Comparison of Chemical Composition and Biological Activities of Eight Selaginella Species

Abstract

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, Selaginellaapoda contained the highest number of identified selaginellins. The majority of the compounds were identified in S. apoda, the fewest compounds in Selaginellacupressina. 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 (Selaginellamyosuroides) to 124 ± 2 (Selaginellacupressina) 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, Selaginellabiformis, 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.

Palmatine, a Bioactive Protoberberine Alkaloid Isolated from Berberis cretica, Inhibits the Growth of Human Estrogen Receptor-Positive Breast Cancer Cells and Acts Synergistically and Additively with Doxorubicin

“…For example, Oluyemisi et al, considered a SI ≤ 10 as weakly selective and a SI > 10 to be interesting in in vitro studies [51]. Meanwhile, a SI > 2 indicates selectivity and a SI = 5.5 indicates a good selectivity in another reports [52]. Moreover, Weerapreeyakul et al, proposed the a SI ≥ 3 for classifying a perspective anticancer sample [53].…”

Synthesis of Selagibenzophenone A and Its Derivatives for Evaluation of Their Antiproliferative, RORγ Inverse Agonistic, and Antimicrobial Effect**

“…They consist of more than 700 species and many of them were used in various traditional folk medicines to treat different diseases, such as jaundice, gonorrhea, acute hepatitis, asthma, dysmenorrhea, or traumatic injuries [4,5] . Extracts from Selaginella have demonstrated anticancer, anti‐inflammatory, antimicrobial, antioxidant, antiviral, and other in vitro and in vivo effects [6–8] …”

“…[4,5] Extracts from Selaginella have demonstrated anticancer, anti-inflammatory, antimicrobial, antioxidant, antiviral, and other in vitro and in vivo effects. [6][7][8] More than 100 structurally diverse polyphenolic structures have been identified in plants from this genus, including selaginellins (1, Figure 1) [9] and selaginpulvilins (2, Figure 1), [10] compounds unique for Selaginella. [11] The isolated constituents displayed a wide variety of biological activities, among which the most extensively investigated is the inhibitory effect on phosphodiesterase 4 (PDE4), an enzyme involved in the degradation of cytosolic cyclic adenosine monophosphate (cAMP).…”

The Biomimetic Synthesis of Polyarylated Fluorenes, Relevant to Selaginellaceae Polyphenols, Leading to the Spontaneous Formation of Stable Radicals

“…Plants from the genus Selaginella are living fossils, with an estimated age of 400 million years, which were used in folklore medicines throughout the world and their extracts showed a variety of biological effects [1–4] . They are a source of a plethora of structurally diverse natural products.…”

“…Plants from the genus Selaginella are living fossils, with an estimated age of 400 million years, which were used in folklore medicines throughout the world and their extracts showed a variety of biological effects. [1][2][3][4] They are a source of a plethora of structurally diverse natural products. Besides some alkaloids or flavonoids, which are however common for other species as well, a lot of attention was drawn to polyphenolic compounds, specific only for Selaginella plants.…”