CHEMICAL CHARACTERIZATION OF A HYPOGLYCEMIC EXTRACT FROM CUCURBITA FICIFOLIA BOUCHE THAT INDUCES LIVER GLYCOGEN ACCUMULATION IN DIABETIC MICE

Effect of Cucurbita ficifolia Bouché on glutathione level and glycosylated hemoglobin percentage in a Mexican rural population with type 2 diabetes

ETHNOPHARMACOLOGICAL IMPORTANCE

Cucurbita ficifolia Bouché fruit is widely used in Mexican traditional medicine to treat type 2 diabetes (T2D) because it has been attributed with antioxidant and hypoglycemic properties in different experimental models and T2D patients. An imbalance in physiological glutathione (GSH) concentrations increases the susceptibility to developing complications associated with oxidative stress in T2D patients.

AIM OF THE STUDY

To investigate the effect of C. ficifolia on the antioxidant properties of GSH, general health measurements, and biochemical parameters in a Mexican rural population, and to evaluate the changes in socio-affective scores of patients due to improvement in T2D.

MATERIALS AND METHODS

Twenty-seven women diagnosed with T2D with poor glycemic control volunteered and were divided into two groups: C. ficifolia (0.5 g/kg of fresh pulp weight) with hypoglycemic pharmacotherapy, and another group with only hypoglycemic pharmacotherapy, for 12 weeks. We evaluated the effect of the fresh pulp of C. ficifolia on body mass index, blood pressure, glucose, glycosylated hemoglobin, cholesterol, triglycerides, and GSH. Expanding the study, we evaluated the quality of life, anxiety, and depression scores before and after the intervention.

RESULTS

Treatment with the fresh pulp of C. ficifolia for 12 weeks reduced glycosylated hemoglobin, similar to the hypoglycemic pharmacotherapy group, and significantly increased GSH concentrations. The patients' moods did not change despite increased GSH concentrations and improved T2D control.

CONCLUSIONS

The increased GSH concentrations due to the consumption of fresh pulp of C. ficifolia could help to protect against oxidative stress and extend therapeutic benefits in addition to the usual hypoglycemic drugs in patients with T2D.

Spray-Drying Microencapsulation of Bauhinia ungulata L. var. obtusifolia Aqueous Extract Containing Phenolic Compounds: A Comparative Study Using Different Wall Materials

Species belonging to the Bauhinia genus, usually known as "pata-de-vaca", are popularly used to treat diabetes. Bauhinia ungulata var. obtusifolia (Ducke) Vaz is among them, of which the leaves are used as a tea for medicinal purposes in the Amazon region. A microencapsulation study of lyophilized aqueous extract from Bauhinia ungulata leaves, which contain phenolic compounds, using five different wall materials (maltodextrin DE 4-7, maltodextrin DE 11-14; β-cyclodextrin; pectin and sodium carboxymethylcellulose) is described in this paper. The microstructure, particle size distribution, thermal behavior, yield, and encapsulation efficiency were investigated and compared using different techniques. Using high-performance liquid chromatography, phenolics, and flavonoids were detected and quantified in the microparticles. The microparticles obtained with a yield and phenolics encapsulation efficiency ranging within 60-83% and 35-57%, respectively, showed a particle size distribution between 1.15 and 5.54 µm, spherical morphology, and a wrinkled surface. Among them, those prepared with sodium carboxymethylcellulose or pectin proved to be the most thermally stable. They had the highest flavonoid content (23.07 and 21.73 mg RUTE/g Extract) and total antioxidant activity by both the DPPH (376.55 and 367.86 µM TEq/g Extract) and ABTS (1085.72 and 1062.32 µM TEq/g Extract) assays. The chromatographic analyses allowed for quantification of the following substances retained by the microparticles, chlorogenic acid (1.74-1.98 mg/g Extract), p-coumaric acid (0.06-0.08 mg/g Extract), rutin (11.2-12.9 mg/g Extract), and isoquercitrin (0.49-0.53 mg/g Extract), compounds which considered to responsible for the antidiabetic property attributed to the species.

