Improvement in Flavonoids and Phenolic Acids Production and Pharmaceutical Quality of Sweet Basil (Ocimum basilicum L.) by Ultraviolet-B Irradiation

A Long-Term Study on Chemical Compounds and Their Location in Sweet Basil Leaves from Organic and Conventional Producers

Bioactive compound profiles in organic and conventional sweet basil were analyzed by HPLC, and the enzymatic status and antioxidant status of plants cultivated with the two systems were also examined. Fluorescence microscopy was used for the determination of compounds' locations in the basil leaves. The experiment was conducted from 2019 to 2021. Organic and conventional basil samples were obtained directly from Polish herb producers. The results showed that the chemical profiles of organic and conventional basil leaves are different. Not only the cultivation method but also the experimental year had a significant impact on the antioxidant content in basil leaves. Organic basil contained significantly more dry matter (11.97 g 100 g-1 FW) compared to conventional one (10.54 g 100 g-1 FW) and a higher tendency for total phenolic compounds (5.24 mg g -1 DW) accumulation. The higher bioactive compound content reflects the antioxidant activity (61.0%, 54.33%, and 46%) in organic basil compared to conventional (46.87%, 38.055, and 39.24%) with respect to the analysis method (ABTS, DPPH, and FRAP). Catalase activity (39 µmol H2O2 min-1 mg-1) in organic basil was higher compared to conventional (23.19 µmol H2O2 min-1 mg-1) ones. The obtained results are very unique and could be used by herb producers as a key for high-quality basil production. The higher concentration of bioactive compounds in organic basil gives a better nutraceutical status to this popular herb.

Preharvest and postharvest techniques that optimize the shelf life of fresh basil (Ocimum basilicum L.): a review

Basil (Ocimum basilicum L.) is a popular specialty crop known for its use as a culinary herb and medicinal plant around the world. However, its profitability and availability are limited by a short postharvest shelf life due to poor handling, cold sensitivity and microbial contamination. Here, we comprehensively review the research on pre- and postharvest techniques that extend the shelf life of basil to serve as a practical tool for growers, distributors, retailers and scientists. Modifications to postharvest storage conditions, pre- and postharvest treatments, harvest time and preharvest production methods have been found to directly impact the quality of basil and its shelf life. The most effective strategies for extending the shelf life and improving the quality of basil are discussed and promising strategies that research and industry employ are identified.

Methyl jasmonate elicitation effect on the metabolic profile of cambial meristematic cells culture derived from sweet basil (Ocimum basilicum L.) in relation to antioxidant activity: Untargeted metabolomics study in a time-based approach

The undifferentiated cambial meristematic cell (CMC) has been recognized as a value-added production platform for plant natural products in comparison to the dedifferentiated plant cell line (DDC). In a time-based approach at 0, 24, 48, and 72 h, the present study aimed at investigating the phytochemical metabolome of methyl jasmonate (MeJA)-elicited CMC cultures derived from sweet basil (Ocimum basilicum L.), including primary and secondary metabolites analyzed using GC/TOF-MS post-silylation and RP-UPLC-C₁₈-FT-MS/MS, respectively, as well as the analysis of aroma composition using headspace SPME-GC-MS. The results revealed a stress response in primary metabolism manifested by an increase in amino and organic acids reaching their maximum levels after 48 (1.3-fold) and 72 (1.7-fold) h, respectively. In addition, phenolic acids (e.g., sagerinic acid, rosmarinic acid, and 3-O-methylrosmarinic acid) followed by flavonoid aglycones (e.g., salvigenin and 5,6,4'-trihydroxy-7,3'-dimethoxyflavone) were the most abundant with prominent increases at 48 (1.2-fold) and 72 (2.1-fold) h, respectively. The aroma was intensified by the elicitation along the time, especially after 48 and 72 h. Furthermore, multivariate data analyses, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) confirmed elicitation effect, especially post 48 and 72 h. The study further assessed the effect of MeJA elicitation on the antioxidant and polyphenolic content. The cultures at 48 h demonstrated a significant (p < 0.05) antioxidant activity concurrently with correlation with total polyphenolic content using Pearson's correlation. Our study provides new insights to the elicitation impact on primary and secondary metabolism, in addition to aroma profile, to orchestrate the stress response and in relation to antioxidant effect.

Effect of Microencapsulated Basil Extract on Cream Cheese Quality and Stability

The antimicrobial and antioxidant effects of plant extracts are well known, but their use is limited because they affect the physicochemical and sensory characteristics of products. Encapsulation presents an option to limit or prevent these changes. The paper presents the composition of individual polyphenols (HPLC-DAD-ESI-MS) from basil (Ocimum basilicum L.) extracts (BE), and their antioxidant activity and inhibitory effects against strains of Staphylococcus aureus, Geobacillus stearothermophilus, Bacillus cereus, Candida albicans, Enterococcus faecalis, Escherichia coli, and Salmonella Abony. The BE was encapsulated in sodium alginate (Alg) using the drop technique. The encapsulation efficiency of microencapsulated basil extract (MBE) was 78.59 ± 0.01%. SEM and FTIR analyses demonstrated the morphological aspect of the microcapsules and the existence of weak physical interactions between the components. Sensory, physicochemical and textural properties of MBE-fortified cream cheese were evaluated over a 28-day storage time at 4 °C. In the optimal concentration range of 0.6-0.9% (w/w) MBE, we determined the inhibition of the post-fermentation process and the improvement in the degree of water retention. This led to the improvement of the textural parameters of the cream cheese, contributing to the extension of the shelf life of the product by 7 days.

Phytochemical characterization, antioxidant activity and antihypertensive evaluation of Ocimum basilicum L. in l-NAME induced hypertensive rats and its correlation analysis

Ocimum basilicum Linn. (basil) is an aromatic culinary herb that has shown a great potential in therapeutic world. It has many promising pharmacological activities that make it centre for investigations for many researchers. Current study has been planned to determine chemical constituents of basil leaves extracts and their in-vitro and ex-vivo antioxidant and in-vivo antihypertensive potential. GC-MS studies of non-polar extracts showed presence of 75 compounds including monoterpenes, hydrocarbons, sesquiterpenes, triterpenes, phyto-sterols and phthalates. Higher percentages of fatty acids were also identified. The major compounds include linalool (7.65%), terpineol (1.42%), tau-cadinol (13.55%), methyl palmitate (14.24%), palmitic acid (14.31%), linolenic acid (1.30%) and methyl linolenate (17.72%). Electron spray ionization mass spectrometry ESI-HRMS/MS of the polar extracts revealed the presence of alkaloids, phenolic acid, amino acid, coumarin, lignin, flavanoid and terpene derivative. Total phenolic content and total flavonoid content were determined using spectrophotometric technique and calculated as gallic acid equivalents GAE/g dry weight and rutin equivalent RE/g of dry weight respectively. The highest phenolic content and flavonoid content were found in ethyl acetate extract 9.40 mg GAE/g and 15.9 mg RE/g of dry weight. All the extracts showed significant antioxidant activity in DPPH and ABTS cation decolorization assays. Dichloromethane extract possess the highest DPPH scavenging activity, i.e., 64.12% ± 0.23 at concentration of 4 mg/ml. Moreover in ex-vivo studies all the extracts showed prominent effect by inhibiting AAPS induce oxidation in Human erythrocytes being 69.24% ± 0.18 in dichloromethane extract, 64.44% ± 0.04 in ethyl acetate and 53.33% ± 0.09 in acetone extract. The methanol extract of O. basilicum exhibited significant decrease in systolic blood pressure in l-Name induced hypertensive rats at the dose of 50 mg/kg for 28 days. Total phenolic content had a higher linear correlation (r = 0.678) with antihypertensive activity, with a level of significance 95% showing that phenolic compounds in the leaves of the plant has important role in inhibiting l -NAME induced hypertension while flavonoid compounds may play a key role in the antioxidant activities of the plant, through synergism. Conclusively, O. basilicum leaves with bioactive metabolites are a potential source for the development of antihypertensive drugs.

