Ohioensins: novel benzonaphthoxanthenones from Polytrichum ohioense

Two new flavanones from Polytrichum commune Hedw

Seven flavanones, including two new compounds coupled with styryl units, communins C (1) and D (2), as well as five known compounds, were isolated from Polytrichum commune Hedw. The planar structures of all compounds were determined using extensive spectroscopic analysis. The absolute configurations of two new compounds were assigned by comparing experimental ECD with calculated ECD. The cytotoxicity of all isolates against HCT-116, BGC803, MCF7 and PANC-1 cell lines was evaluated. Communin D exhibited significant cytotoxic activity on BGC803 cells with an IC50 value of 9.3 μM.

Collagenase and Tyrosinase Inhibitory Effect of Isolated Constituents from the Moss Polytrichum formosum

Mosses from the genus Polytrichum have been shown to contain rare benzonaphthoxanthenones compounds, and many of these have been reported to have important biological activities. In this study, extracts from Polytrichum formosum were analyzed in vitro for their inhibitory properties on collagenase and tyrosinase activity, two important cosmetic target enzymes involved respectively in skin aging and pigmentation. The 70% ethanol extract showed a dose-dependent inhibitory effect against collagenase (IC₅₀ = 4.65 mg/mL). The methanol extract showed a mild inhibitory effect of 44% against tyrosinase at 5.33 mg/mL. Both extracts were investigated to find the constituents having a specific affinity to the enzyme targets collagenase and tyrosinase. The known compounds ohioensin A (1), ohioensin C (3), and communin B (4), together with nor-ohioensin D (2), a new benzonaphthoxanthenone, were isolated from P. formosum. Their structures were determined by mass spectrometry and NMR spectroscopy. Compounds 1 (IC₅₀ = 71.99 µM) and 2 (IC₅₀ = 167.33 µM) showed inhibitory activity against collagenase. Compound 1 also exhibited inhibition of 30% against tyrosinase activity at 200 µM. The binding mode of the active compounds was theoretically generated by an in-silico approach against the 3D structures of collagenase and tyrosinase. These current results present the potential application from the moss P. formosum as a new natural source of collagenase and tyrosinase inhibitors.

Two New Benzophenones From the Endohydric Moss Polytrichastrum formosum

Two new benzophenone derivatives (1 and 2), were obtained from the endohydric moss Polytrichastrum formosum. Their structures were established by 1D and 2D NMR spectroscopic and HRESIMS methods. The cytotoxicity of 1 and 2 against HCT-116, A-549, HepG2 and HeLa cell lines was evaluated, but no obvious cytotoxic activities were observed (IC50 >100 µM). Benzophenones may be characteristic components of Polytrichaceae.

Two new benzophenones from endohydric moss Polytrichum Commune

Two new benzophenones (1 and 2), were isolated from the endohydric moss Polytrichum commune. Their structures were elucidated by spectroscopic methods including extensive 2 D NMR techniques. Compound 2 is the first example of benzophenone with a rare cyclopropylacetamide from the natural resources. Compounds 1 and 2 were screened their cytotoxicity against five cancer cell lines (HCT-116, A-549, MCF-7, HepG2, A-375,), and no cytotoxic activities were observed (IC₅₀ > 100 μM).

Bryophytes: Hoard of remedies, an ethno-medicinal review

Bryophytes are the second largest group of land plants after angiosperms. There is very less knowledge available about medicinal properties of these plants. Bryophytes are popular remedy among the tribal people of different parts of the world. Tribal people use these plants to cure various ailments in their daily lives. Bryophytes are used to cure hepatic disorders, skin diseases, cardiovascular diseases, used as antipyretic, antimicrobial, wound healing and many more other ailments by different tribal communities of Africa, America, Europe, Poland, Argentina, Australia, New Zealand, Turkey, Japan, Taiwan, Pakistan, China, Nepal and different parts of South, North and Eastern India. Apart from ethno-medicinal uses some bryophytes possesses antitumor activities against different cancer cell lines and this property of bryophytes needs to be more focused in the future. Compile information about medicinal properties and anticancer properties of bryophytes is lacking till date. In the present review, the authors tried to compile all the ethno-medicinal and other related information of bryophytes and fill the knowledge lacuna in this particular field. Some published reviews are available but the information is segregated. This manuscript will help people doing research in the bryophytes.

