Effects of space flight on DNA mutation and secondary metabolites of licorice (Glycyrrhiza uralensis Fisch.)

Pharmacological Activities and Phytochemical Constituents

Glycyrrhiza glabra is one of the most popular medicinal plants and it has been used in traditional herbal remedy since ancient times (Blumenthal et al. in Herbal medicine: expanded commission E monographs. Integrative Medicine Communications, Newton, 2000; Parvaiz et al. in Global J Pharmocol 8(1):8–13, 2014; Altay et al. in J Plant Res 129(6):1021–1032, 2016). Many experimental, pharmacological and clinical studies show that liquorice has antimicrobial, antibacterial, antiviral, antifungal, antihepatotoxic, antioxidant, antiulcer, anti-hemorrhoid antihyperglycemic, antidiuretic, antinephritic, anticarcinogenic, antimutagenic, anticytotoxic, anti-inflammatory, and blood stopper activity.

Comparison of space flight and heavy ion radiation induced genomic/epigenomic mutations in rice (Oryza sativa)

Rice seeds, after space flight and low dose heavy ion radiation treatment were cultured on ground. Leaves of the mature plants were obtained for examination of genomic/epigenomic mutations by using amplified fragment length polymorphism (AFLP) and methylation sensitive amplification polymorphism (MSAP) method, respectively. The mutation sites were identified by fragment recovery and sequencing. The heritability of the mutations was detected in the next generation. Results showed that both space flight and low dose heavy ion radiation can induce significant alterations on rice genome and epigenome (P<0.05). For both genetic and epigenetic assays, while there was no significant difference in mutation rates and their ability to be inherited to the next generation, the site of mutations differed between the space flight and radiation treated groups. More than 50% of the mutation sites were shared by two radiation treated groups, radiated with different LET value and dose, while only about 20% of the mutation sites were shared by space flight group and radiation treated group. Moreover, in space flight group, we found that DNA methylation changes were more prone to occur on CNG sequence than CG sequence. Sequencing results proved that both space flight and heavy ion radiation induced mutations were widely spread on rice genome including coding region and repeated region. Our study described and compared the characters of space flight and low dose heavy ion radiation induced genomic/epigenomic mutations. Our data revealed the mechanisms of application of space environment for mutagenesis and crop breeding. Furthermore, this work implicated that the nature of mutations induced under space flight conditions may involve factors beyond ion radiation.

Bioactivity and potential health benefits of licorice

Licorice is an herbal plant named for its unique sweet flavor. It is widely used in the food and tobacco industries as a sweetener. Licorice is also used in traditional Chinese medicine (TCM) and complementary medicine. Because the use of licorice has long been a part of TCM, the details of its therapeutic applications have been thoroughly established. In modern science, licorice is of interest because of its broad range of applications. Extracts of and compounds isolated from licorice have been well studied and biologically characterized. In this review, we discuss the nutraceutical and functional activities of licorice as well as those of the extracts of and the isolated compounds from licorice, including agents with anti-inflammatory activity, cell-protective abilities, and chemopreventive effects. The side effects of licorice are also enumerated. A comparison of the activities of licorice described by modern science and TCM is also presented, revealing the correspondence of certain characteristics.

Effects of Space Flight on the Chemical Constituents and Anti-Inflammatory Activity of Licorice (Glycyrrhiza uralensis Fisch)

Licorice, the oldest Chinese traditional medicine, is widely used in the treatment of human diseases. Due to the deficiency of wild resource, selecting and breeding becomes a key issue to expanding the supply of licorice. Spaceflight technology will become a new method for medicinal plants. The aim of this study was to investigate the effect of spaceflight on the components and anti-inflammatory activity in licorice. After flowing on a recoverable satellite for 18 days, licorice seeds were germinated and grown to maturity and the parallel ground-based seeds were also planted under the same conditions. The main components in licorice root were analyzed through HPLC. The contents of two components in spaceflight groups were higher than that of the ground control ones. Three acute inflammatory models including xylene-induced auricular edema, carrageenan-induced paw edema and acetic acid-induced vascular permeability were utilized to compare the anti-inflammatory activity of licorice pre and post spaceflight. The licorice extract showed the significant anti-inflammation activity. After the spaceflight, the pharmacological activity of licorice got higher than that of the ground control one. All of the models gained the tendency that the spaceflight group of species Hangjinqi had the strongest activity than other groups. The research provided the scientific data for a new breeding of medicinal plant through the spaceflight and indicated that the technology of space flight may be a new effective method for the breeding and cultivation of licorice.