Differential Production of Phenylpropanoid Metabolites in Callus Cultures of Ocimum basilicum L. with Distinct In Vitro Antioxidant Activities and In Vivo Protective Effects against UV stress

Effects of Ocimum basilicum L. Extract on Hippocampal Oxidative Stress, Inflammation, and BDNF Expression in Amnesic Aged Rats

The present study was conducted to investigate the effects of Ocimum basilicum L. (OB) extract on learning and memory impairment in aged rats. Male rats were divided into the following experimental groups: Group 1 (control): including 2 months old rats, Group 2 (aged) including 2 years old rats, Groups 3-5 (aged-OB): including 2 years old rats received 50, 100, and 150 mg/kg OB for 8 weeks by oral gavage. Aging increased the delay to find the platform but, however, decreased the time spent in the target quadrant when tested by Morris water maze (MWM). Aging also reduced the latency to enter the dark chamber in the passive avoidance (PA) test compared to the control group. Moreover, interleukin-6 (IL-6) and malondialdehyde (MDA) levels were raised in the hippocampus and cortex of aged rats. In contrast, thiol levels and enzymatic activity of superoxide dismutase (SOD) and catalase (CAT) significantly reduced. In addition, aging significantly reduced BDNF expression. Finally, OB administration reversed the mentioned effects. The current research showed that OB administration improves learning/memory impairment induced by aging. It also found that this plant extract protects the brain tissues from oxidative damage and neuroinflammation.

Untargeted metabolomic in basil cell cultures - a case study of Ocimum basilicum L. var. minimum Alef

AIMS

Due to the lack of experimental databases, together with the chemical complexity and the dynamic nature of plants' metabolome, most of the metabolites in complex biological materials (like plant in vitro tissue cultures) are not-annotated, unidentified metabolites. In this study, a method for further metabolite characterization and classification based on the UPLC-HESI-HRMS/MS approach for small-leaved basil (Ocimum basilicum L. var. minimum Alef.) callus and cell suspension culture is presented.

KEY RESULTS

A total of 2168 metabolic features were detected, out of which the database for exact mass metabolic profiling for 1949 metabolites is presented here since there is no available database dedicated to O. basilicum. We further focused on secondary metabolites (particularly phenolic compounds). The presence of 60 different phenolic compounds belonging mainly to the groups of flavonoids, glycosides, terpenoids, and phenolic acids is confirmed. By comparing relative abundances of phenolic compounds from callus culture and cell suspension culture, both grown on two types of media, via svd-PCА, univariate analysis, post-hoc tests, and heatmapping of metabolites, we provided a practical example of how resources presented here can be further applied in tissue culture-based basil metabolomics studies.

UTILITY

This study represents the first approach toward routine targeted investigation of secondary metabolites in basil in vitro cultures and provides various opportunities for new-generation analyses.

Differential Impact of Zinc Salt Precursors on Physiognomies, Anticancerous, and Antibacterial Activities of Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnONPs) are enormously popular semi-conductor metal oxides with diverse applications in every field of science. Many physical and chemical methods applied for the synthesis of ZnONPs are being rejected due to their environmental hazards. Therefore, ZnONPs synthesized from plant extracts are steered as eco-friendly showing more biocompatibility and biodegradability. Additionally, various synthesis conditions such as the type of precursor salt also play a role in influencing the physicochemical and biological properties of ZnONPs. In this study, green synthesis of ZnONPs from Acacia nilotica was carried out using zinc acetate (ZA-AN-ZNPs), zinc nitrate (ZN-AN-ZNPs), and zinc sulfate (ZS-AN-ZNPs) precursor salts. Surprisingly, characterization of ZnONPs using UV-visible spectroscopy, TEM, XRD, and EDX revealed the important role precursor salts played in influencing the size and shape of ZnONPs, i.e., 20-23 nm spherical (ZA-AN-ZNPs), 55-59 nm triangular (ZN-AN-ZNPs), and 94-97 nm nano-flowers (ZS-AN-ZNPs). FTIR analysis showed the involvement of alkaloids, alcohols, carboxylic acid, and phenolic compounds present in Acacia nilotica extract during the synthesis process. Since different precursor salts showed different morphology of ZnONPs, their biological activities were also variable. ZN-AN-ZNPs showed the highest cytotoxicity towards HepG2 cells with the lowest cell viability (28.92 ± 0.99%), highest ROS/RNS production (3425.3 ± 184.58 relative DHR123 fluorescence), and loss of mitochondrial membrane potential (1645.2 ± 32.12 relative fluorescence unit) as well as induced significant caspase-3 gene expression. In addition to this, studying the zone of inhibitions and minimum bactericidal and inhibitory concentrations of ZnONPs showed their exceptional potential as antibacterial agents. At MIC as low as 8 µg/mL, ZA-AN-ZNPs and ZN-AN-ZNPs exhibited significant bactericidal activities against human pathogens Klebsiella pneumoniae and Listeria monocytogenes, respectively. Furthermore, alkaline phosphatase, DNA/RNA leakage, and phosphate ion leakage studies revealed that a damage to the bacterial cell membrane and cell wall is involved in mediating the antibacterial effects of ZnONPs.

Encapsulation of purple basil leaf extract by electrospraying in double emulsion (W/O/W) filled alginate-carrageenan beads to improve the bioaccessibility of anthocyanins

The purple basil leaf extract (PBLE) was encapsulated in double emulsion (W1/O/W2)-loaded beads (emulgel) by electrospraying. The influence of κ-carrageenan (κ-CG) and cross-linking agents (Ca2+/K+) on the properties of alginate (SA) beads were assessed. In emulgel beads, κ-CG inclusion resulted in larger sizes and more distorted shapes, wrinkles on the surface, and lower gel strength. The encapsulation efficiency of anthocyanins (ACNs) in emulgel beads ranged from 70.73 to 87.89 %, whereas it ranged from 13.50 to 20.67 % in emulsion-free (hydrogel) beads. Fourier transforms infrared (FTIR) revealed the crosslinking of SA and κ-CG with Ca2+ and K+, thermogravimetric analysis (TGA), derivative thermogravimetric (DTG), and differential scanning calorimetry (DSC) thermograms showed emulgel beads yielded higher thermal stability. The emulgel beads elevated the in vitro bioaccessibility of ACNs under simulated digestion. At the gastric phase, 86 % of ACNs in PBLE, and 46 % of loaded ACNs in hydrogel beads were released, whereas no release was occurred in emulgel beads. At the intestinal phase, after 150 min of digestion, no ACNs were detected in PBLE and hydrogel beads, whereas all emulgel beads continued to release ACNs until 300 min. The incorporation of double emulsions in hydrogel beads can be utilized in the development of functional foods.

Precursors and elicitor induced enhancement of cell biomass and phenolic compounds in cell suspensions of Indian basil-Ocimum basilicum (CIM-Saumya)

CIM-Saumya is an improved, methyl chavicol rich variety of Ocimum basilicum (Family-Lamiaceae), developed by Council of Scientific and Industrial Research-Central Institute of Medicinal and Aromatic Plants. This plant possesses analgesic, anti-ulcerogenic, anti-inflammatory, anti-oxidant, cardiac stimulant, Central Nervous System depressant, hepatoprotective and immunomodulator activities due to the presence of various phytoconstituents. Among them rosmarinic acid, caffeic acid and ferulic acid are the three major phenolic compounds responsible for its therapeutic utility. These compounds are produced in very low amounts in the in vivo plants. Therefore, the present study has been conducted for establishment of cell suspensions, optimization of inoculums size, growth kinetics and screening of elicitor and precursors for the accumulation of cell biomass and the production of the three important phenolic compounds in cell suspension of O. basilicum (CIM-Saumya). Leaf derived friable callus was used for establishing the cell suspension in liquid Murashige and Skoog's medium fortified with 1 g/L casein hydrolysate + 2.26 µM 2,4-dichlorophenoxyacetic acid + 0.465 µM kinetin + 2.68 µM naphthalene acetic acid. The growth kinetic analysis pattern of cell suspension revealed the maximum biomass increments (% BI = 486.7) and production of RA 8.086 mg/g dry weight was found in 30th day harvested cells. Whereas, the other two phenolic compounds i.e. ferulic acid (0.0125 mg/g dry weight) and caffeic acid (0.38 mg/g dry weight) was recorded highest on 25th day of growth cycle. In the present study, one biotic elicitor i.e. yeast extract and three precursors [peptone, tryptone and lactalbumin hydrolysate] were tested, among them, lactalbumin hydrolysate (100 mg/L; added at 16th day) treated cells recorded highest estimated phenolic compounds yield (251.5 mg/L; 6.81 fold compared to the control) and biomass increments i.e. % BI = 1207 with 1.85 fold compared to the control. The highest rosmarinic acid content i.e. 25.47 mg/g DW (4.4 fold compared to the control) and 24.42 mg/g dry weight (4.1 folds compared to the control) was noticed in 30th day harvested cells treated with yeast extract (1 g/L on 0 day) and lactalbumin hydrolysate (100 mg/L added on 16th day), respectively. While caffeic acid content (0.91 mg/g dry weight) showed 2.9 folds higher compared to the control in cells treated with peptone 200 mg/L added on 16th day of culture cycle. All the treated cells showed enhanced phenylalanine ammonia-lyase enzyme activity with highest specific activity in lactalbumin hydrolysate followed by tryptone, peptone, and yeast extract.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01316-6.

