Metabolic effects of calagualine, an antitumoral saponine of Polypodium leucotomos

Antioxidant and photoprotective potential of Polypodium leucotomos

In recent years, Polypodium leucotomos has emerged with a great interest for having medicinal and therapeutic potential. It is producing very promising results due to the presence of antioxidant and photoprotective properties. Electronic libraries and databases, including Scopus, PubMed, Google Scholar, Science Direct, and Web of Science were searched to identify relevant studies; 79 publications contributed to this review regarding Polypodium leucotomos botanical aspects, chemical composition, antioxidant and photoprotective activity. It is used in complementary and alternative therapies with various pharmaceutical dosage forms (systemic or topical). Thanks to the composition of phytochemical constituents present in the leaves and rhizomes which confer antioxidant and photoprotective activity that has clinical therapeutic potential to be used as systemic and topical sunscreen of natural origin for the prevention of different types of skin diseases caused by harmful ultraviolet A and ultraviolet B radiations. However, more studies are needed in the future to test the ability and enhance the capacity of sunscreen and sunblock in cosmetic formulations. To conclude, it is recommended to carry out scientific studies based on different analytical methods to evaluate the phytoconstituents potential and to develop stable pharmaceutical formulations according to the skin phototype.

Combination-Based Strategies for the Treatment of Actinic Keratoses with Photodynamic Therapy: An Evidence-Based Review

Photodynamic therapy (PDT) is a highly effective and widely adopted treatment strategy for many skin diseases, particularly for multiple actinic keratoses (AKs). However, PDT is ineffective in some cases, especially if AKs occur in the acral part of the body. Several methods to improve the efficacy of PDT without significantly increasing the risks of side effects have been proposed. In this study, we reviewed the combination-based PDT treatments described in the literature for treating AKs; both post-treatment and pretreatment were considered including topical (i.e., diclofenac, imiquimod, adapalene, 5-fluorouracil, and calcitriol), systemic (i.e., acitretin, methotrexate, and polypodium leucotomos), and mechanical–physical (i.e., radiofrequency, thermomechanical fractional injury, microneedling, microdermabrasion, and laser) treatment strategies. Topical pretreatments with imiquimod, adapalene, 5-fluorouracil, and calcipotriol were more successful than PDT alone in treating AKs, while the effect of diclofenac gel was less clear. Both mechanical laser treatment with CO2 and Er:YAG (Erbium:Yttrium–Aluminum–Garnet) as well as systemic treatment with Polypodium leucotomos were also effective. Different approaches were relatively more effective in particular situations such as in immunosuppressed patients, AKs in the extremities, or thicker AKs. Conclusions: Several studies showed that a combination-based approach enhanced the effectiveness of PDT. However, more studies are needed to further understand the effectiveness of combination therapy in clinical practice and to investigate the role of acitretin, methotrexate, vitamin D, thermomechanical fractional injury, and microdermabrasion in humans.

Immunomodulatory effect of Polypodium leucotomos (Anapsos) in child palatine tonsil model

BACKGROUND

Recurrent tonsillitis might reduce the immunological capability of fighting against the infection of tonsil tissue. Polypodium leucotomos (Anapsos) immunomodulating effect has been subject of research in the last years. The aim of this research is to test the in vitro immunomodulating capacity of Anapsos in a child palatine tonsil explants model.

METHODS

Palatine tonsils explants of children undergoing amigdalectomy were stimulated with mononuclear cells obtained from their own blood by density gradient centrifugation. Some were then treated with Anapsos while others rest untreated. Cytokines were measured by ELISA, immune cells activation was measured by flow cytometry and activation of immunoglobulins was appreciated by indirect immunofluorescence in tonsils tissue.

RESULTS

Anapsos activates Natural Killers cells. It increases IL-2 and IFN-γ levels by the activation of Th2 lymphocytes, and IL-10, by the Th1 lymphocytes. Anapsos also increases immunoglobulins IgM, IgD and IgG4 by B-lymphocyte activation in tonsils tissue.

CONCLUSION

Anapsos has an immunomodulating effect, both in humoral and cellular responses, which might benefit children suffering of recurrent tonsillitis as it could enhance their immune system. This effect might reduce the number of episodes suffered and therefore the number of children undergoing surgery.

