysfunction of the ubiquitin-proteasome system, activated inflammatory cascade, compromised neuronal survival pathway, mitochondrial dysfunction and finally neuronal apoptosis/necrosis and cell death. Furthermore, evidences from various studies exhibited role of oxidative stress and compromised anti-oxidant defense system as one of the prime factors associated with activation of various signal transduction pathways that would ultimately lead to the formation of amyloid beta or alpha synuclein in the brain. Keeping in view of complex etiology and pathophysiology along with a miniscule of available treatment options associated with these neurodegenerative disorders, the role of natural agents and herbal extracts as therapeutic alternatives alone or in combination with synthetic drugs could not be ruled out. In the same context the present chapter has been aimed to investigate the role of selected natural plants like Withania somnifera, Bacopa monnieri, Curcuma longa, Centella asiatica, Ocimum sanctum, Nardostachys jatamansi and Emblica officinalis in various neurodegenerative disorders and explore their targets to ameliorate neurotoxicity in various experimental models. The rationale for selection of these plants was based on their strong anti-inflammatory and anti-oxidant potential and large body of evidence that suggest their efficacy in preclinical as well as in clinical studies. Active constituents if these herbals might play an important role in preserving the integrity of various neurotransmitters and their receptor in the brain influencing its functions at the molecular level.