Micropropagation for the production of high quality phytochemicals

Plants area source of many valuable secondary metabolites that find a broad field of applications, ranging from the agrochemical to the pharmaceutical industries. Establishing a suitable source for extraction of phytochemicals is, however, not always straightforward. In many instances the production by chemical synthesis is not economically viable due to their complex structures and conservation issues may arise when they are harvested from natural sources. In vitro culture techniques offer an attractive alternative to these issues. Natural grown plants can be replaced by in vitro produced biomass with the advantage that several strategies can be implemented to increase production yields, such as genotype selection, altering growth conditions and use of elicitors, so that the higher investment costs are justified. Also, because plant tissue cultures can be generated on a continuous year-round basis without seasonal constraints, they can guarantee reliable and predictable production levels, which is of great importance for efficient process down-stream. Plant tissue culture techniques offer the possibility of establishing cultures from leaves, stems, roots and meristems, meaning that metabolites produced in specific plant organs can also be prospected. The successful production of a large number of phytochemicals from micropropagated biomass has been reported, and it seems that only in a few cases cultures fail to accumulate compounds of interest. The advantages and the range of possibilities offered by plant tissue culture techniques suggest that these might become a valuable and indispensable tool for the production of phytochemicals. In this work, the example of the prospection of plumbagin from micropropagated D. intermedia plants is described. Plumbagin is a naphthoquinone with potential pharmaceutical applications and results obtained by several hyphenated analytical techniques confirm that an end product with high purity and recoveries can be obtained from in vitro cultured plants. © ISHS 2013

In vitro plantlet production of the endangered Pinguicula vulgaris

This study describes the development of a micropropagation protocol for Pinguicula vulgaris using cultures initiated from in vitro produced seedlings. P. vulgaris is a carnivorous plant with a northern, disjunctly circumpolar distribution and specific habitat requirements, and is hence becoming increasingly rare. Shoot proliferation was significantly influenced by Murashige and Skoog (MS) macronutrient concentration, showing higher proliferation rates in 1/4MS, but was not affected by the addition of 0.1 mg/L 6-benzyladenine (BA) or zeatin (Zea). The best medium for propagating P. vulgaris was plant growth regulator (PGR) free A1/4MS. An average of 7.62 new shoots per initial explant could be obtained after 8 weeks of culture, of which over 79% produced roots during proliferation. Moreover, rooting percentages of 100% were obtained for the initial explants in all the tested media, including media without PGRs. The plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development

Aluminium speciation and internal detoxification mechanisms in plants: where do we stand?

Aluminium (Al) typically has a deleterious impact on plant growth and development but some plants can accumulate otherwise toxic concentrations of this metal by deploying internal detoxification mechanisms (tolerance mechanisms). Although there are scattered reports concerning the regulation of Al uptake, transport and storage in metabolically innocuous forms, the overall picture remains incomplete and there are no accounts of a general overview of Al tolerance mechanisms. This review aims to compile the current knowledge on the physiological basis of Al tolerance and speculate on possible underlying molecular mechanisms regarding the uptake of Al, speciation in internal organs, transport to upper organs and storage in non-vital structures. Given the difficulties in detecting and studying the speciation of Al, special attention will be given to the approaches used so far and new developments that allow greater sensitivity and accuracy in uncovering the fate of Al in planta. © 2013 The Royal Society of Chemistry

Inhibitory Properties of Phenolic Compounds Against Enzymes Linked with Human Diseases

Some drugs currently used are inhibitors of enzymes involved in mediating many disease processes. Concerns over the toxicity and side effects of synthetic enzyme inhibitors have led to a search for new safe and effective inhibitors particularly from natural sources. Owing to their wide range of biological effects, plant phenolic compounds are one of the most studied families of natural products. This chapter aims to provide an overview of the potential of phenolic compounds as enzyme inhibitors. Extensive research has been conducted to study the enzyme inhibitory capacity of many phenolic compounds against several enzymes linked with important human conditions. Investigations conducted are mainly focused on the inhibition of angiotensin I-converting enzyme, α-amylase and α-glucosidase, lipase, cholinesterases, proinflammatory enzymes (cyclooxygenases and 5-lipoxygenase) and tyrosinase, which are related with hypertension, type II diabetes, obesity, Alzheimer’s diseases, inflammation and skin hyperpigmentation, respectively. Overall, among phenolics, flavonoids are probably those with great capacity to inhibit the activity of the enzymes revised. Several studies demonstrated the potent antioxidant and anti-inflammatory properties of flavonoids, which highlight the therapeutic potential of these compounds. Although our literature survey showed that a huge number of phenolic compounds have been studied and there are some promising compounds depending on the enzyme, more in vivo tests and subsequent steps to be a drug candidate are required before therapeutic application

