Antioxidant activity of Sanionia uncinata , a polar moss species from King George Island, Antarctica

Antarctic bryophyte Sanionia uncinata (HEDW.) Loeske, Amblystegiaceae, antimicrobial, antioxidant, cytotoxic, and acetylcholinesterase activities

Sanionia uncinata, or Sickle-leaved-Hook-moss, is a cosmopolitan pleurocarpous moss composing the Antarctic Peninsulae biodiversity, primordially forming dense mats over rocks. The species was collected in 24 different spots located at King George Island and was processed to obtain 24 ethanolic extracts (ADS#) by a serial-24h-maceration, which were prospected for antimicrobial, cytotoxic, antioxidant, and acetylcholinesterase (AChE) inhibition activities by using in vitro tests. Alien material was removed from the non-sterilized plant samples before being submitted for extraction. It was observed that extracts collected in different spots showed different biological activities. Extracts ADS04(10.66±0,17mm) and ADS14(11.37±0,11mm) were active against Staphylococcus aureus, according to the diffusion in bioautography assay. They showed significant antioxidant activity and inhibited AChE; the cytotoxicity observed to the human breast cancer cells MCF-7 and MDA-MB-231 were higher than in normal cell line MCF-10A. ADS04 was 7.62 times more cytotoxic to MCF-7, and ADS14 was 2.03 times more cytotoxic to MDA-MB-231 than to MCF-10A. The extracts showed similar cytotoxicity between PC-3, a human prostate cancer cell line, and MCF-10A. Sanionia uncinata extracts are a vital potential source of biologically active compounds, particularly ADS04 and ADS14, including further prospection on eventual bryophyte's endophytic fungi.

Sphagnum moss and peat comparative study: Metal release, binding properties and antioxidant activity

Peat is the main constituent of cultivation substrates and a precious non-renewable fossil material. Peatlands provide important ecosystem services and allow the absorption and storage of carbon. Protecting peatlands helps tackle climate change and contributes to biodiversity conservation. Due to its importance, it is necessary to implement strategies to reduce the use of peat, such as replacing it with biomass-based alternative growing media constituents, such as Sphagnum moss. In this study, we compared the metal release and binding properties at two different pH, antioxidant activity, and total phenolic content of peat and Sphagnum moss from the Tierra del Fuego (TdF) region of southern Patagonia. Levels of the elements were determined by inductively coupled plasma mass spectrometry (ICP-MS), while the types and amounts of functional groups were characterized and compared using Fourier transform infrared (FTIR) spectroscopy. The total phenol level and antioxidant capacity were assessed using the Folin-Ciocalteu method and 2,2-diphenyl-1-picrylhydrazyl test. There are generally higher concentrations of leachable elements in peat than in Sphagnum moss at pH = 2, except Cs, Rb, Ti, and Zr. In contrast, at pH = 5, levels of all leached elements are highest in Sphagnum moss. Sphagnum moss shows a higher metal adsorption capacity than peat, except for Be, Mn, Tl, and Zn. Finally, the results showed that both matrices contained similar total phenolic contents: 0.018 ± 0.011 mg gallic acid equivalent (GAE) per gram dry sample for peat and 0.020 ± 0.007 mg GAE g-1 for Sphagnum moss. Instead, Sphagnum moss extracts showed a significantly higher antioxidant activity [0.026 ± 0.028 mmol Trolox equivalents (TE) g-1] than that estimated in peat (0.009 ± 0.005 mmol TE g-1). Humic acids, carboxylic acids, and phenolic and lignin groups were identified as the functional groups that mainly determined the antioxidant activity of the Sphagnum moss compared to peat. The present study resulted in an advancement of knowledge of these materials for more thoughtful future use and possible replacements.

