Madecassoside suppresses migration of fibroblasts from keloids: involvement of p38 kinase and PI3K signaling pathways

IGF1 and CXCR4 Respectively Related With Inhibited M1 Macrophage Polarization in Keloids

PURPOSE

The pathophysiology of keloid remains unclear. Exploring the immune heterogeneity and new biomarkers of keloids can help design new therapeutic targets for keloid treatments and prevention.

METHODS

The authors performed single-cell RNA sequencing analysis and bulk data differential gene expression analysis of public datasets(GSE92566 and GSE163973). They used Gene Ontology (GO), Gene Set Enrichment Analysis (GSEA), and immune infiltration analysis to identify the function of the differential expressed genes. Besides, the authors performed qt-PCR on keloid tissue and adjacent normal tissues from 3 patients for further verification.

RESULTS

M2 macrophage increased in keloid samples than M1 macrophage. The authors identified 2 potential novel biomarkers of keloid, IGF1 and CXCR4, which could inhibit M1 macrophage polarization. The potential mechanism could be inhibiting immune responses and anti-inflammatory activities through INF signaling and E2F targeting. The differential expression of the 2 genes was verified by clinical samples.

CONCLUSIONS

The authors identified 2 immune signaling molecules associated with keloid formation (IGF1 and CXCR4) and analyzed their potential pathogenic mechanisms.

Natural products - Dawn of keloid treatment

Keloids are prevalent pathological scars, often leading to cosmetic deformities and hindering joint mobility.They cause discomfort, including burning and itching, while gradually expanding and potentially posing a risk of cancer.Developing effective drugs and treatments for keloids has been a persistent challenge in the medical field. Natural products are an important source of innovative drugs and a breakthrough for many knotty disease.Herein, keywords of "natural, plant, compound, extract" were combined with "keloid" and searched in PubMed and Google Scholar, respectively. A total of 32 natural products as well as 9 extracts possessing the potential for treating keloids were ultimately identified.Current research in this field faces a significant challenge due to the lack of suitable animal models, resulting in a predominant reliance on in vitro studies.In vivo and clinical studies are notably scarce as a result.Moreover, there is a notable deficiency in research focusing on the role of nutrients in keloid formation and treatment.The appropriate dosage form (oral, topical, injectable) is crucial for the development of natural product drugs. Finally, the conclusion was hereby made that natural products, when used as adjuncts to other treatments, hold significant potential in the management of keloids.By summarizing the natural products and elucidating their mechanisms in keloid treatment, the present study aims to stimulate further discoveries and research in drug development for effectively addressing this challenging condition.

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Evidence of inter- and intra-keloid heterogeneity through analysis of dermal fibroblasts: A new insight in deciphering keloid physiopathology

Keloid scars are hypertrophic and proliferating pathological scars extending beyond the initial lesion and without tendency to regression. Usually, keloids are considered and treated as a single entity but clinical observations suggest heterogeneity in keloid morphologies with distinction of superficial/extensive and nodular entities. Within a keloid, heterogeneity could also be detected between superficial and deep dermis or centre and periphery. Focusing on fibroblasts as main actors of keloid formation, we aimed at evaluating intra- and inter-keloid fibroblast heterogeneity by analysing their gene expression and functional capacities (proliferation, migration, traction forces), in order to improve our understanding of keloid pathogenesis. Fibroblasts were obtained from centre, periphery, papillary and reticular dermis from extensive or nodular keloids and were compared to control fibroblasts from healthy skin. Transcriptional profiling of fibroblasts identified a total of 834 differentially expressed genes between nodular and extensive keloids. Quantification of ECM-associated gene expression by RT-qPCR brought evidence that central reticular fibroblasts of nodular keloids are the population which synthesize higher levels of mature collagens, TGFβ, HIF1α and αSMA as compared to control skin, suggesting that this central deep region is the nucleus of ECM production with a centrifuge extension in keloids. Although no significant variations were found for basal proliferation, migration of peripheral fibroblasts from extensive keloids was higher than that of central ones and from nodular cells. Moreover, these peripheral fibroblasts from extensive keloids exhibited higher traction forces than central cells, control fibroblasts and nodular ones. Altogether, studying fibroblast features demonstrate keloid heterogeneity, leading to a better understanding of keloid pathophysiology and treatment adaptation.

