Production of secondary metabolites using tissue culture-based biotechnological applications

Effects of LEDs, macronutrients and culture conditions on biomass and artemisinin production using Artemisia annua L. suspension cultures

Artemisinin is a sesquiterpene lactone extracted from the medicinal plant Artemisia annua L. (sweet wormwood). It has traditionally been utilized in artemisinin-based combination therapies (ACTs) for the malarial parasite, including drug-resistant strains. Natural artemisinin extraction is costly with low yields. Due to its effectiveness, there is a significant rise in the demand for artemisinin production. In vitro cell suspension culture offers a cost-effective and viable technique for artemisinin production. Therefore, this study aimed to optimize a protocol for cell suspension culture of A. annua L. to enhance biomass and artemisinin production. A successful cell suspension culture was initiated from induced callus. The highest cell biomass was obtained in suspension cultures grown with an initial inoculum size of 0.1 g of mixed type cell aggregates, in media with a pH of 6.2 and a rotation speed of 90 rpm. Macronutrient concentrations influenced both biomass and artemisinin content, with optimal biomass achieved at 19 mM KNO3 and 1.56 mM KH2PO4. The absence of these nutrients resulted in the highest artemisinin levels. Different LED wavelengths also significantly influenced biomass and artemisinin production. Red + blue LED increased cell biomass, while the highest artemisinin content was observed under red LED. The upscaling of the culture indicated a variation in biomass yield pattern, but the highest growth index was achieved in the 500 mL Erlenmeyer flask. This study successfully established a cell suspension culture for A. annua L., demonstrating the influence of macronutrients and red LED on biomass and artemisinin production, providing insights for potential large-scale production.

Callus initiation and regeneration of Curculigo orchioides Gaertn. and its untargeted metabolomic profiles using UHPLC-Q-Orbitrap HRMS compared to the parent plant

Curculigo orchioides Gaertn. is a traditional medicinal plant widely used in Asia. However, it is often collected from the wild without replanting efforts. Additionally to its slow growth, its availability is further threatened by natural disasters and land-use shifting, putting its future supply at risk. This work aimed to obtain an efficient method for callus initiation and plant multiplication, investigate whether propagules produce secondary metabolites found in the mother plant. Combinations of plant growth regulators were used to initiate callus and/or shoots from leaf explants, and UHPLC-Q-Orbitrap HRMS identified metabolites. The explants cultured on MS medium supplemented with a combination of BAP (5 mg L-1) and IBA (3 mg L-1) initiated callus and regenerated plantlets. Through LC-HRMS analysis, several compounds with pharmacological effects were found in the in vitro propagules. In callus and plantlet leaves, 24 and 27 compounds were identified respectively, dominated by phenolics. Principal component analysis and hierarchical cluster discriminated the metabolites in the propagules and mother plant organs. The essential compounds, (1S,2R)-O-methylnyasicoside, curculigoside B, orcinol glucoside, 2,4-dichloro-5-methoxy-3-methylphenol were determined in callus at a higher concentration than in the mother plant. Conclusively, in vitro propagules of C. orchioides is a valuable alternative source of bioactive compounds.

Biosynthesized sulfur nanoparticles: a novel strategy to enhance antioxidant secondary metabolites in Lotus arabicus L. callus cultures

BACKGROUND

Secondary metabolites are distinct compounds with significant medicinal value, yet their production and chemical synthesis present considerable challenges. This necessitates the development of innovative strategies to improve their yield. This study investigated the potential of biosynthesized sulfur nanoparticles (SNPs) as an eco-friendly elicitor to enhance the synthesis of antioxidant secondary metabolites in Lotus arabicus L. callus cultures.

RESULTS

After seven weeks, induced calli of L. arabicus L were transferred to MS media supplemented with SNPs at different concentrations (0, 25, 50, 100, and 200 mg/l). The results indicated that SNPs (100 mg/l) induced significantly higher profiles for biomass and secondary metabolite compared to the control treatments. Enzyme activities related to secondary metabolite biosynthesis, specifically phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) were enhanced in a dose-dependent manner, with the greatest increases observed at 100 mg/l SNPs. The SNPs also modulated oxidative stress markers (MDA and H2O2), generally improving callus growth conditions by reducing oxidative stress, except at the highest concentration of 200 mg/l. Additionally, the application of SNPs at 100 mg/l markedly upregulated the expression levels of six crucial genes in the biosynthesis pathway of secondary metabolites (chalcone synthase (CHS), phenylalanine ammonia lyase (PAL), flavonol synthase (FLS), chalcone isomerase (CHI), hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase (HQT), and deoxyxylulose phosphate reductoisomerase (DXR)). Quantitative HPLC profiling of 16 phenolic and flavonoid compounds revealed that supplementation with SNPs resulted in noticeable boots in the majority of the measured compounds with SNP supplementation.

CONCLUSION

Overall, the supplementation of SNPs in the culture media of L. arabicus L callus positively influenced secondary metabolite production at the molecular and physiological levels, increasing its potential for medicinal use.