Effects of White and Blue-Red Light on Growth and Metabolism of Basil Grown under Microcosm Conditions

Indoor farming of basil (Ocimum basilicum L.) under artificial lighting to support year-round produce demand is an area of increasing interest. Literature data indicate that diverse light regimes differently affect downstream metabolic pathways which influence basil growth, development and metabolism. In this study, basil was grown from seedlings to fully developed plants in a microcosm, an innovative device aimed at growing plants indoor as in natural conditions. Specifically, the effects of white (W) and blue-red (BR) light under a photosynthetic photon flux density of 255 μmol m^-2 s^-1 on plant growth, photochemistry, soluble nutrient concentration and secondary metabolism were investigated. Plants grew taller (41.8 ± 5.0 vs. 28.4 ± 2.5 cm) and produced greater biomass (150.3 ± 24.2/14.7 ± 2.0 g vs. 116.2 ± 28.3/12.3 ± 2.5 g fresh/dry biomass) under W light compared to BR light. The two lighting conditions differently influenced the soluble nutrient concentration and the translocation rate. No photosynthetic stress was observed under the two lighting regimes, but leaves grown under W light displayed higher levels of maximum quantum yield of PSII and electron transport rate. Sharp differences in metabolic patterns under the two lighting regimes were detected with higher concentrations of phenolic compounds under the BR light.

Effect of Wide-Spectrum Monochromatic Lights on Growth, Phytochemistry, Nutraceuticals, and Antioxidant Potential of In Vitro Callus Cultures of Moringa oleifera

Moringa oleifera, also called miracle tree, is a pharmaceutically important plant with a multitude of nutritional, medicinal, and therapeutic attributes. In the current study, an in-vitro-based elicitation approach was used to enhance the commercially viable bioactive compounds in an in vitro callus culture of M. oleifera. The callus culture was established and exposed to different monochromatic lights to assess the potentially interactive effects on biomass productions, biosynthesis of pharmaceutically valuable secondary metabolites, and antioxidant activity. Optimum biomass production (16.7 g/L dry weight), total phenolic contents (TPC: 18.03 mg/g), and flavonoid contents (TFC: 15.02 mg/g) were recorded in callus cultures placed under continuous white light (24 h), and of other light treatments. The highest antioxidant activity, i.e., ABTS (550.69 TEAC µM) and FRAP (365.37 TEAC µM), were also noted under white light (24 h). The analysis of phytochemicals confirmed the significant impact of white light exposures on the enhanced biosynthesis of plant secondary metabolites. The enhanced levels of secondary metabolites, i.e., kaempferol (1016.04 µg/g DW), neochlorogenic acid (998.38 µg/g DW), quercetin (959.92 µg/g DW), and minor compounds including luteolin, apigenin, and p-coumaric acid were observed as being highest in continuous white light (24 h with respect to the control (photoperiod). Similarly, blue light enhanced the chlorogenic acid accumulation. This study shows that differential spectral lights demonstrate a good approach for the enhancement of nutraceuticals along with novel pharmacologically important metabolites and antioxidants in the in vitro callus culture of M. oleifera.

Establishment of Afgekia mahidolae B.L. Burtt & Chermsir in vitro culture and effect of elicitation on its bioactive compounds

Afgekia mahidolae is a rare plant species that possesses antioxidant, antimicrobial, and wound healing properties. This study aimed to establish the in vitro culture of A. mahidolae and investigate the effects of elicitors on their phenolic and flavonoid production, including the antioxidant activities. The established callus was prepared in the form of cell suspension cultures to determine the effect of elicitors. After elicitation for 3 days, A. mahidolae cell suspension cultures treated by 5 µM salicylic acid or 100 mg/L yeast extract exhibited significantly higher levels of total phenolic and total flavonoid content than untreated cultures, which correlated to the antioxidant activities. In addition, the profiles of phenolic and flavonoid compounds in the callus and intact leaves of A. mahidolae were determined by LC-MS, which showed different phytochemicals. The findings of this study may encourage more sustainable development of A. mahidolae cultivation.

Extraction Kinetics and Reaction Rates of Sacred Lotus Stamen Tea Infusion-Derived Flavonoids in Relation with Its Antioxidant Capacity

Stamen tea from Nelumbo nucifera Gaertn. (or the so-called sacred lotus) is widely consumed, and its flavonoids provide various human health benefits. The method used for tea preparation for consumption, namely the infusion time, may affect the levels of extractable flavonoids, ultimately affecting their biological effects. To date, there is no report on this critical information. Thus, this study aims to determine the kinetics of solid liquid extraction of flavonoid from sacred lotus stamen using the traditional method of preparing sacred lotus stamen tea. Phytochemical composition was also analyzed using high-performance liquid chromatography (HPLC). The antioxidant potential of stamen tea was also determined. The results indicated that the infusion time critically affects the concentrations of flavonoids and the antioxidant capacity of sacred lotus stamen tea, with a minimum infusion time of 5–12 min being required to release the different flavonoids from the tea. The extraction was modeled using second order kinetics. The rate of release was investigated by the glycosylation pattern, with flavonoid diglycosides, e.g., rutin and Kae-3-Rob, being released faster than flavonoid monoglycosides. The antioxidant activity was also highly correlated with flavonoid levels during infusion. Taken together, data obtained here underline that, among others, the infusion time should be considered for the experimental design of future epidemiological studies and/or clinical trials to reach the highest health benefits.

Light-emitting diode (LED)-directed green synthesis of silver nanoparticles and evaluation of their multifaceted clinical and biological activities

The trend of using plant extracts for the synthesis of nanoparticles has increased in recent years due to environmental safety, low cost, simplicity and sustainability of the green route. Moreover, the morphology of NPs can be fine-tuned by applying abiotic factors such as LEDs, which enhance the bio-reduction of the precursor salt and excite phytochemicals during their green synthesis. Considering this, in present study, the green synthesis of AgNPs was carried out using Dalbergia sissoo leaf extract under the illumination of red, green, blue, yellow and white LEDs. The phytochemical profile of the leaf extract in terms of total phenolic and flavonoid content was responsible for the effective synthesis of AgNPs, where alcohols and phenols were mainly involved in the capping and bio-reduction of the NPs. Moreover, the XRD data showed the face center cubic crystalline nature of the AgNPs with the interesting finding that the LEDs helped to reduce the size of the AgNPs significantly. Among the samples, Y-DS-AgNPs (34.63 nm) were the smallest in size, with the control having a size of 87.35 nm. The LEDs not only reduced the size of the AgNPs but also resulted in the synthesis of non-agglomerated AgNPs with different shapes including spherical, triangular, and hexagonal compared to the mixed-shape control AgNPs, as shown by the SEM analysis. These LED-directed AgNPs showed extraordinary therapeutic potential especially B-DS-AgNPs, which exhibited the highest anti-oxidant, anti-glycation and anti-bacterial activities. Alternatively, Y-DS-AgNPs were the most cytotoxic towards HepG2 cells, inducing intracellular ROS/RNS production, accompanied by a disruption in the mitochondrial membrane potential, caspase-3 gene activation and induction of caspase-3/7 activity. Lastly, AgNPs showed mild toxicity towards brine shrimp and moderately hemolyzed hRBCs, showing their biosafe nature. Here, we conclude that external factors such as LEDs are effective in controlling the morphology of AgNPs, which further enhanced their therapeutic efficacy.

The intestinal absorption mechanism of chicoric acid and its bioavailability improvement with chitosan

Chicoric acid (CA), an active phenolic acid of Echinacea purpurea (Linn.) Moench, has been demonstrated to exhibit antioxidative, antiviral and immunological activities. A prior study showed that CA is a water-soluble compound with low bioavailability. The current study was performed to study the intestinal absorption mechanism of CA and improve its bioavailability using natural biodegradable chitosan. A Caco-2 monolayer cell model was established to characterise the mechanisms involved in the intestinal absorption of CA. The bioavailability improvement of CA was studied in Sprague–Dawley rats after oral (20 mg/kg) administration of 0.5% chitosan. In vitro, the results showed that the absorption transport of CA was fairly poor, with Papp values of 8.2 × 10⁻⁸ to 2.1 × 10⁻⁷ cm/s in the absorption direction and 1.5 × 10⁻⁷ to 2.6 × 10⁻⁷ cm/s in the secretory direction. The permeability was increased by EDTA and chitosan in both directions. Moreover, the transport through the intestinal monolayer was H⁺ dependent, and P-glycoprotein and OATP2B1 transporters were involved in the intestinal transport of CA. In vivo, the absorption of CA was increased and accelerated with chitosan in rats because the bioavailability was 1.74-fold that of the prototype drug. The above mentioned results indicated that CA was a poor absorption drug and that paracellular and carrier-mediated trancellular transport both participated in its transport route. Chitosan is an excellent absorption enhancer for CA. The transport characteristics uncovered in this study lay the groundwork for further studies directed toward the development and utilisation of its new formulations.