Phytochemicals from fern species: potential for medicine applications

Ferns are an important phytogenetic bridge between lower and higher plants. Historically they have been used in many ways by humans, including as ornamental plants, domestic utensils, foods, and in handicrafts. In addition, they have found uses as medicinal herbs. Ferns produce a wide array of secondary metabolites endowed with different bioactivities that could potentially be useful in the treatment of many diseases. However, there is currently relatively little information in the literature on the phytochemicals present in ferns and their pharmacological applications, and the most recent review of the literature on the occurrence, chemotaxonomy and physiological activity of fern secondary metabolites was published over 20 years ago, by Soeder (Bot Rev 51:442-536, 1985). Here, we provide an updated review of this field, covering recent findings concerning the bioactive phytochemicals and pharmacology of fern species.

Primary and Secondary Chemoprevention of Malignant Melanoma

The incidence of malignant melanoma (MM) continues to rise in the United States. While sun protection and full body skin examinations remain the mainstay of preventative care, chemoprevention of the deadly disease has become an increasingly popular field of study. In this focused review, we discuss current findings and analyze the risks and benefits of various agents investigated for the primary and secondary chemoprevention of MM. Such agents include topical retinoids, vitamins, and supplements, Polypodium leucotomas extracts, non-steroidal anti-inflammatory agents (NSAIDs), statins, sunscreens, and field therapy with topical imiquimod for primary and secondary chemoprevention. We further identify a need for expanded high quality human research on the topic.

Benefits of oral Polypodium Leucotomos extract in MM high-risk patients

BACKGROUND

UV radiation and the presence of melanocytic nevi are the main risk factors of sporadic melanoma (MM). Protection of skin by an oral photoprotective agent would have substantial benefits.

OBJECTIVE

We investigated the possible role of an oral Polypodium leucotomos (PL) extract to improve systemic photoprotection in patients at risk of skin cancer analyzing the ability to decrease UV-induced erythema. We also studied the interaction among MC1R polymorphisms and CDKN2A status with the minimal erythematous dose (MED) and their influence in the response after oral PL.

METHODS

A total of 61 patients (25 with familial and/or multiple MM, 20 with sporadic MM and 16 with atypical mole syndrome without history of MM) were exposed to varying doses of artificial UVB radiation without and after oral administration of a total dose of 1080 mg of PL.

RESULTS

Oral PL treatment significantly increased the MED mean in all group patients (0.123 to 0.161 J/cm(2) , p<0.05). Although not significant, we noticed a stronger effect of PL on the MED of patients with familial MM compared to those with MM (U=273, p=0.06). Among the patients with familial MM, those exhibiting a mutated CDKN2A and/or polymorphisms in MC1R had the bigger differences in response to treatment with PL.

LIMITATIONS

Reduced number of patients. No control population.

CONCLUSIONS

Administration of PL leads to a significant reduction of sensitivity to UVR (p<0.05) in all patients. Dark-eye patients and patients with higher UVR sensibility (lower basal MED) would be the most benefited from oral PL treatment.

Fernblock, a nutriceutical with photoprotective properties and potential preventive agent for skin photoaging and photoinduced skin cancers

Many phytochemicals are endowed with photoprotective properties, i.e., the capability to prevent the harmful effects of excessive exposure to ultraviolet (UV) light. These effects include photoaging and skin cancer, and immunosuppression. Photoprotection is endowed through two major modes of action: UV absorption or reflection/scattering; and tissue repair post-exposure. We and others have uncovered the photoprotective properties of an extract of the fern Polypodium leucotomos (commercial name Fernblock). Fernblock is an all-natural antioxidant extract, administered both topically (on the skin) or orally. It inhibits generation of reactive oxygen species (ROS) production induced by UV including superoxide anion. It also prevents damage to the DNA, inhibits UV-induced AP1 and NF-κB, and protects endogenous skin natural antioxidant systems, i.e., CAT, GSH, and GSSR. Its photoprotective effects at a cellular level include a marked decrease of UV-mediated cellular apoptosis and necrosis and a profound inhibition of extracellular matrix remodeling. These molecular and cellular effects translate into long-term inhibition of photoaging and carcinogenesis that, together with its lack of toxicity, postulate its use as a novel-generation photoprotective nutriceutical of phytochemical origin.