Polytrichum commune L.ex Hedw ethyl acetate extract-triggered perturbations in intracellular Ca²⁺ homeostasis regulates mitochondrial-dependent apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Polytrichum commune L.ex Hedw (PCLH), a moss of Bryopsida, has been used as a traditional Chinese medicine and shown to possess anticancer activities. Previous studies have indicated its anti-leukemia effect but the potential mechanisms have not been fully explained.

AIM OF THE STUDY

The present study aimed to further investigate the efficacy of PCLH ethyl acetate fraction (PC-EEF) and the associated mechanisms in human leukemia cells.

MATERIALS AND METHODS

Phytochemical analysis of PC-EEF was performed by spectrophotometry and HPLC. MTT analysis and trypan blue exclusion assay were adopted to examine its cytotoxicity on a panel of leukemia cells (K562, U937, HL-60 and K562/DOX cells) and non-cancerous cells (human PBMCs). Anti-proliferative effect was monitored by colony formation assay and EdU incorporation assay. Ultrastructural alterations on K562 cell membrane surface were observed by scanning electron microscopy. Changes on plasma membrane integrity, cell membrane potential, mitochondrial membrane potential and apoptosis were analyzed by flow cytometry. Fluorescence microscope was performed to assess [Ca(2+)]i level, mitochondrial injury and cytochrome c release. Apoptosis-associated protein expression was analyzed by western blot. The role of Ca(2+) in PC-EEF-induced cell death was investigated by Ca(2+) chelating reagent BAPTA-AM.

RESULTS

PC-EEF possessed relatively high flavonoid content (about 88.84 ± 0.89%) and showed significant cytotoxicity to human leukemia cells. PC-EEF could cause obvious cell morphological deformation, membrane integrity loss and membrane depolarization. Meanwhile, PC-EEF treatment could dramatically potentiate perturbations in cellular Ca(2+) homeostasis. Subsequently, mitochondrial membrane potential (MMP) collapse, cytochrome c release and Bcl-2/Bax down-regulation were all observed. Consistent with these results, PC-EEF treatment resulted in significant activation of caspase 3, poly (ADP-ribose) polymerase (PARP) degradation and apoptosis. Moreover, PC-EEF-caused cytotoxicity, membrane damage, mitochondrial injury and apoptosis were remarkably reversed by BAPTA-AM.

CONCLUSIONS

PC-EEF damaged the membrane system and triggered Ca(2+)-dependent mitochondrial apoptosis, which may provide some new insights into its efficacy against human leukemia cells.

The ethyl acetate fraction of Polytrichum commune L.ex Hedw induced cell apoptosis via reactive oxygen species in L1210 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Polytrichum commune L.ex Hedw is a traditional Chinese herb for treatment of fever, hemostatic, uterine prolapse and especially for leukemia. Previous studies indicated its anti-leukemia effect but the potential mechanisms have not been fully explained.

AIMS OF THE STUDY

The present study was further to investigate the underlying mechanism of ethyl acetate extract of Polytrichum commune L.ex Hedw (EEF)-induced toxicity and apoptosis in L1210 cells.

MATERIALS AND METHODS

Viability, DNA damage and apoptotic protein expressions of L1210 cells were analyzed by ViaCount, comet assay and western blot, respectively. At different times after EEF treatment, Bax redistribution in L1210 cells was examined using confocal microscopy; loss of mitochondrial membrane potential (MMP) was monitored by fluorescence microscope using rhodamine 123 staining; Intracellular reactive oxygen species (ROS) generation and DNA fragmentation were measured by flow cytometry using fluorescent dye, DCFH-DA and PI, respectively.

RESULTS

EEF significantly inhibited L1210 cell survival, promoted Bax translocation onto mitochondria, stimulated caspase-9 activation and subsequent DNA damage in L1210 cells. Abundant ROS was detected in L1210 cells after EEF treatment, and the ROS scavenger NAC significantly relieved EEF-induced cell viability decline, MMP loss, and DNA fragmentation.

