Extraction of phenolic compounds from Vitex agnus-castus L

Metabolic profiling of Vitex Pubescens Vahl bark via UPLC-ESI-QTOF/MS/MS analysis and evaluation of its antioxidant and acetylcholinesterase inhibitory activities

BACKGROUND

Alzheimer's disease is a neurodegenerative age-related disease that primarily affects the elderly population leading to progressive memory impairments and neural deficits. It is counted as a major cause of geriatric dependency and disability. The pathogenesis of Alzheimer's disease incidence is complex and involves various hypotheses, including the cholinergic hypothesis, deposition of β-amyloid plaques, neuroinflammation, oxidative stress, and apoptosis. Conventional treatments such as donepezil aim to delay the symptoms but do not affect the progression of the disease and may cause serious side effects like hepatoxicity. The use of natural candidates for Alzheimer's disease treatment has drawn the attention of many researchers as it offers a multitargeted approach.

METHODS

This current study investigates the metabolic profiles of total defatted methanolic extract of Vitex pubescens bark and its polar fractions, viz. ethyl acetate and n-butanol, using ultra-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight tandem mass spectrometry(UPLC-ESI-QTOF/MS/MS) technique as well as evaluate the antioxidant using free radical scavenging assays, viz. DPPH and ABTS assays and in-vitro acetylcholinesterase inhibitory activities using Ellman's microplate assay.

RESULTS

Metabolic profiling revealed a total of 71, 43, and 55 metabolites tentatively identified in the defatted methanolic extract, ethyl acetate, and n-butanol fractions, respectively. Phenolic acids were the most abundant class, viz. benzoic acids, and acyl quinic acid derivatives followed by flavonoids exemplified mainly by luteolin-C-glycosides and apigenin-C-glycosides. Quantification of the total phenolic and flavonoid contents in the total defatted methanolic extract confirmed its enrichment with phenolics and flavonoids equivalent to 138.61 ± 9.39 µg gallic acid/mg extract and 119.63 ± 4.62 µg rutin/mg extract, respectively. Moreover, the total defatted methanolic extract exhibited promising antioxidant activity confirmed through DPPH and ABTS assays with a 50% inhibitory concentration (IC50) value equivalent to 52.79 ± 2.16 µg/mL and 10.02 ± µg/mL, respectively. The inhibitory activity of acetylcholine esterase (AchE) was assessed using in-vitro Ellman's colorimetric assay, the total defatted methanolic extract, ethyl acetate, and n-butanol fractions exhibited IC50 values of 52.9, 15.1 and 108.8 µg/mL that they proved the significant inhibition of AchE activity.

CONCLUSION

The results obtained herein unraveled the potential use of the total methanolic extract of Vitex pubescens bark and its polar fractions as natural candidates for controlling Alzheimer's disease progression.

Exploring Plants with Flowers: From Therapeutic Nutritional Benefits to Innovative Sustainable Uses

Flowers have played a significant role in society, focusing on their aesthetic value rather than their food potential. This study's goal was to look into flowering plants for everything from health benefits to other possible applications. This review presents detailed information on 119 species of flowers with agri-food and health relevance. Data were collected on their family, species, common name, commonly used plant part, bioremediation applications, main chemical compounds, medicinal and gastronomic uses, and concentration of bioactive compounds such as carotenoids and phenolic compounds. In this respect, 87% of the floral species studied contain some toxic compounds, sometimes making them inedible, but specific molecules from these species have been used in medicine. Seventy-six percent can be consumed in low doses by infusion. In addition, 97% of the species studied are reported to have medicinal uses (32% immune system), and 63% could be used in the bioremediation of contaminated environments. Significantly, more than 50% of the species were only analysed for total concentrations of carotenoids and phenolic compounds, indicating a significant gap in identifying specific molecules of these bioactive compounds. These potential sources of bioactive compounds could transform the health and nutraceutical industries, offering innovative approaches to combat oxidative stress and promote optimal well-being.

Wild Vitex agnus-castus L.: Phytochemical Characterization, Acute Toxicity, and Bioactive Properties

Wild Vitex agnus-castus (VAC) is a Mediterranean plant that is rich in bioactive metabolites. This study aimed to validate, for the first time, the beneficial use of VAC fruits and fruit decoctions (VFDs) through in vitro and in vivo trials. Forty-one volatile components were detected in VAC fruits, with 1,8-cineole (30.3%) comprising the majority. The antioxidant activity of VFD was measured by using different in vitro methods (EC₅₀ of 0.16 mg/mL by β-carotene bleaching inhibition assay) and by measuring the DNA protection power. Using the disc diffusion assay, the antimicrobial activity of VFD was evaluated, and it exhibited a noticeable anticandidal activity. VFD did not cause any toxicity or mortality in rats treated with doses > 200 mg/kg. Using the acetic acid writhing test, the antinociceptive activity of VFD was measured. Our results showed that VFD at 200 mg/kg exhibited a higher analgesic activity (81.68%) than acetylsalicylic acid used as a positive control (74.35%). Its gastroprotective ability was assessed by HCl/ethanol-induced gastric lesions, which were remarkably inhibited (84.62%) by intraperitoneal administration of VFD. This work helps to validate the popular use of VAC to treat nociceptive, inflammatory, and gastric disorders and encourages researchers to further investigate the identification of pharmacological compounds from this species.