Beneficial regulation of matrixmetalloproteinases and their inhibitors, fibrillar collagens and transforming growth factor-beta by Polypodium leucotomos, directly or in dermal fibroblasts, ultraviolet radiated fibroblasts, and melanoma cells

The extracellular matrix (ECM) that gives tissue its structural integrity is remodeled in skin aging/photoaging and cancer via the increased expression/activities of matrixmetalloproteinases (MMP), inhibition of the tissue inhibitors of matrix metalloproteinases (TIMP), or inhibition of collagen synthesis. Transforming growth factor-beta (TGF-beta), a predominant regulator of the ECM, is inhibited in aging/photoaging and stimulated in carcinogenesis. P. leucotomos (fern) extract has potential to counteract these alterations via its antioxidant, anti-inflammatory and photoprotective properties. The goal of this research was to determine the efficacy of P. leucotomos to (a) directly inhibit MMP-1, 2, 3, and 9 activities, (b) inhibit MMP-2, and stimulate TIMPs, fibrillar collagens and TGF-beta in non-irradiated or ultraviolet (UV) radiated fibroblasts, and (c) inhibit MMPs and TGF-beta, and stimulate TIMPs in melanoma cells. To this purpose, we examined the direct effect of P. leucotomos (0-1%) on MMPs' activities, and its effects on the expression (protein and/or transcription levels) of (1) MMPs and TIMPs in dermal fibroblasts, and melanoma cells, (2) TGF-beta in non-irradiated, UVA (2.5 J/cm2) or UVB (2.5 mJ/cm2) irradiated fibroblasts, and melanoma cells, and (3) types I, III, and V collagen in non-irradiated or UV irradiated fibroblasts. P. leucotomos directly inhibited the activities of MMPs as well as the expression of MMPs in fibroblasts, and melanoma cells while stimulating the expression of TIMPs in these cells. P. leucotomos stimulated types I, III, and V collagen in non-irradiated fibroblasts, and types I and V collagen in UV radiated fibroblasts. P. leucotomos had predominant stimulatory effects on TGF-beta expression in non-irradiated or UV radiated fibroblasts, and inhibited TGF-beta expression in melanoma cells. The effects of P. leucotomos were largely similar to that of ascorbic acid. P. leucotomos demonstrated dual protective effects on the ECM via its inhibition of the ECM proteolytic enzymes and the stimulation of the structural ECM collagens. The effects of P. leucotomos on fibroblasts and melanoma cells may be partly via its cell-specific regulation of TGF-beta expression and partly via its antioxidant property. The intake or topical application of P. leucotomos may be beneficial to skin health, in aging and cancer prevention or treatment.

Treatment of vitiligo vulgaris with narrow-band UVB and oral Polypodium leucotomos extract: a randomized double-blind placebo-controlled study

BACKGROUND

The first choice treatment for vitiligo vulgaris is narrow-band UVB (NB-UVB), but no satisfactory treatment exists.

OBJECTIVES

To investigate if Polypodium leucotomos, an antioxidative and immunomodulatory plant extract, improves NB-UVB-induced repigmentation.

METHODS

Fifty patients with vitiligo vulgaris randomly received 250 mg oral P. leucotomos or placebo three times daily, combined with NB-UVB twice weekly for 25-26 weeks.

RESULTS

Repigmentation was higher in the P. leucotomos group vs. placebo in the head and neck area (44% vs. 27%, P = 0.06). Small repigmentation increases (P = n.s.) were observed for the trunk (6% increased repigmentation), extremities (4%), and hands and feet (5%) in the P. leucotomos group vs. placebo. Patients attending more than 80% of required NB-UVB sessions showed increased repigmentation in the head and neck area in the P. leucotomos group vs. placebo (50% vs. 19%, P < 0.002); no significant differences were seen in the other body areas. Patients with skin types 2 and 3 showed more repigmentation in the head and neck area in the P. leucotomos group vs. placebo (47% vs. 21%, P = 0.01), and no significant differences were seen in the other body areas. No conclusions could be drawn on skin types 4 and 5 due to low patient numbers.