Comparative Analysis of Various Plant-Growth-Regulator Treatments on Biomass Accumulation, Bioactive Phytochemical Production, and Biological Activity of Solanum virginianum L. Callus Culture Extracts

Solanum virginianum L. (Solanum xanthocarpum) is an important therapeutic plant due to the presence of medicinally useful plant-derived compounds. S. virginianum has been shown to have anticancer, antioxidant, antibacterial, antiaging, and anti-inflammatory properties. This plant is becoming endangered due to overexploitation and the loss of its native habitat. The purpose of this research is to develop an ideal technique for the maximum biomass and phytochemical accumulation in S. virginianum leaf-induced in vitro cultures, as well as to evaluate their potential antiaging, anti-inflammatory, and antioxidant abilities. Leaf explants were grown on media (Murashige and Skoog (MS)) that were supplemented with various concentrations and combinations of plant hormones (TDZ, BAP, NAA, and TDZ + NAA) for this purpose. When compared with the other hormones, TDZ demonstrated the best response for callus induction, biomass accumulation, phytochemical synthesis, and biological activities. However, with 5 mg/L of TDZ, the optimal biomass production (FW: 251.48 g/L and DW: 13.59 g/L) was estimated. The highest total phenolic level (10.22 ± 0.44 mg/g DW) was found in 5 mg/L of TDZ, whereas the highest flavonoid contents (1.65 ± 0.11 mg/g DW) were found in 10 mg/L of TDZ. The results of the HPLC revealed that the highest production of coumarins (scopoletin: 4.34 ± 0.20 mg/g DW and esculetin: 0.87 ± 0.040 mg/g DW) was determined for 10 mg/L of TDZ, whereas the highest accumulations of caffeic acid (0.56 ± 0.021 mg/g DW) and methyl caffeate (18.62 ± 0.60 mg/g DW) were shown by 5 mg/L of TDZ. The determination of these phytochemicals (phenolics and coumarins) estimates that the results of our study on biological assays, such as antioxidant, anti-inflammatory, and antiaging assays, are useful for future cosmetic applications.

Bio-Assisted Synthesis and Characterization of Zinc Oxide Nanoparticles from Lepidium sativum and Their Potent Antioxidant, Antibacterial and Anticancer Activities

Nanotechnology is an emerging area of research that deals with the production, manipulation, and application of nanoscale materials. Bio-assisted synthesis is of particular interest nowadays, to overcome the limitations associated with the physical and chemical means. The aim of this study was to synthesize ZnO nanoparticles (NPs) for the first time, utilizing the seed extract of Lepidium sativum. The synthesized NPs were confirmed through various spectroscopy and imagining techniques, such as XRD, FTIR, HPLC, and SEM. The characterized NPs were then examined for various in vitro biological assays. Crystalline, hexagonal-structured NPs with an average particle size of 25.6 nm were obtained. Biosynthesized ZnO NPs exhibited potent antioxidant activities, effective α-amylase inhibition, moderate urease inhibition (56%), high lipase-inhibition (71%) activities, moderate cytotoxic potential, and significant antibacterial activity. Gene expression of caspase in HepG2 cells was enhanced along with elevated production of ROS/RNS, while membrane integrity was disturbed upon the exposure of NPs. Overall results indicated that bio-assisted ZnO NPs exhibit excellent biological potential and could be exploited for future biomedical applications. particularly in antimicrobial and cancer therapeutics. Moreover, this is the first comprehensive study on Lepidium sativum-mediated synthesis of ZnO nanoparticles and evaluation of their biological activities.

Differential Flavonoid and Other Phenolic Accumulations and Antioxidant Activities of Nymphaea lotus L. Populations throughout Thailand

Nymphaea lotus L. is a potential plant in the Nymphaeaceae family that is well-recognized as an economic and traditional medicinal plant in Thailand and other countries. Its pharmacological and medicinal effects have been confirmed. However, there is no study going deeper into the population level to examine the phytochemical variation and biological activity of each population that benefits phytopharmaceutical and medical applications using this plant as raw material. This study was intensely conducted to complete this important research gap to investigate the flavonoid profiles from its floral parts, the stamen and perianth, as well as the antioxidant potential of the 13 populations collected from every floristic region by (1) analyzing their flavonoid profiles, including the HPLC analysis, and (2) investigating the antioxidant capacity of these populations using three assays to observe different antioxidant mechanisms. The results indicated that the northeastern and northern regions are the most abundant floristic regions, and flavonoids are the main phytochemical class of both stamen and perianth extracts from N. lotus. The stamen offers higher flavonoids and richer antioxidant potential compared with the perianth. This finding is also the first completed report at the population level to describe the significant correlation between the phytochemical profiles in floral parts extracts and the main antioxidant activity, which is mediated by the electron transfer mechanism. The results from the Pearson correlation coefficients between several phytochemicals and different antioxidant assessments highlighted that the antioxidant capability of these extracts is the result of complex phytochemical combinations. The frontier knowledge from these current findings helps to open up doors for phytopharmaceutical industries to discover their preferred populations and floral parts that fit with their targeted products.

Flavonoid Profiles and Antioxidant Potential of Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum, a New Species from the Genus Monochoria C. Presl

Plants of the genus Monochoria have long been utilized in food, cosmetics, and traditional herbal treatments. Thailand has the highest species diversity of this genus and a new member, Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum has been recently described. This plant is called “Siam Violet Pearl” as a common name or “Khimuk Si Muang Haeng Siam” as its vernacular name with the same meaning in the Thai language. Despite their importance, little research on Monochoria species has been conducted. This study, thus, provides the results to fill in this gap by: (i) determining flavonoid phytochemical profiles of 25 natural populations of M. angustifolia covering the whole floristic regions in Thailand, and (ii) determining antioxidant activity using various antioxidant assays to investigate probable mechanisms. The results revealed that M. angustifolia presents a higher flavonoid content than the outgroup, M. hastata. Our results also revealed that flavonoids might be used to investigate Monochoria evolutionary connections and for botanical authentication. The various antioxidant assays revealed that M. angustifolia extracts preferentially act through a hydrogen atom transfer antioxidant mechanism. Pearson correlation analysis indicated significant correlations, emphasizing that the antioxidant capacity is most probably due to the complex action of several phytochemicals rather than that of a single molecule. Together, these results showed that this new species provide an attractive alternative starting material with phytochemical variety and antioxidant potential for the phytopharmaceutical industry.

Potential antimicrobial, antidiabetic, catalytic, antioxidant and ROS/RNS inhibitory activities of Silybum marianum mediated biosynthesized copper oxide nanoparticles

Use of medicinal plants for the biosynthesis of nanoparticles offers several advantages over other synthesis approaches. Plants contain a variety of bioactive compounds that can participate in reduction and capping of nanoparticles. Plant mediated synthesis has the leverage of cost effectiveness, eco-friendly approach and sustained availability. In the current study Silybum marianum, a medicinally valuable plant rich in silymarin content, is used as a reducing and stabilizing agent for the fabrication of nanoparticles. Biosynthesized CuO-NPs were characterized using High Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering (DLS) techniques. Characterization revealed that CuO-NPs having a crystalline structure showed spherical morphology with an average size of 15 nm. HPLC analysis demonstrated conjugation of various silymarin components, especially the presence of silybin A (705.06 ± 1.59 mg g^-1 DW). CuO-NPs exhibited strong bactericidal potency against clinically important pathogenic bacterial strains e.g. Enterobacter aerogenes and Salmonella typhi with an inhibition zone of 18 ± 1.3 mm and 17 ± 1.2 mm, respectively. Synthesized nanoparticles indicated a dose dependent cytotoxic effect against fibroblast cells exhibiting a percentage cell viability of 83.60 ± 1.505% and 55.1 ± 1.80% at 25 μg mL^-1 and 100 μg mL^-1 concentration, respectively. Moreover, CuO-NPs displayed higher antioxidant potential in terms of (TAC: 96.9 ± 0.26 μg AAE/mg), (TRP: 68.8 ± 0.35 μg AAE/mg), (DPPH: 55.5 ± 0.62%), (ABTS: 332.34 μM) and a significant value for (FRAP: 215.40 μM). Furthermore, enzyme inhibition assays also exhibited excellent enzyme inhibition potential against α-amylase (35.5 ± 1.54%), urease (78.4 ± 1.26%) and lipase (80.50.91%), respectively. Overall findings indicated that biosynthesized CuO-NPs possess immense in vitro biological and biomedical properties and could be used as a broad-spectrum agent for a wider range of biomedical applications.