Antidiabetic and Toxicological Effects of the Tea Infusion of Summer Collection from Annona cherimola Miller Leaves

Annona cherimola Miller (Ac) is a plant used in Mexican traditional medicine for the treatment of diabetes. In this work, the tea infusion extracts obtained from 1.5 g of leaf powder from Ac collected in May (AcMa), June (AcJun), July (AcJul), and August (AcAu) were evaluated on streptozocin-induced diabetic (STID) mice and for subchronic toxicity in STID and non-diabetic (ND) mice. In addition, extracts were subjected to high-performance liquid chromatography with diode array detection (HPLC-DAD). Results showed that the tea infusion extract of the sample collected in August (AcAu) exhibited the most significant antihyperglycemic activity during all acute assays. The analysis of the extracts (AcMa, AcJu, AcJul, and AcAu) by HPLC-DAD revealed that flavonoid glycosides, rutin, narcissin, and nicotiflorin were the major components. In addition, the sample AcAu contained the best concentration of flavonoids. In the case of subchronic oral toxicity, the AcAu sample did not cause mortality in STID mice, and histopathological analysis revealed significant improvement in the changes associated with diabetes in the liver and kidneys. These findings suggest that the Ac leaves collected in August may be a source of flavonoids such as rutin, with antidiabetic potential. In addition, these findings support the use of Ac to treat diabetes in traditional medicine.

Fermentation of the Cucurbita ficifolia Fruit Juice: Its Antioxidant Activity and Effects on the Glycemia

Cucurbita ficifolia is an edible plant whose fruits have hypoglycemic, anti-inflammatory, and antioxidant activities. Fermentation might improve these properties. This research aims to perform and characterize its fermentation in native and induced conditions with Lactobacillus plantarum (Lp) and evaluate its antioxidant activity and effect on glycemia. Fresh juice from mature fruits was characterized. One portion of this juice was spontaneously left to ferment (native fermentation), and the other was inoculated with Lp (controlled fermentation). Fermentation was monitored each 8 h by 56 h to measure microbial growth, pH, acidity, sugars, soluble protein, polyphenols and flavonoids, antioxidant activity, and effects on glycemia. In native fermentation, the growth of total microorganisms increased up to 32 h, decreasing at the end of the process. In Lp fermentation, total microorganisms increased until 16 h to stay constant at the end, with a predominance of Lp. The pH and the sugars decreased in the two fermentations, while polyphenol and flavonoid increased. In spontaneous fermentation, these changes were lesser. Both fermentations, like fresh juice, preserve functional properties (antioxidant, alpha-glucosidase inhibition, and hypoglycemia). The fermentation of this juice with Lp may develop functional beverages, which is significant due to its consumption as an edible fruit with medicinal properties.

4-Hydroxybenzoic Acid and β-Sitosterol from Cucurbita ficifolia Act as Insulin Secretagogues, Peroxisome Proliferator-Activated Receptor-Gamma Agonists, and Liver Glycogen Storage Promoters: In Vivo, In Vitro, and In Silico Studies

Insulin secretion and GLUT4 expression are two critical events in glucose regulation. The receptors G-protein-coupled receptor 40 (GPR40) and peroxisome proliferator-activated receptor-gamma (PPARγ) modulate these processes, and they represent potential therapeutic targets for new antidiabetic agent's design. Cucurbita ficifolia fruit is used in traditional medicine for diabetes control. Previous studies demonstrated several effects: a hypoglycemic effect mediated by an insulin secretagogue action, antihyperglycemic effect, and promoting liver glycogen storage. Anti-inflammatory and antioxidant effects were also reported. Moreover, some of its phytochemicals have been described, including d-chiro-inositol. However, to understand these effects integrally, other active principles should be investigated. The aim was to perform a chemical fractionation guided by bioassay to isolate and identify other compounds from C. ficifolia fruit that explain its hypoglycemic action as insulin secretagogue, its antihyperglycemic effect by PPARγ activation, and on liver glycogen storage. Three different preparations of C. ficifolia were tested in vivo. Ethyl acetate fraction derived from aqueous extract showed antihyperglycemic effect in an oral glucose tolerance test and was further fractioned. The insulin secretagogue action was tested in RINm5F cells. For the PPARγ activation, C2C12 myocytes were treated with the fractions, and GLUT4 mRNA expression was measured. Chemical fractionation resulted in the isolation and identification of β-sitosterol and 4-hydroxybenzoic acid (4-HBA), which increased insulin secretion, GLUT4, PPARγ, and adiponectin mRNA expression, in addition to an increase in glycogen storage. 4-HBA exhibited an antihyperglycemic effect, while β-sitosterol showed hypoglycemic effect, confirming the wide antidiabetic related results we found in our in vitro models. An in silico study revealed that 4-HBA and β-sitosterol have potential as dual agonists on PPARγ and GPR40 receptors. Both compounds should be considered in the development of new antidiabetic drug development.