Ocimum Species: A Review on Chemical Constituents and Antibacterial Activity

Infection by bacteria is one of the main problems in health. The use of commercial antibiotics is still one of the treatments to overcome these problems. However, high levels of consumption lead to antibiotic resistance. Several types of antibiotics have been reported to experience resistance. One solution that can be given is the use of natural antibacterial products. There have been many studies reporting the potential antibacterial activity of the Ocimum plant. Ocimum is known to be one of the medicinal plants that have been used traditionally by local people. This plant contains components of secondary metabolites such as phenolics, flavonoids, steroids, terpenoids, and alkaloids. Therefore, in this paper, we will discuss five types of Ocimum species, namely O. americanum, O. basilicum, O. gratissimum, O. campechianum, and O. sanctum. The five species are known to contain many chemical constituents and have good antibacterial activity against several pathogenic bacteria.

Vitamin contents and antioxidant capacity of hydroponic grown sweet basil inoculated with endophytic bacteria

The aim of this study was to assess the effect of inoculated endophytic bacteria on the concentrations of vitamins E (tocopherols), K (phylloquinone), B1 (thiamine), B2 (riboflavin), C (ascorbic acid) and the peroxyl radical scavenging capacity of hydroponically grown sweet basil. Endophytic strains were all isolated from hydrocarbon-stressed herbaceous plants or from basil showing superior growth. Plants inoculated with the endophytes displayed up to 40% increase (p &lt; 0.05) in the concentration of the reduced form of vitamin C relative to control [0.56 mg/g fresh weight (FW)] which indicated less oxidative stress in the presence of endophytes. In the case of γ-tocopherol, the highest content [25.8 μg/g of fresh weight (FW)] in inoculated basils was significantly higher compared to control plants (18.5 ± 1.2 μg/g FW) (p &lt; 0.05). Antioxidant activity (ROO∙ radicals scavenging) was as high as 94 ± 4 μM Trolox equivalents (TE)/g FW vs. 53 ± 5 μM TE/g FW for the control basil. Concentrations of vitamins C, B1, and B2 were not affected by most strains. The results showed that endophytic bacteria have the capacity to alter free radical quenching capacity and vitamin concentrations in basil plants and, that their effect is strain and nutrient dependent.

Differential Nutrition-Health Properties of Ocimum basilicum Leaf and Stem Extracts

(1) Background: Ocimum basilicum L. is an aromatic medicinal plant of the Lamiaceae family known as sweet basil. It is used in traditional medicine for its beneficial effects on gastrointestinal disorders, inflammation, immune system, pyrexia or cancer among others. Ocimum basilicum (OB) leaf extracts contain many phytochemicals bearing the plant health effects but no reports is available on the potential bioactivity of stem extracts. Our investigation aimed at assessing the differential biological activity between basil leaf and stem to promote this co-product valorization. (2) Method: For this purpose we explored phytochemical composition of both parts of the plant. Antioxidant activity was evaluated through total polyphenol content measure, DPPH and ORAC tests. Anti-inflammatory markers on stimulated macrophages, including NO (nitric oxide), TNFa (tumor necrosis factor alpha), IL-6 (interleukin 6), MCP1 (monocyte attractant protein 1) and PGE-2 (prostaglandin E2), were evaluated. In addition, we investigated OB effects on jejunum smooth muscle contractility. (3) Results: OB extracts from leaves and stems demonstrated a different biological activity profile at the level of both antioxidant, anti-inflammatory and smooth muscle relaxation effects. (4) Conclusion: Taken together our results suggest that Ocimum basilicum extracts from co-product stems, in addition to leaves, may be of interest at the nutrition-health level with specific therapeutic potential.

In Vitro and In Vivo Anticancer Activity of Basil (Ocimum spp.): Current Insights and Future Prospects

Simple Summary

Basil (Ocimum basilicum) is a medicinal herb of the family Lamiaceae that contains a variety of potential bioactive compounds, such as polyphenols, flavonoids, phenolics, and essential oils. Ocimum basilicum can boost phagocytic action of neutrophils and immunostimulant effect, antimicrobial activity due to linalool by having inhibitory action toward all tested microorganism, and additionally, rosmarinic acid shows inhibition in DNA synthesis, as well as protein synthesis when experimented on hepatoma-derived cell line (HepG2), this resulted by lower DNA fragments plus suppression on caspase-3 activation, which blocks apoptosis. The aim of this review is to spotlight and discuss the anti-cancer activity of basil (Ocimum) and its implications in cancer prevention and treatment. Antioxidants and other bioactive compounds in basil leaves show important potential anti-cancer activity regards to cell death and viability inhibition, cytotoxicity, inducing apoptosis, slowing down tumor growth and especially on cell cycle arrest both in vivo and in vitro.

Abstract

Background: Cancer is an irregular proliferation of cells that starts with a gene mutation that alters cellular function, is triggered by several factors, and can be inherited or acquired. The aim of this review is to discuss the anticancer activity of basil and its components’ strength, focusing on its implication in cancer prevention and treatment. Methods: This systematic review involves all of the studies published from 1 January 2010 through 1 January 2022. Results: In this review, 16 research articles are included to discuss the potential anticancer ability of the extracts of various Ocimum basilicum varieties at various dosages, applied to different cancer cells. Of those 16 articles, 2 were in vivo studies, 13 were in vitro studies, and 1 study conducted both in vivo and in vitro experiments. Antioxidants and other bioactive compounds in basil leaves show important potential anticancer activity at dosage of 4 mg/mL as aqueous extract or essential oil up to 200 µg/mL could slow-down tumor growth and progression with regards to cell death and viability inhibition. At dosages from 50 to 500 µg/mL is effective as anti-proliferative activities. cytotoxicity, inducing apoptosis, slowing down tumor growth, and especially cell cycle arrest, both in vivo and in vitro. Human studies show effects at dosages from 1 to 2.5 mg/daily on general vital activities and on reducing cytokines activity. Conclusions: Based on 16 published studies, basil demonstrates important anticancer activities in vivo and vitro models, and it could act as a potential cancer.