CONCLUSION

EEF could induce mitochondria-dependent cell apoptosis in L1210 cells, and ROS may play an important role in this action.

Anti-tumor and pro-apoptotic activity of ethanolic extract and its various fractions from Polytrichum commune L.ex Hedw in L1210 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Polytrichum commune L.ex Hedw is a traditional Chinese herb for treatment of fever, hemostatic, uterine prolapse and especially for lymphocytic leukemia, but the antitumor effect and its potential mechanism remains unclear.

AIMS OF THE STUDY

The present study was to investigate the possible anti-proliferative activity of ethanolic extract and the organic fractions from P. commune on murine leukemia L1210 cells.

MATERIALS AND METHODS

The content of ethanolic extract and its fractions was performed on HPLC analysis with gradient elution. L1210 cells were treated with different concentrations of ethanolic extract and its fractions at different time intervals. Cell viability was evaluated using MTT assay. Apoptotic cell death was monitored by nuclear condensation and confirmed by exposure of phosphatidylserine to outer leaflet of plasma membrane. Loss of mitochondrial membrane potential was analyzed by flow cytometry using rhodamine 123 staining.

RESULTS

The obtained results showed that the cell viability of L1210 cells was reduced by ethanolic extract of P. commune in a concentration-dependent manner, and the IC(50) value was about 77.22 μg/ml at 24h post treatment. The ethylacetate fraction displayed higher anti-tumor effect than that of chloroform and butanol fractions with 32.29 μg/ml (IC(50) value, 48 h). Microscopy studies revealed that ethanolic extract and ethylacetate fraction treated cells showed morphological characteristics of apoptosis such as chromatin condensation and DNA aggregation. Further, Annexin V-PE/ 7-AAD double staining showing the out leaflet of phosphatidylserine and the decline of mitochondrial membrane potential by flow cytometry confirmed that the extracts do, in fact, induce apoptosis in L1210 cells.

CONCLUSION

This is the first report on anti-tumor and pro-apoptotic effect of P. commune in cultured leukemia cells, which provides scientific basis for its usefulness as traditional medicine. Further studies are needed to confirm the precise mechanism not only the crude extract but as well the monomeric chemical substances of Polytrichum commune L.ex Hedw.

Pharmacological screening of bryophyte extracts that inhibit growth and induce abnormal phenotypes in human HeLa cancer cells

Antitumor activities of substances from natural sources apart from vascular plants and micro-organisms have been poorly investigated. Here we report on a pharmacological screening of a bryophyte extract library using a phenotypic cell-based assay revealing microtubules, centrosomes and DNA. Among the 219 moss extracts tested, we identified 41 extracts acting on cell division with various combinations of significant effects on interphasic and mitotic cells. Seven extracts were further studied using a cell viability assay, cell cycle analysis and the phenotypic assay. Three distinct pharmacological patterns were identified including two unusual phenotypes.

Constituents of the moss Polytrichum commune

Two unusual flavonones coupled with styryl units, communins A (1) and B (2), and a new benzonaphthoxanthenone, ohioensin H (3), together with 11 known compounds, were isolated from the moss Polytrichum commune. The structures of 1-3 were assigned by spectroscopic data interpretation. The new compounds were evaluated for cytotoxicity against a small panel of cancer cell lines.

Ohioensins F and G: protein tyrosine phosphatase 1B inhibitory benzonaphthoxanthenones from the Antarctic moss Polytrichastrum alpinum

Ohioensins F and G (1 and 2), two new benzonaphthoxanthenones, have been isolated from the MeOH extract of Antarctic moss Polytrichastrum alpinum by various chromatographic methods. The structures of these compounds were determined mainly by analysis of NMR spectroscopic data. The known compounds ohioensins A and C (3 and 4) were also obtained. Compounds 1-4 showed potent inhibitory activity against therapeutically targeted protein tyrosine phosphatase 1B (PTP1B). Kinetic analysis of PTP1B inhibition by ohioensin F (1) suggested that benzonaphthoxanthenones inhibited PTP1B activity in a non-competitive manner.