Metabolite profiling, antioxidant activity, and glycosidase inhibition property of the mesocarp tissue extracts of sugar date palm [Phoenix sylvestris (L.) Roxb.] fruits

Comparison of phenolic composition in Australian-grown date fruit (Phoenix dactylifera L.) seeds from different varieties and ripening stages

In this research, different seeds of Australian-grown date palm (Phoenix dactylifera L.) were studied to evaluate the antioxidant potential and analyze their phenolic constituents. Phenolic compounds were extracted from seeds of various Australian-grown date varieties at different ripening stages. Eight varieties of date seeds (Zahidi, Medjool, Deglet nour, Thoory, Halawi, Barhee, Khadrawy, and Bau Strami) at three ripening stages (Kimri, Khalal, and Tamar) were investigated in this study. Date seeds at Khalal (9.87-16.93 mg GAE/g) and Tamar (9.20-27.87 mg GAE/g) stages showed higher total phenolic content than those at Kimri stage (1.81-5.99 mg GAE/g). For antioxidant assays like DPPH, FRAP, ABTS, RAP, FICA, and TAC, date seeds at Khalal and Tamar stages also showed higher antioxidant potential than Kimri stage. However, date seeds at Kimri stage (55.24-63.26 mg TE/g) expressed higher radical scavenging activity than Khalal (13.58-51.88 mg TE/g) and Tamar (11.06-50.92 mg TE/g) stages. Phenolic compounds were characterized using LC-ESI-QTOF-MS/MS, revealing the presence of 37 different phenolic compounds, including 8 phenolic acids, 18 flavonoids, and 11 other phenolic compounds. Further, phenolic compounds were quantified using LC-DAD, revealing that Zahidi variety of date seeds exhibited the highest content during the Kimri stage. In contrast, during the Khalal and Tamar stages, Deglet nour and Medjool date seeds displayed higher concentrations of phenolic compounds. The results indicated an increase in phenolic content in date seeds after the Kimri stage, with significant variations observed among different date varieties.

Comparative polyphenolic profiling of five ethnomedicinal plants and their applicative potential in the treatment of type 2 diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

The medicinal plants Salvia officinalis, Trifolium pratense, Agrimonia eupatoria, Cichorium intybus and Vinca minor are traditionally used for the prevention and treatment of numerous diseases, including diabetes.

AIM OF THE STUDY

Type 2 diabetes (T2D) is one of the most common diseases nowadays, often accompanied by oxidative stress and microbial infections. The aim of our work was to examine the antidiabetic, antioxidant, and antimicrobial properties of ethanol extracts of five medicinal plants for the purpose of their possible use in the treatment of T2D.

MATERIALS AND METHODS

The polyphenolic profile of the plant extracts was analyzed by Ultra-High Performance Liquid Chromatography with a diode array detector configured with a triple quadrupole mass spectrometer (UHPLC/DAD/(-)HESI-MS2). In vitro antidiabetic activity of extracts was determined by measuring the percentage of α-amylase and α-glucosidase inhibition. The antioxidant activity of the extract was determined by different spectrophotometric methods, while the antimicrobial activity was determined by agar dilution and disc diffusion methods.

RESULTS

A. eupatoria extract contains the highest percentage of flavonoids (94%, with isoquercetin, vitexin, and rutin as the most abundant) in relation to the concentration of total phenolic compounds and exhibits excellent antidiabetic, antioxidant, and antimicrobial activity. S. officinalis extract contains 60% flavonoids (predominately cirsimaritin and epigallocatechin gallate) and 40% phenolic acids (with rosmarinic acid being the most abundant from this group) and exhibits weak antidiabetic activity, significant antioxidant activity, and excellent antibacterial activity. A 45% percentage of flavonoids (with isoquercetin as the most abundant one) and 55% of phenolic acids (with ferulic acid as the most abundant) were measured in the extract of T. pratense, which had excellent antidiabetic activity but weaker antioxidant and antimicrobial activity. A similar percentage of flavonoids (52%, with epigallocatechin gallate in the highest concentration) and phenolic acids (48%, with chlorogenic acid as the most abundant) was measured in the extract of C. intybus which showed moderate antidiabetic, antioxidant, and antimicrobial properties. The extract of V. minor was the richest in phenolic acids (80%, with the most abundant chlorogenic acid), which resulted in weaker antidiabetic and antioxidant activities (except for Fe2+ chelating ability) and antimicrobial activity.