Toxicity, Antioxidant Activity, and Phytochemicals of Basil (Ocimum basilicum L.) Leaves Cultivated in Southern Punjab, Pakistan

Basil (Ocimum basilicum L.) is one of the most common aromatic herbs, a rich source of bioactive compounds, and is used extensively to add aroma and flavor to food. The leaves, both in fresh and dried form, are used as a culinary ingredient in different cultures. O. basilicum is also famous for its therapeutic potential and preservation effects. The present study investigated the cytotoxicity of basil at three different growth stages (GS), i.e., GS-1 (58 days of growth), GS-2 (69 days of growth), and GS-3 (93 days of growth) using the brine shrimp lethality assay. The results revealed that cytotoxicity was influenced by GS and the concentration of extracts. Aqueous extracts of basil at a concentration of 10 to 1000 µg/mL did not show notable toxicity. The lowest mortality rate, i.e., 8.9%, was recorded for GS-2 at the highest tested dose of basil extracts. The mortality rate at GS-1, GS-2, and GS-3 was found to be 26.7 ± 3.34%, 8.91 ± 0.10%, and 16.7 ± 0.34%, respectively, at 1000 µg/mL. GS-2 basil powder with the lowest toxicological risk was extracted with different solvents, viz., n-hexane, dichloromethane, ethanol, and water. The highest concentration of plant secondary metabolites including total phenolic acid, flavonoids, and tannin content was observed in ethanol extracts. Ethanol extracts also exhibited the highest antioxidant activity in DPPH, FRAP and H₂O₂ assays. LC-ESI-MS/MS analysis presented ethanol extracts of basil as a promising source of known health-promoting and therapeutic compounds such as rosmarinic acid, ellagic acid, catechin, liquiritigenin, and umbelliferone. The results suggest basil, a culinary ingredient, as a potential source of bioactive compounds which may offer an array of health promoting and therapeutic properties.

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.

Effects of sweet basil leaves (Ocimum basilicum L) addition on the chemical, antioxidant, and storage stability of roselle calyces (Hibiscus sabdariffa) drink

Consumers expect greater functionality from food and beverage products. Celebrated for a range of health benefits, polyphenols have been linked to a preventive role for chronic diseases and viral infections and have the ability to relieve oxidative stress. A drink made with roselle calyces (Hibiscus sabdariffa) and sweet basil leaves (Ocimum basilicum L) may provide therapeutic or preventive effects against chronic and infectious diseases. Damage caused by oxidative stress may be alleviated by the polyphenols found in roselle calyces and sweet basil leaves. The roselle-basil samples at different blend ratio were analysed for pH, total soluble solids, total titratable acidity, vitamin C, lycopene, total phenolic contents, antioxidant properties, and storage stability at different temperature (4 and 29 °C). The incorporation of sweet basil leaves to roselle calyces slightly decreased the vitamin C and lycopene content of the processed drink but increased the total carotenoid and antioxidant activities (ABTS and ORAC) of the drink. The radical scavenging properties of the processed drink increased with the addition of the dried sweet basil leaves and samples kept at a higher temperature of 29 °C showed a rise in antioxidant activities compared to samples stored at 4 °C. The increase in the free radical scavenging power of the drinks show that the roselle-basil drink may serve as health drink and addition of sweet basil leaves up to 5% may be suitable to produce roselle-basil drink.

Effects of various Agrobacterium rhizogenes strains on hairy root induction and analyses of primary and secondary metabolites in Ocimum basilicum

The hairy root (HR) culture system is an excellent alternative strategy to the whole plant system for producing valuable compounds. However, selection of suitable Agrobacterium strain for the successful induction of HR is an essential step for enhanced production of beneficial secondary metabolites. In this study, we examined the transformation efficiency of various A. rhizogenes strains (ATCC 13333, ATCC 15834, A4, R1000, R1200, and R1601) for transgenic HRs induction in Ocimum basilicum. Among the tested strains, the R1601 was found to be one of the most promising strain for mass production of HR in terms of transformation efficiency (94%) and the number and length of HR (8.4 ± 0.52 and 1.68 ± 0.14 cm). The HR induced by the same strain exhibited highest levels of rosmarinic acid level (62.05 ± 4.94 µg/g DW) and total phenolic content (62.3 ± 4.95 µg/g DW). A total of 55 metabolites were identified using high-performance liquid chromatography (HPLC) and gas chromatography-time-of-flight mass spectrometry (GC-TOFMS). The PCA and PLS-DA plot of the identified metabolites showed that HR induced by A4 and ATCC 15834 displayed variation in primary and secondary metabolite contents. Analysis of the metabolic pathway identified a total of 56 pathways, among which 35 were found to be impacted. A heat map and hierarchical clustering analysis indicated that HR induced by different Agrobacterium strains exhibited differential metabolites profiles. In conclusion, Agrobacterium strains R1601 is one of the best and most promising strains for inducing mass HR production and enhanced levels of secondary metabolites in O. basilicum.

Time-Course of Changes in Photosynthesis and Secondary Metabolites in Canola (Brassica napus) Under Different UV-B Irradiation Levels in a Plant Factory With Artificial Light

This study aimed to evaluate short-duration (24 h) UV-B irradiation as a preharvest abiotic stressor in canola plants. Moreover, we quantified the expression levels of genes related to bioactive compounds synthesis in response to UV-B radiation. Canola seedlings were cultivated in a plant factory under artificial light (200 μmol m^-2 s^-1 photosynthetic photon flux density; white LED lamps; 16 h on/8 h off), 25°C/20°C daytime/nighttime air temperature, and 70% relative humidity. Eighteen days after sowing, the seedlings were subjected to supplemental UV-B treatment. The control plants received no UV-B irradiation. The plants were exposed to 3, 5, or 7 W m^-2 UV-B irradiation. There were no significant differences in shoot fresh weight between the UV-B-irradiated and control plants. With increasing UV-B irradiation intensity and exposure time, the H₂O₂ content gradually increased, the expression levels of genes related to photosynthesis downregulated, and phenylpropanoid and flavonoid production, and also total phenolic, flavonoid, antioxidant, and anthocyanin concentrations were significantly enhanced. The genes related to secondary metabolite biosynthesis were immediately upregulated after UV-B irradiation. The relative gene expression patterns identified using qRT-PCR corroborated the variations in gene expression that were revealed using microarray analysis. The time point at which the genes were induced varied with the gene location along the biosynthetic pathway. To the best of our knowledge, this is the first study to demonstrate a temporal difference between the accumulation of antioxidants and the induction of genes related to the synthesis of this compound in UV-B-treated canola plants. Our results demonstrated that short-term UV-B irradiation could augment antioxidant biosynthesis in canola without sacrificing crop yield or quality.

The Effect of Antagonist Abiotic Stress on Bioactive Compounds from Basil (Ocimum basilicum)

Drought and flooding are some of the most common stressful conditions for plants. Due to the recent climate changes, they can occur one after another. This study is focused on the effect of antagonistic abiotic stress such as drought and flooding on the different metabolites from Ocimum basilicum leaves. Six-week-old plants of Ocimum basilicum were exposed to drought or flooding stress for 15 days, followed by antagonist stress for 14 days. The assimilation rates decrease drastically for plants under consecutive stresses from 18.9 to 0.25 µmol m−2 s−1 starting at day 3 of treatment. The stomatal conductance to water vapor gs was also reduced from 86 to 29 mmol m−2 s−1. The emission of green leaf volatiles compounds increases from 0.14 to 2.48 nmol m−2 s−1, and the emission of monoterpenes increased from 2.00 to 7.37 nmol m−2 s−1. The photosynthetic pigment concentration (chlorophyll a and b, and β-carotene), the flavonoid content, and total phenolic content decrease for all stressed plants. The results obtained in this study could indicate that the water status (drought and/or flooding) directly impacts basil plants’ physiological parameters and secondary metabolites.

