Plumbagin Production Research Articles

Enhancement of Plumbagin Production through Elicitation in In Vitro-Regenerated Shoots of Plumbago indica L.

Plumbago indica L. contains a valuable bioactive compound called plumbagin. Elicited regenerated shoots grown in vitro could be another source of high-yielding plumbagin. The purpose of this investigation was to examine the effects of elicitor type and concentration, as well as elicitation period, on plumbagin content in in vitro-regenerated shoots of P. indica. Nodal explants were cultured on Murashige and Skoog (MS) medium containing 1 mg/L benzyladenine (BA) in combination with 0-150 mg/L yeast extract or 50-150 µM salicylic acid for four weeks. Plumbagin levels of 3.88 ± 0.38% and 3.81 ± 0.37% w/w g dry extract were achieved from the 50 and 100 mg/L yeast extract-elicited shoots, which were higher than the value obtained for the control. However, the addition of salicylic acid did not increase the plumbagin content. In the elicitation period experiment, nodal explants were cultured on MS medium supplemented with 1 mg/L BA and 50 mg/L yeast extract for durations of three, four and five weeks. The 4-week yeast extract-elicited shoot had a maximum plumbagin content of 3.22 ± 0.12% w/w g dry extract, greater than that of the control. In summary, the plumbagin content of the in vitro P. indica shoots was enhanced by 4-week elicitation using 50 mg/L yeast extract.

MeJA-induced hairy roots in Plumbago auriculata L. by RNA-seq profiling and key synthase provided new insights into the sustainable production of plumbagin and saponins.

Naturally synthesized secondary metabolites in plants are considered an important source of drugs, food additives, etc. Among them, research on natural plant medicinal components and their synthesis mechanisms has always been of high concern. We identified a novel medicinal floral crop, Plumbago auriculata L., that can be treated with methyl jasmonate (MeJA) for the rapid or sustainable production of natural bioactives from hairy roots. In the study, we globally analyzed the changes in the accumulation of plumbagin and others in the hairy roots of Plumbago auriculata L. hairy roots (PAHR) 15834 in P. auriculata L. based on 100 μmol/L of MeJA treatment by RNA-seq profiling, and we found that there was a significant increase in the accumulation of plumbagin and saponin before 24h. To explain the principle of co-accumulation, it showed that MeJA induced JA signaling and the shikimic acid pathway, and the methylvaleric acid (MVA) pathway was activated downstream subsequently by the Mfuzz and weighted gene co-expression analysis. Under the shared metabolic pathway, the high expression of PAL3 and HMGR promoted the activity of the "gateway enzymes" phenylalanine ammonia lyase (PAL) and 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), which respectively induced the high expression of key reaction enzyme genes, including chalcone synthase (CHS), isopentenyl diphosphate (IPP), and farnesyl pyrophosphate synthase (FPS), that led to the synthesis of plumbagin and saponin. We speculated that large amounts of ketones and/or aldehydes were formed under the action of these characteristic enzymes, ultimately achieving their co-accumulation through polyketone and high-level sugar and amino acid metabolism. The study results provided a theoretical basis for carrying out the factory refinement and biosynthesis of plumbagin and saponins and also provided new ideas for fully exploiting multifunctional agricultural crops and plants and developing new agricultural by-products.

Enhanced production of bioactive plumbagin in hairy root cultures and adventitious root cultures of Plumbago zeylanica L. by a novel apocarotenoid elicitor, α-ionone