Supercritical Fluid Extraction in Resveratrol Isolation Technology

The article discusses the use of supercritical fluid extraction in the technology for the isolation of resveratrol, a phenolic compound found in Vitis vinifera L. A technology was developed for obtaining the sum of polyphenolic compounds with a quantitative content of resveratrol. As a raw material for the production of the substance, Vitis pomace was used after the production of wine and juice, which makes it possible to introduce complex processing of plant raw materials. For the first time, by the method of carbon dioxide extraction, the conditions for the isolation of resveratrol from Vitis pomace raw materials of the Kazakhstani varieties Saperavi and Cabernet were optimized. The influence of pressure (from 10 to 35 MPa), duration (from 60 to 180 min), temperature (from 50 to 70 °C) was studied when optimizing the extraction mode. The quantitative content of resveratrol in carbon dioxide extracts was determined by high-performance liquid chromatography( HPLC). The optimal parameters for the extraction of Vitis vinifera L. pomace (pressure, duration, temperature) were established, which provide a relatively high content of resveratrol in the extracts.

Phenolic Compound Analysis and Pharmacological Screening of Vitex agnus-castus Functional Parts

Vitex agnus-castus is a medicinal plant of the Verbenaceae family, widely used in traditional medicine. This study is aimed at investigating the functional variability of phenolic compounds in different parts (leaves, stems, flowers, roots, and seeds) of Vitex agnus-castus methanolic extracts and at assessing their in vitro antidiabetic, antioxidant, and antibacterial activities. The results of HPLC-DAD-QTOF-MS indicated the presence of 25 phenolic compounds with a remarkable variability between plant parts; high levels were registered in chlorogenic, vanillic, 3,4-dihydroxybenzoic, and 3-hydroxybenzoic acids; hesperidin; and luteolin. V. agnus castus fruits and stems presented higher antioxidant activities. The extracts inhibited the growth of five pathogenic bacteria with MIC values documented between 7.81 and 31.25 mg/mL. In vitro antihyperglycemic effect revealed higher effect in flowers (2921.84 μg/mL) and seeds (2992.75 μg/mL) against α-glucosidase and of leaves (2156.80 μg/mL) and roots (2357.30 μg/mL) against α-amylase. The findings of this showed that V. agnus castus is a promising source for antidiabetic bioactive compounds. However, further investigations regarding the evaluation of in vivo antidiabetic effects of these compounds are needed.

Vitex Diterpenoids: Structural Diversity and Pharmacological Activity

Plants of the genus Vitex (Verbenaceae) are mainly distributed throughout tropical and temperate regions, and many Vitex plants have been traditionally used in folk medicine. Plants of this genus are a rich source of diterpenoids, which not only displayed versatile structural diversity with potential chemotaxonomical significance but also exhibited a wide range of biological activities, mainly including in vitro cytotoxic, antiinflammatory, antimicrobial, hormone level-regulating and antiangiogenic activities. Recently, a series of bioactive diterpenoids, with interesting carbon skeletons, have been reported and gathered considerable interest. This article systematically reviewed diterpenoids isolated from the genus Vitex that appeared in the literature up to December 2018, critically highlighting their structural diversity and pharmacological activities. Up to now, a total of 154 diterpenoids with diverse structures have been isolated and identified from Vitex plants. The authors also summarized the reported structure-activity relationships of those well explored Vitex diterpenoids. Finally, the authors discussed the challenges and potential applications of these diterpenoids in the future.

A Bioactive Olive Pomace Extract Prevents the Death of Murine Cortical Neurons Triggered by NMDAR Over-Activation

We have recently demonstrated that bioactive molecules, extracted by high pressure and temperature from olive pomace, counteract calcium-induced cell damage to different cell lines. Here, our aim was to study the effect of the same extract on murine cortical neurons, since the preservation of the intracellular Ca²⁺-homeostasis is essential for neuronal function and survival. Accordingly, we treated neurons with different stimuli in order to evoke cytotoxic glutamatergic activation. In these conditions, the high-pressure and temperature extract from olive pomace (HPTOPE) only abolished the effects of N-methyl-d-aspartate (NMDA). Particularly, we observed that HPTOPE was able to promote the neuron rescue from NMDA-induced cell death. Moreover, we demonstrated that HPTOPE is endowed with the ability to maintain the intracellular Ca²⁺-homeostasis following NMDA receptor overactivation, protecting neurons from Ca²⁺-induced adverse effects, including aberrant calpain proteolytic activity. Moreover, we highlight the importance of the extraction conditions used that, without producing toxic molecules, allow us to obtain protecting molecules belonging to proanthocyanidin derivatives like procyanidin B2. In conclusion, we can hypothesize that HPTOPE, due to its functional and nontoxic properties on neuronal primary culture, can be utilized for future therapeutic interventions for neurodegeneration.