The interactive effect of aromatic amino acid composition on the accumulation of phenolic compounds and the expression of biosynthesis-related genes in Ocimum basilicum

Sweet basil (Ocimum basilicum L.), a well-known medicinal and aromatic herb, rich in essential oils and antioxidants (contributed by phenolics), is widely used in traditional medicine. The biosynthesis of phytochemicals occurs via different biochemical pathways, and the expression of selected genes encoding enzymes involved in the formation of phenolic compounds is regulated in response to environmental factors. The synthesis of the compounds is closely interrelated: usually, the products formed in the first reaction steps are used as substrates for the next reactions. The current study attempted a comprehensive overview of the effect of aromatic amino acid composition (AAAs) in Ocimum basilicum in respect to the expression of genes related to the biosynthesis of phenolic compound and their content. The transcript expression levels of EOMT, PAL, CVOMT, HPPR, C4L, EGS, and FLS increased depending on the AAAs concentration compared to the control plants. The highest mRNA accumulation was obtained in EOMT, FLS, and HPPR in the leaves of sweet basil. The expression of the TAT gene in the leaves significantly reduced in response to all AAAs applications compared to untreated groups and it had the lowest transcript accumulation. Eleven individual phenolic compounds were determined in the basil leaves, and the contents of chicoric acid, methyl chavicol, caffeic acid, and vanillic acid increased depending on administered concentration to control (p < 0.05). Additionally, AAAs lead to an incremental change in the amount of chlorogenic acid at 50 and 100 mg kg^-1 compared to control plants (p < 0.05). Rutin and rosmarinic acid were detected as the main phenolic compounds in all experimental groups of sweet basil in terms of quantity. However, their amount significantly decreased as compared to control plants based on the increase in AAAs concentrations (p < 0.05). Also, the accumulation of cinnamic acid, eugenol, and quercetin did not significantly change in the leaves of AAAs treated plants compared to control (p < 0.05). When AAAs was applied, total flavonoid content increased in all treatments compared to the control plants, but total phenolic content did not change significantly (p < 0.05). To the best of our knowledge, our work is the first detailed work to evaluate in detail the impact of AAAs on individual phenolic compounds at the phytochemistry and transcriptional levels in the O. basilicum plant. For a detailed understanding of the whole mechanism of phenolic compound regulation, further research is required to fill in some gaps and to provide further clarification.

Valorization of waste cabbage leaves by postharvest photochemical treatments monitored with a non-destructive fluorescence-based sensor

The biosynthesis of polyphenolic compounds in cabbage waste, outer green leaves of white head cabbage (Brassica oleracea L. var. capitata subvar. alba), was stimulated by postharvest irradiation with UVB lamps or sunlight. Both treatments boosted the content of kaempferol and quercetin glycosides, especially in the basal leaf zone, as determined by the HPLC analysis of leaf extracts and by a non-destructive optical sensor. The destructive analysis of samples irradiated by the sun for 6 days at the end of October 2015 in Skierniewice (Poland) showed an increase of leaf flavonols by 82% with respect to controls. The treatment by a broadband UVB fluorescent lamp, with irradiance of 0.38 W m^-2 in the 290-315 nm range (and 0.59 W m^-2 in the UVA region) for 12 h per day at 17 °C along with a white light of about 20 μmol m^-2 s^-1, produced a flavonols increase of 58% with respect to controls. The kinetics of flavonols accumulation in response to the photochemical treatments was monitored with the FLAV non-destructive index. The initial FLAV rate under the sun was proportional to the daily radiation doses with a better correlation for the sun global irradiance (R² = 0.973), followed by the UVA (R² = 0.965) and UVB (R² = 0.899) irradiance. The sunlight turned out to be more efficient than the UVB lamp in increasing the flavonols level of waste leaves, because of a significant role played by UVA and visible solar radiation in the regulation of the flavonoid accumulation in cabbage. The FLAV index increase induced on the adaxial leaf side was accompanied by a lower but still significant FLAV increase on the unirradiated abaxial side, likely due to a systemic signaling by mean of the long-distance movement of macromolecules. Our present investigation provides useful data for the optimization of postharvest photochemical protocols of cabbage waste valorization. It can represent a novel and alternative tool of vegetable waste management for the recovery of beneficial phytochemicals.

In-Vivo In-Vitro Screening of Ocimum basilicum L. Ecotypes with Differential UV-B Radiation Sensitivity

Elevated UV-B radiation (UV-B) has been previously reported to affect plant development, physiology, and promote the biosynthesis of UV-absorbing compounds. Sweet basil (Ocimum basilicum L.) is an aromatic herb, widely cultivated worldwide for its use in the food, pharmaceuticals, and cosmetics industry. This species exhibits high diversity among different ecotypes based on their geographical locations. There has been little research on intra-specific photosynthetic and metabolic differences in UV-B tolerance across ecotypes from different geographical areas. This study evaluated the protection responses to high UV-B radiation of nine O. basilicum accessions with different geographic origins. Specifically, the changes in chlorophyll a fluorescence parameters and the leaf rosmarinic acid (RA) compound were assessed using an “in vivo-vitro system” in a closed-type plant production system. Our results revealed a significant variation in UV-B protection mechanisms among accessions when plants were treated with high UV-B doses. The accumulation of RA increased significantly by UV-B light treatment in OCI142, OCI148, OCI30, OCI160, and OCI102, with the highest concentration measured in OCI160 plants. This ecotype showed the highest value of the Fv/Fm ratio, 0.70, after 48 h. Recovery of leaf functionality was more rapid in OCI160 than in other sweet basil accessions, which may indicate better photosynthetic capacity associated with enhanced biosynthesis of UV absorbing compounds. This study shows that the biosynthesis of the UV-absorbing compound (RA) represents an effective mechanism to reduce the photoinhibitory and photooxidative damage caused by high UV stress.

