Protection of immunocompromised mice from fungal infection with a thymus growth-stimulatory component fromSelaginella involvens, a fern

Comparison of Chemical Composition and Biological Activities of Eight Selaginella Species

Selaginella P. Beauv. is a group of vascular plants in the family Selaginellaceae Willk., found worldwide and numbering more than 700 species, with some used as foods and medicines. The aim of this paper was to compare methanolic (MeOH) and dichloromethane (DCM) extracts of eight Selaginella species on the basis of their composition and biological activities. Six of these Selaginella species are underinvestigated. Using ultra-high performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) analysis, we identified a total of 193 compounds among the tested Selaginella species, with flavonoids predominating. MeOH extracts recovered more constituents that were detected, including selaginellins, the occurrence of which is only typical for this plant genus. Of all the tested species, Selaginella apoda contained the highest number of identified selaginellins. The majority of the compounds were identified in S. apoda, the fewest compounds in Selaginella cupressina. All the tested species demonstrated antioxidant activity using oxygen radical absorption capacity (ORAC) assay, which showed that MeOH extracts had higher antioxidant capacity, with the half maximal effective concentration (EC₅₀) ranging from 12 ± 1 (Selaginella myosuroides) to 124 ± 2 (Selaginella cupressina) mg/L. The antioxidant capacity was presumed to be correlated with the content of flavonoids, (neo)lignans, and selaginellins. Inhibition of acetylcholinesterase (AChE) was mostly discerned in DCM extracts and was only exhibited in S. myosuroides, S. cupressina, Selaginella biformis, and S. apoda extracts with the half maximal inhibitory concentration (IC₅₀) in the range of 19 ± 3 to 62 ± 1 mg/L. Substantial cytotoxicity against cancer cell lines was demonstrated by the MeOH extract of S. apoda, where the ratio of the IC₅₀ HEK (human embryonic kidney) to IC₅₀ HepG2 (hepatocellular carcinoma) was 7.9 ± 0.2. MeOH extracts inhibited the production of nitrate oxide and cytokines in a dose-dependent manner. Notably, S. biformis halved the production of NO, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 at the following concentrations: 105 ± 9, 11 ± 1, and 10 ± 1 mg/L, respectively. Our data confirmed that extracts from Selaginella species exhibited cytotoxicity against cancer cell lines and AChE inhibition. The activity observed in S. apoda was the most promising and is worth further exploration.

Vascular Epiphytic Medicinal Plants as Sources of Therapeutic Agents: Their Ethnopharmacological Uses, Chemical Composition, and Biological Activities

This is an extensive review on epiphytic plants that have been used traditionally as medicines. It provides information on 185 epiphytes and their traditional medicinal uses, regions where Indigenous people use the plants, parts of the plants used as medicines and their preparation, and their reported phytochemical properties and pharmacological properties aligned with their traditional uses. These epiphytic medicinal plants are able to produce a range of secondary metabolites, including alkaloids, and a total of 842 phytochemicals have been identified to date. As many as 71 epiphytic medicinal plants were studied for their biological activities, showing promising pharmacological activities, including as anti-inflammatory, antimicrobial, and anticancer agents. There are several species that were not investigated for their activities and are worthy of exploration. These epipythes have the potential to furnish drug lead compounds, especially for treating cancers, and thus warrant indepth investigations.

Acute Thymic Involution and Mechanisms for Recovery

Acute thymic involution (ATI) is usually regarded as a virulence trait. It is caused by several infectious agents (bacteria, viruses, parasites, fungi) and other factors, including stress, pregnancy, malnutrition and chemotherapy. However, the complex mechanisms that operate during ATI differ substantially from each other depending on the causative agent. For instance, a transient reduction in the size and weight of the thymus and depletion of populations of T cell subsets are hallmarks of ATI in many cases, whereas severe disruption of the anatomical structure of the organ is also associated with some factors, including fungal, parasitic and viral infections. However, growing evidence shows that ATI may be therapeutically halted or reversed. In this review, we highlight the current progress in this field with respect to numerous pathological factors and discuss the possible mechanisms. Moreover, these new observations also show that ATI can be mechanistically reversed.

Application of the ITS2 Region for Barcoding Medicinal Plants of Selaginellaceae in Pteridophyta

BACKGROUND

Selaginellaceae is a family of nonseed plants with special evolutionary significance. Plants of the family Selaginellaceae are similarly shaped and easily confused, complicating identification via traditional methods. This study explored, for the first time, the use of the DNA barcode ITS2 to identify medicinal plants of the Selaginellaceae family.

METHODOLOGY/PRINCIPAL FINDINGS

In our study, 103 samples were collected from the main distribution areas in China; these samples represented 34 species and contained almost all of the medicinal plants of Selaginellaceae. The ITS2 region of the genome was amplified from these samples and sequenced using universal primers and reaction conditions. The success rates of the PCR amplification and sequencing were 100%. There was significant divergence between the interspecific and intraspecific genetic distances of the ITS2 regions, while the presence of a barcoding gap was obvious. Using the BLAST1 and nearest distance methods, our results proved that the ITS2 regions could successfully identify the species of all Selaginellaceae samples examined. In addition, the secondary structures of ITS2 in the helical regions displayed clear differences in stem loop number, size, position, and screw angle among the medicinal plants of Selaginellaceae. Furthermore, cluster analysis using the ITS2 barcode supported the relationship between the species of Selaginellaceae established by traditional morphological methods.

CONCLUSION

The ITS2 barcode can effectively identify medicinal plants of Selaginellaceae. The results provide a scientific basis for the precise identification of plants of the family Selaginellaceae and the reasonable development of these resources. This study may broaden the application of DNA barcoding in the medicinal plant field and benefit phylogenetic investigations.

Anti-diabetic activity of active fractions of Stereospermum tetragonum DC and isolation of active principles

OBJECTIVES

To identify the active principles, determine the anti-diabetes activity of fraction of Stereospermum tetragonum root.

MATERIALS AND METHODS

The efficacy was evaluated in streptozotocin induced type 2 diabetic rats and the anti-hyperglycemic activity was studied by glucose tolerance test. The major active compounds were isolated by solvent fractionation and chromatographic techniques and characterized with spectral data.

RESULTS

The active fraction of S. tetragonum showed presence of anti-diabetes mellitus activity in type-2 diabetic rats. It did not significantly influence insulin release from cultured islets. Two active principles (active at 2 mg/kg dose) were isolated and characterized with spectral data. One of them was identified as an iridoid type glycoside and the other one was a lapachol like compound (derivative of naphthoquinone).

CONCLUSIONS

Two active principles from the anti-diabetes fraction of S. tetragonum root were isolated and identified as an iridoid glycoside and a naphthoquinone derivative.