Therapeutic properties and pharmacological activities of asiaticoside and madecassoside: A review

Centella asiatica is an ethnomedicinal herbaceous species that grows abundantly in tropical and sub-tropical regions of China, India, South-Eastern Asia and Africa. It is a popular nutraceutical that is employed in various forms of clinical and cosmetic treatments. C. asiatica extracts are reported widely in Ayurvedic and Chinese traditional medicine to boost memory, prevent cognitive deficits and improve brain functions. The major bioactive constituents of C. asiatica are the pentacyclic triterpenoid glycosides, asiaticoside and madecassoside, and their corresponding aglycones, asiatic acid and madecassic acid. Asiaticoside and madecassoside have been identified as the marker compounds of C. asiatica in the Chinese Pharmacopoeia and these triterpene compounds offer a wide range of pharmacological properties, including neuroprotective, cardioprotective, hepatoprotective, wound healing, anti-inflammatory, anti-oxidant, anti-allergic, anti-depressant, anxiolytic, antifibrotic, antibacterial, anti-arthritic, anti-tumour and immunomodulatory activities. Asiaticoside and madecassoside are also used extensively in treating skin abnormalities, burn injuries, ischaemia, ulcers, asthma, lupus, psoriasis and scleroderma. Besides medicinal applications, these phytocompounds are considered cosmetically beneficial for their role in anti-ageing, skin hydration, collagen synthesis, UV protection and curing scars. Existing reports and experimental studies on these compounds between 2005 and 2022 have been selectively reviewed in this article to provide a comprehensive overview of the numerous therapeutic advantages of asiaticoside and madecassoside and their potential roles in the medical future.

Dermal Fibroblast Migration and Proliferation Upon Wounding or Lipopolysaccharide Exposure is Mediated by Stathmin

The dermal fibroblast is a crucial executor involved in wound healing, and lipopolysaccharide is a key factor in initiating the migration and proliferation of the dermal fibroblasts, followed by wound healing. However, the underlying molecular mechanism is still unknown. In this study, we demonstrated that stathmin increased concomitantly with p38/MAPK pathway activation by lipopolysaccharide stimulation of the human dermal fibroblast (HDF), which induced microtubule (MT) depolymerization followed by increased HDF migration and proliferation. In contrast, the application of taxol, the small interfering RNA transfection of stathmin, or the application of the p38/MAPK inhibitor SB203580 suppressed MT depolymerization and HDF migration and proliferation. Additionally, the overexpression of a MKK6(Glu) mutant, which constitutively activated p38/MAPK, resulted in MT depolymerization and, subsequently, promoted HDF migration and proliferation. Our data reveal a crucial role of stathmin in HDF migration and proliferation. These findings will provide new targets and strategies for clinical interventions in wound healing.

Actions and Therapeutic Potential of Madecassoside and Other Major Constituents of Centella asiatica: A Review

Centella asiatica is a popular herb well-known for its wide range of therapeutic effects and its use as a folk medicine for many years. Its therapeutic properties have been well correlated with the presence of asiaticoside, madecassoside, asiatic and madecassic acids, the pentacyclic triterpenes. The herb has been extensively known to treat skin conditions; nevertheless, several pre-clinical and clinical studies have scientifically demonstrated its effectiveness in other disorders. Among the active constituents that have been identified in Centella asiatica, madecassoside has been the subject of only a relatively small number of scientific reports. Therefore, this review, while including other major constituents of this plant, focuses on the therapeutic potential, pharmacokinetics and toxicity of madecassoside.

Identification of differentially expressed circular RNAs in keloid and normal skin tissue by high-throughput sequencing

Keloid is a kind of pathological skin scar with unclear molecular pathology. Circular RNAs (circRNAs) are involved in the occurrence and development of many diseases; however, their relationship with keloid is not well understood. To investigate the involvement of dysregulated circRNAs in keloid. Thirty-seven keloids and 37 normal skin tissues were collected, and the changes of circRNAs, microRNAs (miRNAs) and mRNAs in 3 keloids and 3 normal samples by high-throughput sequencing were detected first. Based on the circRNA-miRNA-mRNA interaction network construction, gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis combining several signaling pathways associated with keloid formation and progression, the circRNAs required further verification were screened out. The expression levels of the selected circRNAs were verified in 37 keloids and 37 normal skin tissues using quantitative real-time polymerase chain reaction (QPCR). The interaction of candidate circRNA and its predicted binding miRNA was tested by dual-luciferase reporter gene experiment. Compared with normal controls, there was an average of 120 and 12 circRNAs, 44 and 63 miRNAs, 656 and 156 mRNAs were upregulated and downregulated, respectively, in keloids. According to the analysis of bioinformation, six circRNAs were picked out. The QPCR validation results of two upregulated circRNAs (hsa_circ_0001320 and circCOL5A1) were consistent with previous sequencing results. The interaction between hsa_circ_0001320 and miR-574-5p was confirmed. This study makes it clear that the abnormal expression of circRNAs may be related to the pathological process of keloid.