Effects of Elicitation on Abeliophyllum distichum Leaf Callus and Changes in Verbascoside Content

Abeliophyllum distichum is a monotypic species in the family Oleaceae that contains a range of phenolic compounds and components such as coumaric acid, catechin, and verbascoside, the latter of which is a major candidate of commercial interest. In this study, we assessed the potential for producing verbascoside using callus culture. To enhance callus productivity in this regard, we evaluated the efficacy of treatment with the elicitors salicylic acid (SA) and methyl jasmonate (MeJA) based on changes in verbascoside content with callus development using Petri dish cultures. Whereas the initial content of verbascoside in A. distichum callus was approximately 50 mg/g, in response to treatment with 50 μM MeJA, we detected an increase to approximately 97.05 mg/g. In contrast, treatment with SA had no significant effects on verbascoside content. In addition, we found that the fresh weight of callus receiving elicitor treatment was lower than that of control callus. Conversely, however, in bioreactor cultures, the fresh weight of callus following treatment with 50μM MeJA for 1 week was higher than that of control callus, and the content of verbascoside in callus treated with 50 μM MeJA was higher than that in control callus. Our findings in this study thus indicate that with appropriate elicitation, the production of verbascoside by A. distichum callus pieces can be enhanced.

Trends in plant tissue culture, production, and secondary metabolites enhancement of medicinal plants: a case study of thyme

MAIN CONCLUSION

Thymus plants are greatly threatened by overharvesting and climate change. Plant cell and tissue culture techniques provide effective alternatives for the production and the enhancement of both biomass and bioactive compounds. Medicinal and aromatic plants are rich sources of various bioactive compounds known as secondary metabolites, which are used across a range of fields, including medicinal, cosmetics, pharmaceuticals, perfumes, agrochemicals and agrofood industries. Thyme is considered one of the most popular herbs globally, valued for its significant medicinal, pharmaceutical, and nutritional benefits. However, its natural habitats are rapidly diminishing due to excessive harvesting and climate change. Consequently, several approaches have been developed to find alternatives to harvesting wild thyme. Plant cell and tissue culture techniques offer a superior alternative to traditional propagation methods, such as seeds, cuttings, or tuft division. These techniques enable the production of large quantities of uniform, disease-free plantlets for commercial cultivation and facilitate the development of new genotypes. Additionally, they support the production and enhancement of bioactive compounds from thyme plants. This review explores the application of plant cell, tissue, and organ culture biotechnology in thyme plants, focusing on enhancing production and improving secondary metabolite yields and biomass production.

Sex and salt stress response - physiological and biochemical aspects of hydroponic culture of dioecious Rumex thyrsiflorus Fingerh

This study investigates the sex-specific physiological and biochemical responses to salt stress in male and female Rumex thyrsiflorus plants under hydroponic culture conditions. In vitro regenerated plants were exposed to different sodium chloride (NaCl) concentrations (0, 43, and 86 mM), and the resulting changes in morphology, photosynthetic performance, and biochemical profiles were analyzed. Salt stress resulted in significant morphological adaptations, including reduced leaf area and closed stomata, particularly in the male plants, indicating adaptive strategies to minimize water loss and ion toxicity. Photosynthetic efficiency, especially the photochemical performance of photosystem II, decreased under elevated NaCl levels, with a marked reduction observed at 86 mM. Biochemical analyses revealed remarkable responses, including increased enzymatic antioxidant activities and the accumulation of free proline, a known compatible osmolyte, as well as branched-chain amino acids, soluble proteins, and carbohydrates. These shifts in metabolite profiles varied by sex, with male plants showing a greater increase in compounds such as proline, γ-aminobutyric acid, methionine, and the osmoprotectant sucrose, highlighting sex-specific patterns of metabolic adaptation. Females showed higher chlorophyll retention and greater resistance to oxidative damage, suggesting a range of different adaptive strategies. The study highlights the importance of identifying sex-specific stress responses in R. thyrsiflorus, which has implications for breeding programmes aiming to improve crop resilience. These results expand our understanding of plant stress biology and provide valuable insights for further research into how dioecious plants respond to environmental challenges.

Trends and Challenges in Plant Cryopreservation Research: A Meta-Analysis of Cryoprotective Agent Development and Research Focus

The stable long-term preservation of plant cells is crucial for biopharmaceuticals and food security. Therefore, the long-term cryopreservation of plant cells using a cryoprotective agent (CPA) is a crucial area of study. However, research on low-toxicity CPAs remains limited. We analyzed 1643 abstracts related to plant-cryopreservation (PCP) research published from 1967 to May 2023, spanning 56 years, from academic citation databases, with the search conducted in May 2023. Grouping these abstracts by five-year intervals revealed an increase in PCP papers until 2015, followed by a decline in the 2020s. In order to confirm the declining trend, we performed text-mining analysis using the Latent Dirichlet Allocation (LDA) algorithm, which identifies underlying topics across diverse documents to aid decision-making and classified the abstracts into three distinct topics: Topic 1, "Seed bank"; Topic 2, "Physiology"; and Topic 3, "Cryopreservation protocol". The decline, particularly in "Cryopreservation protocol" research, is an important observation in this study. At the same time, this decrease may be due to the limited scope of Topic 3. However, we expect improvements with the development of new CPAs. This expectation is based on numerous ongoing studies focused on developing new CPAs for the cryopreservation of various animal and medical cell lines, with particular attention on polysaccharides as components that could reduce the required concentrations of existing CPAs.