Spicy and Aromatic Plants for Meat and Meat Analogues Applications

Aromatic and spicy plants are an important factor that contributes not only to improving the taste of meat, meat products, and meat analogues, but also to increasing the nutritional value of the products to which they are added. The aim of this paper is to present the latest information on the bioactive antioxidant and antimicrobial properties of the most commonly used herbs and spices (parsley, dill, basil, oregano, sage, coriander, rosemary, marjoram, tarragon, bay, thyme, and mint) used in the meat and meat analogues industry, or proposed to be used for meat analogues.

Flavonoids from Sacred Lotus Stamen Extract Slows Chronological Aging in Yeast Model by Reducing Oxidative Stress and Maintaining Cellular Metabolism

Nelumbo nucifera is one of the most valuable medicinal species of the Nelumbonaceae family that has been consumed since the ancient historic period. Its stamen is an indispensable ingredient for many recipes of traditional medicines, and has been proved as a rich source of flavonoids that may provide an antiaging action for pharmaceutical or medicinal applications. However, there is no intense study on antiaging potential and molecular mechanisms. This present study was designed to fill in this important research gap by: (1) investigating the effects of sacred lotus stamen extract (LSE) on yeast lifespan extension; and (2) determining their effects on oxidative stress and metabolism to understand the potential antiaging action of its flavonoids. A validated ultrasound-assisted extraction method was also employed in this current work. The results confirmed that LSE is rich in flavonoids, and myricetin-3-O-glucose, quercetin-3-O-glucuronic acid, kaempferol-3-O-glucuronic acid, and isorhamnetin-3-O-glucose are the most abundant ones. In addition, LSE offers a high antioxidant capacity, as evidenced by different in vitro antioxidant assays. This present study also indicated that LSE delayed yeast (Saccharomyces cerevisiae, wild-type strain DBY746) chronological aging compared with untreated control yeast and a positive control (resveratrol) cells. Moreover, LSE acted on central metabolism, gene expressions (SIR2 and SOD2), and enzyme regulation (SIRT and SOD enzymatic activities). These findings are helpful to open the door for the pharmaceutical and medical sectors to employ this potential lotus raw material in their future pharmaceutical product development.

Validation of a High-Performance Liquid Chromatography with Photodiode Array Detection Method for the Separation and Quantification of Antioxidant and Skin Anti-Aging Flavonoids from Nelumbo nucifera Gaertn. Stamen Extract

Nelumbo nucifera Gaertn., or the so-called sacred lotus, is a useful aquatic plant in the Nelumbonaceae family that has long been used to prepare teas, traditional medicines as well as foods. Many studies reported on the phytochemicals and biological activities of its leaves and seeds. However, to date, only few studies were conducted on its stamen, which is the most important ingredient for herbal medicines, teas and other phytopharmaceutical products. Thus, this present study focuses on the following: (1) the application of high-performance liquid chromatography with photodiode array detection for a validated separation and quantification of flavonoids from stamen; (2) the Nelumbo nucifera stamen’s in vitro and in cellulo antioxidant activities; as well as (3) its potential regarding the inhibition of skin aging enzymes for cosmetic applications. The optimal separation of the main flavonoids from the stamen ethanolic extract was effectively achieved using a core-shell column. The results indicated that stamen ethanolic extract has higher concentration of in vitro and in cellulo antioxidant flavonoids than other floral components. Stamen ethanolic extract showed the highest protective effect against reactive oxygen/nitrogen species formation, as confirmed by cellular antioxidant assay using a yeast model. The evaluation of potential skin anti-aging action showed that the stamen extract has higher potential to inhibit tyrosinase and collagenase compared with its whole flower. These current findings are the first report to suggest the possibility to employ N. nucifera stamen ethanolic extract as a tyrosinase and collagenase inhibitor in cosmetic applications, as well as the utility of the current separation method.

Phytochemical Diversity and Antioxidant Potential of Natural Populations of Nelumbo nucifera Gaertn. throughout the Floristic Regions in Thailand

Asian lotus has long been consumed as a food and herbal drug that provides several health benefits. The number of studies on its biological activity is significant, but research at the population level to investigate the variation in phytochemicals and biological activity of each population which is useful for a more efficient phytopharmaceutical application strategy remains needed. This present study provided the frontier results to fill-in this necessary gap to investigating the phytopharmaceutical potential of perianth and stamen, which represent an important part for Asian traditional medicines, from 18 natural populations throughout Thailand by (1) determining their phytochemical profiles, such as total contents of phenolic, flavonoid, and anthocyanin, and (2) determining the antioxidant activity of these natural populations using various antioxidant assays to examine different mechanisms. The result showed that Central is the most abundant floristic region. The stamen was higher in total phenolic and flavonoid contents, whereas perianth was higher in monomeric anthocyanin content. This study provided the first description of the significant correlation between phytochemical contents in perianth compared with stamen extracts, and indicated that flavonoids are the main phytochemical class. This analysis indicated that the stamen is a richer source of flavonoids than perianth, and provided the first report to quantify different flavonoids accumulated in stamen and perianth extracts under their native glycosidic forms at the population level. Various antioxidant assays revealed that major flavonoids from N. nucifera prefer the hydrogen atom transfer mechanism when quenching free radicals. The significant correlations between various phytochemical classes and the different antioxidant tests were noted by Pearson correlation coefficients and emphasized that the antioxidant capability of an extract is generally the result of complex phytochemical combinations as opposed to a single molecule. These current findings offer the alternative starting materials to assess the phytochemical diversity and antioxidant potential of N. nucifera for phytopharmaceutical sectors.

Green synthesis of biocompatible core–shell (Au–Ag) and hybrid (Au–ZnO and Ag–ZnO) bimetallic nanoparticles and evaluation of their potential antibacterial, antidiabetic, antiglycation and anticancer activities

The fabrication of bimetallic nanoparticles (BNPs) using plant extracts is applauded since it is an environmentally and biologically safe method. In this research, Manilkara zapota leaf extract was utilized to bioreduce metal ions for the production of therapeutically important core–shell Au–Ag and hybrid (Au–ZnO and Ag–ZnO) BNPs. The phytochemical profiling of the leaf extract in terms of total phenolic and flavonoid content is attributed to its high free radical scavenging activity. FTIR data also supported the involvement of these phytochemicals (polyphenols, flavonoids, aromatic compounds and alkynes) in the synthesis of BNPs. Whereas, TEM and XRD showed the formation of small sized (16.57 nm) spherical shaped core–shell Au–Ag BNPs and ZnO nano-needles with spherical AuNPs (48.32 nm) and ZnO nano-rods with spherical AgNP (19.64 nm) hybrid BNPs. The biological activities of BNPs reinforced the fact that they show enhanced therapeutic efficacy as compared to their monometallic components. All BNPs showed comparable antibacterial activities as compared to standard tetracycline discs. While small sized Au–Ag BNPs were most effective in killing human hepato-cellular carcinoma cells (HepG2) in terms of lowest cell viability, highest intracellular ROS/RNS production, loss of mitochondrial membrane potential, induction of caspase-3 gene expression and enhanced caspase-3/7 activity. BNPs also effectively inhibited advanced glycation end products and carbohydrate digesting enzymes which can be used as a nano-medicine for aging and diabetes. The most important finding was the permissible biocompatibility of these BNPs towards brine shrimp larvae and human RBCs, which suggests their environmental and biological safety. This research study gives us insight into the promise of using a green route to synthesize commercially important BNPs with enhanced therapeutic efficacy as compared to conventional treatment options.

Graphical demonstartion of the Manikara zapota-mediated biosynthesis of Bimetallic nanoparticles (BNPs) and evalution of their biological activities.

Effect of Traditional Cooking and In Vitro Gastrointestinal Digestion of the Ten Most Consumed Beans from the Fabaceae Family in Thailand on Their Phytochemicals, Antioxidant and Anti-Diabetic Potentials

The edible beans in Fabaceae have been used for foods and medicines since the ancient time, and being used more and more. It is also appeared as a major ingredient in dairy cooking menu in many regions including Thailand, a rich biodiversity country. Many studies reported on health benefits of their flavonoids, but there is no report on the effect of cooking on phytochemical profile and pharmacological potentials. Thus, this present study aims to complete this knowledge, with the 10 most consumed Fabaceae beans in Thailand, by determining the impact of traditional cooking and gastrointestinal digestion on their phytochemicals, their antioxidant and anti-diabetic activities using different in vitro and in cellulo yeast models. The results showed that Vigna unguiculata subsp. sesquipedalis were the richest source of phytochemicals, whereas the population of V. mungo, Phaseolus vulgaris, V. angularis, and V. unguiculata subsp. sesquipedalis were richest in monomeric anthocyanin contents (MAC). Furthermore, the results clearly demonstrated the impact of the plant matrix effect on the preservation of a specific class of phytochemicals. In particular, after cooking and in vitro digestion, total flavonoid contents (TFC) in Glycine max extract was higher than in the uncooked sample. This study is the first report on the influence of cooking and in vitro gastrointestinal digestion on the inhibition capacity toward advanced glycation end products (AGEs). All samples showed a significant capacity to stimulate glucose uptake in yeast model, and V. angularis showed the highest capacity. Interestingly, the increase in glucose uptake after in vitro digestion was higher than in uncooked samples for both P. vulgaris and G. max samples. The current study is the first attempt to investigate at the effects of both processes not only on the natural bioactive compounds but also on antioxidant and anti-diabetic activities of Thailand's 10 most consumed beans that can be applied for agro-industrial and phytopharmaceutical sectors.