Cytotoxicity of Ocimum basilicum and Impatiens walleriana Extracts on AGS and SKOV-3 Cancer Cell Lines by Flow Cytometry Analysis

Background: Numerous studies investigate finding new drug candidates with an increasing death rate caused by cancer. Nowadays, herbal medicine has been noticed again because of the many side effects of chemical drugs. Objectives: In the current study, anthocyanin and carotenoid types of compounds of Ocimum basilicum and Impatiens walleriana were determined and their cytotoxic effect on human gastric adenocarcinoma (AGS) and human ovarian carcinoma (SKOV-3) cancer cell lines were investigated. The cytotoxic effect of I. walleriana on cancer cells has not been reported so far. Methods: The amount of anthocyanin and carotenoid derivatives in these two plant species were investigated by biochemical tests, 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and flow cytometry methods were applied for the cytotoxicity effect of the extracts on the AGS and SKOV3 cancer cell lines. Cell necrosis and apoptosis were determined by annexin V-fluorescent isothiocyanate/propidium iodide (FITC/PI) staining and quantification by flow cytometry. Results: Ocimum basilicum and I. walleriana contained a noticeable amount of the mentioned compounds. According to the results, the lowest IC50 (Half- maximal inhibitory concentration) value with an amount of 2.5 ± 0.21 mg/mL that indicates the most cytotoxic extract on the AGS cancer cell line belonged to I. walleriana extract. Besides, the lowest IC50 value of O. basilicum was about 0.9 ± 0. 11 mg/mL on the SKOV3 cancer cell line. The flow cytometry analysis has also proved that the toxicity of O. basilicum is more than I. walleriana on the SKOV3 cell line and the toxicity of I. walleriana was higher than O. basilicum on the AGS cancer cell line. Conclusions: Ocimum basilicum and I. walleriana contain antioxidant compounds, which showed the cytotoxic effect on AGS and SKOV3 cancer cell lines. Further studies on animal models and subsequent trials are necessary for revealing the full potential of the extracts.

UV Lighting in Horticulture: A Sustainable Tool for Improving Production Quality and Food Safety

Ultraviolet (UV) is a component of solar radiation that can be divided into three types defined by waveband: UV-A (315–400 nm), UV-B (280–315 nm), and UV-C (<280 nm). UV light can influence the physiological responses of plants. Wavelength, intensity, and exposure have a great impact on plant growth and quality. Interaction between plants and UV light is regulated by photoreceptors such as UV Resistance Locus 8 (UVR8) that enables acclimation to UV-B stress. Although UV in high doses is known to damage quality and production parameters, some studies show that UV in low doses may stimulate biomass accumulation and the synthesis of healthy compounds that mainly absorb UV. UV exposure is known to induce variations in plant architecture, important in ornamental crops, increasing their economic value. Abiotic stress induced by UV exposure increases resistance to insects and pathogens, and reduce postharvest quality depletion. This review highlights the role that UV may play in plant growth, quality, photomorphogenesis, and abiotic/biotic stress resistance.

Quantitative Analysis of UV-B Radiation Interception and Bioactive Compound Contents in Kale by Leaf Position According to Growth Progress

UV-B (280-315 nm) radiation has been used as an effective tool to improve bioactive compound contents in controlled environments, such as plant factories. However, plant structure changes with growth progress induce different positional distributions of UV-B radiation interception, which cause difficulty in accurately evaluating the effects of UV-B on biosynthesis of bioactive compounds. The objective of this study was to quantitatively analyze the positional distributions of UV-B radiation interception and bioactive compound contents of kales (Brassica oleracea L. var. acephala) with growth progress and their relationships. Short-term moderate UV-B levels did not affect the plant growth and photosynthetic parameters. Spatial UV-B radiation interception was analyzed quantitatively by using 3D-scanned plant models and ray-tracing simulations. As growth progressed, the differences in absorbed UV-B energy between leaf positions were more pronounced. The concentrations of total phenolic compound (TPC) and total flavonoid compound (TFC) were higher with more cumulative absorbed UV-B energy. The cumulative UV energy yields for TFC were highest for the upper leaves of the older plants, while those for TPC were highest in the middle leaves of the younger plants. Despite the same UV-B levels, the UV-B radiation interception and UV-B susceptibility in the plants varied with leaf position and growth stage, which induced the different biosynthesis of TFC and TPC. This attempt to quantify the relationship between UV-B radiation interception and bioactive compound contents will contribute to the estimation and production of bioactive compounds in plant factories.

Short-Term Pre-Harvest UV-B Supplement Enhances the Polyphenol Content and Antioxidant Capacity of Ocimum basilicum Leaves during Storage

Ocimum basilicum (basil) leaves are rich in polyphenols, conferring them a high antioxidant activity. The application of UV-B can be used to maintain the post-harvest nutraceutical quality of basil leaves. We aimed to investigate the effects of pre-harvest UV-B application on polyphenolic and pigment contents, antioxidant capacity, and the visual quality of basil stored leaves. We also evaluated the applicability of the non-invasive Dualex® for monitoring the accumulation of leaf epidermal phenolics (Flav Index). After exposing plants to white light (control) and to supplemental UV-B radiation for 4 d, the leaves were harvested and stored for 7d (TS7). The UV-B leaves showed both a higher phenolic content and antioxidant capacity than the controls at TS7. In addition, the correlations between the Flav Index and phenolic content demonstrated that Dualex® can reliably assess the content of epidermal phenolics, thus confirming its promising utilization as a non-destructive method for monitoring the phytochemical quality of O. basilicum leaves. In conclusion, a pre-harvesting UV-B application may be a tool for enhancing the content of polyphenols and the antioxidant potential of basil stored leaves without detrimental effects on their visual quality. These results are important considering the nutraceutical value of this plant and its wide commercial distribution.

Metabolic Insights into the Anion-Anion Antagonism in Sweet Basil: Effects of Different Nitrate/Chloride Ratios in the Nutrient Solution

Sweet basil (Ocimum basilicum L.) is a highly versatile and globally popular culinary herb, and a rich source of aromatic and bioactive compounds. Particularly for leafy vegetables, nutrient management allows a more efficient and sustainable improvement of crop yield and quality. In this work, we investigated the effects of balanced modulation of the concentration of two antagonist anions (nitrate and chlorine) in basil. Specifically, we evaluated the changes in yield and leaf metabolic profiles in response to four different NO3-:Cl- ratios in two consecutive harvests, using a full factorial design. Our work indicated that the variation of the nitrate-chloride ratio exerts a large effect on both metabolomic profile and yield in basil, which cannot be fully explained only by an anion-anion antagonist outcome. The metabolomic reprogramming involved different biochemical classes of compounds, with distinctive traits as a function of the different nutrient ratios. Such changes involved not only a response to nutrients availability, but also to redox imbalance and oxidative stress. A network of signaling compounds, including NO and phytohormones, underlined the modeling of metabolomic signatures. Our work highlighted the potential and the magnitude of the effect of nutrient solution management in basil and provided an advancement towards understanding the metabolic response to anion antagonism in plants.

Effects of Light on Secondary Metabolites in Selected Leafy Greens: A Review

In contrast to the primary metabolism, responsible for essential synthesis mechanisms and mass balance in plants, the secondary metabolism is not of particular importance for each cell but for the plant organism as its whole. Most of these metabolites show antioxidant properties and are beneficial for human health. In order to affect accumulation of those metabolites, light is an essential factor. It is possible to select various combinations of light intensity and light quality to address corresponding photoreceptors and synthesis. However, the plethora of additional variables considering environmental conditions such as temperature, relative humidity or cultivation method complicate defining specific "light recipes". This review summarizes experiments dealing with consumable leafy greens such as lettuce or basil and the enhancement of three selected metabolites - anthocyanins, carotenoids and flavonols.