CD26 upregulates proliferation and invasion in keloid fibroblasts through an IGF-1-induced PI3K/AKT/mTOR pathway

Background

Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion. These pathological behaviours may be related to the heterogeneity of keloid fibroblasts (KFs); however, because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism. Our previous studies revealed that the expansion of CD26⁺ KFs was responsible for increased keloid proliferation and invasion capabilities; the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation. The aim of this study was to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities, and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.

Methods

Flow cytometry was performed to isolate CD26⁺/CD26⁻ fibroblasts from KFs and normal fibroblasts. To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor (IGF-1R), lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection. Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay. Scratching assay and transwell assay were used to assess cell migration and invasion abilities. To further quantify the regulatory role of CD26 expression in the relevant signalling pathway, RT-qPCR, western blot, ELISA, PI3K activity assay and immunofluorescence were used.

Results

Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs. Furthermore, the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion. The PI3K/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.

Conclusions

CD26 can be the effective biomarker for KFs, and its expression is closely related to proliferation and invasion in keloids through the IGF-1-induced PI3K/AKT/mTOR pathway. This work provides a novel perspective on the pathological mechanisms affecting KFs and therapeutic strategies against keloids.

Dynamics of the Activity of MAP-Kinase Cascades in the Healing Process of Postoperative Musculocutaneous Wounds

Background. Management of the reparative process is an urgent task of modern medicine. In our opinion, the development of pathogenetically grounded approaches to optimizing the repair process for managing the interrelations of stromal cells is promising. One of the promising areas in this regard is the impact on the MAPK-cascades.Aim: to study the expression of MAP-kinase mechanisms in the regulation of repair by the example of a musculocutaneous wound.Methods. A linear muscular skin wound was modeled using Wistar rats weighing 220–250 g at the age of 9 months (n = 24). Immunofluorescence staining was performed to detect the activity of p38, JNK, and ERK MAPK cascades from 1 to 30 days.Results. It was established that specific staining in the area of connective tissue formation during staining with p38 MAPK and its phosphorylated form was first observed on the 3rd day, and its maximum severity occurred at the same time. On the 7th and 14th day, small zones in the area of scar formation were minimally stained. The phosphorylated part of the JNK-cascade in the zone of traumatic injury was detected starting from the 1st day after the injury. Bright color persisted on the 3rd day. On the 7th day, the color was minimal, and by the 14th day a second wave of expression was observed. ERK-staining was observed from the 1st to the 14th day with a peak activity on the 3rd day.Conclusion. Thus, we revealed the simultaneous involvement of p38, JNK-, and ERK-cascades in the regulation of the reparative process in the conditions of a musculoskeletal wound. At the same time, it is noteworthy that the peak activity of all cascades coincides and falls on the 3rd day.

Scarring in Patients With PIK3CA-Related Overgrowth Syndromes

Importance

Patients with somatic overgrowth commonly require surgical intervention to preserve function and improve cosmesis. To our knowledge no observation of scarring outcomes in this population has been published to date.

Objective

To observe the frequency of abnormal scarring in patients with somatic overgrowth and sequencing-verified mutations in the PIK3CA gene.

Design, Setting, and Participants

This retrospective study evaluated scarring outcomes in patients with PIK3CA-related overgrowth. Samples of affected tissue were sequenced between July 2015 and October 2016. Medical records from multiple large academic tertiary care centers were reviewed for surgical history and scar descriptions, and clinical photographs were assessed by 2 surgeons (J.N.J. and D.M.K.) to confirm abnormal scarring. Analysis of medical records and photographs was performed between April 2017 and June 2017 by a multidisciplinary team from dermatology, plastic surgery, orthopedic surgery, radiology, and genetics departments. All patients considered for the study were diagnosed with somatic overgrowth and previously had affected tissue sent for next-generation sequencing. Those with pathogenic PIK3CA variants and 1 or more prior surgical procedures were reviewed.

Main Outcomes and Measures

Presence of excessive scarring in patients with PIK3CA overgrowth.

