Effect of explant type and plant growth regulators on callus induction, growth and secondary metabolites production in Cnidium officinale Makino

Establishment of callus cultures and quantification of Caffeic acid using HPTLC from Desmodium gangeticum (L.)

Desmodium gangeticum (L.) belonging to family Fabaceae is an economically important medicinal plant which isutilised in Dashmoolarishta. Various bioactive compounds have been isolated from whole plant and roots, and one of them is an important phenolic compound - caffeic acid (CA). This phenolic acid and its derivatives have antioxidant, anti-inflammatory, anticarcinogenic and hepatocarcinoma, a highly aggressive and causing considerable mortality across the world. In the present study, leaf explants were placed on MS medium fortified with different concentration of cytokinin (BA/Kn) and auxin (IAA/NAA) for establishing callus cultures. MS medium fortified with BA (20 µM) and IAA (2 µM) was optimised for the same. Methanolic extracts of in vivo leaf sample (DG1) and in vitro sample (leaf derived callus) (DG2) were assessed for CA quantification using HPTLC. Thus, the chemical fingerprint that was obtained, confirmed that DG 2 of D. gangeticum exhibited the potency to synthesise more amount of CA (316 ± 7.5 µg/g DW) in comparison to DG1 which was 194 ± 2.3 µg/g DW.

Cnidium officinale Makino: Phytology, Phytochemistry, Toxicology, Pharmacology and Prescriptions (1967-2023)

Cnidium officinale Makino (COM), a perennial herbaceous plant in the Apiaceous family, widely distribute in Eastern Asia and Asia-Temperate. It has a long history application as a traditional medicine for invigorating the blood and removing blood stasis, and also has been employed to diet, pesticide, herbal bathing materials, the cosmetic and skin care industry. However, there has been no associated review of literature in the past half a century (1967-2023). By searching the international authoritative databases and collecting 229 literatures closely related to COM, herewith a comprehensive and systematic review was conducted. The phytology includes plant distribution and botanical characteristics. The phytochemistry covers 8 major categories, 208 compounds in total, and the quantitative determination of 14 monomer compounds, total polyphenols and total flavonoids. The clinical trial in pregnant women and toxic experiments in mice, the pharmacology of 7 aspects and 82 frequently used prescriptions are summarized. It is expected that this paper will provide forward-looking scientific thinking and literature support for the further modern research, development and utilization of COM.

Phytomediated selenium nanoparticles and light regimes elicited in vitro callus cultures for biomass accumulation and secondary metabolite production in Caralluma tuberculata

Introduction

Caralluma tuberculata holds significant importance as a medicinal plant due to its abundance of bioactive metabolites, which offer a wide range of therapeutic potentials. However, the sustainable production of this plant is challenged by overexploitation, changes in natural conditions, slow growth rate, and inadequate biosynthesis of bioactive compounds in wild populations. Therefore, the current study was conducted to establish an in vitro based elicitation strategy (nano elicitors and light regimes) for the enhancement of biomass and production of secondary metabolites.

Methods

Garlic clove extract was employed as a stabilizing, reducing, or capping agent in the green formulation of Selenium nanoparticles (SeNPs) and various physicochemical characterization analyses such as UV visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray (EDX) Spectroscopy, fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were performed. Furthermore, the effects of phytosynthesized SeNPs at various concentrations (0, 50, 100, 200, and 400 µg/L on callus proliferation and biosynthesis of medicinal metabolites under different light regimes were investigated.

Results and discussion

Cultures grown on Murashige and Skoog (MS) media containing SeNPs (100 µg/L), in a dark environment for two weeks, and then transferred into normal light, accumulated maximum fresh weight (4,750 mg/L FW), phenolic contents (TPC: 3.91 mg/g DW), flavonoid content (TFC: 2.04 mg/g DW) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity (85%). Maximum superoxide dismutase (SOD: 4.36 U/mg) and peroxide dismutase activity (POD: 3.85 U/mg) were determined in those cultures exposed to SeNPs (100 µg/L) under complete dark conditions. While the callus cultures proliferate on media augmented with SeNPs (200 µg/L) and kept under dark conditions for two weeks and then shifted to normal light conditions exhibited the highest catalase (CAT: 3.25 U/mg) and ascorbate peroxidase (APx: 1.93 U/mg) activities. Furthermore, LC-ESI-MS/MS analysis confirmed the effects of SeNPs and light conditions that elicited the antidiabetic metabolites (cumarins, gallic acid, caffeic acid, ferulic acid, catechin, querctin and rutin). This protocol can be scaled up for the industrial production of plant biomass and pharmacologically potent metabolites using in vitro callus cultures of C. tuberculata.