CONCLUSION

There is a clear trend towards an increase in repigmentation of vitiligo vulgaris affecting the head and neck area when NB-UVB phototherapy is combined with oral P. leucotomos. This effect may be more pronounced in light skin types.

Photoprotective activity of oral polypodium leucotomos extract in 25 patients with idiopathic photodermatoses

BACKGROUND

The incidences of idiopathic photodermatoses (IP) are increasing and the available therapeutic methods are often inadequate.

AIM

To evaluate whether, in subjects affected by IP not responding to the usual available therapies, the oral administration of an extract of Polypodium leucotomos (PL) could provide an effective photoprotective activity.

METHODS

26 patients with polymorphic light eruption and two with solar urticaria were recruited to enter the study. The protocol excluded the use of ultraviolet protection filters or other drugs that could in some way interfere with exposure to light. All patients exposed themselves to sunlight while consuming 480 mg/day of PL orally. The response of the skin to sunlight exposure of 25 evaluable patients was compared with that occurring previously without administration of PL.

RESULTS

With PL, we observed a relevant and statistically significant reduction of skin reaction and subjective symptoms. The tolerance of the drug has been excellent.

CONCLUSION

PL extract administration has shown to be an effective and safe method, leading to a significant protection of skin in IP.

Oral Polypodium leucotomos extract decreases ultraviolet-induced damage of human skin

BACKGROUND

UV radiation induces damage to human skin. Protection of skin by an oral photoprotective agent would have substantial benefits. Objective We investigated the photoprotective effect of oral administration of an extract of the natural antioxidant Polypodium leucotomos (PL).

METHODS

A total of 9 healthy participants of skin types II to III were exposed to varying doses of artificial UV radiation without and after oral administration of PL (7.5 mg/kg). At 24 hours after exposure the erythema reaction was assessed and paired biopsy specimens were obtained from PL-treated and untreated skin.

RESULTS

A significant decrease in erythema was found in PL-treated skin (P < .01). Histologically, PL-treated biopsy specimens showed less sunburn cells (P < .05), cyclobutane pyrimidine dimers (P < .001), proliferating epidermal cells (P < .001), and dermal mast cell infiltration (P < .05). A trend toward Langerhans cell preservation was seen.

CONCLUSION

Oral administration of PL is an effective systemic chemophotoprotective agent leading to significant protection of skin against UV radiation.

Orally administered polypodium leucotomos extract decreases psoralen-UVA–induced phototoxicity, pigmentation, and damage of human skin

BACKGROUND

The use of psoralen-UVA (PUVA) in patients of skin phototype I to II is limited by side effects of acute phototoxicity and possible long-term carcinogenesis.

OBJECTIVE

We sought to assess oral Polypodium leucotomos (PL) extract in decreasing PUVA-induced phototoxicity of human skin on a clinical and histologic level.

METHODS

A total of 10 healthy patients with skin phototypes II to III were exposed to PUVA alone (using 0.6 mg/kg oral 8-methoxypsoralen) and to PUVA with 7.5 mg/kg of oral PL.

RESULTS

Clinically, phototoxicity was always lower in PL-treated skin after 48 to 72 hours (P<.005), and pigmentation was also reduced 4 months later. Histologically, PL-treated skin showed a significant numeric reduction of sunburn cells (P=.05), preservation of Langerhans cells (P< or =.01), decrease of tryptase-positive mast cell infiltration (P<.05), and decrease of vasodilation (P< or =.01). No differences were found in Ki-67+ proliferating cells.

CONCLUSIONS

PL is an effective chemophotoprotector against PUVA-induced skin phototoxicity and leads to substantial benefits of skin protection against damaging effects of PUVA as evidenced by histology.