Naturally-occurring nematicides of plant origin: two decades of novel chemistries

Plant-parasitic nematodes are among the most destructive plant pathogens, resulting in a global annual economic loss of about 358 billion dollars. Using synthetic nematicides to control plant-parasitic nematodes has resulted in broad-spectrum toxicity to the environment. Plant-derived secondary metabolites have recently emerged as viable options that provide effective, greener, and renewable routes for managing plant-parasitic nematodes in various cropping systems. However, limited comprehensive information on plant-derived secondary metabolites sources, chemical structures, and nematicidal activities is available. This study aims to compile and analyze data on plant-based secondary metabolites with nematicidal properties collected over the last two decades. In this review, we identified 262 plant-based metabolites with nematicidal activities that were isolated from 35 plant families and 65 plant species. Alkaloids, terpenoids, saponins, flavonoids, coumarins, thiophenes, and annonaceous acetogenins were among the most studied compounds. In addition to the structure-activity relation for specific metabolites with nematicidal potency, various techniques for their extraction and isolation from plant material are discussed. Our findings demonstrate the potential of plants as a feedstock for sourcing nematicidal compounds and discovering new chemistries that could potentially be used for developing the next generation of nematicides. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Metabolite Profiling and Anti-Inflammatory Activities of Fritillaria cirrhosa D. Don Bulbs Derived from Tissue Culture

Fritillaria cirrhosa D. Don (known as Chuan-Bei-Mu in Chinese) is a prominent medicinal plant utilized in traditional medicine for chronic respiratory ailments. It has garnered global acknowledgment because of its incorporation in many herbal preparations, resulting in a significant increase in demand and, consequently, leading to the decimation of wild populations. The study aimed to obtain regenerated plantlets of F. cirrhosa using in vitro propagation techniques and evaluate the accumulation of active metabolites and anti-inflammatory properties from in vitro and natural plant bulbs. UHPLC-Q-TOF/MS analysis identified 267 metabolites. Notably, 118 metabolites showed significantly different intensities between the wild bulbs (WBs) and in vitro tissue culture-regenerated bulbs (RBs). Higher edpetiline amounts were obtained from the RBs, and 14 steroid-related metabolites were elevated in RBs. Both RB and WB extracts had comparable anti-inflammatory abilities and significantly inhibited TNF-α-induced epithelial cell TSLP release. Subsequent mechanistic studies revealed that the efficacy of WB and RB extracts depended on the regulation of the TRPV1/NFAT pathway. These findings highlight the viability of in vitro regeneration and medicinal part replacement as sustainable alternatives to the existing detrimental overharvesting of wild Chuan-Bei-Mu populations.

The Influence of Basal Medium on Polyphenol Accumulation in Shoot Cultures of Clerodendrum trichotomum and Clerodendrum colebrookianum

Plants of the Clerodendrum genus, known for their rich phytochemical profiles, are used in traditional Chinese, Korean, Japanese, and Indian medicine to treat various ailments, including inflammation, hypertension, diabetes, hyperlipidemia, and cancer. Due to the limited natural availability of these plants, there is a growing interest in utilizing in vitro culture techniques to produce their bioactive compounds sustainably. In this study, the effects are compared of Murashige and Skoog (MS), Woody Plant medium (WP), Gamborg B5 (B5), and Schenk and Hildebrandt (SH) basal media on growth, biomass accumulation, and polyphenolic compound production in shoot cultures of Clerodendrum colebrookianum and Clerodendrum trichotomum. The composition of the culture medium significantly influenced the growth and metabolic profiles of both species. C. trichotomum exhibited the highest proliferation potential on WP and SH media, while C. colebrookianum was similar on WP, SH, and B5 media (multiplication factor of about 20). Dry weight accumulation was highest in C. trichotomum grown on SH medium (0.292 g/culture), while C. colebrookianum achieved a comparable biomass on SH and WP media (0.240 g/culture and 0.228 g/culture, respectively). The chemical analysis showed similar secondary metabolite profiles between the two Clerodendrum species with phenylethanoids such as acteoside being the predominant bioactive compounds in hydromethanolic extracts. WP medium was the most favorable for polyphenol accumulation in C. colebrookianum (64.5 mg/g DW), while the SH medium yielded the highest total polyphenol content in C. trichotomum (36.6 mg/g DW). In this study, the importance is underscored of basal medium selection in optimizing the in vitro production of bioactive polyphenolic compounds in Clerodendrum species, providing a foundation for the sustainable and scalable production of these pharmacologically significant metabolites.