In Vitro Cultivation and Ginsenosides Accumulation in Panax ginseng: A Review

The use of in vitro tissue culture for herbal medicines has been recognized as a valuable source of botanical secondary metabolites. The tissue culture of ginseng species is used in the production of bioactive compounds such as phenolics, polysaccharides, and especially ginsenosides, which are utilized in the food, cosmetics, and pharmaceutical industries. This review paper focuses on the in vitro culture of Panax ginseng and accumulation of ginsenosides. In vitro culture has been applied to study organogenesis and biomass culture, and is involved in direct organogenesis for rooting and shooting from explants and in indirect morphogenesis for somatic embryogenesis via the callus, which is a mass of disorganized cells. Biomass production was conducted with different types of tissue cultures, such as adventitious roots, cell suspension, and hairy roots, and subsequently on a large scale in a bioreactor. This review provides the cumulative knowledge of biotechnological methods to increase the ginsenoside resources of P. ginseng. In addition, ginsenosides are summarized at enhanced levels of activity and content with elicitor treatment, together with perspectives of new breeding tools which can be developed in P. ginseng in the future.

Optimization of Callus and Cell Suspension Cultures of Lycium schweinfurthii for Improved Production of Phenolics, Flavonoids, and Antioxidant Activity

Lycium schweinfurthii is a traditional medicinal plant grown in the Mediterranean region. As it is used in folk medicine to treat stomach ulcers, it took more attention as a source of valuable secondary metabolites. The in vitro cultures of L. schweinfurthii could be a great tool to produce secondary metabolites at low costs. The presented study aimed to introduce and optimize a protocol for inducing callus and cell suspension cultures as well as estimating phenolic, flavonoid compounds, and antioxidant activity in the cultures of the studied species. Three plant growth regulators (PGRs) were supplemented to MS medium solely or in combination to induce callus from leaf explants. The combination between 2,4-dichlorophenoxy acetic acid (2,4-D) and 1-naphthyl acetic acid (NAA) induced callus in all explants regardless of the concentration. The highest fresh weight of callus (3.92 g) was obtained on MS medium fortified with 1 mg L−1 of both 2,4-D and NAA (DN1) after 7 weeks of culture. DN1 was the best medium for callus multiplication regarding the increase in fresh weight and size of callus. Otherwise, the highest phenolics, flavonoids, and antioxidant activity against DPPH free radicals were of callus on MS fortified with 2 mg L−1 NAA (N2). The cell suspension cultures were cultivated on a liquid N2 medium with different sucrose concentrations of 5–30 g L−1 to observe the possible effects on cells’ multiplication and secondary metabolite production. The highest fresh and viable biomass of 12.01 g was obtained on N2 containing 30 g L−1 sucrose. On the other hand, the cell cultures on N2 medium of 5 and 30 g L−1 sucrose produced phenolics and flavonoids, and revealed antioxidant activity against DPPH and ABTS+ free radicals more than other sucrose concentrations. The presented protocol should be useful in the large-scale production of phenolic and flavonoid compounds from callus and cell cultures of L. schweinfurthii.