Calagualine inhibits nuclear transcription factors-kappaB activated by various inflammatory and tumor promoting agents

Calagualine derived from the fern of the genus Polypodium, commonly called calaguala, has had clinically documented medicinal uses in South America and Spain and been shown to block tumor metastasis, proliferation, and inflammation, all known to require the activation of nuclear transcription factor-kappaB (NF-kappaB). Therefore, we investigated the effect of calagualine on NF-kappaB activation induced by various inflammatory and tumor promoting agents. Calagualine blocked tumor necrosis factor (TNF)-induced activation of NF-kappaB through inhibition of phosphorylation and degradation of IkappaBalpha, an inhibitor of NF-kappaB. The effects of calagualine were not cell type-specific, as it blocked TNF-induced NF-kappaB activation in a variety of cells. NF-kappaB-dependent reporter gene transcription activated by TNF was also suppressed by calagualine. The TNF-induced NF-kappaB activation cascade involving TNFR1-TNF receptor-associated death domain-TNF receptor-associated factor 2 (TRAF2)-NF-kappaB-inducing kinase (NIK)-IkappaBalpha kinase was interrupted at the TRAF2 and NIK sites by calagualine, which would account for its suppression of NF-kappaB reporter gene expression. Calagualine blocked NF-kappaB activation induced by phorbol ester and lipopolysaccharide. Overall our results indicate that calagualine inhibits activation of NF-kappaB and this may provide a molecular basis for calagualine's ability to suppress inflammation and tumorigenesis.

An extract of Polypodium leucotomos appears to minimize certain photoaging changes in a hairless albino mouse animal model. A pilot study

Chronic ultraviolet B (UVB) exposure of human or murine skin is known to induce cutaneous photoaging and enhanced carcinogenic risk. An extract of Polypodium leucotomos (PL), a tropical fern plant, has been known to exhibit interesting antioxidant and photoprotective properties against acute exposure to ultraviolet radiation. The objective of this preliminary (or pilot) study was to determine the photoprotective role of topically applied Polypodium leucotomos extract in the prevention or amelioration of cutaneous changes of photoaging in hairless mice. PL-treated mice showed significant reduction of skinfold thickness than those observed in PL-untreated controls. Additionally, PL-treated mice showed a significantly lower degree of histologic parameters of photoaging damage, including dermal elastosis, compared with positive control mice. Interestingly, PL treatment also showed reduction in the number of mice showing skin tumors at 8 weeks after the cessation of the UVB exposure protocol. The results of this preliminary study illustrate that PL treatment helped to ameliorate and to partially inhibit some of the histologic damage associated with photoaging of skin and appeared to contribute to a decrease in the prevalence of UVB-induced skin tumors in mice.

Topical or oral administration with an extract of Polypodium leucotomos prevents acute sunburn and psoralen-induced phototoxic reactions as well as depletion of Langerhans cells in human skin

Sunburn, immune suppression, photoaging, and skin cancers result from uncontrolled overexposure of human skin to solar ultraviolet radiation (UVR). Preventive measures, including photoprotection, are helpful and can be achieved by topical sunscreening agents. Polypodium leucotomos (PL) has been used for the treatment of inflammatory diseases and has shown some in vitro and in vivo inmunomodulating properties. Its beneficial photoprotective effects in the treatment of vitiligo and its antioxidant properties encouraged us to evaluate in vivo the potentially useful photoprotective property of natural extract of PL after topical application or oral ingestion. Twenty-one healthy volunteers [either untreated or treated with oral psoralens (8-MOP or 5-MOP)] were enrolled in this study and exposed to solar radiation for evaluation of the following clinical parameters: immediate pigment darkening (IPD), minimal erythema dose (MED), minimal melanogenic dose (MMD), and minimal phototoxic dose (MPD) before and after topical or oral administration of PL. Immunohistochemical assessment of CD1a-expressing epidermal cells were also performed. PL was found to be photoprotective after topical application as well as oral administration. PL increased UV dose required for IPD (P < 0.01), MED (P < 0.001) and MPD (P < 0.001). After oral administration of PL, MED increased 2.8 +/- 0.59 times and MPD increased 2.75 +/- 0.5 and 6.8 +/- 1.3 times depending upon the type of psoralen used. Immunohistochemical study revealed photoprotection of Langherhans cells by oral as well as topical PL. The observed photoprotective activities of oral or topical PL reveal a new avenue in examining the potentially useful field of systemic photoprotection and suggests that PL can be used as adjunct treatment and can make photochemotherapy and phototherapy possibly safe and effective when the control of cutaneous phototoxicity to PUVA or UVB is a limiting factor in such phototherapies.