Plumbagin, a medicinally important secondary metabolite is produced in the roots of Plumbago zeylanica Linn. Natural harvest of plumbagin from roots is a destructive process that destroys the entire plant. The aim of this study was the in vitro production of plumbagin at high concentrations. For this purpose, hairy root cultures (HRCs) and adventitious root cultures (ARCs) were induced from P. zeylanica leaf explants. Additionally, first-time α-ionone was used as an elicitor to trigger plumbagin biosynthesis. HRCs were developed using the two different strains of Agrobacterium rhizogenes (LBA1334, and R1000). R1000 strain showed the highest HR induction efficiency. ARCs were induced from the leaf explants growing in Murashige and Skoog (MS) solid media supplemented with 1 mg/L indole-3-butyric acid. Newly emerged adventitious roots were used to develop root suspension cultures in a liquid MS medium. Plumbagin content was determined by HPLC/DAD. Both HRCs and ARCs showed fast growth kinetics. The greatest increase in the production of plumbagin was achieved with 10 µM α-ionone. As compared to untreated controls, the optimum α-ionone dose resulted in a 3.6-fold and 3.1-fold increase in plumbagin in HRCs, and ARCs, respectively. These results support that α-ionone elicitor-treated HRCs and ARCs are promising technology for improved production of plumbagin to meet commercial demand.

Approaches for in vitro propagation and production of plumbagin in Plumbago spp.

The genus Plumbago (family Plumbaginaceae), commonly known as leadwort, is a sub-tropical shrub that produces secondary metabolite plumbagin, which is employed by pharmaceutical companies and in clinical research. Plumbagin is a potent pharmaceutical because of its anti-microbial, anti-malarial, antifungal, anti-inflammatory, anti-carcinogenic, anti-fertility, anti-plasmodium, antioxidant, anti-diabetic, and other effects. This review documents the biotechnological innovations used to produce plumbagin. The use of modern biotechnological techniques can lead to a variety of benefits, including better yield, increased extraction efficiency, mass production of plantlets, genetic stability, increased biomass, and more. Large-scale in vitro propagation is necessary to minimize over-exploitation of the natural population and allow the use of various biotechnological techniques to improve the plant species and secondary metabolite production. During in vitro culture, optimum conditions are requisites for explant inoculation and plant regeneration. In this review, we provide information on various aspects of plumbagin, depicting its structure, biosynthesis, and biotechnological aspects (both conventional and advanced) along with the future prospects. KEY POINTS: • Critical assessment on in vitro biotechnology in Plumbago species • In vitro propagation of Plumbago and elicitation of plumbagin • Biosynthesis and sustainable production of plumbagin.

Biotic elicitation for enhanced production of plumbagin in regenerated shoot cultures of Plumbago zeylanica using response surface methodology

Biotic elicitation for enhanced production of plumbagin in regenerated shoot cultures of Plumbago zeylanica using response surface methodology

Correction to: Efficient in vitro organogenesis, micropropagation, and plumbagin production in Plumbago europaea L.

Correction to: Efficient in vitro organogenesis, micropropagation, and plumbagin production in Plumbago europaea L.

Light emitting diodes optimisation for secondary metabolites production by Droseraceae plants

The most abundant active compound in Droseraceae is plumbagin, a naphthoquinone widely used for medical purposes due to its antimicrobial, antitussive, antimalarial and anticancer properties. In this work, we created a light-emitting diode (LED) based culture illumination setup as an alternative to fluorescent lamps traditionally used as a light source in plant in vitro cultures. The plants of Drosera binata and Drosera peltata cultured under LED illumination grew equally well and produced similar amounts of biologically active compounds as plants grown under fluorescent lamps. The plants were cultured on two media differing in mineral composition, sucrose content and pH. Secondary metabolites were extracted with ethanol from the plants after harvesting. The extracts were subjected to HPLC and microbiological analyses. We observed differences in morphology and secondary metabolism between plants of the same species grown on different media. However, we did not note significant changes in secondary metabolite yield under assessed lighting conditions. We propose LEDs as a more efficient, eco-friendly and economically reasonable source of light for big scale in vitro production of plumbagin in Drosera species than fluorescent lamps.