Production of Plant Secondary Metabolites by Using Biotechnological Tools

Plants are a remarkable source of high-value secondary metabolites with applications in various domains. Plant cell and tissue culture techniques appear as environmentally friendly alternatives for the production of secondary metabolites when natural supply is limited or chemical synthesis is unviable. In this chapter, the main advantages of using plant cell and tissue culture techniques for the production of plant secondary metabolites are presented as well as the different biotechnological approaches available to improve their production. In addition, the production of anticancer compounds (camptothecin, podophyllotoxin, taxol, vinblastibe, and vincristine) and metabolites from Lamiaceae spp. (phenolics as rosmarinic acid) were selected as examples to be highlighted. The study reviewed shows that undifferentiated cells are the preferred culture system used for the production of high-value secondary metabolites in vitro although there are many examples reporting the production in differentiated tissues particularly in hairy roots. Efforts have been made to scale up the production, and several strategies have been successfully applied to increase the production yields at the laboratorial scale. Nevertheless, there are only few examples of plant secondary metabolites production at commercial level, and further in-depth studies are still required

Chemical and Biological Characteristics of <em>Ficus carica</em> L. Fruits, Leaves, and Derivatives (Wine, Spirit, and Liqueur)

Ficus carica L. is a native plant to Southwest Asia and widely spread from ancient times in the Mediterranean region. Its fruits (figs) and leaves present important nutritional components (vitamins, minerals, sugars, amino acids, etc.) and health-related effects due to their phytochemical composition. Numerous bioactive compounds, such as phenolic compounds (phenolic acids), flavonoids (flavonols, flavones, and anthocyanins), coumarins, sterols, and volatiles (monoterpenes, sesquiterpenes, norisoprenoids, ketones, alcohols, esters, etc.), among others, have been isolated from fruits and leaves of F. carica that are the main ingredients used in the production of different alcoholic beverages such as wine, liqueur, and spirit. This chapter aims to review the different chemical and biological characteristics found both in raw materials (fruits and leaves) and in the final product (wine, liqueur, and spirit) that have been consumed and known throughout human history

Water loss and morphological modifications in leaves during acclimatization of cork oak micropropagated plantlets

This study characterises some aspects of foliar anatomy of cork oak micropropagated plantlets, and rates of water loss by different types of leaves during the acclimatization period. Water loss from leaves of in vitro cultured plantlets was much higher than that of acclimatized plants or seedlings. Leaves from in vitro plantlets lost 53% of their water within the first 30 min under water stress conditions, while leaves from acclimatized plants lost 14%. Leaves of in vitro grown plants presented open stomata and collapsed guard cells, while acclimatized leaves presented closed stomata. Shade-leaf structure was observed in transverse sections of in vitro leaves, with large intercellular air spaces and a low mesophyll cell density, but with a differentiated palisade cell layer. Leaves from acclimatized plants showed a sun-leaf structure with small intercellular air spaces, high cell density and two or three palisade cell layers. During acclimatization leaf thickness increased, as well as cell compactness and differentiation. Stomatal density, stomatal aperture and guard cell protuberance decreased during the acclimatization period, while trichome density increased

Antioxidant activity and inhibitory effect of L. viridis extract on Fe2+-induced lipid peroxidation in brain homogenates