Inhibition of Fusarium culmorum, Penicillium chrysogenum and Rhizoctonia solani by n-hexane extracts of three plant species as a wood-treated oil fungicide

AIMS

Wood as a packing tool is used for packaging and transportation of fruits and vegetables for a time period varying from hours to days. During transportation, fruits and vegetables can be affected by moulds with significant postharvest problems. The present study describes the possibility of using wood-treated oil fungicide of n-hexane extracts from Eucalyptus camaldulensis (aerial parts), Vitex agenus-castus (leaves) and Matricaria chamomilla (flowers) against the infestation of Fusarium culmorum, Rhizoctonia solani and Penicillium chrysogenum.

METHODS AND RESULTS

Air-dried wood samples of Melia azedarach were prepared with the dimensions of 0·5 × 1 × 2 cm and treated with the oily extracts at the concentrations of 0, 1, 2 and 3%. Oils extracted with n-hexane from E. camaldulensis and V. agenus-castus showed promising antifungal activities against the isolated and molecularly identified three fungi F. culmorum, R. solani and P. chrysogenum, while M. chamomilla observed the lowest activity against the studied fungi. GC/MS analysis of oils reported that the major components in E. camaldulensis were β-fenchol (25·51%), Cyclobuta[1,2:3,4]dicyclooctene-1,7(2H,6bH)-dione,dodecahydro,(6αβ,6βα,12αα,12ββ)- (17·05), 1,8-cineole (eucalyptol) (12·01%) and sabinene (9·45%); in V. agenus-castus were eucalyptol (22·17%), (E)-β-caryophyllene (18·39%), and β-sitosterol (12·44%); while in M. chamomilla were bisabolol oxide A (27·87%), (Z)-β-farnesene (16·11%), D-limonene (14·18%) and chamazulene (11·27%).

CONCLUSIONS

The results suggest using n-hexane oily extracts from E. camaldulensis and V. agenus-castus as a biofungicide for wood protection.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlights the importance of using bio-friendly fungicide agents to protect wood against most common moulds occurring during handling of food packaging.

Enhanced production of the pharmaceutically important polyphenolic compounds in Vitex agnus castus L. shoot cultures by precursor feeding strategy

Agitated Vitex agnus castus L. shoot cultures were established to analyse the content of selected pharmaceutically important flavonoids and phenolic acids. Two variants (selected from nine ones) of MS medium were prepared: A (BAP 1 mg/L; NAA 0.5 mg/L; GA₃ 0.25 mg/L) and B (BAP 2 mg/L; NAA 0.5 mg/L). The biomass was harvested after 1, 2, 3,4, 5 and 6 weeks. Four-week cultures (variant A) were selected to perform the precursor feeding experiment. The L-phenylalanine dose of 1.6 g/L appears to be the most advantageous. Compared to the control cultures, the content of the individual compounds increased in a range from 1.4 to 17.3-fold (e.g. p-coumaric acid - 17.3 fold; casticin - 4.8-fold). The biomass from in vitro cultures is richer in neochlorogenic acid (16-fold), p-coumaric acid (5.3-fold), rutin (2.8-fold), caffeic acid (1.5-fold) and cinaroside (1.5-fold) than the leaves of its parent greenhouse-cultivated plants. Extracts contained 30 mg/100 g DW of casticin, but after the hydrolysis its amount increased up to 200 mg/100 g DW and twice exceeded the content in the greenhouse leaves. The results indicate that V. agnus castus agitated shoot cultures might be considered as a potential biotechnological source of some pharmaceutically important compounds, especially casticin, rutin, neochlorogenic and p-coumaric acids.

Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.

Antibacterial and antioxidant activity of Portuguese Lavandula luisieri (Rozeira) Rivas-Martinez and its relation with their chemical composition

Lavandula luisieri (Rozeira) Rivas-Martinez is an endemic aromatic Labiatae the Iberian Peninsula, common in semi-arid regions of southern Portugal and southwestern Spain, that produces an active antibacterial essential oil from the leaves and flowers. This work presents the study of the chemical variation in various stages of growth of leaves and flowers of L. luisieri. It has been found that the essential oils are mainly constituted by 1,8-cineol, camphor, linalool and trans-α-necrodil acetate. It was also studied the total phenol content and the antioxidant activity on leaves and flowers. The ethanol extraction from de leaves contents the highest total phenol, important factor for the antioxidant activity of the plant, extract. It has been studied too, the antibacterial activity against Escherichia coli, Salmonella spp. and Staphylococcus aureus. In accordance with the obtained results, the antibacterial activities stand out against Staphylococcus, of the oil of L. luisieri (leaves and flowers).

Optimisation of phenolics recovery from Vitex agnus-castus Linn. leaves by high-pressure and temperature extraction

To optimise recovery of phenolics from Vitex agnus-castus Linn., a non-conventional high-pressure (2-24 bar) and temperature (100-180°C) extraction method was used under nitrogen atmosphere with methanol as a solvent. Optimal temperature was between 100 and 140°C, and optimal extraction time was about one half that of conventional solid/liquid extraction at room temperature. Final yields of total polyphenols, total flavonoids, o-diphenols and anthocyanins extraction were 2.0, 3.0, 2.5 and 11-fold those obtained by conventional extraction.