Isolation and optimization of plumbagin production in root callus of Plumbago zeylanica L. augmented with chitosan and yeast extract

Chitrak (Plumbago zeylanica L.), a renowned traditional medicinal plant, is being exploited extensively for its roots which are employed in the preparations of many important herbal products (e.g. Dashmularisht, Chitrakadivati) possessing anticancer, anti-atherogenic, cardiotonic, hepatoprotective and neuroprotective properties. P. zeylanica roots, being the major source of plumbagin, were used for its isolation. Plumbagin isolation from in vivo roots was done employing column chromatography and thin layer chromatography (TLC) using a hexane: ethyl acetate (70:30) mobile phase. A total of 65 fractions were obtained which pooled down to 8 (F1–F8) based on their similar Rf values. Of the 8 fractions, F2 gave a single spot corresponding to that of the standard plumbagin which subsequently was validated and confirmed through 1H-NMR and FT-IR. For elicitation to increase plumbagin, in vitro root callus initially raised on Murashige and Skoog medium +5 μM TDZ was augmented with different concentrations of precursors (sodium acetate, l-tyrosine), biotic (chitosan, proline, lysine, salicylic acid, yeast extract) and abiotic [Pb(NO3)2, CdCl2] elicitors either alone or in combinations. The optimum increase of up to 2.07 and 2.64–folds in plumbagin was seen when callus cultures were fed individually with sodium acetate (1 mg/L) and l-tyrosine (25 mg/L), respectively. Similarly, chitosan and yeast extract when used alone, the plumbagin content was enhanced 4.58–fold at 50 mg/L and 6.50–fold at 100 mg/L, respectively. However, an enormous increase of 12.08–fold plumbagin content occurred when a combination of 50 mg/L chitosan + 100 mg/L yeast extract was used. A combination of salicylic acid (25 μM) and yeast extract (100 mg/L) also enhanced plumbagin content up to 8.23–fold. Thus, this is our first report of scaling up to 12.08–fold plumbagin content using simple and cost effective elicitors.

Enhanced plumbagin production in Plumbago indica root culture by simultaneous and sequential dual elicitations using chitosan with \u029f-alanine and methyl-\u03b2-cyclodextrin

The simultaneous and sequential dual elicitation effect on plumbagin production in Plumbago indica L. root cultures, revealed that combination of chitosan (150 mg L−1) with ʟ-alanine (5 mM) or methyl-β-cyclodextrin (MCD; 2 mM) significantly increased plumbagin production, but in the different treatment manners. The simultaneous treatment using chitosan + ʟ-alanine on a 14-day-old culture enhanced plumbagin production to 14.62 mg g−1 DW, while the sequential additions of MCD to a 12-day-old culture followed by chitosan after 48 h enhanced production of plumbagin to 14.33 mg g−1 DW. The plumbagin productivity from both treatments were up to 1.3- and 8-fold higher than the chitosan treated (10.93 mg g−1 DW) and untreated root cultures (1.76 mg g−1 DW). Moreover, the present studies provided new information on the effect of simultaneous and sequential elicitation on plumbagin-producing P. indica root cultures using chitosan in combinations with MCD or ʟ-alanine.

Potential of the genetically transformed root cultures of Plumbago europaea for biomass and plumbagin production.

Plumbago europaea L. is the main source of plumbagin which is a well-known pharmacological active compound. In this investigation, genetically transformed roots of P. europaea were obtained by improving some factors affecting the efficiency of Agrobacterium rhizoigenes-mediated transformation such as explant type, A. rhizoigenes strain, bacterial infection period, co-cultivation period and acetosyringone concentration. The leaf, hypocotyl and stem explants from in vitro grown plantlets were infected with bacterial strains (A4, ATCC15834, MSU440 and A13). The highest transformation rate of 69.3% was achieved after 7-9 days by inoculating A. rhizogenes MSU440 strain onto the 3-week-old stem explants followed by a co-cultivation period of 2 days on a medium containing 100 μM acetosyringone. To investigate the existence of the rolB gene, polymerase chain reaction was carried out using specific primers. Effects of growth media (MS, 1/2 MS, MS-B5 and ½ MS-B5), different sucrose concentrations and illumination on biomass production and plumbagin biosynthesis in P. europaea hairy root cultures were analyzed using stem explants after infection with MSU440 strain. ½ MS-B5 liquid medium containing 30 g L-1 sucrose incubated in the dark resulted in the efficient biomass production of transformed hairy roots (12.5 g fresh weight, 1.8 g dry weight) with 3.2 mg g-1 DW plumbagin accumulation. This procedure provides a framework for large-scale cultivation of hairy roots for plumbagin production. This is the first report describing the establishment of P. europaea hairy root culture with special emphasis on plumbagin production.