Unlocking specialized metabolism in medicinal plant biotechnology through plant-microbiome interactions

Medicinal plants produce specialized metabolites (SM) that are used as drugs. However, due to low yields of field cultivation and the increasing market demand, this production method often failed to meet supply needs. Biotechnological alternatives, such as in vitro plant cultures, offer promising solutions. Nonetheless, SM production in these systems remains too low for industrial exploitation, necessitating an elicitation step to induce the plant defense metabolism. Traditional elicitation methods mimic environmental conditions that trigger plant-specialized metabolism, often with an artificial signal that mimics microbial interaction. Recent insights into the essential role of the plant microbiota, provides new opportunities for elicitation strategies by microbial coculture in a controlled environment. The successful co-culture of in vitro medicinal plants with synthetic microbial communities could enable sustainable production of pharmaceutically important SM.

Seasonal and altitudinal dynamics in secondary metabolite composition of Commelina forage species in Konso zone, southern Ethiopia

Exploring the type and amounts of the secondary metabolites (SMs) in a given fodder species was considered as a meaningful act for safe and profitable utilization of that particular feedstuff in the livestock industry. This study was conducted in the Konso zone, southern Ethiopia, to explore the secondary metabolite composition of Commelina species in two seasons and at two different altitudes. Samples were collected from the two altitudes and seasons. A completely randomized design was used in a factorial arrangement (five species (C. benghalensis, C. imberbis, C. diffusa, C. albescens, and C. africana), two altitudes, and two seasons) with three repetitions per treatment. The SM contents of the Commelina species were reasonably influenced by both seasonal and altitudinal changes. The mean alkaloid (3.67%), total phenols (9.76 mg GAE/g), flavonoid (3.81 mg CE/g) and condensed tannin (1.10 mg CE/g) values for the herb species in wet season inclined (p < 0.001) to 7.02%, 14.07 mg GAE/g, 7.68 mg CE/g and 2.38 mg CE/g, respectively, in dry season. The wet season saponin concentration of the species (2.65 g/Kg) significantly decreased (p < 0.001) to 1.28 g/Kg in the dry season. Similarly, the lowland saponin (2.26 g/Kg), alkaloid (3.70%), total phenols (10.89 mg GAE/g), flavonoid (4.71 mg CE/g), and condensed tannin (0.98 mg CE/g) contents were increased (p < 0.01) to 3.03 g/Kg, 5.47%, 13.61 mg GAE/g, 6.37 mg CE/g, and 1.81 mg CE/g, respectively, in the midlands. Alkaloids, total phenols, flavonoids and condensed tannin concentrations showed positive correlations with each other (P<0.05) and with seasonal (P<0.001) and altitudinal changes (P<0.001) as well. The findings of this study suggested that the SM concentrations of Commelina species were within the limits tolerable for ruminants. In conclusion, Commelina species could serve as a safe and beneficial forage herb to boost nutrient intake, improve nutrient use efficiency and hinder methane emissions, for animals consuming them, in areas where they are available in abundance.

Synthetic biology in plants

Synthetic biology, an interdisciplinary field at the intersection of engineering and biology, has garnered considerable attention for its potential applications in plant science. By exploiting engineering principles, synthetic biology enables the redesign and construction of biological systems to manipulate plant traits, metabolic pathways, and responses to environmental stressors. This review explores the evolution and current state of synthetic biology in plants, highlighting key achievements and emerging trends. Synthetic biology offers innovative solutions to longstanding challenges in agriculture and biotechnology for improvement of nutrition and photosynthetic efficiency, useful secondary metabolite production, engineering biosensors, and conferring stress tolerance. Recent advances, such as genome editing technologies, have facilitated precise manipulation of plant genomes, creating new possibilities for crop improvement and sustainable agriculture. Despite its transformative potential, ethical and biosafety considerations underscore the need for responsible deployment of synthetic biology tools in plant research and development. This review provides insights into the burgeoning field of plant synthetic biology, offering a glimpse into its future implications for food security, environmental sustainability, and human health.

Evaluation of the Antidiabetic Potential of Xanthone-Rich Extracts from Gentiana dinarica and Gentiana utriculosa

Despite the existence of various therapeutic approaches, diabetes mellitus and its complications have been an increasing burden of mortality and disability globally. Hence, it is necessary to evaluate the efficacy and safety of medicinal plants to support existing drugs in treating diabetes. Xanthones, the main secondary metabolites found in Gentiana dinarica and Gentiana utriculosa, display various biological activities. In in vitro cultured and particularly in genetically transformed G. dinarica and G. utriculosa roots, there is a higher content of xanthones. The aim of this study was to investigate and compare antidiabetic properties of secondary metabolites (extracts) prepared from these two Gentiana species, cultured in vitro and genetically transformed with those collected from nature. We compare HPLC secondary metabolite profiles and the content of the main extract compounds of G. dinarica and G. utriculosa methanol extracts with their ability to scavenge DPPH free radicals and inhibit intestinal α-glucosidase in vitro. Anti-hyperglycemic activity of selected extracts was tested further in vivo on glucose-loaded Wistar rats. Our findings reveal that the most prominent radical scavenging potential and potential to control the rise in glucose level, detected in xanthone-rich extracts, were in direct correlation with an accumulation of xanthones norswertianin and norswertianin-1-O-primeveroside in G. dinarica and decussatin and decussatin-1-O-primeveroside in G. utriculosa.