Protection against UV-induced oxidative stress and DNA damage by Amazon moss extracts

Amazon mosses, such as Holomitriopsis laevifolia and Leucobryum sp. are naturally exposed to high levels of solar ultraviolet (UV) radiation. Theoretically, under environmental stress conditions these mosses have developed protective chemical and metabolic strategies against UV damage, by way of biosynthesis of secondary metabolites, such as flavonoids. The present paper aimed to evaluate the free-radical scavenging activity, and the photoprotective, mutagenic and photomutagenic potencies of the methanolic (ME), aqueous (AE), hydroalcoholic (HE), ethanolic (EE) extracts of H. laevifolia and Leucobryum sp. The phenolic contents were evaluated by spectrophotometry and by High-Performance Liquid Chromatography (HPLC). The present findings showed that the AE and HE of H. laevifolia and the AE of Leucobryum sp. presented the highest phenolic contents. The HPLC analysis indicated the presence mainly of phenolic and cinnamic acids, flavonols, flavones and flavanones. The AE and EE of H. laevifolia and the AE and HE of Leucobryum sp. efficiently scavenged the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical. All extracts showed significant values of in vitro Sun Protection Factor alone, and HE of Leucobryum sp. showed a synergistic effect in association with benzophenone-3. None of the extracts induced mutagenicity in the auxotrophic strains for histidine of Salmonella typhimurium, and photomutagenicity of the TA102 and TA104 strains was not detected after exposure to UV-A radiation. Besides, all extracts showed photoprotective activity against UV-A radiation for the TA104 strain, including synergistic protection in association with BP-3. Thus, the constituents in H. Laevifolia and Leucobryum sp. could be good candidates for cosmetic and dermatological applications, particularly in association with synthetic UV filters, since the concentration of the filters in the final product could be reduced.

Photoprotective and toxicological activities of extracts from the Antarctic moss Sanionia uncinata

Background:

The Antarctic moss Sanionia uncinata (Hedw.) Loeske has shown high ultraviolet (UV)-absorbers content after exposition to high levels of UV-B radiation and can be an important source of antioxidants.

Objective:

The aim was to investigate photoprotection and mutagenicity by the aqueous extract (AE) and hydroethanolic extract (HE) from the Antarctic moss S. uncinata.

Materials and Methods:

Photoprotective activities were determined through survival curves of Escherichia coli strains, after UV irradiation in an aqueous solution of thymine and in vitro sun protection factor (SPF). The Salmonella/microsome assays were applied to assess the mutagenicity.

Results:

Both extracts induced photoprotection against UV-C radiation. The AE showed a higher protection than the hydroethanolic one against UV-induced thymine dimerization. The SPFs were low in both extracts. In association to benzophenone-3 a significant increase in the SPF was detected for the AE, and a significant decrease was induced by the HE. No mutagenicity was found in the both extracts. Furthermore, it was observed absence of cytotoxicity.

Conclusion:

Water-extractable compounds seem to contribute on photoprotection of this Antarctic moss.

Estimation of antioxidant, antimicrobial activity and brine shrimp toxicity of plants collected from Oymyakon region of the Republic of Sakha (Yakutia), Russia

BACKGROUND

Several plants are reported to be produced various biological active compounds. Lichens from the extreme environments such as high altitude, high UV, drought and cold are believed to be synthesized unique types of secondary metabolites than the other one. Several human pathogenic bacteria and fungi have been muted into drug resistant strains. Various synthetic antioxidant compounds have posed carcinogenic effects. This phenomenon needs further research for new effective drugs of natural origin. This manuscript aimed to screen new source of biological active compounds from plants of subarctic origin.

RESULTS

A total of 114 plant species, including 80 species of higher plants, 19 species of lichens and 15 species of mosses, were collected from Oymyakon region of the Republic of Sakha (Yakutia), Russia (63˚20'N, 141˚42'E-63˚15'N, 142˚27'E). Antimicrobial, DPPH free radical scavenging and brine shrimp (Artemia salina) toxicity of all crude extract were evaluated. The obtained result was analyzed and compared with commercial standards. A total of 28 species of higher plants showed very strong antioxidant activity (DPPH IC50, 0.45-5.0 μg/mL), 13 species showed strong activity (DPPH IC50, 5-10 μg/mL), 22 species showed moderate antioxidant activity (DPPH IC50,10-20 μg/mL) and 17 species showed weak antioxidant activity (DPPH IC50 more than 20 μg/mL). Similarly, 3 species of lichen showed strong antioxidant activity, one species showed moderate and 15 species showed weak DPPH reducing activity. In addition, 4 species of mosses showed moderate antioxidant activity and 11 species showed weak antioxidant activity. Similarly, extracts of 51 species of higher plants showed antimicrobial (AM) activity against Staphylococcus aureus and 2 species showed AM activity against Candida albicans. Similarly, 11 species of lichen showed AM activity against S. aureus and 3 species showed AM activity against Escherichia coli. One species of moss showed AM activity against S. aureus. And finally, one species of higher plant Rheum compactum and one species of lichen Flavocetraria cucullata showed the toxicity against Brine shrimp larvae in 100 μg/mL of concentration.