Artificial color light sources and precursor feeding enhance plumbagin production of the carnivorous plants Drosera burmannii and Drosera indica

Plumbagin is the main pharmacologically active compound of carnivorous plants in the genera Drosera. It possesses various pharmacological activities, including anticancer and antimalarial activities, and is used in traditional medicine. In this study, we reported a sustainable production system of plumbagin by adding sodium acetate and L-alanine as precursors to in vitro cultures of Drosera burmannii Vahl and Drosera indica L. In addition, plumbagin production was reported in the cultures subjected to different color LED lights. The highest plumbagin level (aerial part 14.625 ± 1.007 mg·g−1 DW and root part 1.806 ± 0.258 mg·g−1 DW) was observed in D. indica cultured under blue LED light for 14 days, and further culturing did not increase plumbagin production. In addition, plumbagin enhancement by precursor feeding (9.850 ± 0.250 mg·g−1 DW, 1.2-fold) was observed in the aerial part of D. indica treated with 50 mg·L−1 sodium acetate for 3 days. Comparing both plants, up to 700-fold higher plumbagin was observed in D. indica than in D. burmannii. Moreover, in both plants, the aerial part accumulated higher plumbagin (up to 10-fold) than the roots. This is the first report on the effect of artificial LED lights on the plumbagin level of Dorsera plants. The culturing of D. indica under blue LED light showed enhanced plumbagin levels and suggests a fast and simple system for the in vitro production of plumbagin.

Fungal endophytes of Plumbago zeylanica L. enhances plumbagin content

BackgroundPlumbagin is one of the pharmaceutically important biomolecule with anticancer potential. Among the plants reported to produce plumbagin, P. zeylanica topped the list. The plumbagin production is very slow with low yield and maximum 0.5% (of dry weight) was reported in P. zeylanica. To meet the increasing demand of the plumbagin at global level, the P. zeylanica are exploited at commercial level, which may pose serious threat on the germplasm of the plant populations. So, it is needed to enhance the contents of plumbagin in P. zeylanica using biotechnological approaches. Among the various methods used to enhance the contents of plumbagin in P. zeylanica, utilization of fungal endophytes to enhance the plumbagin contents is a widely accepted approach. As fungal endophytes have the potential to synthesize various secondary metabolites and also reported to influence the synthesis of the secondary metabolites in plants. In the present study, an attempt was made to assess the effect of fungal endophytes of the Plumbago zeylanica L. on enhancement of plumbagin contents at in vivo level.ResultsTotal 3 fungal endophytes were recorded from the roots of P. zeylanica collected from Khadki, Pune. The fungal endophytes were identified at morphological and molecular level. After 1 year of the treatment with fungal endophytes, significant enhancement of plumbagin was recorded in the roots of the P. zeylanica. Plumbagin contents in each were quantified against the standard plumbagin by employing LCMS-MS technique. Among the three fungal endophytes, the maximum enhancement of plumbagin content (122.67%) was reported with the treatment of Alternaria sp. (Isolate-3) in the roots of the P. zeylanica compared to control.ConclusionAmong the three fungal endophytes, the maximum enhancement of plumbagin content (122.67%) was reported with Alternaria sp. (Isolate 3) in the roots of the pot-grown plants of P. zeylanica at in vivo level.

Cell Suspension Culture of Plumbago europaea L. Towards Production of Plumbagin.