Characterization of Bioactive Phenolics and Antioxidant Capacity of Edible Bean Extracts of 50 Fabaceae Populations Grown in Thailand

Fabaceae is the third largest family containing great variation among populations. However, previous studies mainly focus on single species, and phytochemicals at population level have never been reported. This work aims to complete this knowledge with 50 populations from throughout Thailand by (1) determining total phenolic (TPC), flavonoid (TFC), and anthocyanin (TAC) contents; and (2) investigating in vitro and cellular antioxidant potentials. Phytochemicals of 50 populations from different localities are differed, illustrating high heterogeneity occurring in polyphenols accumulations. Vigna unguiculata subsp. sesquipedalis populations showed low variability in TPC ranging from 628.3 to 717.3 mg/100 g DW gallic acid equivalent, whereas the high variability found in TFC and TAC range from 786.9 to 1536.1 mg/100 g DW quercetin equivalent, and 13.4 to 41.6 mg/100 g DW cyanidin equivalent. Red cultivar population #16 had the greatest TAC, but surprisingly the cream cultivars were relatively high in anthocyanins. HPLC quantification of genistein and daidzein showed great variations among populations. In vitro antioxidant results indicated that antioxidant capacity mediated by electron transfer. Cellular antioxidants ranged from 59.7% to 87.9% of ROS/RNS in yeast model. This study investigated at the population level contributing to better and frontier knowledge for nutraceutical/phytopharmaceutical sectors to seek potential raw plant material.

Green Extraction of Antioxidant Flavonoids from Pigeon Pea (Cajanus cajan (L.) Millsp.) Seeds and Its Antioxidant Potentials Using Ultrasound-Assisted Methodology

Pigeon pea is an important pea species in the Fabaceae family that has long been used for food, cosmetic, and other phytopharmaceutical applications. Its seed is reported as a rich source of antioxidants and anti-inflammatory flavonoids, especially isoflavones, i.e., cajanin, cajanol, daidzein, and genistein. In today’s era of green chemistry and green cosmetic development, the development and optimization of extraction techniques is increasing employed by the industrial sectors to provide environmentally friendly products for their customers. Surprisingly, there is no research report on improving the extraction of these isoflavonoids from pigeon pea seeds. In this present study, ultrasound-assisted extraction (USAE) methodology, which is a green extraction that provides a shorter extraction time and consumes less solvent, was optimized and compared with the conventional methods. The multivariate strategy, the Behnken–Box design (BBD) combined with response surface methodology, was employed to determine the best extraction conditions for this USAE utilizing ethanol as green solvent. Not only in vitro but also cellular antioxidant activities were evaluated using different assays and approaches. The results indicated that USAE provided a substantial gain of ca 70% in the (iso)flavonoids extracted and the biological antioxidant activities were preserved, compared to the conventional method. The best extraction conditions were 39.19 min with a frequency of 29.96 kHz and 63.81% (v/v) aqueous ethanol. Both the antioxidant and anti-aging potentials of the extract were obtained under optimal USAE at a cellular level using yeast as a model, resulting in lower levels of malondialdehyde. These results demonstrated that the extract can act as an effective activator of the cell longevity protein (SIR2/SIRT1) and cell membrane protector against oxidative stress. This finding supports the potential of pigeon pea seeds and USAE methodology to gain potential antioxidant and anti-aging (iso)flavonoids-rich sources for the cosmetic and phytopharmaceutical sectors.

Early detection of Huanglongbing with EESI-MS indicates a role of phenylpropanoid pathway in citrus

Huanglongbing (HLB), a devastating disease for citrus worldwide, is caused by Candidatus Liberibacter asiaticus (CLas). In this study, we employed a novel extractive electrospray ionization-mass spectrometry (EESI-MS) method to analyze the metabolites in leaves of uninfected and HLB-infected Newhall navel orange. The results showed that uninfected and HLB-infected leaves could be readily distinguished based on EESI-MS combined by multivariable analysis. Nine phenolic compounds involved in phenylpropanoid pathway, such as p-coumaric acid, naringin, and apigenin, were principal components to distinguish the leaves of uninfected and HLB-infected Newhall navel orange. Gene expression was also conducted to further explore the molecular mechanism of phenylpropanoid branch pathway in HLB. The expression of genes (4CL, HCT, CHI, CHS, CYP, and C12R) involved in phenylpropanoid branch pathway was increased in asymptomatic and early period of HLB-infected leaves, while decreased in later period of HLB-infected leaves. This study provides a novel method for early detection of citrus HLB and suggests the regulation mechanism of phenylpropanoid pathway in the interaction between citrus and CLas.

Effect of UV Irradiation (A and C) on Casuarina equisetifolia-Mediated Biosynthesis and Characterization of Antimicrobial and Anticancer Activity of Biocompatible Zinc Oxide Nanoparticles

The green synthesis of nanoparticles has emerged as a simple, safe, sustainable, reliable and eco-friendly protocol. Among different types of NPs, green-synthesized zinc oxide NPs (ZnONPs) show various promising biological uses due to their interesting magnetic, electrical, optical and chemical characteristics. Keeping in view the dependence of the therapeutic efficacy of NPs on their physico-chemical characteristics, the green synthesis of ZnONPs using Casuarina equisetifolia leaf extract under UV-A and UV-C light was carried out in this study. UV-irradiation helped to control the size and morphology of ZnONPs by exciting the electrons in the photoactive compounds of plant extracts to enhance the bio-reduction of ZnO into ZnONPs. C. equisetifolia leaf extract was found enriched with phenolic (2.47 ± 0.12 mg GAE/g DW) and flavonoid content (0.88 ± 0.28 mg QE/g DW) contributing to its 74.33% free-radical scavenging activity. FTIR spectra showed the involvement of polyphenols in the bio-reduction, stabilization and capping of ZnONPs. Moreover, SEM-EDX and XRD analyses showed great potential of UV-C light in yielding smaller (34–39 nm) oval-shaped ZnONPs, whereas UV-A irradiation resulted in the formation of fairly spherical 67–71 nm ZnONPs and control ZnONPs were of mixed shape and even larger size (84–89 nm). Green-synthesized ZnONPs, notably CE-UV-C-ZnONPs, showed promising anti-bacterial activities against Bacillus subtilis, Pseudomonas fluorescens and Pseudomonas aeruginosa. Moreover, ZnONPs also enhanced ROS production which led to a significant loss of mitochondrial membrane potential and activated caspase-3 gene expression and caspase-3/7 activity in human hepatocellular carcinoma (HepG2) cells. CE-UV-C-ZnONP treatment reduced HepG2 cell viability to as low as 36.97% owing to their unique shape and smaller size. Lastly, ZnONPs were found to be highly biocompatible towards brine shrimp and human red blood cells suggesting their bio-safe nature. This research study sheds light on the plausible role of UV radiation in the green synthesis of ZnONPs with reasonable control over their size and morphology, thus improving their biological efficacy.