CONCLUSION

The experimental results showed that subarctic plant species could be potential sources of various biologically active natural compounds.

Potential antioxidant activity of the moss Bryum moravicum

A limited number of mosses has ever been studied regarding antioxidant activity among which only a few are European species. As a part of our ongoing screening of new promising bryophyte resources of natural antioxidants, a relevant biological activity investigation was conducted on the moss Bryum moravicum Podp. (Bryaceae) collected in Germany. The antioxidant activity of an aqueous extract of the species was evaluated in vitro by analysing its ABTS [2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)] cation scavenging activity and total phenolic content. The study led to the detection of a moderate antioxidant activity: 1 mg of the extract was equivalent to 84.56 ± 7.93 µg of ascorbic acid. The total phenolic content in 1 mg of the extract was equivalent to 356.44 ± 9.56 µg of ferulic acid used as a standard. These results have indicated for the first time potential importance of B. moravicum in searching for novel antioxidant agents.

Ramalin, a novel nontoxic antioxidant compound from the Antarctic lichen Ramalina terebrata

Ramalin (γ-glutamyl-N'-(2-hydroxyphenyl)hydrazide), a novel compound, was isolated from the methanol-water extract of the Antarctic lichen Ramalina terebrata by several chromatographic methods. The molecular structure of ramalin was determined by spectroscopic analysis. The experimental data showed that ramalin was five times more potent than commercial butylated hydroxyanisole (BHA) in scavenging 1-diphenyl-2-picryl-hydazil (DPPH) free radicals, 27 times more potent in scavenging 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid free radicals (ABTS(+)) than the vitamin E analogue, trolox, and 2.5 times more potent than BHT in reducing Fe(3+) to Fe(2+) ions. Similarly, ramalin was 1.2 times more potent than ascorbic acid in scavenging superoxide radicals and 1.25 times more potent than commercial kojic acid in inhibiting tyrosinase enzyme activity, which ultimately leads to whitening of skin cells. Ramalin showed no or very little cytotoxicity in human keratinocyte and fibroblast cells at its antioxidant concentration. Furthermore, ramalin was assessed to determine its antioxidant activity in vivo. One microgram per milliliter ramalin significantly reduced the released nitric oxide (NO) and 0.125 μg/ml ramalin reduced the produced hydrogen peroxide (H(2)O(2)) in LPS (lipopolysaccharide)-stimulated murine macrophage Raw264.7 cells. Considering all the data together, ramalin can be a strong therapeutic candidate for controlling oxidative stress in cells.

Effects of Sanionia uncinata extracts in protecting against and inducing DNA cleavage by reactive oxygen species

When mosses are exposed to increased quantities of ultraviolet (UV) radiation, they produce more secondary metabolites. Antarctica moss Sanionia uncinata (Hedw.) Loeske has presented high carotenoid contents in response to an increase in UVB radiation. This moss has been recommended as a potential source of antioxidants. In the present work, the protective and enhancing effects of aqueous (AE) and hydroalcoholic (HE) extracts of S. uncinata on the cleavage of supercoiled DNA were evaluated through topological modifications, quantified by densitometry after agarose gel electrophoresis. Total phenolic contents reached 5.89 mg/g. Our data demonstrated that the extract does not induce DNA cleavage. Furthermore, both extracts showed antioxidant activity that protected the DNA against cleavage induced by (i) O(2)(•-), 89% (AE) and 94% (HE) (P<0.05), and (ii) (.)OH, 17% (AE) and 18% (HE). However, the extracts intensified cleavage induced by Fenton-like reactions: (i) Cu(2+)/H(2)O(2), 94% (AE) and 100% (HE) (P<0.05), and (ii) SnCl(2), 62% (AE) and 56% (HE). DNA damages seem to follow different ways: (i) in the presence of Fenton-like reactions could be via reactive oxygen species generation and (ii) with HE/Cu(2+) could have also been triggered by other mechanisms.