HNCGAT: a method for predicting plant metabolite-protein interaction using heterogeneous neighbor contrastive graph attention network

The prediction of metabolite-protein interactions (MPIs) plays an important role in plant basic life functions. Compared with the traditional experimental methods and the high-throughput genomics methods using statistical correlation, applying heterogeneous graph neural networks to the prediction of MPIs in plants can reduce the cost of manpower, resources, and time. However, to the best of our knowledge, applying heterogeneous graph neural networks to the prediction of MPIs in plants still remains under-explored. In this work, we propose a novel model named heterogeneous neighbor contrastive graph attention network (HNCGAT), for the prediction of MPIs in Arabidopsis. The HNCGAT employs the type-specific attention-based neighborhood aggregation mechanism to learn node embeddings of proteins, metabolites, and functional-annotations, and designs a novel heterogeneous neighbor contrastive learning framework to preserve heterogeneous network topological structures. Extensive experimental results and ablation study demonstrate the effectiveness of the HNCGAT model for MPI prediction. In addition, a case study on our MPI prediction results supports that the HNCGAT model can effectively predict the potential MPIs in plant.

An update on biotechnological intervention mediated by plant tissue culture to boost secondary metabolite production in medicinal and aromatic plants

Since prehistoric times, medicinal and aromatic plants (MAPs) have been employed for various therapeutic purposes due to their varied array of pharmaceutically relevant bioactive compounds, i.e. secondary metabolites. However, when secondary metabolites are isolated directly from MAPs, there is occasionally very poor yield and limited synthesis of secondary metabolites from particular tissues and certain developmental stages. Moreover, many MAPs species are in danger of extinction, especially those used in pharmaceuticals, as their natural populations are under pressure from overharvesting due to the excess demand for plant-based herbal remedies. The extensive use of these metabolites in a number of industrial and pharmaceutical industries has prompted a call for more research into increasing the output via optimization of large-scale production using plant tissue culture techniques. The potential of plant cells as sources of secondary metabolites can be exploited through a combination of product recovery technology research, targeted metabolite production, and in vitro culture establishment. The plant tissue culture approach provides low-cost, sustainable, continuous, and viable secondary metabolite production that is not affected by geographic or climatic factors. This study covers recent advancements in the induction of medicinally relevant metabolites, as well as the conservation and propagation of plants by advanced tissue culture technologies.

Phytochemical Profiles and Cytotoxic Activity of Bursera fagaroides (Kunth) Engl. Leaves and Its Callus Culture

Bursera fagaroides, popularly used in México, possesses bioactive lignans. These compounds are low in the bark, and its extraction endangers the life of the trees. The aim of the present investigation was to search for alternative sources of cytotoxic compounds in B. fagaroides prepared as leaves and in vitro callus cultures. The friable callus of B. fagaroides was established using a combination of plant growth regulators: 4 mgL-1 of 2,4-dichlorophenoxyacetic acid (2,4-D), 1 mgL-1 Naphthaleneacetic Acid (NAA) and 1 mgL-1 Zeatin. The maximum cell growth was at day 28 with a specific growth rate of μ = 0.059 days-1 and duplication time td = 11.8 days. HPLC quantification of the dichloromethane callus biomass extract showed that Scopoletin, with a concentration of 10.7 µg g-1 dry weight, was the main compound inducible as a phytoalexin by the addition of high concentrations of 2,4-D, as well as by the absence of nutrients in the culture medium. In this same extract, the compounds γ-sitosterol and stigmasterol were also identified by GC-MS analysis. Open column chromatography was used to separate and identify yatein, acetyl podophyllotoxin and 7',8'-dehydropodophyllotoxin in the leaves of the wild plant. Cytotoxic activity on four cancer cell lines was tested, with PC-3 prostate carcinoma (IC50 of 12.6 ± 4.6 µgmL-1) being the most sensitive to the wild-type plant extract and HeLa cervical carcinoma (IC50 of 72 ± 5 µgmL-1) being the most sensitive to the callus culture extract.

The Effect of Combined Elicitation with Light and Temperature on the Chlorogenic Acid Content, Total Phenolic Content and Antioxidant Activity of Berula erecta in Tissue Culture

Chlorogenic acid is one of the most prominent bioactive phenolic acids with great pharmacological, cosmetic and nutritional value. The potential of Berula erecta in tissue culture was investigated for the production of chlorogenic acid and its elicitation combined with light of different wavelengths and low temperature. The content of chlorogenic acid in the samples was determined by HPLC-UV, while the content of total phenolic compounds and the antioxidant activity of their ethanol extracts were evaluated spectrophotometrically. The highest fresh and dry biomasses were obtained in plants grown at 23 °C. This is the first study in which chlorogenic acid has been identified and quantified in Berula erecta. The highest chlorogenic acid content was 4.049 mg/g DW. It was determined in a culture grown for 28 days after the beginning of the experiment at 12 °C and under blue light. The latter also contained the highest content of total phenolic compounds, and its extracts showed the highest antioxidant activity. Berula erecta could, potentially, be suitable for the in vitro production of chlorogenic acid, although many other studies should be conducted before implementation on an industrial scale.

