For centuries plants have been intensively utilized as reliable sources of food, flavoring, agrochemical and pharmaceutical ingredients. However, plant natural habitats are being rapidly lost due to climate change and agriculture. Plant biotechnology offers a sustainable method for the bioproduction of plant secondary metabolites using plant in vitro systems. The unique structural features of plant-derived secondary metabolites, such as their safety profile, multi-target spectrum and “metabolite likeness,” have led to the establishment of many plant-derived drugs, comprising approximately a quarter of all drugs approved by the Food and Drug Administration and/or European Medicinal Agency. However, there are still many challenges to overcome to enhance the production of these metabolites from plant in vitro systems and establish a sustainable large-scale biotechnological process. These challenges are due to the peculiarities of plant cell metabolism, the complexity of plant secondary metabolite pathways, and the correct selection of bioreactor systems and bioprocess optimization. In this review, we present an integrated overview of the possible avenues for enhancing the biosynthesis of high-value marketable molecules produced by plant in vitro systems. These include metabolic engineering and CRISPR/Cas9 technology for the regulation of plant metabolism through overexpression/repression of single or multiple structural genes or transcriptional factors. The use of NMR-based metabolomics for monitoring metabolite concentrations and additionally as a tool to study the dynamics of plant cell metabolism and nutritional management is discussed here. Different types of bioreactor systems, their modification and optimal process parameters for the lab- or industrial-scale production of plant secondary metabolites are specified.

Diverse groups of factors are leading to increased weight gain and obesity, such as certain genetic phenotypes, neuroendocrine disturbances, the administration of some drugs, behavioral, social and environmental factors. The progressively escalating rates of overweight and obesity worldwide have led to an introduction of a new term "globesity". Excessive accumulation of body fat and especially of visceral adipose tissue is the main predisposing factor for the development of metabolic syndrome and other obesity related co-morbidities. At the present moment only few pharmacotherapeuticals are used for long-term treatment of obesity acting on narrow target spectra, e.g. pancreatic and gastric lipase inhibition, acting as adrenomimetics or activating the satiety centers in hypothalamus. Plant-based medications that accelerate weight loss, proved to be safe, effective and widely available, would be a preferable alternative for anti-obesity treatments. As plant extracts are multi-component systems they could also act by more than one mechanism, including decreased lipid absorption, decreased energy intake, increased energy expenditure, decreased pre-adipocyte differentiation and proliferation, decreased lipogenesis and increased lipolysis. The current review gives a summary of the risk factors for obesity development and its characteristics consequences. Current treatment options, combining lifestyle changes and conventional treatment with commercial anti-obesity drugs have been described as well. Special emphasis on in vitro, in vivo and human studies, of potential medicinal plant extracts and phytochemicals, such as polyphenols, terpenoids, alkaloids, saponins, able to modulate the molecular pathways and gene/protein expressions related to obesity, have been highlighted.