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

Paudel, Bishnu Hari; Bhattarai, Hari Datta; Koh, Hye Yeon; Lee, Sung Gu; Han, Se Jong; Lee, Hong Kum; Oh, Hyuncheol; Shin, Hyun Woung; Yim, Joung Han

doi:10.1016/j.phymed.2011.06.007

Cited by 56 publications

(45 citation statements)

References 32 publications

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“…(Zahlbr.) (Manojlovic et al, 2010), and ramalin compound (Paudel et al, 2011). Behera et al (2003Behera et al ( , 2006a) assessed the xanthine oxidase inhibitory capacity for many species of the family Graphidaceae; the ferrous ion-chelating activity was investigated in Umbilicaria cylindrica (Manojlovic et al, 2012c) and Toninia candida (Manojlovic et al, 2012b); and the tyrosinase inhibitory activity has been studied in some lichens and isolated compounds (Behera et al, 2006b;Kim & Cho, 2007;Paudel et al, 2011).…”

Section: Antioxidant Properties Of Lichensmentioning

confidence: 99%

Antioxidant potential of lichen species and their secondary metabolites. A systematic review

Fernández-Moriano¹,

Gómez-Serranillos²,

Crespo

2015

Pharmaceutical Biology

108

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Context: Pharmacological interest of lichens lies in their capacity to produce bioactive secondary metabolites, being most of them phenolic compounds with reactive hydroxyl groups that confer antioxidant potential through various mechanisms. Increasing incidence and impact of oxidative stress-related diseases (i.e., neurodegenerative disorders) has encouraged the search of new pharmacological strategies to face them. Lichens appear to be a promising source of phenolic compounds in the discovery of natural products exerting antioxidant activity.Objective: The present review thoroughly discusses the available knowledge on antioxidant properties of lichens, including both in vitro and in vivo studies and the parameters assessed so far on lichen constituents. Methods: Literature survey was performed by using as main databases PubMed, Google Scholar, Scopus, Science Direct, and Recent Literature on Lichens. We reviewed 98 highlighted research articles without date restriction. Results: Current report collects data related to antioxidant activities of more than 75 lichen species (from 18 botanical families) and 65 isolated metabolites. Much information comes from in vitro investigations, such as chemical assays evaluating radical scavenging properties, lipid peroxidation inhibition, and reducing power of lichen species and compounds; similarly, research on cellular substrates and animal models generally measures antioxidant enzymes levels and other antioxidant markers, such as glutathione levels or tissue peroxidation. Conclusion: Since consistent evidence demonstrated the contribution of oxidative stress on the development and progression of several human diseases, reviewed data suggest that some lichen compounds are worthy of further investigation and better understanding of their antioxidant and neuroprotective potentials.

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Section: Antioxidant Properties Of Lichensmentioning

confidence: 99%

Antioxidant potential of lichen species and their secondary metabolites. A systematic review

Fernández-Moriano¹,

Gómez-Serranillos²,

Crespo

2015

Pharmaceutical Biology

108

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“…Ramalin isolated from the Antarctic lichen Ramalina terebrata has been suggested to be derived by condensation of γ-glutamyl-N′-(2-hydroxyphenyl) hydrazide 14,15) (Fig. 1).…”

Section: )mentioning

confidence: 99%

“…Recently, ramalin was demonstrated to have antioxidant and anti-inflammatory activities. 15) However, the basis of this effectiveness remains unknown. As the adhesion of monocytes to the vascular cells is a critical step in the inflammatory response, we hypothesized that ramalin might inhibit the expression of adhesion molecule induced by proinflammatory cytokine, TNF-α.…”

Section: )mentioning

confidence: 99%

Ramalin inhibits VCAM-1 expression and adhesion of monocyte to vascular smooth muscle cells through MAPK and PADI4-dependent NF-kB and AP-1 pathways

Park

Yim

Lee

et al. 2015

Bioscience, Biotechnology, and Biochemistry

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Cell adhesion molecules play a critical role in inflammatory processes and atherosclerosis. In this study, we investigated the effect of ramalin, a chemical compound from the Antarctic lichen Ramalina terebrata, on vascular cell adhesion molecule-1 (VCAM-1) expression induced by TNF-α in vascular smooth muscular cells (VSMCs). Pretreatment of VSMCs with ramalin (0.1–10 μg/mL) concentration-dependently inhibited TNF-α-induced VCAM-1 expression. Additionally, ramalin inhibited THP-1 (human acute monocytic leukemia cell line) cell adhesion to TNF-α-stimulated VSMCs. Ramalin suppressed TNF-α-induced production of reactive oxygen species (ROS), PADI4 expression, and phosphorylation of p38, ERK, and JNK. Moreover, ramalin inhibited TNF-α-induced translocation of NF-κB and AP-1. Inhibition of PADI4 expression by small interfering RNA or the PADI4-specific inhibitor markedly attenuated TNF-α-induced activation of NF-κB and AP-1 and VCAM-1 expression in VSMCs. Our study provides insight into the mechanisms underlying ramalin activity and suggests that ramalin may be a potential therapeutic agent to modulate inflammation within atherosclerosis.