Light-Emitting Diodes and Liquid System Affect the Caffeoylquinic Acid Derivative and Flavonoid Production and Shoot Growth of Rhaponticum carthamoides (Willd.) Iljin

Plant in vitro cultures can be an effective tool in obtaining desired specialized metabolites. The purpose of this study was to evaluate the effect of light-emitting diodes (LEDs) on phenolic compounds in Rhaponticum carthamoides shoots cultured in vitro. R. carthamoides is an endemic and medicinal plant at risk of extinction due to the massive harvesting of its roots and rhizomes from the natural environment. The shoots were cultured on an agar-solidified and liquid-agitated Murashige and Skoog's medium supplemented with 0.1 mg/L of indole-3-acetic acid (IAA) and 0.5 mg/L of 6-benzyladenine (BA). The effect of the medium and different treatments of LED lights (blue (BL), red (RL), white (WL), and a combination of red and blue (R:BL; 7:3)) on R. carthamoides shoot growth and its biosynthetic potential was observed. Medium type and the duration of LED light exposure did not affect the proliferation rate of shoots, but they altered the shoot morphology and specialized metabolite accumulation. The liquid medium and BL light were the most beneficial for the caffeoylquinic acid derivatives (CQAs) production, shoot growth, and biomass increment. The liquid medium and BL light enhanced the content of the sum of all identified CQAs (6 mg/g DW) about three-fold compared to WL light and control, fluorescent lamps. HPLC-UV analysis confirmed that chlorogenic acid (5-CQA) was the primary compound in shoot extracts regardless of the type of culture and the light conditions (1.19-3.25 mg/g DW), with the highest level under R:BL light. BL and RL lights were equally effective. The abundant component was also 3,5-di-O-caffeoylquinic acid, accompanied by 4,5-di-O-caffeoylquinic acid, a tentatively identified dicaffeoylquinic acid derivative, and a tricaffeoylquinic acid derivative 2, the contents of which depended on the LED light conditions.

Secondary metabolites in topical infectious diseases and nanomedicine applications

Topical infection affects nearly one-third of the world's population; it may result from poor sanitation, hygienic conditions and crowded living and working conditions that accelerate the spread of topical infectious diseases. The problems associated with the anti-infective agents are drug resistance and long-term therapy. Secondary metabolites are obtained from plants, microorganisms and animals, but they are metabolized inside the human body. The integration of nanotechnology into secondary metabolites is gaining attention due to their interaction at the subatomic and skin-tissue levels. Hydrogel, liposomes, lipidic nanoparticles, polymeric nanoparticles and metallic nanoparticles are the most suitable carriers for secondary metabolite delivery. Therefore, the present review article extensively discusses the topical applications of nanomedicines for the effective delivery of secondary metabolites.

Comparative transcriptome and metabolite profiling reveal diverse pattern of CYP-TS gene expression during corosolic acid biosynthesis in Lagerstroemia speciosa (L.) Pers

KEY MESSAGE

Extensive leaf transcriptome profiling and differential gene expression analysis of field grown and elicited shoot cultures of L. speciosa suggest that differential synthesis of CRA is mediated primarily by CYP and TS genes, showing functional diversity. Lagerstroemia speciosa L. is a tree species with medicinal and horticultural attributes. The pentacyclic triterpene, Corosolic acid (CRA) obtained from this species is widely used for the management of diabetes mellitus in traditional medicine. The high mercantile value of the compound and limited availability of innate resources entail exploration of alternative sources for CRA production. Metabolic pathway engineering for enhanced bioproduction of plant secondary metabolites is an attractive proposition for which, candidate genes in the pathway need to be identified and characterized. Therefore, in the present investigation, we focused on the identification of cytochrome P450 (CYP450) and oxidosqualene cyclases (OSC) genes and their differential expression during biosynthesis of CRA. The pattern of differential expression of these genes in the shoot cultures of L. speciosa, elicited with different epigenetic modifiers (azacytidine (AzaC), sodium butyrate (NaBu) and anacardic acid (AA)), was studied in comparison with field grown plant. Further, in vitro cultures with varying (low to high) concentrations of CRA were systematically assessed for the expression of CYP-TS and associated genes involved in CRA biosynthesis by transcriptome sequencing. The sequenced samples were de novo assembled into 180,290 transcripts of which, 92,983 transcripts were further annotated by UniProt. The results are collectively given in co-occurrence heat maps to identify the differentially expressed genes. The combined transcript and metabolite profiles along with RT-qPCR analysis resulted in the identification of CYP-TS genes with high sequence variation. Further, instances of concordant/discordant relation between CRA biosynthesis and CYP-TS gene expression were observed, indicating functional diversity in genes.

The exogenous application of naringenin and rosmarinic acid modulates functional traits in Lepidium sativum

BACKGROUND

Phenolic modulators have attracted attention for their potential in shaping functional traits in plants. This work investigated the impact of naringenin (Nar) and rosmarinic acid (RA) on the functional properties of Lepidium sativum leaves and roots.