CONCLUSION

The results indicate that specific phenolic compounds are responsible for the different biological activities of the plant extracts. Among the investigated plants, the extract of A. eupatoria has the greatest potential for applications in the treatment of T2D.

Untargeted metabolomics analysis of four date palm (Phoenix dactylifera L.) cultivars using MS and NMR

Since ancient times, the inhabitants of dry areas have depended on the date palm (Phoenix dactylifera L.) as a staple food and means of economic security. For example, dates have been a staple diet for the inhabitants of the Arabian Peninsula and Sahara Desert in North Africa for millennia and the local culture is rich in knowledge and experience with the benefits of dates, suggesting that dates contain many substances essential for the human body. Madinah dates are considered one of the most important types of dates in the Arabian Peninsula, with Ajwa being one of the most famous types and grown only in Madinah, Saudi Arabia. Date seeds are traditionally used for animal feed, seed oil production, cosmetics, and as a coffee substitute. Phytochemical compounds that have been detected in date fruits and date seeds include phenolic acids, carotenoids, and flavonoids. Phenolic acids are the most prevalent bioactive constituents that contribute to the antioxidant activity of date fruits. The bioactive properties of these phytochemicals are believed to promote human health by reducing the risk of diseases such as chronic inflammation. Ajwa dates especially are thought to have superior bioactivity properties. To investigate these claims, in this study, we compare the metabolic profiles of Ajwa with different types of dates collected from Saudi Arabia and Tunisia. We show by UHPLC-MS that date seeds contain several classes of flavonoids, phenolic acids, and amino acid derivatives, including citric acid, malic acid, lactic acid, and hydroxyadipic acid. Additionally, GC-MS profiling showed that date seeds are richer in metabolite classes, such as hydrocinnamic acids (caffeic, ferulic and sinapic acids), than flesh samples. Deglet N fruit extract (minimum inhibitory concentration: 27 MIC/μM) and Sukkari fruit extract (IC50: 479 ± 0.58μg /mL) have higher levels of antibacterial and antioxidative activity than Ajwa fruits. However, the seed analysis showed that seed extracts have better bioactivity effects than fruit extracts. Specifically, Ajwa extract showed the best MIC and strongest ABTS radical-scavenging activity among examined seed extracts (minimum inhibitory concentration: 20 μM; IC50: 54 ± 3.61μg /mL). Our assays are a starting point for more advanced in vitro antibacterial models and investigation into the specific molecules that are responsible for the antioxidative and anti-bacterial activities of dates.

A Comparison of the Nutritional and Biochemical Quality of Date Palm Fruits Obtained Using Different Planting Techniques

