Ultraviolet absorbance of Sphagnum magellanicum, S. fallax and S. fuscum extracts with seasonal and species-specific variation

Abstract

Bryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species.

Salix spp. Bark Hot Water Extracts Show Antiviral, Antibacterial, and Antioxidant Activities—The Bioactive Properties of 16 Clones

“…This assay is based on single electron transfer (SET) and measures the ability of an antioxidant to reduce ferric (Fe III ) to ferrous (Fe II ) ions ( Benzie and Strain, 1996 ). The test protocol was described by Tienaho et al (2021) . In brief, a series of four dilutions of each sample, with three technical replicates, in a 96-well format were used in the assay.…”

“…The Folin-Ciocalteu method ( Singleton and Rossi, 1965 ; Singleton et al, 1999 ; Ainsworth and Gillespie, 2007 ) was used to analyze the total phenolic content, which is known to reflect antioxidant capacity. The test protocol was described by Tienaho et al (2021) . In brief, the samples were mixed with Folin-Ciocalteu reagent (Merck KGaA, Darmstadt, Germany) and 20% Na 2 CO 3 (Merck KGaA, Darmstadt, Germany), and absorbance was measured at 750 nm with gallic acid (Sigma-Aldrich Chemie GmbH, Steinheim, Germany) as a reference compound.…”

Unknown effects of daily‐scale solar activity on the plant growth: Data from 6‐year growth monitoring of Sphagnum riparium

“…Photoreceptor UVR8 is rich in tryptophan residues, giving the main spectrum sensitivity of 280–300 nm (Christie et al, 2012; Jiang et al, 2012; Wu et al, 2015). This radiation is present in negligible amounts in ecologically relevant conditions, however current research shows that plants are not only able to effectively recognize it (Robson et al, 2019), but also respond specifically to different wavelengths (Brown et al, 2009; Díaz‐Ramos et al, 2018; Mironov et al, 2020b; Tienaho et al, 2021).…”

Physiological and Biochemical Responses, and Comparative Transcriptome Profiling of Two Angelica sinensis Cultivars Under Enhanced Ultraviolet-B Radiation

“…The absorbance of flavonoids is 280∼340 nm, which is equivalent to that of sunscreen (Tienaho et al, 2021). It can act as a UV filter in plants to prevent rays from penetrating tissues, to protect the photosynthetic system from damage (McLay et al, 2020).…”