Results

A total of 57 patients with segmental overgrowth syndromes were sequenced. Of the 57 patients, 25 (44%) had pathogenic or likely pathogenic variants in PIK3CA. Of those with pathogenic PIK3CA variants, 6 (24%) had past surgical procedures, all with preoperative and postoperative photographs. Of 6 patients with PIK3CA-related overgrowth and a history of 1 or more surgical procedure, 4 (67%) developed excessive scarring. The cohort with abnormal scarring comprised 3 females and 1 male, with a median age of 8.5 years. All abnormal scarring occurred in affected overgrowth tissue. Three of the 4 patients developed the excessive scarring after debulking procedures for overgrowth and/or vascular malformations of the upper or lower extremity.

Conclusions and Relevance

Excessive scarring occurred frequently in patients with PIK3CA-related overgrowth syndromes. The risk of abnormal scarring should therefore be discussed preoperatively. Given the activating nature of these PIK3CA variants, we suggest that the excessive scarring may be owing in part to up-regulation of the PI3K-Akt-mTOR pathway. Additional studies are needed to assess scarring outcomes in patients with other types of overgrowth.

Propionibacterium acnes related anti-inflammation and skin hydration activities of madecassoside, a pentacyclic triterpene saponin from Centella asiatica

Madecassoside is a major pentacyclic triterpene saponin from Centella asiatica with multiple pharmaceutical activities. In this study, we focused on its Propionibacterium acnes related anti-inflammation and skin hydration activities, both of which play important roles in skin homeostasis and barrier function. Madecassoside significantly inhibited the pro-inflammatory cytokine IL-1β, TLR2 and nuclear translocation of NF-κB in P. acnes stimulated THP-1 human monocytic cells. In addition, madecasssoside exhibited significant effects on enhancement of skin hydration through increasing the key moisturizing contributors of aquaporin-3, loricrin and involucrin in HaCaT keratinocytes as well as hyaluronan (HA) secretion in human dermal fibroblasts. The upregulation of HA synthases (HAS1, HAS2, HAS3) and inhibition to ROS formation accounted for the increment of HA content. Together, the in vitro study implied the potential medical and cosmetic application of madecassoside in skin protection.

A Prospective Randomized, Controlled, Double-Blind Trial of the Efficacy Using Centella Cream for Scar Improvement

Objective

This study was performed to evaluate the efficacy of Centella asiatica extract in cream, a preparation for the prevention of scar development of the split-thickness skin graft (STSG) donor site.

Methods

A prospective randomized, double-blind control study was performed to evaluate the efficacy of Centella cream in 30 patients who underwent a STSG operation. Both Centella cream and placebo were applied equally to the donor site at least 2 weeks after epithelialization was completed. A scar assessment using the Vancouver Scar Scale (VSS) was taken at 4, 8, and 12 weeks.

Results

Of the original 30 patients, 23 patients completed evaluation. There were significant differences in pigmentation parameter of VSS and comparative total VSS scores between 4 and 12 weeks in Centella cream group.

Conclusion

The effect of Centella cream on scar development of a STSG operation may be attainable in terms of better pigmentation. By means of objective measurements and longer follow-up times, Centella cream may prove to be an alternative product for hypertrophic scar amelioration.

Madecassoside impedes invasion of rheumatoid fibroblast-like synoviocyte from adjuvant arthritis rats via inhibition of NF-κB-mediated matrix metalloproteinase-13 expression

Fibroblast-like synoviocytes (FLS) play a pivotal role in Rheumatoid arthritis (RA) pathogenesis through aggressive migration and invasion. Madecassoside (Madec), a triterpenoid saponin present in Centella asiatica herbs, has a potent anti-inflammatory effect. In the present study, Madec exerted an obvious therapeutic effect in reversing the histological lesions in adjuvant-induced arthritis (AIA) rats. To recognize the anti-rheumatoid potentials of Madec, we further investigated whether Madec interfered with FLS invasion and metalloproteinase (MMP) expression. In cultures of primary FLS isolated from the AIA rats, Madec (10 and 30 μmol·L^-1) was proven to considerably inhibit migration and invasion of FLS induced by interleukin 1β (IL-1β), but exhibiting no obvious effect on cell proliferation. Madec repressed IL-1β-triggered FLS invasion by prohibiting the expression of MMP-13. Additionally, Madec suppressed MMP-13 transcription via inhibiting the MMP-13 promoter-binding activity of NF-κB. Our results further showed that Madec down-regulated the translocation and phosphorylation of NF-κB as demonstrated by Western blotting and immunofluorescence assays. In conclusion, our results suggest that Madec exerts anti-RA activity via inhibiting the NF-κB/MMP-13 pathway.