Nutraceutical Profiles of Two Hydroponically Grown Sweet Basil Cultivars as Affected by the Composition of the Nutrient Solution and the Inoculation With Azospirillum brasilense

Sweet basil (Ocimum basilicum L.) is one of the most produced aromatic herbs in the world, exploiting hydroponic systems. It has been widely assessed that macronutrients, like nitrogen (N) and sulfur (S), can strongly affect the organoleptic qualities of agricultural products, thus influencing their nutraceutical value. In addition, plant-growth-promoting rhizobacteria (PGPR) have been shown to affect plant growth and quality. Azospirillum brasilense is a PGPR able to colonize the root system of different crops, promoting their growth and development and influencing the acquisition of mineral nutrients. On the bases of these observations, we aimed at investigating the impact of both mineral nutrients supply and rhizobacteria inoculation on the nutraceutical value on two different sweet basil varieties, i.e., Genovese and Red Rubin. To these objectives, basil plants have been grown in hydroponics, with nutrient solutions fortified for the concentration of either S or N, supplied as SO₄ ^2- or NO₃ ^-, respectively. In addition, plants were either non-inoculated or inoculated with A. brasilense. At harvest, basil plants were assessed for the yield and the nutraceutical properties of the edible parts. The cultivation of basil plants in the fortified nutrient solutions showed a general increasing trend in the accumulation of the fresh biomass, albeit the inoculation with A. brasilense did not further promote the growth. The metabolomic analyses disclosed a strong effect of treatments on the differential accumulation of metabolites in basil leaves, producing the modulation of more than 400 compounds belonging to the secondary metabolism, as phenylpropanoids, isoprenoids, alkaloids, several flavonoids, and terpenoids. The primary metabolism that resulted was also influenced by the treatments showing changes in the fatty acid, carbohydrates, and amino acids metabolism. The amino acid analysis revealed that the treatments induced an increase in arginine (Arg) content in the leaves, which has been shown to have beneficial effects on human health. In conclusion, between the two cultivars studied, Red Rubin displayed the most positive effect in terms of nutritional value, which was further enhanced following A. brasilense inoculation.

Influence of basil (Ocimum basilicum Lamiaceae) addition on functional, technological and sensorial characteristics of fresh cheeses made with organic buffalo milk

The inclusion of basil in the development of fresh cheeses made with organic buffalo milk was studied. The treatments were: 0 (without basil), 2.5, 5.0 and 7.5 g dried basil/kg of cheese. The cheeses were stored under refrigeration at 4 ± 1 °C during 21 days. The addition of basil did not modify fat, protein, moisture and mineral content of cheeses. The total polyphenol content and antioxidant activity of cheeses increased with basil addition at day one, with a significant reduction in cheeses with 21 days of storage. Cheeses with basil presented higher antioxidant activity and lower pH. The inclusion of basil changed hardness and chewiness, but not influenced springiness and cohesiveness. The microstructure was less homogeneous in cheeses with basil. Cheese with 2.5 and 5.0 g dried basil/kg cheese were preferred by consumers. Thus, the basil improves functional and modify technological characteristics of fresh cheeses and presented good acceptability.

Phytochemical profile and protective effect of Ocimum basilicum aqueous extract in doxorubicin/irradiation-induced testicular injury

Objectives

Combined chemotherapy and radiotherapy usually associated with various comorbidities especially on rapidly proliferating cells as testis. This study aimed to characterize main constituents of Ocimum basilicum L. (OB) aqueous extract and examine its protective effect on doxorubicin/irradiation (DOXO/IR)-induced testicular injury in rats.

Methods

Spectrophotometric analysis showed considerable amount of polyphenolic (146.31 µg/mg) and flavonoid contents (28.63 µg/mg); UPLC-ESI-MS/MS analysis revealed that the major flavonoid was apigenin-O-glucoside (7.53%) followed by luteolin (5.94%), while rosmarinic acid was the major polyphenolic (15.76%) followed by caftaric acid (9.39%); rutin and querctin were also present and were quantified using high-performance liquid chromatography. Administration of OB extract (200 mg/kg per day; p.o.) to DOXO/IR rats resulted in marked improvement of associated testicular damage.

Key findings

Ocimum basilicum L. significantly decreased testicular levels of nuclear factor-kappa B and B-cell lymphoma-2 (Bcl2)-associated protein X, along with caspase-3 immunohistochemical staining. In addition, OB elevated testicular total antioxidant capacity, nuclear erythroid-related factor-2, Bcl2 and testosterone contents and Ki-67 immunohistochemical staining. Such changes were also accompanied by restoration of testicular architecture.

Conclusions

The study highlights the protective role of OB aqueous extract in hampering most of the harmful chemotherapy/radiotherapy-induced outcomes via its antioxidant, antiapoptotic and cell regeneration abilities. Such findings may offer an incentive in expanding its use during chemotherapy and radiotherapy.

Improvement of Phenolic Compounds, Essential Oil Content and Antioxidant Properties of Sweet Basil (Ocimum basilicum L.) Depending on Type and Concentration of Selenium Application

The effect of selenium biofortification on phytomass yield, selenium, essential oil and phenolic compounds content as well as antioxidant properties of basil leaves was investigated. Selenium in form of sodium selenate was applied either in nutrient solution or by foliar spraying at three levels (2.0, 5.0 and 10.0 μM). Selenium treatment significantly increased Se concentration in leaves up to 20.23 μg g⁻¹ (addition in nutrient solution) and 10.74 μg g⁻¹ (foliar application). Neither a toxic nor a beneficial effect of Se addition on the plants was observed. Se application of 2 µM Se in nutrient solution and of 5 µM Se by foliar spraying successfully enhanced production of essential oils, hydroxycinnamic acids, total phenolics and antioxidant activity of basil leaves. The anthocyanin content was positively affected only by application of Se in nutrient solution. Considering both an increase in the Se concentration in basil leaves and an increase in the production of phytonutrients, the optimal doses of selenium can be considered to be 5 and 10 μM for Se addition in nutrient solution and by foliar treatment, respectively. The results confirm the possibility of the enrichment of basil plants with selenium and thereby improving the nutritional qualities of the human diet.

Pre-Harvest UV-B Radiation and Photosynthetic Photon Flux Density Interactively Affect Plant Photosynthesis, Growth, and Secondary Metabolites Accumulation in Basil (Ocimum Basilicum) Plants

Phenolic compounds in basil (Ocimum basilicum) plants grown under a controlled environment are reduced due to the absence of ultraviolet (UV) radiation and low photosynthetic photon flux density (PPFD). To characterize the optimal UV-B radiation dose and PPFD for enhancing the synthesis of phenolic compounds in basil plants without yield reduction, green and purple basil plants grown at two PPFDs, 160 and 224 μmol·m−2·s−1, were treated with five UV-B radiation doses including control, 1 h·d−1 for 2 days, 2 h·d−1 for 2 days, 1 h·d−1 for 5 days, and 2 h·d−1 for 5 days. Supplemental UV-B radiation suppressed plant growth and resulted in reduced plant yield, while high PPFD increased plant yield. Shoot fresh weight in green and purple basil plants was 12%–51% and 6%–44% lower, respectively, after UV-B treatments compared to control. Concentrations of anthocyanin, phenolics, and flavonoids in green basil leaves increased under all UV-B treatments by 9%–18%, 28%–126%, and 80%–169%, respectively, and the increase was greater under low PPFD compared to high PPFD. In purple basil plants, concentrations of phenolics and flavonoids increased after 2 h·d−1 UV-B treatments. Among all treatments, 1 h·d−1 for 2 days UV-B radiation under PPFD of 224 μmol·m−2·s−1 was the optimal condition for green basil production under a controlled environment.