Light Tailoring: Impact of UV-C Irradiation on Biosynthesis, Physiognomies, and Clinical Activities of Morus macroura-Mediated Monometallic (Ag and ZnO) and Bimetallic (Ag-ZnO) Nanoparticles

A nano-revolution based on the green synthesis of nanomaterials could affect all areas of human life, and nanotechnology represents a propitious platform for various biomedical applications. During the synthesis of nanoparticles, various factors can control their physiognomies and clinical activities. Light is one of the major physical factors that can play an important role in tuning/refining the properties of nanoparticles. In this study, biocompatible monometallic (AgNPs and ZnONPs) and bimetallic Ag-ZnONPs (0.1/0.1 and 0.1/0.5) were synthesized under UV-C light irradiation from the leaf extract of Morus macroura, which possesses enriched TPC (4.238 ± 0.26 mg GAE/g DW) and TFC (1.073 ± 0.18 mg QE/g DW), as well as strong FRSA (82.39%). These green synthesized NPs were evaluated for their anti-diabetic, anti-glycation, and biocompatibility activities. Furthermore, their anti-cancerous activity against HepG2 cell lines was assessed in terms of cell viability, production of reactive oxygen/nitrogen species, mitochondrial membrane potential, and apoptotic caspase-3/7 expression and activity. Synthesized NPs were characterized by techniques including ultraviolet-visible spectroscopy, SEM, EDX, FTIR, and XRD. UV-C mediated monometallic and bimetallic NPs showed well-defined characteristic shapes with a more disperse particle distribution, definite crystalline structures, and reduced sizes as compared to their respective controls. In the case of clinical activities, the highest anti-diabetic activity (67.77 ± 3.29% against α-amylase and 35.83 ± 2.40% against α-glucosidase) and anti-glycation activity (37.68 ± 3.34% against pentosidine-like AGEs and 67.87 ± 2.99% against vesperlysine-like AGEs) was shown by UV-C mediated AgNPs. The highest biocompatibility (IC50 = 14.23 ± 1.68 µg/mL against brine shrimp and 2.48 ± 0.32% hemolysis of human red blood cells) was shown by UV-C mediated ZnONPs. In the case of anti-cancerous activities, the lowest viability (23.45 ± 1.40%) with enhanced ROS/NOS production led to a significant disruption of mitochondrial membrane potential and greater caspase-3/7 gene expression and activity by UV-C mediated bimetallic Ag-ZnONPs (0.1/0.5). The present work highlights the positive effects of UV-C light on physico-chemical physiognomies as well as the clinical activities of NPs.

Copper oxide (CuO) and manganese oxide (MnO) nanoparticles induced biomass accumulation, antioxidants biosynthesis and abiotic elicitation of bioactive compounds in callus cultures of Ocimum basilicum (Thai basil)

Nano-elicitation is one among the prioritised strategies considered globally for sustainable and uniform production of industrially important medicinal compounds. Ocimum basilicum (Thai basil), a renowned medicinal species is a reservoir of commercially vital metabolites and proved for its health assuring effects in cancer, diabetes, microbial and cardiovascular diseases. However, its consumption and industrial demand raised intent to divert towards better alternates for ensuring sustainable production of medicinal compounds. Herein, we investigated the comparative potential of metal oxide [copper oxide (CuO) and manganese oxide (MnO)] nanoparticles to elicit the biosynthesis of bioactive metabolites and antioxidative capacity of O.basilicum callus cultures. Results showed that callus grown on MS media supplemented with 10 mg/L CuO-NPs resulted in the highest biomass accumulation (FW: 172.8 g/L, DW: 16.7 g/L), phenolic contents (TPC: 27.5 mg/g DW), and flavonoid contents (TFC: 9.1 mg/g DW) along with antioxidant activities (DPPH: 94%, ABTS: 881 μM TEAC, FRAP: 386 μM TEAC) compared with MnO-NPs and control. Likewise, the Superoxide dismutase (SOD: 1.28 nM/min/mg FW) and Peroxidase (POD: 0.48 nM/min/mg FW) activities were also recorded maximum in CuO-NPs elicited cultures than MnO-NPs and control. Moreover, the HPLC results showed that rosmarinic acid (11.4 mg/g DW), chicoric acid (16.6 mg/g DW), eugenol (0.21 mg/g DW) was found optimum in cultures at 10 mg/L CuO-NPs. Overall, it can be concluded that CuO nanoparticles can be effectively used as a elicitor for biosynthesis of metabolites in callus cultures of O. basilicum (Thai basil). The study is indeed a contribution to the field that will help decoding the mechanism of action of CuO NPs. However, further molecular investigations are needed to fully develop understanding about the metabolic potential of O. bascillicum and scalling up this protocol for bulkup production of bioactive compounds.

Scarlet Flax Linum grandiflorum (L.) In Vitro Cultures as a New Source of Antioxidant and Anti-Inflammatory Lignans

In vitro cultures of scarlet flax (Linum grandiflorum L.), an important ornamental flax, have been established as a new possible valuable resource of lignans and neolignans for antioxidant and anti-inflammatory applications. The callogenic potential at different concentrations of α-naphthalene acetic acid (NAA) and thidiazuron (TDZ), alone or in combinations, was evaluated using both L. grandiflorum hypocotyl and cotyledon explants. A higher callus induction frequency was observed on NAA than TDZ, especially for hypocotyl explants, with a maximum frequency (i.e., 95.2%) on 1.0 mg/L of NAA. The presence of NAA (1.0 mg/L) in conjunction with TDZ tended to increase the frequency of callogenesis relative to TDZ alone, but never reached the values observed with NAA alone, thereby indicating the lack of synergy between these two plant growth regulators (PGRs). Similarly, in terms of biomass, NAA was more effective than TDZ, with a maximum accumulation of biomass registered for medium supplemented with 1.0 mg/L of NAA using hypocotyls as initial explants (DW: 13.1 g). However, for biomass, a synergy between the two PGRs was observed, particularly for cotyledon-derived explants and for the lowest concentrations of TDZ. The influence of these two PGRs on callogenesis and biomass is discussed. The HPLC analysis confirmed the presence of lignans (secoisolariciresinol (SECO) and lariciresinol (LARI) and neolignan (dehydrodiconiferyl alcohol [DCA]) naturally accumulated in their glycoside forms. Furthermore, the antioxidant activities performed for both hypocotyl- and cotyledon-derived cultures were also found maximal (DPPH: 89.5%, FRAP 866: µM TEAC, ABTS: 456 µM TEAC) in hypocotyl-derived callus cultures as compared with callus obtained from cotyledon explants. Moreover, the anti-inflammatory activities revealed high inhibition (COX-1: 47.4% and COX-2: 51.1%) for extract of hypocotyl-derived callus cultures at 2.5 mg/L TDZ. The anti-inflammatory action against COX-1 and COX-2 was supported by the IC₅₀ values. This report provides a viable approach for enhanced biomass accumulation and efficient production of (neo)lignans in L. grandiflorum callus cultures.

Improvement and prediction of secondary metabolites production under yeast extract elicitation of Azadirachta indica cell suspension culture using response surface methodology

Neem is a medicinal plant used as antimalarial, antibacterial, antiviral, insecticide, and antimicrobial drug. This study aimed to investigate and predict the effect of yeast extract and sampling time on cell growth, secondary metabolites synthesis, SQS1 and MOF1 genes expression by response surface methodology. The highest fresh and dry cell weights were 580.25 g/L and 21.01 g/L, respectively obtained 6 days after using 100 mg/L yeast extract. The highest azadirachtin accumulation and production were 16.08 mg/g DW and 219.78 mg/L obtained 2 and 4 days, respectively after using 25 mg/L yeast extract. Maximum mevalonic acid accumulation (1.75 mg/g DW) and production (23.77 mg/L) were observed 2 days after application of 50 mg/L yeast extract. The highest amount of squalene accumulation (0.22 mg/g DW) and production (4.53 mg/L) were achieved 4 days after using 50 mg/L yeast extract. Prediction results exhibited the highest azadirachtin accumulation (13.61 mg/g DW) and production (190.50 mg/L), mevalonic acid accumulation (0.50 mg/g DW) and production (5.57 mg/L), and squalene accumulation (0.30 mg/g DW) by using 245 mg/L yeast extract for 2 days, 71 mg/L yeast extract for 2 days, 200 mg/L yeast extract for 4.96 days, without yeast extract for 6.54 days and 4 days, respectively. Also, it was predicted that the highest squalene production is achieved by long-term exposure to high concentrations of yeast extract. The qRT-PCR analysis displayed the maximum relative gene expression of SQS1 and MOF1 by using 150 and 25 mg/L yeast extract for 4 and 2 days treatment.

Nano-Elicitation as an Effective and Emerging Strategy for In Vitro Production of Industrially Important Flavonoids

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.

Chitosan Elicitation Impacts Flavonolignan Biosynthesis in Silybum marianum (L.) Gaertn Cell Suspension and Enhances Antioxidant and Anti-Inflammatory Activities of Cell Extracts

Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S. marianum were exploited for their in vitro potential to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension cultures were maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 ± 1.7 g/L fresh weight (FW) and 17.7 ± 0.5 g/L dry weight (DW) productions. All chitosan treatments resulted in an overall increase in the accumulation of total flavonoids (5.0 ± 0.1 mg/g DW for 5.0 mg/L chitosan), total phenolic compounds (11.0 ± 0.2 mg/g DW for 0.5 mg/L chitosan) and silymarin (9.9 ± 0.5 mg/g DW for 0.5 mg/L chitosan). In particular, higher accumulation levels of silybin B (6.3 ± 0.2 mg/g DW), silybin A (1.2 ± 0.1 mg/g DW) and silydianin (1.0 ± 0.0 mg/g DW) were recorded for 0.5 mg/L chitosan. The corresponding extracts displayed enhanced antioxidant and anti-inflammatory capacities: in particular, high ABTS antioxidant activity (741.5 ± 4.4 μM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan, whereas highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 ± 1.3 %), secretory phospholipase A2 (sPLA2, 33.9 ± 1.3 %) and 15-lipoxygenase (15-LOX-2, 31.6 ± 1.2 %) enzymes involved in inflammation process were measured in extracts obtained in the presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation in the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.