Effect of Anapsos (Polypodium leucotomos extract) on in vitro production of cytokines

AIMS

The aim of the study was to test the immunomodulating capacity of Anapsos, Polypodium leucotomos extract, in vitro in an attempt to explore how this extract acts from an immunological point of view and thus to identify a common link capable of explaining most of its effects.

METHODS

Polypodium leucotomos rhizomes were harvested in Guatemala and the extract, Anapsos, obtained. Mononuclear cells were obtained by density gradient centrifugation from healthy donors, and stimulated with phytohemagglutinin or Pokeweed with and without Anapsos and with Anapsos alone. Cell proliferation was determined by thymidine incorporation. Cells were also stimulated and the following cytokines determined by ELISA at 0, 12, 24, 48, 72, and 96 h: IL-1 beta, TNF-alpha, IL-2, INF-8, IL-4 and IL-10.

RESULTS

Anapsos, Polypodium leucotomos extract, has a modulating effect on the in vitro production and release of cytokines by peripheral blood mononuclear cells of healthy subjects. At doses effective in vivo, Anapsos can stimulate PBMNc proliferation, delay IL-1 beta secretion and at the same time increase that of IL-2, IL-10, and INF-gamma.

CONCLUSIONS

Anapsos may have an antagonistic effect on some of the cytokines released on cell stimulation with LPS and/or PHA, which suggests that this product has a pleiotropic effect on different populations in the immune system.

Inhibition of ultraviolet-induced formation of reactive oxygen species, lipid peroxidation, erythema and skin photosensitization by polypodium leucotomos

The acute reactions of human skin to solar ultraviolet radiation (290-400 nm) are recognized as a form of inflammation reactions that are mediated by several possible mechanisms including (a) direct action of photons on DNA, (b) generation of reactive free radicals and reactive oxygen species involving the formation of O2.-, 1O2, H2O2, OH, etc., (c) generation of prostaglandins (PGD2, PGE2, etc.), histamine, leucotrienes, and other inflammatory mediators. It is conceivable that UV-induced reactions represent oxidative stress mediated by the formation of free radicals, reactive oxygen, lipid peroxidation, liberation of membrane phospholipids, and subsequent formation of prostaglandins by cyclo-oxygenase pathway. In this study, we examined the role of reactive oxygen species and lipid peroxidation in in vitro reactions as well as in vivo skin inflammation reactions induced by (a) UVB radiation (290-320 nm), and (b) skin photosensitization reaction by PUVA treatment involving 8-methoxypsoralen and UVA (320-400 nm) radiation and presented data for the generation of superoxide anion O2.-) and lipid peroxides. We have also evaluated, both in vitro as well as in vivo systems, the quenching or the inhibition of O2.- by a plant extract known as Polypodium leucotomos. The P. leucotomos extract was found to exhibit interesting antioxidant and anti-inflammatory as well as photoprotective properties against photo-oxidative stress involving the generation of reactive oxygen, lipid peroxidation under in vitro reactions as well as in vivo experimental conditions. Significant inhibition of UVB-induced erythemal response, and 8-methoxypsoralen plus UVA-induced phototoxic reaction after topical application or oral administration of the photosensitizer could be demonstrated in guinea pig skin and human skin following the topical application of P. leucotomos extract. The photoprotective mechanism of P.leucotomos involving interaction with reactive oxygen species or free radicals appears to have potential clinical usefulness in preventing sunburn and inhibiting phototoxic reaction.

Anapsos, an antipsoriatic drug which increases the proportion of suppressor cells in human peripheral blood

Anapsos, an antipsoriatic drug, was administered to normal volunteers in order to study its possible activity on the immune system. After three days of treatment, the drug decreased the lymphoblastic response to PWM and very slightly reduced the serum levels of immunoglobulins. After five days of treatment, however, both values were normal. The response to ConA decreased, and there was an increase in the suppressor index and in the proportion of OKT 8+. The drug did not vary the proportion of OKT 4+ and OKT 3+ cells. These results suggest that anapsos acts by increasing the number of suppressor cells. Such anapsos-induced suppressor cells are probably responsible for the diminished response to ConA, but did not seem to significantly affect response to PWM and serum levels of Ig after five days of treatment.