BackgroundPlumbagin is as an important bioactive secondary metabolite found in the roots of Plumbago spp. The only one species, Plumbago europaea L., grows wild in Iran. The therapeutic use of plumbagin is limited due to its insufficient supply from the natural sources as the plants grow slowly and take several years to produce quality roots.ObjectivesTo develop an efficient protocol for the establishment of callus and cell suspension cultures of P. europaea and to evaluate production of plumbagin in callus and cell suspension cultures of P. europaea for the first time.Material and MethodsStems and leaves explants were cultured on agar solidified (7% w/v) MS media, supplemented with different combination of 2, 4-D and Kin or 6-Benzylaminopurin (BA) for callus induction. The rapid growing calli were cultured in liquid Murashige and Skoog (MS) media in agitated condition for establishing cell suspension cultures of P. europaea. Moreover, the effects of light and dark conditions on the cell growth, cell viability and plumbagin production in cell suspension cultures of P. europaea were assessed.ResultsFriable calli were successfully induced using stem segments of P. europaea in semisolid MS medium supplemented with 1 mg.L-1 2, 4-Dichlorophenoxy acetic acid (2, 4-D) and 0.5 mg.L-1of kinetin (Kin). Optimal cell growth was obtained when the cells were grown in MS liquid media supplemented with 1 mg.L-1 2, 4-D and 0.5 mg.L-1 kinetin with an initial cell density of ~3×105 cells per ml incubated in the dark at 25 ± 1 °C. Growth curve revealed that the maximum cell growth rate (14.83×105 cells per ml) achieved on the day 18 and the highest plumbagin content (0.9 mg.g-1 Dry Cell Weight (DCW)) in the cells was obtained at the late exponential phase under dark condition which determined by High Performance Liquid Chromatography (HPLC) technique. Based on the obtained results, cell viability remained around 82.73% during the 18 days of cell culture in darkness. These suspension cultures showed continuous and stable production of plumbagin.ConclusionsOur study suggests that cell suspension cultures of P. europaea represent an effective system for biosynthesis and production of plumbagin as a valuable bioactive compound.

Establishment of root suspension culture of Plumbago zeylanica and enhanced production of plumbagin

Plumbagin found in the roots of Plumbago zeylanica L. possesses various biological activities like anticancer, antibacterial, anti-inflammatory, etc. In this investigation, roots were initiated from P. zeylanica nodal explants, highest root number (24.1 ± 0.73) was achieved in Murashige and Skoog MS media + 1 mg/L indole-3-butyric acid (IBA) whereas maximum root length (3.33 ± 0.53 cm) was observed in MS media + 2 mg/L indole-3-acetic acid (IAA). MS liquid medium containing 1 mg/L IBA was used for establishing root suspension culture. Optimization of culture parameters reveals that half strength liquid MS media + 3% sucrose + 2 g/L inoculum density resulted in highest plumbagin production. Application of different concentrations of abiotic (yeast extract and malt extract) and biotic elicitors (methyl jasmonate and salicylic acid) enhanced plumbagin content significantly. Up to threefold increase in plumbagin concentration was achieved by treating the root suspension culture with 150 mg/L yeast extract. Results indicate that utilization of elicitor can enhance plumbagin production as well as other phytochemicals in P. zeylanica root culture.

Improving large-scale biomass and plumbagin production of Drosera communis A.St.-Hil. by temporary immersion system

Drosera communis A.St.-Hil. is a carnivorous plant with ornamental and medicinal values. Productions of biomass and plumbagin, a main bioactive compound in a semi-solid system (SSS), continuous immersion system (CIS) and temporary immersion system (TIS) were compared. After pre-induction, leaves were cultured for 8 weeks, TIS promoted better growth and development compared to SSS and CIS. The highest biomass per clump at 3.40 g fresh weight (FW) and 0.36 g dry weight (DW) was obtained from TIS at about 3 and 1.8 times higher than SSS and CIS, respectively. The highest shoot number per clump (30.4 shoots) was also derived from TIS at around 2.6 and 1.6 times higher than SSS and CIS, respectively. Moreover, growth performances per replication of TIS were significantly higher than SSS and CIS. Over 600 shoots were obtained from one TIS, while only around 236 and 379 shoots were obtained from SSS and CIS, respectively. Likewise, maximal biomass per replication (68.0 g FW and 7.1 g DW) obtained from TIS was two or three times greater than CIS and SSS, respectively. For plumbagin production, the highest plumbagin content was gained from CIS (4.91 μg/g DW) followed by SSS (4.22 μg/g DW) and TIS (2.44 μg/g DW). Although TIS provided the lowest plumbagin content, the highest plumbagin yield per replication (17.31 μg/replication) was gained from TIS, which was significantly higher than SSS and CIS. Results suggested that TIS was a suitable method for large-scale production of biomass and plumbagin of D. communis.