Interactive effects of zinc oxide nano particles and different light regimes on growth and silymarin biosynthesis in callus cultures of Silybum marianum L

Silybum marianum L. commonly known as milk thistle is a medicinally potent plant with a multitude of pharmacological applications. The present investigations demonstrated the effects of Zinc Oxide nanoparticles (ZnO NPs) on callus growth and biosynthesis of silymarin in milk thistle under various light conditions. The callus cultures developed on Murashige and Skoog (MS) basal media containing ZnO NPs (0.15 mg/L), under the dark condition maintained for two weeks, followed by transference into normal light produced the maximum callus fresh weight (2294 mg/L FW). Further, the metabolite profiling revealed that ZnO NPs significantly augmented the production of silymarin and upregulated the antioxidant system in the callus cultures. Maximum TPC (total phenolic content: 37 ± 0.20 mg/g DW), TFC (total flavonoid content: 8.9 ± 0.023), DPPH antioxidant activity (91.5 ± 1.75%), Superoxide dismutase activity (SOD: 4.1 ± 0.045 nM/min/mg FW) and the highest silymarin content (14.6 ± 0.023 mg/g DW) were recorded in the callus cultures developed on MS media supplemented with solitary ZnO NPs (0.15 mg/L). While the callus culture evolved in presence of only PGRs (2,4 D and BA: 2 mg/L, each) accumulated the lesser fresh weight (562 mg/L FW). A higher concentration of ZnO NPs (0.15 mg/L) enhanced the secondary metabolite accumulation and silymarin content in the callus of Silybum marianum. This is the first standardized protocol to be applied on the industrial level for the production of silymarin.

Traditional in vitro strategies for sustainable production of bioactive compounds and manipulation of metabolomic profile in medicinal, aromatic and ornamental plants

Precursor feeding, elicitation and culture medium parameters are traditional in vitro strategies to enhance bioactive compounds of medicinal, aromatic, and ornamental plants (MAOPs). Machine learning can help researchers find the best combination of these strategies to increase the secondary metabolites content of MAOPs. Many requirements for human life, from food, pharmaceuticals and cosmetics to clothes, fuel and building materials depend on plant-derived natural products. Essential oils, methanolic and ethanolic extracts of in vitro undifferentiated callus and organogenic cultures of medicinal, aromatic, and ornamental plants (MAOPs) contain bioactive compounds that have several applications for various industries, including food and pharmaceutical. In vitro culture systems provide opportunities to manipulate the metabolomic profile of MAOPs. Precursors feeding, elicitation and culture media optimization are the traditional strategies to enhance in vitro accumulation of favorable bioactive compounds. The stimulation of plant defense mechanisms through biotic and abiotic elicitors is a simple way to increase the production of secondary metabolites in different in vitro culture systems. Different elicitors have been applied to stimulate defense machinery and change the metabolomic profile of MAOPs in in vitro cultures. Plant growth regulators (PGRs), stress hormones, chitosan, microbial extracts and physical stresses are the most applied elicitors in this regard. Many other chemical tolerance-enhancer additives, such as melatonin and proline, have been applied along with stress response-inducing elicitors. The use of stress-inducing materials such as PEG and NaCl activates stress tolerance elicitors with the potential of increasing secondary metabolites content of MAOPs. The present study reviewed the state-of-the-art traditional in vitro strategies to manipulate bioactive compounds of MAOPs. The objective is to provide insights to researchers involved in in vitro production of plant-derived natural compounds. The present review provided a wide range of traditional strategies to increase the accumulation of valuable bioactive compounds of MAOPs in different in vitro systems. Traditional strategies are faster, simpler, and cost-effective than other biotechnology-based breeding methods such as genetic transformation, genome editing, metabolic pathways engineering, and synthetic biology. The integrate application of precursors and elicitors along with culture media optimization and the interpretation of their interactions through machine learning algorithms could provide an excellent opportunity for large-scale in vitro production of pharmaceutical bioactive compounds.

Influence of different types of explants in chickpea regeneration using thidiazuron seed-priming

A comparative regeneration of three types of explants prepared from axillary meristems, plumular apices and hypocotyls of chickpea (Cicer arietinum) was carried out using four thidiazuron (TDZ) treatment methods. The first and third ones included the short-term 20 μM TDZ pre-treatment for all three explant types followed by non-supplementation or supplementation of TDZ (4 μM) into the shoot induction medium (SIM), while the second and fourth ones lacked TDZ pre-treatment followed by non-addition or addition of 4 μM TDZ in the SIM. Axillary meristem explants produced the best results with seed pre-treatment using 20 μM TDZ without TDZ in SIM and showed the highest rate of regeneration efficiency (71.33 ± 1.5%) after 20 days. Concurrently, plumular apex explants from TDZ-primed seeds was ranked second, exhibiting a regeneration percentage of 54.33 ± 2.3% in SIM without supplementation of TDZ, whereas explants from hypocotyls generated from seeds subjected to any of the TDZ treatments were not regenerated on any SIMs after 20 days.