A Cosmetic Perspective on the Antioxidant Flavonoids from Nymphaea lotus L

Nymphaea lotus L. or water lily is a well-known traditional medicinal plant in Thailand, Indonesia, Vietnam, India, Sri Lanka, China, Nepal, Egypt and many African countries. This species has been reported as a promising flavonoid-rich raw material that can be used as an active ingredient for the development of cosmetic/cosmeceutical products. This review aims to illustrate the cosmetic potential of this species by providing botanical information, traditional uses, flavonoid accumulation, biological activities and future research challenges in the production of N. lotus extracts for cosmetic applications.

Correlations on Phenolic Screening Related to In Vitro and In Ovo Assessment of Ocimum basilicum L. Hydro-Alcoholic Extracts Used as Skin Active Ingredient

The current study was aimed to evaluate the phenolic composition parameters of two hydro-alcoholic extracts of Ocimum basilicum L. (OB) obtained from the aerial part (without leaves) and leaves, in order to determine their contribution to the antioxidant activity (AOA). Both hydro-alcoholic extracts have proven to be rich in polyphenolic compounds, flavonoids, flavonols and tannins. Therefore, the leaves’ extracts reveal an inhibition percentage of 89%, almost comparable with the standard reference (95%). To complete the toxicological profile, the study also assessed the potential cytotoxicity of basil hydro-alcoholic extracts on immortalized human keratinocytes (HaCaT), skin human fibroblasts (1BR3), mice epidermis (JB6Cl41-5a) and primary human melanocytes (HEMa) cells, correlated to A375 antitumor in vitro activity. The extracts did not induce significant cytotoxic effect on any of the selected normal cell lines but showed relevant activity on A375 cells. Considering the low values obtained regarding the irritative effects in the chorionallantoic membrane of the egg on blood vessels, we can emphasize that both extracts can be considered as biocompatible ingredients. Regarding the potential activity of hydro-alcoholic extracts on human skin, the decrease of erythema values after the application of extracts was a relevant observation which indicates the anti-inflammatory potential of Ocimum basilicum L.

Flavonoids Profile, Taxonomic Data, History of Cosmetic Uses, Anti-Oxidant and Anti-Aging Potential of Alpinia galanga (L.) Willd

Alpinia galanga is a well-known medicinal plant in Southeast Asia and has been used for a long time as food and medicine. A large number of flavonoid phytochemical compounds have been identified in various parts of this medicinal herb. Flavonoids are commonly known as attractive compounds that can be applied to cosmetic or cosmeceutical product development because of their antioxidant, anti-aging and many other potential biological activities. This recent review aims to illustrate and update the taxonomic status as well as the species description that will be helpful for a rigorous identification and authenticate the raw material or living specimen from A. galanga. The flavonoid phytochemical compounds and the bioactivity of this medicinal plant are also provided. The future perspectives and research directions of A. galanga and its flavonoids are pointed out in this study as well.

Callus Culture of Thai Basil Is an Effective Biological System for the Production of Antioxidants

Thai basil is a renowned medicinal plant and a rich source of bioactive antioxidant compounds with several health benefits, with actions to prevent of cancer, diabetes and cardiovascular disease. Plant cell and tissue culture technologies can be routinely established as an important, sustainable and low-cost biomass source to produce high-value phytochemicals. The current study aimed at developing an effective protocol to produce Thai basil leaf-derived callus cultures with sustainable and high production of biomass and antioxidants as an alternative of leaves production. MS basal medium with various concentrations of plant growth regulators (PGRs) compatible with nutraceutical applications (i.e., gibberellic acid (GA₃) and 6-benzylaminopurine (BAP) either alone or in combination with naphthalene acetic acid (NAA)) were evaluated. Among all tested PGRs, the combination BAP:NAA (5 mg/L:1 mg/L) yields the maximum biomass accumulation (fresh weight (FW): 190 g/L and dry weight (DW): 13.05 g/L) as well as enhanced phenolic (346.08 mg/L) production. HPLC quantification analysis indicated high productions of chicoric acid (35.77 mg/g DW) and rosmarinic acid (7.35 mg/g DW) under optimized callus culture conditions. Antioxidant potential was assessed using both in vitro cell free and in vivo cellular antioxidant assays. Maximum in vitro antioxidant activity DPPH (93.2% of radical scavenging activity) and ABTS (1322 µM Trolox equivalent antioxidant capacity) was also observed for the extracts from callus cultures grown in optimal conditions. In vivo cellular antioxidant activity assay confirmed the effective protection against oxidative stress of the corresponding extract by the maximum inhibition of ROS and RNS production. Compared to commercial leaves, callus extracts showed higher production of chicoric acid and rosmarinic acid associated with higher antioxidant capacity. In addition, this biological system also has a large capacity for continuous biomass production, thus demonstrating its high potential for possible nutraceutical applications.

Enrichment in Antioxidant Flavonoids of Stamen Extracts from Nymphaea lotus L. Using Ultrasonic-Assisted Extraction and Macroporous Resin Adsorption

Nymphaea lotus L. is the medicinal plant that has long been used for food, cosmetics and traditional medicines in Africa and Asia since ancient times. Its flavonoids and other interesting phytochemical compounds from rhizome, leaf and the whole flowers have been reported in the previous published research. However, stamens, which are essential for reproductive functions, may also represent new alternative sources of potential antioxidant flavonoids, as investigated in this study. The innovative green chemistry methods, i.e., ultrasound-assisted extraction (UAE) as well as a macroporous resin (MPR) purification procedure, were employed in this current research. Using a full factorial design coupled to three-dimensional (3D) surface plot methodology, the influence of three variables, namely aqEtOH concentration (ranging from 50 to 100% (v/v), US frequency (ranging from 0 (no US applied) to 45 kHz), and the extraction duration (ranging from 20 to 60 min), were evaluated. Five MPRs with different surface areas, average pore diameters, matrix types and polarities were also investigated for the purification of total flavonoids. The optimal UAE condition is 90% (v/v) aqEtOH with 34.65 khz ultrasonic frequency and 46 min of extraction duration. Compared with the conventional heat reflux extraction (HRE) method, a significant 1.35-fold increase in total flavonoids content was obtained using optimized UAE conditions (169.64 for HRE vs. 235.45 mg/g dry weight for UAE), causing a 2.80-fold increase when this UAE associated with MPR purification (475.42 mg/g dry weight). In vitro cell free antioxidant activity of N. lotus stamen extracts and in cellulo antioxidant investigation using yeast model showed the same trend, indicating that the best antioxidant flavonoid can be found in UAE coupled with MPR purification. Moreover, in the yeast model, the expression of key antioxidant genes such as SIR2 and SOD2 were expressed at the highest level in yeast cells treated with the extract from UAE together with MPR purification. Consequently, it can be seen that the UAE combined with MPR purification can help enhance the flavonoid antioxidant potential of the stamens extract from this medicinal species.

Almond Skin Extracts and Chlorogenic Acid Delay Chronological Aging and Enhanced Oxidative Stress Response in Yeast

Almond (Prunus dulcis (Mill.) D.A.Webb) is one of the largest nut crops in the world. Recently, phenolic compounds, mostly stored in almond skin, have been associated with much of the health-promoting behavior associated with their intake. The almond skin enriched fraction obtained from cold-pressed oil residues of the endemic Moroccan Beldi ecotypes is particularly rich in chlorogenic acid. In this study, both almond skin extract (AE) and chlorogenic acid (CHL) supplements, similar to traditional positive control resveratrol, significantly increased the chronological life-span of yeast compared to the untreated group. Our results showed that AE and CHL significantly reduced the production of reactive oxygen and nitrogen species (ROS/RNS), most likely due to their ability to maintain mitochondrial function during aging, as indicated by the maintenance of normal mitochondrial membrane potential in treated groups. This may be associated with the observed activation of the anti-oxidative stress response in treated yeast, which results in activation at both gene expression and enzymatic activity levels for SOD2 and SIR2, the latter being an upstream inducer of SOD2 expression. Interestingly, the differential gene expression induction of mitochondrial SOD2 gene at the expense of the cytosolic SOD1 gene confirms the key role of mitochondrial function in this regulation. Furthermore, AE and CHL have contributed to the survival of yeast under UV-C-induced oxidative stress, by reducing the development of ROS/RNS, resulting in a significant reduction in cellular oxidative damage, as evidenced by decreased membrane lipid peroxidation, protein carbonyl content and 8-oxo-guanine formation in DNA. Together, these results demonstrate the interest of AE and CHL as new regulators in the chronological life-span and control of the oxidative stress response of yeast.