The Superficial Dermis May Initiate Keloid Formation: Histological Analysis of the Keloid Dermis at Different Depths

Several studies have reported on certain aspects of the characteristics of different sites within a keloid lesion, but detailed studies on the keloid dermis at different depths within a keloid lesion are scarce. The aim of this study was to investigate the histology of the keloid dermis at different depths. This study included 19 keloid tissue samples that were collected from 19 patients and 19 normal skin samples, which were harvested from subjects without keloids or hypertrophic scar. Samples were studied by light microscopy using routine hematoxylin and eosin histochemical staining, and immunohistochemistry to detect CD20-positive B-lymphocytes and CD3-positive T-lymphocytes. Sirius Red histochemical staining was used to determine the type of collagen in keloid tissue and normal skin samples. The migratory properties of fibroblasts within the keloid dermis at different depths was compared, using an in vitro migration assay. The findings of this study showed that although the papillary and reticular dermis could be clearly distinguished in normal skin, three tissue layers were identified in the keloid dermis. The superficial dermis of keloid was characterized by active fibroblasts and lymphocytes; the middle dermis contained dense extracellular matrix (ECM) with large numbers fibroblasts, and the deep dermis was poorly cellular and characterized by hyalinized collagen bundles. In the keloid samples, from the superficial to the deep dermis, type I collagen increased and type III collagen decreased, and fibroblasts from the superficial dermis of the keloid were found to migrate more rapidly. In conclusion, the findings of this study showed that different depths within the keloid dermis displayed different biological features. The superficial dermis may initiate keloid formation, in which layer intralesional injection of pharmaceuticals and other treatments should be performed for keloid.

18ß-glycyrrhetinic acid derivative promotes proliferation, migration and aquaporin-3 expression in human dermal fibroblasts

Licorice (Glycyrrhiza) species have been widely used as a traditional medicine and a natural sweetener in foods. The 18β-glycyrrhetinic acid (18β-GA) is a bioactive compound in licorice that exhibits potential anti-cancer, anti-inflammatory, and anti-microbial activities. Many synthesized derivatives of 18β-GA have been reported to be cytotoxic and suggested for the treatment of malignant diseases. In this study, we explored the possible pharmacological roles of an 18β-GA derivative in skin biology using primary human dermal fibroblasts and HaCaT keratinocytes as cell models. We found that this 18β-GA derivative did not cause cell death, but significantly enhanced the proliferation of dermal fibroblasts and HaCaT keratinocytes. A scratch wound healing assay revealed that the 18β-GA derivative promoted the migration of fibroblasts. Due to the important role of aquaporin-3 in cell migration and proliferation, we also investigated the expression of aquaporin-3 and found this compound up-regulated the expression of aquaporin-3 in dermal fibroblasts and HaCaT keratinocytes. In dermal fibroblasts, the 18β-GA derivative induced the phosphorylation of Akt, ERK, and p38. The inhibitor of Akt predominantly suppressed the 18β-GA derivative-induced expression of aquaporin-3. Collectively, this compound had a positive effect on the proliferation, migration, and aquaporin-3 expression of skin cells, implying its potential role in the treatment of skin diseases characterized by impaired wound healing or dermal defects.

A Comparison of Gene Expression of Decorin and MMP13 in Hypertrophic Scars Treated With Calcium Channel Blocker, Steroid, and Interferon: A Human-Scar-Carrying Animal Model Study

BACKGROUND

The formation of hypertrophic scaring (HSc) is an abnormal wound-healing response. In a previous study, an animal model with human scar tissue implanted into nude mice (BALB/c) has been successfully established. The effects of verapamil as well as combination therapy with verapamil and kenacort have been studied and compared.

OBJECTIVE

To treat persistent hypertrophic scars, local injection of drugs composed of steroids, calcium channel blockers (CCBs), and interferon might be a good method. What is the best dose of the regimen and what are the mechanisms are also a worthwhile study.