Agrobacterium-Mediated Genetic Transformation of Taiwanese Isolates of Lemna aequinoctialis

Duckweed (Lemna aequinoctialis) is one of the smallest flowering plants in the world. Due to its high reproduction rate and biomass, duckweeds are used as biofactors and feedstuff additives for livestock. It is also an ideal system for basic biological research and various practical applications. In this study, we attempt to establish a micropropagation technique and Agrobacterium-mediated transformation in L. aequinoctialis. The plant-growth regulator type and concentration and Agrobacterium-mediated transformation were evaluated for their effects on duckweed callus induction, proliferation, regeneration, and gene transformation efficiency. Calli were successfully induced from 100% of explants on Murashige and Skoog (MS) medium containing 25.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.0 μM thidiazuron (TDZ). MS medium containing 4.5 μM 2,4-D and 2.0 μM TDZ supported the long-lasting growth of calli. Fronds regenerated from 100% of calli on Schenk and Hildebrandt (SH) medium containing 1.0 μM 6-benzyladenine (6-BA). We also determined that 200 μM acetosyringone in the cocultivation medium for 1 day in the dark was crucial for transformation efficiency (up to 3 ± 1%). Additionally, we propose that both techniques will facilitate efficient high-throughput genetic manipulation in Lemnaceae.

Influence of photoperiod on growth, bioactive compounds and antioxidant activity in callus cultures of Basella rubra L

Basella rubra L. is an important green leafy vegetable vine and is known for its health benefits in traditional medicine. Light is a basic physical factor essential to the development and bioactive secondary metabolite production in in vitro callus cultures. The present study researched the impact of different photoperiods on biomass, bioactive compounds, and antioxidant activity in callus cultures of B. rubra. The in vitro seedling based cotyledonary leaf explants responded differently, when cultured on Murashige and Skoog (MS) medium with varying concentrations and combination of auxins and cytokinins. The best callus proliferation was found in MS medium with 0.1 mg.L^-1 1-naphthaleneacetic acid (NAA) and 6 mg.L^-1 6-benzylaminopurine (BAP), with greenish callus inception by about 2 weeks. The growth curve recorded for 6 weeks of culturing revealed that the photoperiod effect was found to be pivotal for acquiring biomass. At the fifth week, the continuous light supported maximum biomass (12.42 g) production followed by the 16:8 h photoperiod (9.02 g) and continuous darkness (4.28 g). The 80% ethanol extract of 1-week-old callus that grows under the 16:8 h photoperiod showed the highest total phenolic content (TPC) (74 mg.100 g^-1 fresh weight, FW) when compared to all other extracts at different stages. The ferric reducing antioxidant power assay showed the highest (336.23 mg.100 g^-1 FW) activity in methanol extractions of first-week callus cultures maintained in the continuous light condition. HPLC-UV identification and quantification of individual phenolics and flavonoids, such as gallic, trans-cinnamic, quercetin, protocatechuic and rutin, were highest in the callus cultures. The outcome of this study is significant to this plant, as B. rubra is familiar for its important health constituents with high-value bioactives and applications in the pharma and nutraceutical industries.