Effect of various culture conditions on shoot multiplication and GC–MS analysis of Plumbago zeylanica accessions for plumbagin production

Plumbago zeylanica, a pharmaceutically important medicinal plant, contains a wide range of phytocompounds. Culture parameters like carbon source, nitrogen source, and culture media are essential for the development and growth of explants. In this investigation, the influence of various carbon sources (sucrose, glucose, and fructose at 3% concentration), nitrogen source (ammonium nitrate, sodium nitrate, and potassium nitrate) and plant tissue culture media (MS medium, Gamborg’s B5 medium, White medium and Nitsch medium) on shoot multiplication of five different accessions was studied. Optimum growth of all five accessions was observed in MS media containing 3% sucrose and ammonium nitrate as a source of carbon and nitrogen. Out of five accessions, IC-524441 showed the highest shoot multiplication. Further, methanolic extracts of all accessions (grown in MS media containing 3% sucrose and ammonium nitrate as nitrogen source) were prepared and comparison of extracts in DPPH assay indicated that accession number IC-524441 was the most effective free radical scavenging agent. Total phenolic, flavonoid and tannin content ranges were from 20 to 70 µg/ml, 40 to 100 µg/ml and 55 to 120 µg/ml, respectively, and the highest amount was found in accession number IC-524441. Sucrose and ammonium nitrate content may be responsible for increased antioxidant activity, flavonoids content, phenolic content, and tannin content in accession number IC-524441. GC–MS of ethyl acetate extract of all five accessions of P. zeylanica was conducted (grown in MS media containing 3% sucrose and ammonium nitrate as nitrogen source). GC–MS analysis of the aerial part showed the presence of various phytocompounds, which include 1,4-naphthalenedione, 3-eicosene, 5-eicosene, phthalic acid, o-anisic acid, thioctic acid, 1-octadecene, 5-t-butyl-cycloheptene, 2-benzoyl-1,2-dihydro-1-isoquinolinecarbonitrile, octadecanal, silane, 3-methoxy-2-methyl-2-(1-phenyl-ethylamino)-propionic acid, and 1-nonadecene. Accession number IC-524441 contains the highest amount of plumbagin, i.e. 14.19 ± 0.5 µg/ml as compared to the others.

Effects of Cytokinin and Auxin on In Vitro Organ Development and Plumbagin Content of Drosera peltata Thunb.

A rapid propagation and plumbagin production of Drosera peltata was developed and investigated. The research aims to study the effects of cytokinins and auxins on organ development and plumbagin production from shoot tip cultures. In vitro generated shoot tips were cultured on the semi-solid 1/2 MS medium containing 3.0% sucrose, 2.0% gelrite, and 0.1, 0.5, 1.0, and 2.0 mg L –1 cytokinins (BA, Kn, TDZ) and auxins (IAA, IBA, NAA and 2,4-D) for 12 weeks. The highest number of shoots (12.0 ± 1.2) was formed on the medium containing 1.0 mg L –1 TDZ, which was four-fold higher than in the control. Meanwhile, the highest number of roots per explant (9.4 ± 1.3) and rhizomes per explant (8.1 ± 0.8) were formed on the medium containing 2.0 mg L –1 NAA. The best callus induction (100%) was found on the 0.5–2.0 mg L –1 2,4-D-containing medium. Moreover, the highest plumbagin content (12.04 mg g –1 DW) was detected from shoots regenerated on the 0.1 mg L –1 BA-containing medium, which was approximately two-fold higher than that in the control. The study is efficient for organs induction and enhances plumbagin content from shoot tip explants of D. peltata .

Biotechnological Approaches for the Production of Pharmaceutically Important Compound: Plumbagin.