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Section: Lichens As Antioxidants and Tau Inhibitors Sourcementioning

confidence: 99%

“…Moreover, ramalin isolated from Antartic Ramalina terebrata presented scavenging activity and it inhibits tyrosine enzyme activity. In addition, ramalina possess a very little toxicity in keratinocyte and fibroblast [37,38].A β-orcinol depsidone, stictic acid and salazinic acid showed neuroprotective effect on U373MG cell line by diminishing ROS production. These compounds would be useful as antioxidant agents in Alzheimer´s disease [39], but it is important to notice that none of them have been tested as anti-tau inhibitors.…”

mentioning

confidence: 98%

Secondary Metabolites of Lichens as Both Anti-aggregative and Antioxidant Agents in Tauopathies

Cornejo¹,

Areche²

2017

J Clin Cell Immunol

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This commentary described our findings of parietin, an anthraquinone, isolated from Ramalina terebrata as inhibitor of tau protein. Moreover, we considered important to link tauopathies with reactive oxygen species since oligomers and fibril-forming elements are responsible for activating reactive oxygen species, which cause inflammatory response and neurodegeneration. Together, we considered important to find naturally occurring compounds that might be able to stop aggregation and reduce ROS cells damage.Keywords: Tauopathies; Secondary metabolites; Lichens; Reactive oxygen species; Inflammatory response; Neurodegeneration Tauopathies and NeurotoxicityTaoupathies are neurodegenerative disorders involving tau protein, such as progressive nuclear palsy (PSP), corticobasal degeneration (CBD), Pick´s disease among others. Tau is an unfolded protein which is found mainly in axons of mature and physiologically is involved in microtubule stability and axonal transport [1]. However, once tau becomes hyperphosphorylated it detaches from microtubule starting the aggregation process [2,3]. Pathological tau aggregates are able to activate glia cells that release cytotoxic factors, which cause pro inflammatory cytokines such as TNF-α, IL-1 and IL-6 and chemokines [4]. Tau phosphorylation is increased in both physiologically and pathological state [5], however phosphorylation is increased during development, suggesting that process is needed for neuronal plasticity [6]. Tau phosphorylation is an event highly regulated by kinases and phosphatases. Its balance is deregulated due to several stimuli such as oxidative stress [7]. Tau is able to form paired helical filaments closely related to neurofibrillary tangles [8,9]. Hyperphosphorylated tau protein is found in patients suffering with tauopathies in cerebrospinal fluid (CNS), which correlates well with hypocampal atrophy [10]. In addition, tauopathies have tau hyperphosphorylated as a hallmark; however, the degree of phosphorylation differs among them. In addition, it is important to notice that there is no single phosphorylation site associated to a particular tauopathy [5]. Moreover, tau has the propensity to form aggregates, since inside the full length protein (441 aminoacids) resides a region known as 4R (four microtubule binding domain) containing two hexapeptides 275 VQIINK 280 and 306 VQIVYK 311 both associated to β sheet formation [11]. Increased tau phosphorylation decreased its binding for microtubules. These species prone to form aggregates which are toxic in both cell and transgenic mouse model [12,13]. Despite that fact, there are evidences showing that soluble species and pre fibrils which are more related to toxicity [14]. An interesting UV raman spectroscopy study showed that at early stages, within the first hour, fibrillar aggregates possess a mixture of β-sheet and disordered content. Afterward, the UVRR spectra shows a consolidation in fibril structure, augmenting the content of β sheet [15], interesting is to remark that toxicity apparently reli...

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

Cited by 56 publications

References 32 publications

Antioxidant potential of lichen species and their secondary metabolites. A systematic review

Antioxidant potential of lichen species and their secondary metabolites. A systematic review

Ramalin inhibits VCAM-1 expression and adhesion of monocyte to vascular smooth muscle cells through MAPK and PADI4-dependent NF-kB and AP-1 pathways

Secondary Metabolites of Lichens as Both Anti-aggregative and Antioxidant Agents in Tauopathies

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