Biosynthesis of anti-leishmanial natural products in callus cultures of Artemisia scoparia

Clinically, available synthetic chemotherapeutics in the treatment for leishmaniasis are associated with serious complications, such as toxicity and emergence of resistance. Natural products from plants can provide better remedies against the Leishmania parasite and can possibly minimize the associated side effects. In this study, various extracts of the callus cultures of Artimisia scoparia established in response to different plant growth regulators (PGRs) were evaluated for their anti-leishmanial effects against Leishmania tropica promastigotes, followed by an investigation of the possible mechanism of action through reactive apoptosis assay using fluorescent microscopy. Amongst the different callus extracts, higher anti-leishmanial activity (IC₅₀:19.13 µg/mL) was observed in the callus raised in-vitro in the presence of 6-Benzylaminopurine (BA) plus 2,4-Dichlorophenoxyacetic Acid (2,4-D) at the concentration of 1.5 mg/L, each. Further, the results of apoptosis assay showed a large number of early-stage apoptotic (EA) and late-stage apoptotic (LA) cells in the Leishmania under the effect of callus extract grown in-vitro at BA plus 2,4-D. For the determination of the potent natural products in the callus extracts responsible for the anti-leishmanial activity, extracts were subjected to Gas chromatography-mass spectrometry (GC-MS) for the metabolite analysis. Nonetheless, higher levels of the metabolites, such as nerolidol (22%), pelletierine (18%), aspidin (15%) and ascaridole (11%) were detected in the callus grown in vitro at BA plus 2,4-D (1.5 mg/L, each). This protocol determines a novel method of production of anti-leishmanial natural products through callus cultures of A. scoparia, a medicinal plant.

Biologically active metabolite(s) from haemolymph of red-headed centipede Scolopendra subspinipes possess broad spectrum antibacterial activity

The discovery of novel antimicrobials from animal species under pollution is an area untapped. Chinese red-headed centipede is one of the hardiest arthropod species commonly known for its therapeutic value in traditional Chinese medicine. Here we determined the antibacterial activity of haemolymph and tissue extracts of red-headed centipede, Scolopendra subspinipes against a panel of Gram-positive and Gram-negative bacteria. Lysates exhibited potent antibacterial activities against a broad range of bacteria tested. Chemical characterization of biologically active molecules was determined via liquid chromatography mass spectrometric analysis. From crude haemolymph extract, 12 compounds were identified including: (1) L-Homotyrosine, (2) 8-Acetoxy-4-acoren-3-one, (3) N-Undecylbenzenesulfonic acid, (4) 2-Dodecylbenzenesulfonic acid, (5) 3H-1,2-Dithiole-3-thione, (6) Acetylenedicarboxylate, (7) Albuterol, (8) Tetradecylamine, (9) Curcumenol, (10) 3-Butylidene-7-hydroxyphthalide, (11) Oleoyl Ethanolamide and (12) Docosanedioic acid. Antimicrobial activities of the identified compounds were reported against Gram-positive and Gram-negative bacteria, fungi, viruses and parasites, that possibly explain centipede's survival in harsh and polluted environments. Further research in characterization, molecular mechanism of action and in vivo testing of active molecules is needed for the development of novel antibacterials.

Light elicited growth, antioxidant enzymes activities and production of medicinal compounds in callus culture of Cnidium officinale Makino

Cnidium officinale Makino is an important medicinal plant of oriental clinics and is considered as the main source of phthalides, polyphenols, and flavonoids. However, there is no available report regarding the effect of different light colors on the secondary metabolites composition of C. officinale. In this study different light (dark, white, blue, red and red: blue) conditions were arranged to raise callus on MS medium containing 0.5 mg·L^-1 of each 2,4-D and BAP. Callus grown in dark condition showed maximum (2.0 g) fresh weight with lower total phenolic and flavonoids contents. Also, in dark condition callus faced higher catalase (CAT) and guaiacol peroxidase (GPX) activities to avoid free radicals. Mix (red: blue) light condition favored the synthesis of phenolics and flavonoids in callus at the cost of higher ascorbate peroxidase (APX) and superoxide dismutase (SOD) enzymes expression. However, DPPH free radical scavenging activity was less variable among the samples from the different light conditions. Interestingly, the HPLC profile showed higher (28.3 μg·g^-1 DW) phthalide accumulation in dark grown-cultures. Compared to other light conditions, 3-butyledinephthalide accumulation was higher (0.43 μg·g^-1 DW) in white light-grown callus. These findings suggest that light conditions play an important role in the regulation of in vitro callus growth and synthesis of important medicinal compounds of C. officinale.