Selected Species of the Cucurbitaceae Family Used in Mexico for the Treatment of Diabetes Mellitus

In Mexico, Diabetes mellitus (DM) is a serious health problem, and although the current pharmacological treatments for DM such as insulin and oral hypoglycemics are available, the Mexican population continues to use medicinal plants in the treatment of DM. The antidiabetic properties of the plant species that belong to the Cucurbitaceae family has already been recognized worldwide. Since Mexico is one of the most important centers of diversity of Cucurbitaceae, the present work contributes to the review of the most used species of Cucurbitaceae in the treatment of DM in Mexico. The reviewed species (Cucurbita ficifolia, C. maxima, C. moschata, C. pepo, Ibervillea sonorae, Sechium edule, Citrullus lanatus, Cucumis melo, and C. sativus) revealed that the antidiabetic effects exerted are effective in a number of mechanisms involved in the complex pathogenesis of DM: hypoglycemic, antioxidant, anti-inflammatory, anti-obesity, protective effects on diverse organs and cells, as well as in the control of dyslipidemias; furthermore, the select species of the Cucurbitaceae family could also be essential components of diets for the control of DM in patients with the disease. Thus, the Cucurbitaceae species selected in the present work represent a source of antidiabetic agents that perhaps establish the bases for novel clinical treatments.

Contrasting Metabolic Fingerprints and Seed Protein Profiles of Cucurbita foetidissima and C. radicans Fruits from Feral Plants Sampled in Central Mexico

Cucurbita foetidissima and C. radicans are scarcely studied wild pumpkin species that grow in arid and semi-arid areas of Mexico and the United States. This study describes the morphological, proximal composition, metabolic finger-prints and seed protein profiles of C. foetidissima and C. radicans fruits collected in the wild during a one-year period in different locations of central-western Mexico. The results obtained complement the limited information concerning the fruit composition of C. foetidissima and greatly expand information in this respect regarding C. radicans. Morphology and proximal composition of their fruits varied significantly. Different metabolic fingerprints and seed protein profiles were detected between them and also with the chemical composition of domesticated Cucurbita fruits. The neutral lipids in seed, pulp and peels were rich in wax content and in unsaturated compounds, probably carotenoids and tocopherols, in addition to tri-, di- and mono-acylglycerols. The tri- and diacylglycerol profiles of their seed oils were different from commercial seed oils and between each other. They also showed unusual fatty acid compositions. Evidence of a possible alkaloid in the pulp and peel of both species was obtained in addition to several putative cucurbitacins. An abundance of phenolic acids was found in all fruit parts, whereas flavonoids were only detected in the peels. Unlike most cucurbits, globulins were not the main protein fraction in the seeds of C. radicans, whereas the non-structural carbohydrate and raffinose oligosaccharide content in their fruit parts was lower than in other wild cucurbit species. These results emphasize the significantly different chemical composition of these two marginally studied Cucurbita species, which was more discrepant in C. radicans, despite the notion regarding C. foetidissima as an aberrant species with no affinity to any other Cucurbita species.

Hypoglycemic effect and bioactive compounds associated with the ripening stages of the Cucurbita ficifolia Bouché fruit

BACKGROUND

The fruit of Cucurbita ficifolia Bouché is known in Mexico as 'chilacayote'. The scientific interest that C. ficifolia Bouché has acquired is due to its important hypoglycemic effect. The present research aimed (i) to discover whether this hypoglycemic property is present at different stages of development of this fruit, and (ii) to characterize some bioactive compounds with antioxidant or anti-inflammatory properties. Ethylene production, respiration rate, and maturity indices were determined during fruit development. The chemical characterization of the aqueous extracts of each stage of maturity studied was determined and their hypoglycemic effects were bioassayed using groups of normal mice with diabetes induced by streptozotocin at a dose of 500 mg^-1 kg^-1 body weight.

RESULTS

Respiration rate and ethylene production showed a typical pattern for non-climacteric fruit and the quality parameters did not show significant changes. Phenolic compounds such as gallic acid and chlorogenic acid were found to have the highest concentration at 15 days of development. Extracts at 15 days showed a hypoglycemic effect that was 11% greater than that of glibenclamide in diabetized mice.

CONCLUSION

All stages of development of C. ficifolia fruit had a hypoglycemic effect; however, the aqueous extract from the fruit at 15 days of development showed a better effect than glibenclamide. This finding highlights the potential of this maturity stage, and shows that it is appropriate for inclusion in treatments of type 2 diabetes mellitus. The results also indicate that phenolic compounds are mainly responsible for this effect and not d-chiro-inositol as previously thought. © 2020 Society of Chemical Industry.