MATERIALS AND METHODS

Scar specimens were harvested from patients with HSc or Keloid resulting from burn injury, and then implanted to BALB/c-nu nude mice for 4 weeks. Before implantation, the specimen was either injected with or without drugs such as steroids (kenacort), CCBs (verapamil), and interferons (INFα2b), respectively. After the removal of implants, quantitative gene expressions of decorin and collagenase (MMP13) were measured using a real-time polymerase chain reaction to detect their mRNAs. Two way-ANOVA and Post Hoc were used for statistical analysis using the software SPSS 15.0.

RESULTS

All drug-treated groups increased the expressions of decorin and MMP13 in comparison with those in noninjected group (p < .001) in a dose-dependent manner. Comparing equal amounts of individual drugs, gene expression of decorin was increased with increasing injection amount, and the best result in low amount of injection (0.02 mL of each) was shown in the group injected with INFα2b followed by kenacort and verapamil. However, the results were changed while injection amount was up to 0.04 mL and the strongest decorin gene expression was found in kenacort injection. Regarding MMP-13 expression, low-amount injection (0.02 mL) of INFα2b has strongest gene expression followed by kenacort and verapamil, but in the large-amount regimes (0.04 mL), verapamil had strongest gene expression followed by INFα2b and kenacort.

CONCLUSION

This study showed that the kenacort, verapamil, and INFα2b all inhibited HSc in a dose-dependent manner through the evidence of gene expression of decorin and MMP13. In comparison with the injections between small amounts of drugs, INFα2b potentiated the strongest decorin and MMP13 expression. On the contrary, among the large-amount injection regimes, kenacrot was more effective on decorin expression as verapamil to MMP13 expression. To decrease side effects from the drugs and produce promising results for the clinical practice, it is suggested to maintain the dose of INFα2b along with an increased dose of verapamil for HSc improvement.

Madecassoside ameliorates bleomycin-induced pulmonary fibrosis in mice through promoting the generation of hepatocyte growth factor via PPAR-γ in colon

BACKGROUND AND PURPOSE

Madecassoside has potent anti-pulmonary fibrosis (PF) effects when administered p.o., despite having extremely low oral bioavailability. Herein, we explored the mechanism of this anti-PF effect with regard to gut hormones.

EXPERIMENTAL APPROACH

A PF model was established in mice by intratracheal instillation of bleomycin. Haematoxylin and eosin stain and Masson's trichrome stain were used to assess histological changes in the lung. Quantitative-PCR and Western blot detected mRNA and protein levels, respectively, and cytokines were measured by ELISA. Small interfering RNA was used for gene-silencing. EMSA was applied to detect DNA-binding activity.

KEY RESULTS

Administration of madecassoside, p.o., but not its main metabolite madecassic acid, exhibited a direct anti-PF effect in mice. However, i.p. madecassoside had no anti-PF effect. Madecassoside increased the expression of hepatocyte growth factor (HGF) in colon tissues, and HGF receptor antagonists attenuated its anti-PF effect. Madecassoside facilitated the secretion of HGF from colonic epithelial cells by activating the PPAR-γ pathway, as shown by an up-regulation of PPAR-γ mRNA expression, nuclear translocation and DNA-binding activity both in vitro and in vivo. Also GW9662, a selective PPAR-γ antagonist, almost completely prevented the madecassoside-induced increased expression of HGF and amelioration of PF.

CONCLUSIONS AND IMPLICATIONS

The potent anti-PF effects induced by p.o. madecassoside in mice are not mediated by its metabolites or itself after absorption into blood. Instead, madecassoside increases the activity of PPAR-γ, which subsequently increases HGF expression in colonic epithelial cells. HGF then enters into the circulation and lung tissue to exert an anti-PF effect.

Protective effects of madecassoside against Doxorubicin induced nephrotoxicity in vivo and in vitro

Madecassoside (MA), a triterpenoid saponin isolated from C. asitica, exerts various pharmacological activity including antioxidative and antinflammatory. Doxorubicin (DOX), a common chemotherapeutic drug, has been reported to induce numerous toxic side effects including renal-toxicity. We hypothesized that MA administration may decrease renal-toxicity caused by DOX. In this study, we investigated this hypothesis by introducing MA and DOX into the culture of Human Proximal Tubule Cells HK-2 and mice model. Our in vivo study demonstrated that MA (12 mg/kg), treatment for two weeks attenuated DOX-induced renal injury via protecting renal function, recovering antioxidant enzyme activity, inhibiting Bax, p-ERK1/2, NF-κB p65, iNOS expression and increasing Bcl-2 expression. Similar findings were obtained in our in vitro studies with treatment of DOX and/or MA. Further studies with application of iNOS inhibitor and ERK1/2 kinase inhibitor indicated that the inhibitory effects of MA on DOX-induced apoptosis and inflammation might be mediated by the suppression of the activation of cleaved caspase-3, ERK1/2 pathways, NF-κB p65 and NO production. These results suggest that MA is a promising protective agent for DOX-induced renal toxicity and can be a potential candidate to protect against renal toxicity in DOX-treated cancer patients.