Increased demand for compounds that are derived from natural source are gaining more and more importance. Plumbagin is a plant naphthoquinone which is present in several families, including Iridaceae, Plumbaginaceae, Ebenceae, Drosophyllaceae, Nepenthaceae and Droseraceae. Plumbagin possesses high therapeutic efficacy and minimal side effects. It has various pharmaceutical activities which include anticancer, antibacterial, anti-inflammatory, antioxidant, antifungal, neuroprotective and hypolipidemic activities. In natural habitat, production of plumbagin is low due to species variations and environmental changes, considering importance of this bioactive compound, alternative techniques for its enhanced production needs to be devised. In the present review, various production techniques and scale-up strategies for plumbagin production are discussed. Aim of this review is to provide an insight into the chemistry of plumbagin, its pharmaceutical activities, perspective of cell suspension culture, root culture, hairy root culture and scale up strategies for its production. All the data compiled and presented here were obtained from various E-resources like Pubmed, Science Direct, and Google Scholar up to February 2018. This review comprises isolation, extraction and quantification method for plumbagin, its pharmaceutical activities, various tissue culture production techniques and scale-up strategies for enhanced production. Plumbagin is an important phytocompound which shows potential towards treatments of various diseases. Demand for the production of plumbagin continuously increasing worldwide due to its pharmacological properties. To fulfil commercial demand of plumbagin alternative technologies need to be investigated. Biotechnological approaches like cell suspension culture, root suspension culture and hairy root culture are alternative techniques for plumbagin production. These techniques provide continuous supply of bioactive compounds. However, research on various aspects of tissue culture production techniques is in preparatory stage and requires culture and process optimization for development of a commercially practical process.

Enhanced plumbagin production in Plumbago indica root cultures by ʟ-alanine feeding and in situ adsorption

Plumbagin is associated with potent antimicrobial and anticancer properties. However, due to poor supply of the natural product, efforts are being made to improve plumbagin biosynthesis and bioproduction. The aim of this work was to enhance production of plumbagin from root cultures of Plumbago indica L. through precursor feeding using l-alanine followed by in situ adsorption of plumbagin on the nonpolar copolymer adsorbent, styrene–divinylbenzene resin (Diaion® HP-20). l-alanine fed at a concentration of 5 mM to 14 days old root culture followed by the sequential addition of Diaion® HP-20 (10 g L−1) after 36 h of l-alanine-fed significantly increased plumbagin production to 22.4 mg g−1 dry weight (DW). The level of productivity obtained was 14- and 1.6-fold higher than that achieved using untreated root cultures (1.6 mg g−1 DW) or l-alanine feeding alone (14.4 mg g−1 DW) within 16 days of the culture. The results of this work suggest the use of precursor feeding in combination with in situ adsorption as an easy and cost effective tool for the large-scale production of medicinally valued compounds like plumbagin.

Chitosan elicitation and sequential Diaion® HP-20 addition a powerful approach for enhanced plumbagin production in Plumbago indica root cultures

Abstract Plumbago indica L. is an important source of plumbagin, a bioactive naphthoquinone known for its potent anticancer and antimicrobial properties. However, due to its low supply, this work aimed to enhance the production of plumbagin using root cultures of P. indica through the combined action of chitosan elicitation and in situ adsorption using a nonpolar copolymer adsorbent, styrene-divynilbenzene resin (Diaion® HP-20). Treatment with chitosan at concentrations of 150 mg L−1 to 14 days old culture for 72 h markedly increased the production of plumbagin [13.08 mg g−1 dry weight (DW)] by up to 6.6-fold compared to the level of an untreated root culture (1.97 mg g−1). The sequential addition of Diaion® HP-20 (10 g L−1) to the root cultures after the chitosan treatment for 48 h markedly increased the plumbagin production up to 19.93 mg g−1 DW, which was 1.2- and 10-fold higher than the chitosan treated and untreated root cultures respectively. These results indicated that the chitosan elicitation and sequential addition of Diaion® HP-20 was a powerful approach for increasing the production of plumbagin, and thus this key strategy with P. indica root cultures may be considered for development as a commercialized method for production of plumbagin.