Molecules Isolated from Mexican Hypoglycemic Plants: A Review

Like in many developing countries, in Mexico, the use of medicinal plants is a common practice. Based on our own field experience, there are at least 800 plants used for treating diabetes nowadays. Thus, their investigation is essential. In this context, this work aims to provide a comprehensive and critical review of the molecules isolated from Mexican hypoglycemic plants, including their source and target tested. In the last few years, some researchers have focused on the study of Mexican hypoglycemic plants. Most works describe the hypoglycemic effect or the mechanism of action of the whole extract, as well as the phytochemical profile of the tested extract. Herein, we analyzed 85 studies encompassing 40 hypoglycemic plants and 86 active compounds belonging to different classes of natural products: 28 flavonoids, 25 aromatic compounds, other than flavonoids, four steroids, 23 terpenoids, 4 oligosaccharides, and 1 polyalcohol. These compounds have shown to inhibit α-glucosidases, increase insulin secretion levels, increase insulin sensitivity, and block hepatic glucose output. Almost half of these molecules are not common metabolites, with a narrow taxonomic distribution, which makes them more interesting as lead molecules. Altogether, this analysis provides a necessary inventory useful for future testing of these active molecules against different hypoglycemic targets, to get a better insight into the already described mechanisms, and overall, to contribute to the knowledge of Mexican medicinal plants.

Diabetes and plant-derived natural products: From ethnopharmacological approaches to their potential for modern drug discovery and development

Diabetes is a disease of serious concern faced by the health care industry today. Primary diabetes mellitus and its complications are still costly to manage with modern drugs. Extensive research on the screening of anti-diabetic agents in past decades established natural products as one of the major potential sources of drug discovery. However, only a few drugs of plant origin have been scientifically validated. Therefore, the development of new anti-diabetic drugs is of great demand. Hence, natural products could be explored as potential anti-diabetic drugs. Natural plants derived extracts and molecules like berberine, ginsenosides, curcumin, stevioside, gingerols, capsaicin, catechins, simple phenolic compounds, anthocyanins, resveratrol, genistein and hesperidin obtained from different species are used for curing diabetes and found to possess different action mechanisms. In this review, the importance of medicinal plants and their active constituents for anti-diabetic agents are described. The present study also emphasized the importance of diabetes control, reduction in its complications and use of the anti-diabetic agents. The detailed action mechanism of these extracts/compounds for their activities are also described. However, the anti-diabetic drugs from plant origin require scientific validation through animal and clinical studies to exploit in terms of modern commercial medicines.

Gold nanoparticles synthesized with Smilax glabra rhizome modulates the anti-obesity parameters in high-fat diet and streptozotocin induced obese diabetes rat model

Diabetes is a major emerging health consequence across the world which directly associated with the obesity. Contemporary anti-diabetic drugs have numeral limitations, and investigation of herbal remedies for diabetes give novel guide for the expansion of new drugs that can be used as harmonizing to present anti-diabetic allopathic medications. Gold nanoparticles (AuNPs) of 21 nm have been formerly well portrayed in vitro for their capability to intend active uptake in cell. Our present study was dealing with the synthesis of gold nanoparticles by means of Smilax glabra rhizome amend the anti-obesity constraints in high-fat diet by streptozotocin provoked obese diabetes in rat model. Characterization studies like UV -Spectroscopy, XRD analysis, SEM, TEM microscopy, Energy Dispersive X-Ray Spectroscopy, and FT-IR investigation confirms the availability of dimension, shape and size. Biochemical parameters like blood glucose and insulin sufferance and its release, lipid profile, aterogenic & coronary index, liver markers, inflammatory markers, hormones like leptin, resistin, adiponectin indicates the therapeutic effect of gold nanoparticles harvested from Smilax glabra on obese and diabetic rats. Histopathological examinations displayed the disturbed internal structures of obese and diabetic rats liver and heart tissues. Whereas, treatment with gold nanoparticles synthesized from Smilax glabra restored the internal membrane, nuclei and cytoplasm. All these findings confirmed the anti-obesity and anti-diabetic effect of synthesized gold nanoparticles from Smilax glabra.

Cucurbita Plants: From Farm to Industry

The Cucurbita genus, a member of Cucurbitaceae family, also known as cucurbits, is native to the Americas. Genus members, like Cucurbita pepo and Cucurbita maxima, have been used for centuries in folk medicine for treating gastrointestinal diseases and intestinal parasites. These pharmacological effects are mainly attributed to their phytochemical composition. Indeed, Cucurbita species are a natural source of carotenoids, tocopherols, phenols, terpenoids, saponins, sterols, fatty acids, functional carbohydrates, and polysaccharides, that beyond exerting remarkable biological effects, have also been increasingly exploited for biotechnological applications. In this article, we specifically cover the habitat, cultivation, phytochemical composition, and food preservative abilities of Cucurbita plants.