A Quick, Green and Simple Ultrasound-Assisted Extraction for the Valorization of Antioxidant Phenolic Acids from Moroccan Almond Cold-Pressed Oil Residues

Almond (Prunus dulcis (Mill.) D.A. Webb) is one of the most important nut crops both in terms of area and production. Over the last few decades, an important part of the beneficial actions for health associated with their consumption was attributed to the phenolic compounds, mainly accumulated in almond skin. Interestingly, after cold-pressed oil extraction, most of these antioxidant phenolic compounds are retained in a skin-enriched by-product, a so-called almond cold-pressed oil residue. In Morocco, the fifth highest ranking producer in the world, this production generates an important part of this valuable byproduct. In the present study, using a multivariate Box–Behnken design, an ultrasound-assisted extraction method of phenolic compounds from Moroccan almond cold-pressed oil residue was developed and validated. Response surface methodology resulted in the optimal extraction conditions: the use of aqueous ethanol 53.0% (v/v) as a green solvent, applying an ultrasound frequency of 27.0 kHz for an extraction duration of 29.4 min. The present ultrasound-assisted extraction allowed substantial gains in terms of extraction efficiency compared to conventional heat reflux extraction. Applied to three different local Beldi genotypes growing at three different experimental sites, the optimal conditions for ultrasound-assisted extraction led to a total phenolic content of 13.86 mg/g dry weight. HPLC analysis revealed that the main phenolic compounds from this valuable byproduct were: chlorogenic acid followed by protocatechuic acid, p-hydroxybenzoic acid, and p-coumaric acid. The accumulation of these phenolic compounds appeared to be more dependent on the genetic background than on the environmental impact here represented by the three experimental culture sites. Both in vitro cell free and cellular antioxidant assays were performed, and revealed the great potential of these extracts. In particular, correlation analysis provided evidence of the prominent roles of chlorogenic acid, protocatechuic acid, and p-hydroxybenzoic acid. To summarize, the validated ultrasound-assisted extraction method presented here is a quick, green, simple and efficient for the possible valorization of antioxidant phenolic compounds from Moroccan almond cold-pressed oil residues, making it possible to generate extracts with attractive antioxidant activities for future nutraceutical and/or cosmetic applications.

Plant Polyphenols, More than Just Simple Natural Antioxidants: Oxidative Stress, Aging and Age-Related Diseases

The present editorial serves as an introduction to the Special Issue "Antioxidant and Anti-aging Action of Plant Polyphenols". It also provides a summary of the polyphenols, their biological properties and possible functions as medicines, the importance of traditional medicines as a source of inspiration, the rationalization of new uses of plant extracts which lead to applications in modern medicine, the status of modern green-chemistry extraction methods, and some reflections on future prospects. Here, the articles from this Special Issue, and the main aspects of the antioxidant and anti-aging effects of plant polyphenols are discussed in the form of seven questions.

Interactive Effects of Wide-Spectrum Monochromatic Lights on Phytochemical Production, Antioxidant and Biological Activities of Solanum xanthocarpum Callus Cultures

Solanum xanthocarpum is considered an important traditional medicinal herb because of its unique antioxidant, and anti-diabetic, anti-aging, and anti-inflammatory potential. Because of the over exploitation linked to its medicinal properties as well as destruction of its natural habitat, S. xanthocarpum is now becoming endangered and its supply is limited. Plant in vitro culture and elicitation are attractive alternative strategies to produce biomass and stimulate biosynthesis of medicinally important phytochemicals. Here, we investigated the potential influence of seven different monochromatic light treatments on biomass and secondary metabolites accumulation in callus culture of S. xanthocarpum as well as associated biological activities of the corresponding extracts. Among different light treatments, highest biomass accumulation was observed in white light-treated callus culture. Optimum accumulation of total flavonoid contents (TFC) and total phenolic contents (TPC) were observed in callus culture kept under continuous white and blue light respectively than control. Quantification of phytochemicals through HPLC revealed that optimum production of caffeic acid (0.57 ± 0.06 mg/g DW), methyl-caffeate (17.19 mg/g ± 1.79 DW), scopoletin (2.28 ± 0.13 mg/g DW), and esculetin (0.68 ± 0.07 mg/g DW) was observed under blue light callus cultures. Compared to the classic photoperiod condition, caffeic acid, methyl-caffeate, scopoletin, and esculetin were accumulated 1.7, 2.5, 1.1, and 1.09-folds higher, respectively. Moreover, high in vitro cell free antioxidant, anti-diabetic, anti-aging, and anti-inflammatory activities were closely associated with the production of these secondary metabolites. These results clearly showed the interest to apply multispectral light as elicitor of in vitro callus cultures S. xanthocarpum to promote the production of important phytochemicals, and allow us to propose this system as an alternative for the collection of this endangered species from the wild.

Interactive Effect of Melatonin and UV-C on Phenylpropanoid Metabolite Production and Antioxidant Potential in Callus Cultures of Purple Basil (Ocimum basilicum L. var.s purpurascens)

The present study evaluated the interactive effect of melatonin and UV-C on phenylpropanoid metabolites profile and antioxidant potential of Ocimum basilicum L. Callus was treated with varying concentrations of melatonin and UV-C radiations for different time durations, either alone and/or in combination. Individual treatments of both UV-C and melatonin proved to be more effective than combine treatments. Results indicated that UV-C (10 min) exposure increased rosmarinic acid (134.5 mg/g dry weight (DW)), which was 2.3-fold greater than control. Chichoric acid (51.52 mg/g DW) and anthocyanin (cyanide 0.50 mg/g DW) were almost 4.1-fold, while peonidin was found 2.7-fold higher in UV-C (50 min) exposure. In the case of melatonin, 1.0 mg/L concentrations showed maximum rosmarinic acid (79.4 mg/g DW) accumulation; i.e., 1.4-fold more, as compared to the control. However, 2 mg/L melatonin accumulate chichoric acid (39.99 mg/g DW) and anthocyanin (cyanide: 0.45 mg/g DW and peonidin: 0.22 mg/g DW); i.e., 3.2, 3.7 and 2.0-fold increase, as compared to the control, respectively. On the other hand, melatonin-combined treatment (melatonin (Mel) (4 mg/L) + UV-C (20 min)) was proved to be effective in caffeic acid elicitation, which was 1.9-fold greater than the control. Furthermore, antioxidant potential was evaluated by both in vitro (DPPH, ABTS and FRAP assays) and in cellulo methods. Maximum in vitro antioxidant activity (DPPH: 90.6% and ABTS: 1909.5 µM) was observed for UV-C (50 min)-treated cultures. The highest in vitro antioxidant activity measured with the ABTS assay as compared to the FRAP assay, suggesting the main contribution of antioxidants from basil callus extracts acting through a hydrogen atom transfer (HAT) over an electron transfer (ET)-based mechanism. Cellular antioxidant assay was evaluated by production of ROS/RNS species using yeast cell cultures and further confirmed the protective action of the corresponding callus extracts against oxidative stress. Overall, both melatonin and UV-C are here proved to be effective elicitors since a positive correlation between the induced production of phenolic compounds, and in cellulo antioxidant action of basil callus extracts were observed.

A Comparative Evaluation of the Antiproliferative Activity against HepG2 Liver Carcinoma Cells of Plant-Derived Silver Nanoparticles from Basil Extracts with Contrasting Anthocyanin Contents

Nanotechnology is a well-established and revolutionized field with diverse therapeutic properties. Several methods have been employed using different reducing agents to synthesize silver nanoparticles (AgNPs). Chemical mediated synthetic methods are toxic and resulted in non-desired effects on biological systems. Herein, we, synthesized silver nanoparticles using callus extract of purple basil (BC-AgNPs) and anthocyanin extract deriving from the same plant (i.e. purple basil) (AE-AgNPs), and systematically investigated their antiproliferative potential against HepG2 Liver Carcinoma Cells. The phyto-fabricated AgNPs were characterized by different techniques like UV-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Energy dispersive X-rays (EDX). Morphologically, both types of NPs were found spherical. The average size of BC-AgNPs and AE-AgNPs as revealed through XRD and SEM analyses were calculated as 50.97 ± 0.10 nm and 42.73 ± 1.24 nm, respectively. FT-IR spectral analysis demonstrates the existence of possible phytochemicals required for the capping and reduction of Ag ions. Herein, following solid phase extraction (SPE) coupled to HPLC analysis, we report for the first-time the anthocyanin mediated synthesis of AgNPs and conforming the successful capping of anthocyanin. Small sized AE-AgNPs showed significant cytotoxic effect against human hepatocellular carcinoma (HepG2) cell line as compared to BC-AgNPs. Therefore, the results revealed that the prevalent group of flavonoids present in purple basil is the anthocyanins and AE-AgNPs could be employed as potential anticancer agents in future treatments strategies.