Effects of Different Oligochitosans on Isoflavone Metabolites, Antioxidant Activity, and Isoflavone Biosynthetic Genes in Soybean ( Glycine max) Seeds during Germination

Five oligochitosans with increasing degrees of polymerization (DPs), i.e., from chitotriose to chitoheptaose, were examined to clarify the structure-bioactivity relationship between the DPs of oligochitosans and their effects on the isoflavone metabolites, total phenolic and flavonoid contents (TPC and TFC, respectively), and antioxidant activity of soybean ( Glycine max) seeds during germination. Oligochitosans of different DPs exhibited varying influences on the TPC, TFC, and antioxidant activities of soybean seeds. Chitohexaose exerted a strong effect and significantly increased the aforementioned parameters in soybean seeds 72 h after germination. Genistin, malonylgenistin, and genistein were the main isoflavones found, and the genistin and genistein contents were significantly enhanced by 67.32% and 131.38%, respectively, after chitohexaose treatment. Several critical genes involved in the isoflavone biosynthesis (i.e., PAL, CHS, CHI, IFS) of soybeans treated with and without chitohexaose were analyzed, and results suggested that chitohexaose application could dramatically stimulate the transcription of these genes.

Epigenetic control of UV-B-induced flavonoid accumulation in Artemisia annua L

UV-B-induced flavonoid biosynthesis is epigenetically regulated by site-specific demethylation of AaMYB1, AaMYC, and AaWRKY TF-binding sites inAaPAL1promoter-causing overexpression ofAaPALgene inArtemisia annua. The present study was undertaken to understand the epigenetic regulation of flavonoid biosynthesis under the influence of ultraviolet-B radiation using Artemisia annua L. as an experimental model. In-vitro propagated and acclimatized plantlets were treated with UV-B radiation (2.8 W m^-2; 3 h), which resulted in enhanced accumulation of total flavonoid and phenolics content as well as eleven individual flavonoids measured through HPLC-DAC. Expression of eight genes (phenylanaline ammonia lyase, cinnamate-4-hydroxylase, 4-coumarate: CoA ligase; chalcone synthase, chalcone isomerase, cinnamoyl reductase, flavonoid-3'-hydroxylase, and flavones synthase) from upstream and downstream flavonoid biosynthetic pathways was measured through RT-PCR and RT-Q-PCR and all were variably induced under UV-B irradiation. Among them, AaPAL1 transcript and its protein were most significantly upregulated. Global DNA methylation analysis revealed hypomethylation of genomic DNA in A. annua. Further epigenetic characterization of promoter region of AaPAL1 revealed cytosine demethylation at five sites, which in turn caused epigenetic activation of six transcription factor-binding sites including QELEMENT, EBOXBNNAPA/MYCCONSENSUSAT, MYBCORE, MYBCOREATCYCB1, and GCCCORE. MYB transcription factors are positive regulators of flavonoid biosynthesis. Epigenetic activation of transcription-enhancing cis-regulatory elements in AaPAL1 promoter and subsequent overexpression of AaMYB1 and AaMYC and AaWRKY transcription factors under UV-B irradiation may probably be the reason for higher AaPAL1 expression and hence greater biosynthesis of flavonoids in A. annua L. The present study is the first report that provides mechanistic evidence of epigenetic regulation of flavonoid biosynthesis under UV-B radiation in A. annua L.

Looking at Flavonoid Biodiversity in Horticultural Crops: A Colored Mine with Nutritional Benefits

Flavonoids represent a wide group of plant secondary metabolites implicated in many physiological roles, from the attraction of pollinators to the protection against biotic or abiotic stresses. Flavonoids are synthetized in a number of horticultural crops that are important components of our daily diet. In the last decades, the consumption of vegetables rich in antioxidants has been strongly promoted from the perspective of prevention/protection against chronic diseases. Therefore, due to their nutritional importance, several attempts have been made to enhance flavonoid levels in species of agronomic interest. In this review, we focus on the flavonoid biodiversity among the major horticultural species, which is responsible of differences among closely related species and influences the qualitative/quantitative composition. We also review the role of flavonoids in the nutritional quality of plant products, contributing to their organoleptic and nutritional properties, and the main strategies of biofortification to increase their content.

Effect of environmental variables on phytonutrients of Origanum vulgare L. in the sub-humid region of the northwestern Himalayas

Ecological and soil physiochemical parameters impact the crop quality and development. In spite of the huge commercial prospective, the phytonutrient and chemometric profiles of Himalayan oregano (Origanum vulgare L.) have not been evaluated, and their relationships with ecological parameters are still lacking. The objective of this research study was to evaluate the disparity in the phytonutrient profiles of different ecotypes of O. vulgare in wild and cultivated populations and determine whether such variation was related to the diverse climatic and edaphic conditions prevailing in the northwestern Himalayas. Micrometeorological, atomic absorption spectroscopy for micro-elemental analysis was determined for soil. HPLC was used to determine the disparity in phytonutrient (quercetin, betacarotene, ascorbic acid, and catechin) and phytochemical (arbutin) levels. Cultivated populations had lower phytonutrient levels than wild populations. The habitat exhibiting pH values ranging from 6 to 7 elevated organic carbon (2.42%), nitrogen (97.41 kg ha^-1), and manganese (10-12 μg g^-1) and zinc contents (0.39-0.50%) show luxirant growth of Origanum vulgarel. The phytonutrient (quercetin, betacarotene, ascorbic acid, arbutin, and catechin) levels had a direct relationship with UV-B flux (r² = 0.82) and potassium (r² = 0.97). Wild accessions predominantly contained catechin and ascorbic acid, with maximum values of 163.8 and 46.88 μg g^-1, respectively, while the cultivated accessions had the highest level of arbutin (53.42 μg g^-1). Maximum variation was observed in quercetin (114.61%) followed by β-carotene (87.53%). Cultivated accessions had less quercetin (0.04-1.25 μg g^-1) than wild accessions (1.25-2.87 μg g^-1). Wild accessions had higher phytonutrient values for catechin, β-carotene, and ascorbic acid while cultivated accessions had maximum values for arbutin. The correlation of environmental variables with phytonutrient levels paves the way for metabolomic-guided enhancement of agricultural practices for better herb quality.