Heat Shock Protein 90 Inhibitor Decreases Collagen Synthesis of Keloid Fibroblasts and Attenuates the Extracellular Matrix on the Keloid Spheroid Model

BACKGROUND

The 90-kDa heat-shock protein (heat-shock protein 90) is an abundant cytosolic chaperone, and inhibition of heat-shock protein 90 by 17-allylamino-17-demethoxygeldanamycin (17-AAG) compromises transforming growth factor (TGF)-β-mediated transcriptional responses by enhancing TGF-β receptor I and II degradation, thus preventing Smad2/3 activation. In this study, the authors evaluated whether heat-shock protein 90 regulates TGF-β signaling in the pathogenesis and treatment of keloids.

METHODS

Keloid fibroblasts were treated with 17-AAG (10 μM), and mRNA levels of collagen types I and III were determined by real-time reverse- transcriptase polymerase chain reaction. Also, secreted TGF-β1 was assessed by enzyme-linked immunosorbent assay. The effect of 17-AAG on protein levels of Smad2/3 complex was determined by Western blot analysis. In addition, in 17-AAG-treated keloid spheroids, the collagen deposition and expression of major extracellular matrix proteins were investigated by means of Masson trichrome staining and immunohistochemistry.

RESULTS

The authors found that heat-shock protein 90 is overexpressed in human keloid tissue compared with adjacent normal tissue, and 17-AAG decreased mRNA levels of type I collagen, secreted TGF-ß1, and Smad2/3 complex protein expression in keloid fibroblasts. Masson trichrome staining revealed that collagen deposition was decreased in 17-AAG-treated keloid spheroids, and immunohistochemical analysis showed that expression of collagen types I and III, elastin, and fibronectin was markedly decreased in 17-AAG-treated keloid spheroids.

CONCLUSION

These results suggest that the antifibrotic action of heat-shock protein 90 inhibitors such as 17-AAG may have therapeutic effects on keloids.

Medicinal plants for the treatment of hypertrophic scars

Hypertrophic scar is a complication of wound healing and has a high recurrence rate which can lead to significant abnormity in aesthetics and functions. To date, no ideal treatment method has been established. Meanwhile, the underlying mechanism of hypertrophic scarring has not been clearly defined. Although a large amount of scientific research has been reported on the use of medicinal plants as a natural source of treatment for hypertrophic scarring, it is currently scattered across a wide range of publications. Therefore, a systematic summary and knowledge for future prospects are necessary to facilitate further medicinal plant research for their potential use as antihypertrophic scar agents. A bibliographic investigation was accomplished by focusing on medicinal plants which have been scientifically tested in vitro and/or in vivo and proved as potential agents for the treatment of hypertrophic scars. Although the chemical components and mechanisms of action of medicinal plants with antihypertrophic scarring potential have been investigated, many others remain unknown. More investigations and clinical trials are necessary to make use of these medical plants reasonably and phytotherapy is a promising therapeutic approach against hypertrophic scars.

Molecular signalings in keloid disease and current therapeutic approaches from natural based compounds

CONTEXT

Keloid is an excessive dermal scar occurring in response to skin injuries. Several therapeutic strategies have been proposed to ease the aggressiveness of keloid scarring. Even though the principle mechanism underlying the disease propagation still remains unidentified, several signaling pathways were highly focused as plausible pathways involving keloid formation, including transforming growth factor-beta 1 (TGF-β1), mitogen-activated protein kinase (MAPK), insulin-like growth factor-I (IGF-I), and integrin pathways. Natural compounds containing multiple bioeffective properties such as quercetin, asiaticoside, Astragalus membranaceus Bunge. (Leguminosae), and Salvia miltiorrhiza Bunge. (Lamiaceae) extracts, curcuminoids, oxymatrine, madecassoside, and Aneilema keisak Hassk. (Commelinaceae) are claimed as candidates for therapeutic treatment against keloid disorder.

OBJECTIVE

This review investigates current mechanisms regarding keloid formation and provides scientific evidence supporting the therapeutic potential of natural compounds.