RESULTS

Untargeted metabolomics identified a diverse phenolic profile, including flavonoids, phenolic acids, low molecular weight phenolics, lignans, and stilbenes. Cluster, analysis of variance multiblock orthogonal partial least squares (AMOPLS), and orthogonal projection to latent structures discriminant analysis (OPLS-DA) multivariate analyses confirmed tissue-specific modulation of bioactive compounds. The tissue was the hierarchically most influential factor, explaining 27% of observed variability, while the treatment and their interaction were statistically insignificant. Thereafter, various in vitro assays were employed to assess antioxidant capacity, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, cupric ion reducing antioxidant capacity (CUPRAC), and ferric ion reducing antioxidant power (FRAP), metal chelating ability, and phosphomolybdenum (PMD) assays. Extracts were also tested for inhibitory effects on cholinesterase, amylase, glucosidase, and tyrosinase enzymes. RA application positively impacted antioxidant and enzyme inhibitory activities, holding valuable implications in shaping the health-promoting properties of L. sativum.

CONCLUSION

The untargeted metabolomics analysis showed a significant tissue-dependent modulation of bioactive compounds, determining no synergistic effect between applying phenolic compounds in combination. Specifically, the sole application of RA increased anthocyanins and hydroxyphenyl propanoic acid content on leaves, which was strictly related to enhancing the biological activities. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Understanding mechanistic aspect of the therapeutic role of herbal agents on neuroplasticity in cerebral ischemic-reperfusion injury

ETHNOPHARMACOLOGICAL RELEVANCE

Stroke is one of the leading causes of death and disability. The only FDA-approved therapy for treating stroke is tissue plasminogen activator (tPA), exhibiting a short therapeutic window. Due to this reason, only a small number of patients can be benefitted in this critical period. In addition, the use of endovascular interventions may reverse vessel occlusion more effectively and thus help further improve outcomes in experimental stroke. During recovery of blood flow after ischemia, patients experience cognitive, behavioral, affective, emotional, and electrophysiological changes. Therefore, it became the need for an hour to discover a novel strategy for managing stroke. The drug discovery process has focused on developing herbal medicines with neuroprotective effects via modulating neuroplasticity.

AIM OF THE STUDY

We gather and highlight the most essential traditional understanding of therapeutic plants and their efficacy in cerebral ischemia-reperfusion injury. In addition, we provide a concise summary and explanation of herbal drugs and their role in improving neuroplasticity. We review the pharmacological activity of polyherbal formulations produced from some of the most frequently referenced botanicals for the treatment of cerebral ischemia damage.

MATERIALS AND METHODS

A systematic literature review of bentham, scopus, pubmed, medline, and embase (elsevier) databases was carried out with the help of the keywords like neuroplasticity, herbal drugs, neural progenitor cells, neuroprotection, stem cells. The review was conducted using the above keywords to understand the therapeutic and mechanistic role of herbal neuroprotective agents on neuroplasticity in cerebral ischemic-reperfusion injury.

RESULTS

Neuroplasticity emerged as an alternative to improve recovery and management after cerebral ischemic reperfusion injury. Neuroplasticity is a physiological process throughout one's life in response to any stimuli and environment. Traditional herbal medicines have been established as an adjuvant to stroke therapy since they were used from ancient times and provided promising effects as an adjuvant to experimental stroke. The plants and phytochemicals such as Curcuma longa L., Moringa oliefera Lam, Panax ginseng C.A. Mey., and Rehmannia glutinosa (Gaertn.) DC., etc., have shown promising effects in improving neuroplasticity after experimental stroke. Such effects occur by modulation of various molecular signalling pathways, including PI3K/Akt, BDNF/CREB, JAK/STAT, HIF-1α/VEGF, etc. CONCLUSIONS: Here, we gave a perspective on plant species that have shown neuroprotective effects and can show promising results in promoting neuroplasticity with specific targets after cerebral ischemic reperfusion injury. In this review, we provide the complete detail of studies conducted on the role of herbal drugs in improving neuroplasticity and the signaling pathway involved in the recovery and management of experimental stroke.

Biological Properties of Extracts Obtained from In Vitro Culture of Plectranthus scutellarioides in a Cell Model

Plectranthus scutellarioides (L.) R.Br. is a medicinal plant that has long been used in traditional medicine to treat conditions such as abscesses, ulcers, and ear and eye infections. It is known to have a wide range of biological properties, such as antibacterial, antioxidant, antifungal, anti-inflammatory, anti-diabetic and anti-cancer effects. In this study, we established in vitro cultures from both the aerial parts and roots of Plectranthus scutellarioides. Subsequently, we compared the basic phytochemical profile of the obtained extracts and conducted a biological analysis to assess their potential for inducing apoptosis in breast (MCF-7) and lung (A549) cancer cells. Phytochemical analysis by HPLC-MS revealed the presence of compounds belonging to phenolic acids (ferulic, syringic, vanillic, rosmarinic, chlorogenic, caffeic, coumaric, dihydroxybenzoic acids), flavonoids (eriodyctiol and cirsimaritin), and terpenes such as 6,11,12,14,16-Pentahydroxy-3,17diacetyl-8,11,13-abietatrien-7-one, 6,11,12,14,16-Pentahydroxy-3,17-diacetyl5,8,11,13-abietatetraen-7-one, and 3,6,12-Trihydroxy-2-acetyl-8,12-abietadien7,11,14-trione. The results show that both extracts have a cytotoxic and genotoxic effect against MCF-7 and A549 cancer cells, with a different degree of sensitivity. It was also shown that both extracts can induce apoptosis by altering the expression of apoptotic genes (Bax, Bcl-2, TP53, Fas, and TNFSF10), reducing mitochondrial membrane potential, increasing ROS levels, and increasing DNA damage. In addition, it has been shown that the tested extracts can alter blood coagulation parameters. Our results indicate that extracts from in vitro cultures of Plectranthus scutellarioides aerial parts and roots have promising therapeutic application, but further research is needed to better understand the mechanisms of their action in the in vitro model.