Elevated CO2 induces a global metabolic change in basil (Ocimum basilicum L.) and peppermint (Mentha piperita L.) and improves their biological activity

Many studies have discussed the influence of elevated carbon dioxide (eCO₂) on modeling and crop plants. However, much less effort has been dedicated to herbal plants. In this study, a robust monitoring for the levels of 94 primary and secondary metabolites and minerals in two medicinal herbs, basil (Ocimum basilicum L.) and peppermint (Mentha piperita L.), grwon under both ambient (aCO₂, 360 ppm) and eCO₂ (620 ppm) was performed. We also assessed how the changes in herbal tissue chemistry affected their biological activity. Elevated CO₂ significantly increased herbal biomass, improved the rates of photosynthesis and dark respiration, and altered the tissue chemistry. Principal Component Analysis of the full data set revealed that eCO₂ induced a global change in the metabolomes of the two plants. Moreover, Hierarchical Clustering Analyses showed quantitative differences in the metabolic profiles of the two plants and in their responsiveness to eCO₂. Out of 94 metabolites, 38 and 31 significantly increased in basil and peppermint, respectively, as affected by eCO₂. Regardless of the plant species, the levels of non-structural carbohydrates, fumarate, glutamine, glutathione, ascorbate, phylloquinone (vitamin K1), anthocyanins and a majority of flavonoids and minerals were significantly improved by eCO₂. However, some metabolites tended to show species specificity. Interestingly, eCO₂ caused enhancement in antioxidant, antiprotozoal, anti-bacterial and anticancer (against urinary bladder carcinoma; T24P) activities in both plants, which was consequent with improvement in the levels of antioxidant metabolites such as glutathione, ascorbate and flavonoids. Therefore, this study suggests that the metabolic changes triggered by eCO₂ in the target herbal plants improved their biological activities.

Assessment and comparison of phytochemical constituents and biological activities of bitter bean (Parkia speciosa Hassk.) collected from different locations in Malaysia

Background

Parkia speciosa seeds are a common ingredient in Malay cuisine with traditional interest because of its medicinal importance and content of health-promoting phytochemicals. This study evaluated the phytochemical constituents and biological activities (antioxidant and antibacterial activities) of Parkia speciosa Hassk seeds collected from three different regions of Malaysia (Perak, Negeri Sembilan and Johor). Phytochemical constituents (total flavonoid and total phenolic) were measured using the spectrophotometric method, and individual flavonoids and phenolic acids were identified using ultra-high-performance liquid chromatography. Ferric reducing antioxidant potential (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay we used in order to evaluation of antioxidant activities. Disc diffusion method was employed for the evaluation of antibacterial activity of extracts against Gram-positive and Gram-negative bacterial strains.

Results

The primary screening of phytochemicals showed that P. speciosa seeds contain alkaloids, terpenoids, flavonoids, and phenolics. Samples collected from Perak contained the highest levels of the phytochemical constituents, with highest DPPH and FRAP activity followed by Negeri sembilan and Johor. From the identified compounds, quercetin and gallic acid were identified as the most abundant compounds. Seeds collected from the Perak location exhibited potent antibacterial activity, against both Gram-positive and Gram-negative bacteria strains. Staphylococcus aureus and Bacillus subtilis were recorded as the bacterial strains most sensitive to P. speciosa seed extracts. Correlation analysis showed that flavonoid compounds are responsible for the antioxidant activities of the P. speciosa seeds studied, while antibacterial activity showed a high correlation with the levels of gallic acid.

Conclusions

Parkia speciosa seed grown in Perak exhibit the highest concentrations of phytochemicals, as well as the highest biological activity. It may also be recommended for the food industry to use seeds from this area for their products, which are going to compete in the expanding functional food markets.

Tomato plants use non-enzymatic antioxidant pathways to cope with moderate UV-A/B irradiation: A contribution to the use of UV-A/B in horticulture

Plants developed receptors for solar UV-A/B radiation, which regulate a complex network of functions through the plant's life cycle. However, greenhouse grown crops, like tomato, are exposed to strongly reduced UV radiation, contrarily to their open-field counterparts. A new paradigm of modern horticulture is to supplement adequate levels of UV to greenhouse cultures, inducing a positive mild stress necessary to stimulate oxidative stress pathways and antioxidant mechanisms. Protected cultures of Solanum (cv MicroTom) were supplemented with moderate UV-A (1h and 4h) and UV-B (1min and 5min) doses during the flowering/fruiting period. After 30days, flowering/fruit ripening synchronization were enhanced, paralleled by the upregulation of blue/UV-A and UV-B receptors' genes cry1a and uvr8. UV-B caused moreover an increase in the expression of hy5, of HY5 repressor cop1 and of a repressor of COP1, uvr8. While all UV-A/B conditions increased SOD activity, increases of the generated H₂O₂, as well as lipid peroxidation and cell mebrane disruption, were minimal. However, the activity of antioxidant enzymes downstream from SOD (CAT, APX, GPX) was not significant. These results suggest that the major antioxidant pathways involve phenylpropanoid compounds, which also have an important role in UV screening. This hypothesis was confirmed by the increase of phenolic compounds and by the upregulation of chs and fls, coding for CHS and FLS enzymes involved in the phenylpropanoid synthesis. Overall, all doses of UV-A or UV-B were beneficial to flowering/fruiting but lower UV-A/B doses induced lower redox disorders and were more effective in the fruiting process/synchronization. Considering the benefits observed on flowering/fruiting, with minimal impacts in the vegetative part, we demonstrate that both UV-A/B could be used in protected tomato horticulture systems.

Metabolic analyses reveal different mechanisms of leaf color change in two purple-leaf tea plant (Camellia sinensis L.) cultivars

Purple-leaf tea plants, as anthocyanin-rich cultivars, are valuable materials for manufacturing teas with unique colors or flavors. In this study, a new purple-leaf cultivar "Zixin" ("ZX") was examined, and its biochemical variation and mechanism of leaf color change were elucidated. The metabolomes of leaves of "ZX" at completely purple, intermediately purple, and completely green stages were analyzed using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF-MS). Metabolites in the flavonoid biosynthetic pathway remained at high levels in purple leaves, whereas intermediates of porphyrin and chlorophyll metabolism and carotenoid biosynthesis exhibited high levels in green leaves. In addition, fatty acid metabolism was more active in purple leaves, and steroids maintained higher levels in green leaves. Saponin, alcohol, organic acid, and terpenoid-related metabolites also changed significantly during the leaf color change process. Furthermore, the substance changes between "ZX" and "Zijuan" (a thoroughly studied purple-leaf cultivar) were also compared. The leaf color change in "Zijuan" was mainly caused by a decrease in flavonoids/anthocyanins. However, a decrease in flavonoids/anthocyanins, an enhancement of porphyrin, chlorophyll metabolism, carotenoid biosynthesis, and steroids, and a decrease in fatty acids synergistically caused the leaf color change in "ZX". These findings will facilitate comprehensive research on the regulatory mechanisms of leaf color change in purple-leaf tea cultivars.

Flavonoids and Phenolic Acids from Oregano: Occurrence, Biological Activity and Health Benefits

Several herb species classified as oregano have been widely used in folk medicine to alleviate inflammation-related diseases, respiratory and digestive disorders, headaches, rheumatism, diabetes and others. These potential health benefits are partially attributed to the phytochemical compounds in oregano such as flavonoids (FL) and phenolic acids (PA). Flavonoids and phenolic acids are among the most abundant and most studied phytochemicals in oregano species. Epidemiological, in vitro and in vivo experiments have related long-term consumption of dietary FL and PA with a decreased risk of incidence of chronic diseases. The aim of this manuscript is to summarize the latest studies on the identification and distribution of flavonoids and phenolic compounds from oregano species and their potential antioxidant, anti-inflammatory and anti-cancer health benefits.