The brain is particularly susceptible to oxidative stress damaging effects due such events as the high consumption of oxygen, limited concentration of antioxidants and a relatively high degree of polyunsaturated fatty acids that are particularly good substrates for peroxidation reactions [1–3]. Oxidative stress could lead to damage biological target molecules, affecting the cellular function and integrity [4]. The ability of natural antioxidants, mainly phenolic compounds, to protect cells from oxidative stress has been previously demonstrated [5]. In this work, the methanol extract from Lavandula viridis L'Hér. (Lamiaceae), a xerophytic aromatic shrub endemic to the south-west Iberian Peninsula [6], was investigated for its effect on deoxyribose degradation, its reducing properties, Fe2+-chelating ability and total phenol content. The capacity of this extract to prevent Fe2+-induced lipid peroxidation in mouse brain (in vitro) was also evaluated. L. viridis extract showed Fe2+ chelating activity, reducing power and the ability to prevent Fe2+/H2O2-induced decomposition of deoxyribose in a dose-dependent manner. This extract also revealed a high phenol content (893.01±17.09µmol gallic acid equivalents/g extract) evaluated by Folin-Ciocalteu method. Moreover, in brain homogenates, the methanol extract of L. viridis caused a high decrease in the MDA production in both the basal and the Fe2+-induced lipid peroxidation. The effective protective properties of L. viridis could be attributed to its higher phenol content, Fe2+ chelating ability, reducing properties and HO· radical scavenging ability. The findings suggest that methanol extract from L. viridis could be a potential source of natural antioxidants

The influence of in vitro gastrointestinal digestion on the chemical composition and antioxidant and enzyme inhibitory capacities of carob liqueurs obtained with different elaboration techniques

Carob liqueur is a traditional Mediterranean alcoholic beverage obtained via a wide range of production techniques contributing to the different organoleptic attributes of the final product. The aim of this research was to evaluate the stability of the chemical composition and biological capacities (antioxidant and enzyme inhibition) under in vitro simulated gastrointestinal digestion of liqueurs prepared by flavouring the fig spirit with carob pulp by maceration, distillation, percolation, or aqueous and hydro-alcoholic infusions. For this purpose, the phenolic and furanic compositions, the total phenolic (TPC) and flavonoid (TFC) contents, antioxidant capacity (AC), and enzyme inhibitory potential against acethylcholinesterase, tyrosinase, α-glucosidase and α-amylase enzymes were evaluated. The content of gallic acid decreased after gastrointestinal digestion, while TPC, TFC, and AC significantly increased after each digestion phase. Overall, no significantly different enzyme inhibitions (p < 0.05) were observed among digested liqueurs, with moderate inhibition against acethylcholinesterase and tyrosinase (enzymes related with neurodegenerative diseases), and potent and low inhibitory capacities for α-glucosidase and α-amylase, respectively (ideal conditions employed in antidiabetic therapy). The study indicates that hydro-alcoholic infusion and maceration were the most appropriate methods to obtain liqueurs with higher values of the aforementioned parameters and safe levels of toxic furanics.Fundação para a Ciência e a Tecnologia, I.P.: SFRH/BPD/103086/2014; DL 57/2016/CP1361/CT0022; project INTERREG-MD.NET: When Brand Meets Peopleinfo:eu-repo/semantics/publishedVersio

Carob pulp: A nutritional and functional by-product worldwide spread in the formulation of different food products and beverages: A review

Carob (Ceratonia siliqua L.) pod is a characteristic fruit from the Mediterranean regions. It is composed by seeds, the valuable part due to the extraction of locust bean gum, and the pulp, considered a by-product of the fruit processing industry. Carob pulp is a mixture of macro- and micronutrients, such as carbohydrates, vitamins and minerals, and secondary metabolites with functional properties. In the last few years, numerous studies on the chemical and biological characteristics of the pulp have been performed to encourage its commercial use. Its potential applications as a nutraceutical ingredient in many recipes for food and beverage elaborations have been extensively evaluated. Another aspect highlighted in this work is the use of alternative processes or conditions to mitigate furanic production, recognized for its toxicity. Furthermore, carob pulp’s similar sensorial, chemical and biological properties to cocoa, the absence of the stimulating alkaloids theobromine and caffeine, as well as its low-fat content, make it a healthier potential substitute for cocoa. This paper reviews the nutritional and functional values of carob pulp-based products in order to provide information on the proclaimed health-promoting properties of this interesting by-productUIDB/05183/2020info:eu-repo/semantics/publishedVersio