Date palm fruit (Phoenix dactylifera L.) is commonly consumed around the world and has recently become an economical crop in Eastern Thailand, especially the Barhi cultivar that can be consumed as fresh fruit. To maintain genetic qualities, date palm is populated through cell culture. This leads to high production costs, while access to this technique is limited. Increasing date palm population by simple seed planting is currently of interest as an alternative for local farmers. Nevertheless, information on nutritive values, bioactive compounds, and health-promoting bioactivities of seed originating from date palm fruit is unavailable. Effects of different planting origins (cell culture origin (CO) and seed origin (SO)) of date palm fruits at the Khalal stage of Barhi cultivar were investigated for nutritive values, bioactive compounds, and in vitro health-promoting properties via key enzyme inhibitions against obesity (lipase), diabetes (α-amylase, α-glucosidase, and dipeptidyl peptidase-IV), Alzheimer's disease (cholinesterases and β-secretase), and hypertension (angiotensin-converting enzyme). Waste seeds as a by-product from date palm production were also examined regarding these properties to increase seed marketing opportunities for future food applications and other health-related products. CO and SO exhibited insignificant differences in energy, fat, and carbohydrate contents. SO had higher protein, dietary fiber, vitamin A, vitamin E, and calcium contents than CO, while CO contained higher contents of fructose, glucose and maltose. Higher phenolic contents in SO led to greater enzyme inhibitory activities than CO. Interestingly, seeds of date palm fruits mostly contained higher nutritive values than the flesh. No carotenoids were detected in seeds but higher phenolic contents resulted in greater enzyme inhibitory activities than recorded for fruit flesh. Results suggest that appropriate planting of date palm can support the development of novel date palm fruit products, leading to expansion of economic opportunities and investment in date palm fruit agriculture.

In silico design of enzyme α-amylase and α-glucosidase inhibitors using molecular docking, molecular dynamic, conceptual DFT investigation and pharmacophore modelling

Type 2 diabetes mellitus (T2DM) is characterized by elevated blood glucose levels and can lead to serious complications such as nephropathy, neuropathy, retinopathy and cardiovascular disease. The aim of this work is to identify and investigate the inhibition mechanism of natural flavonoids and phenolics acids against, the α-amylase (αA) and α-glucosidase (αG). Therefore, we used different approaches; such as conceptual DFT and pharmacophore mapping in addition to molecular mechanics, dynamics and docking simulations. Whereas, a close agreement was found out to decide that Linarin (Flavones) provides more optimized inhibition of αA and αG enzymes. Our results have shown that Linarin could be useful as preventative agent, and possibly therapeutic modality for the treatment of metabolic diseases.Communicated by Ramaswamy H. Sarma.

LC-ESI-QTOF/MS Characterization of Phenolic Compounds in Palm Fruits (Jelly and Fishtail Palm) and Their Potential Antioxidant Activities

Palm fruits have gained growing attention for their nutrition values and health promotion perspectives. They have a diverse range of bioactive compounds including carotenoids, vitamins, dietary fibres and especially polyphenolic compounds. These polyphenolic compounds contribute to the putative health benefits of palm fruits. Nevertheless, the detailed information about these polyphenols in palm fruits is limited. The present work was conducted to comprehensively characterize polyphenols in two palm fruits, jelly palm (Butia ordorata) and fishtail palm (Caryota uren), using liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS) and assess their antioxidant potential. The total phenolic content (TPC), total tannins content (TTC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant assay and 2,2′-azinobis-(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS) scavenging abilities and ferric reducing antioxidant power (FRAP) were higher in the jelly palm fruit while total flavonoid contents (TFC) were higher in the fishtail palm. The LC-ESI-QTOF/MS tentatively identified a total of 86 phenolic compounds in both jelly and fishtail palm fruits. Although both palm fruits exhibited different phenolic profiles, hydroxycinnamic acids and flavonols were the most common in both. In high performance liquid chromatography photodiode array (HPLC-PDA) quantification, 4-hydroxybenzoic acid (317.46 ± 4.68 µg/g) and catechin (4724.00 ± 32.39 µg/g) were the most abundant phenolic acid and flavonoid quantified in the jelly palm fruit, respectively. Quercetin (557.28 ± 7.81 µg/g) and kaempferol 3-O-glucoside (220.99 ± 2.06 µg/g) were the most abundant flavonoids quantified in the fishtail palm. Our study indicates that palm fruit is a good source of polyphenols and has strong antioxidant potential for health promotion. Furthermore, this study provides the scientific basis for an exploitation of jelly and fishtail palm fruits in the food, pharmaceutical and nutraceutical industries.