Anti-leishmanial effects of Eryngium planum and Ecbilliun elaterum methanolic extract against Leishmania major

Leishmaniasis is a vector-borne disease, one of the most important neglected tropical diseases. Existing anti-leishmanial treatments are not effective for a long time and associated with toxic side effects so searching for a new, effective and safe alternative treatments against infectious diseases is greatly needed. This study is aimed to assess the leishmaniacidal effects of methanolic extracts of Eryngium planum (E. planum) and Ecbilliun elaterum (E. elaterum) on Leishmania major (L. major), In vitro. The selected plants were collected from northern areas of Iran. The methanolic extract from the aerial parts of plants were prepared using maceration methods. GC- Mass analysis was used to determine the compounds of the plants. Promastigotes of L. major was cultured in RPMI-1640 medium and the anti-leishmanial and cytotoxicity effects of extracts at concentrations of 100, 200, 400 and 800 µg/ml were assessed using MTT assay. The data obtained from gas chromatography revealed that α-Pinene, Caryophyllene oxide, β-Caryophyllene, Bicyclogermacrene and α-Bisabolol are the main compounds extracted from E. planum and α-Pinene, Germacrene D, Caryophyllene oxide, γ-Eudesmol and α-Bisabolol are the main components of E. elaterum. The results of MTT Assay revealed that E. planum at concentrations of 800 µg/ml after 24 h at 400 µg/ml after 48 h and the E. elaterium at concentrations of 800 µg/ml after 48 h at 400 µg/ml after 72 h had similar anti-leishmanial effects to the positive control. These results indicated that E. planum and E. elaterum are the potential sources for the discovery of novel anti-leishmanial treatments.

Taste of common prebiotic oligosaccharides: impact of molecular structure

Prebiotic oligosaccharides are naturally occurring nondigestible carbohydrates with demonstrated health benefits. They are also a chemically diverse class of nutrients, offering an opportunity to investigate the impact of molecular structure on oligosaccharide taste perception. Accordingly, a relevant question is whether these compounds are detected by the human gustatory system, and if so, whether they elicit sweet or "starchy" taste. Here, in 3 psychophysical experiments, we investigated the taste perception of 3 commercially popular prebiotics [fructooligosaccharides (FOS), galactooligosaccharides (GOS), xylooligosaccharides (XOS)] in highly pure form. Each of these classes of prebiotics differs in the type of glycosyl residue, and position and type of bond between those residues. In experiments I and II, participants were asked to discriminate a total of 9 stimuli [FOS, GOS, XOS; degree of polymerization (DP) of 2, 3, 4] prepared at 75 mM in the presence and absence of lactisole, a sweet receptor antagonist. We found that all 9 compounds were detectable (P < 0.05). We also found that GOS and XOS DP 4 were discriminable even with lactisole, suggesting that their detection was not via the canonical sweet receptor. Accordingly, in experiment III, the taste of GOS and XOS DP 4 were directly compared with that of MOS (maltooligosaccharides) DP 4-6, which has been reported to elicit "starchy" taste. We found that GOS and MOS were perceived similarly although narrowly discriminable, while XOS was easily discriminable from both GOS and MOS. The current findings suggest that the molecular structure of oligosaccharides impacts their taste perception in humans.

Returning to Nature for the Next Generation of Antimicrobial Therapeutics

Antibiotics found in and inspired by nature are life-saving cures for bacterial infections and have enabled modern medicine. However, the rise in resistance necessitates the discovery and development of novel antibiotics and alternative treatment strategies to prevent the return to a pre-antibiotic era. Once again, nature can serve as a source for new therapies in the form of natural product antibiotics and microbiota-based therapies. Screening of soil bacteria, particularly actinomycetes, identified most of the antibiotics used in the clinic today, but the rediscovery of existing molecules prompted a shift away from natural product discovery. Next-generation sequencing technologies and bioinformatics advances have revealed the untapped metabolic potential harbored within the genomes of environmental microbes. In this review, we first highlight current strategies for mining this untapped chemical space, including approaches to activate silent biosynthetic gene clusters and in situ culturing methods. Next, we describe how using live microbes in microbiota-based therapies can simultaneously leverage many of the diverse antimicrobial mechanisms found in nature to treat disease and the impressive efficacy of fecal microbiome transplantation and bacterial consortia on infection. Nature-provided antibiotics are some of the most important drugs in human history, and new technologies and approaches show that nature will continue to offer valuable inspiration for the next generation of antibacterial therapeutics.