METHODS

This review obtained and analyzed a number of literature data items from various databases including Pubmed, ScienceDirect, and Elton B. Stephens Company (EBSCO).

RESULT

Several phytochemical compounds are able to suppress keloid scar development through manipulating various components in the complex signaling cascades.

CONCLUSION

The present review may be helpful to future studies that further examine the molecular mechanism of keloid etiology as well as investigate the anti-keloid property in natural compounds.

Inhibition of mechanical stress-induced hypertrophic scar inflammation by emodin

At least 50% of hypertrophic scarring (HS) is characterized by inflammation, for which there is currently no effective treatment available. Emodin is a major component of the widely used Chinese herb, rhubarb, which has been used to treat inflammation in several types of disease. However, few studies have investigated the efficacy of emodin in the treatment of HS. In the present study, a mouse model with mechanical stress-induced HS was used to investigate the effects of emodin (20, 40, 80, or 120 mg/ml) on HS, and to determine the potential underlying mechanisms. Treatment with emodin significantly attenuated HS inflammation, as determined by histopathological assessment of the scar elevation index, collagen structure and inflammation (P<0.05). Furthermore, treatment with emodin (40 mg/ml) markedly inhibited phosphoinositide 3-kinase (PI3K)/Akt activity (P<0.01) and this attenuation was associated with reduced expression levels of tumor necrosis factor-α, interleukin-6 and monocyte chemoattractant protein-1 (P<0.05) in the HS tissue. The results of the present study indicated that administration of emodin had therapeutic effects on the progression of HS and the underlying mechanism of this may be due to inhibition of the PI3K/Akt signaling pathway.

Co‑culture with human fetal epidermal keratinocytes promotes proliferation and migration of human fetal and adult dermal fibroblasts

The repair strategy for the healing of skin wounds in fetuses differs from that in adults. Proliferation and migration of dermal fibroblasts are the main mechanisms associated with skin wound healing, as well as the complex interactions between epidermal keratinocytes (KCs) and dermal fibroblasts. In order to investigate the effects of fetal skin epidermal KCs on fetal and adult human dermal fibroblasts, KCs and fibroblasts were isolated from the skin tissue of mid‑gestational human fetuses and adults, and co‑cultured using a Transwell® system. When fetal mid‑gestational KCs were co‑cultured with either fetal or adult dermal fibroblasts, the proliferative and migratory potential of the fibroblasts was significantly enhanced. Furthermore, these phenotypic changes were concomitant with the upregulation of numerous proteins including mouse double minute 2 homolog, cyclin B1, phospho‑cyclin‑dependent kinase 1, phospho‑extracellular signal‑regulated kinase, and phospho‑AKT, along with C‑X‑C chemokine receptor 4, phospho‑p38 mitogen activated protein kinase, matrix metalloproteinase (MMP)‑2 and MMP‑9. Notably, no significant differences were observed between fetal and adult dermal fibroblasts in their responses to fetal mid‑gestational epidermal KCs, indicating that the cells from these two developmental stages respond in a similar manner to co‑culture with KCs.

Combined treatment with Epimedium koreanum Nakai extract and gefitinib overcomes drug resistance caused by T790M mutation in non-small cell lung cancer cells

Although the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, such as gefitinib, have shown promising therapeutic efficacy in nonsmall cell lung cancer (NSCLC) patients harboring EGFR activating mutation, development of acquired resistance is almost inevitable. We investigated whether the addition of Epimedium koreanum Nakai extract (EEF) to gefitinib could overcome the resistance of NSCLC cells to gefitinib. In our study, the growth inhibitory effects of cotreatment differed between mutant EGFR and wild type EGFR. A synergistic antiproliferative effect was observed in the combined treatments in H1975 and PC-9GR cells carrying T790M EGFR. In addition, the cotreatment exhibited a much greater inhibition than either agent alone on the following metastatic processes: (a) invasion, (b) wound healing, and (c) tubule formation by endothelial cells. The phosphorylations of EGFR family (EGFR, HER-2, and HER-3) and EGFR downstream PI3K/Akt/mTOR pathway in H1975 and PC-9/GR cells were also attanuated, whereas EEF or gefitinib alone had no obvious effects. Similarly, the combination effectively suppressed tumor growth and increased mice survival in PC-9GR xenografts. The results indicate that the addition of EEF to gefitinib is a promising strategy to overcome T790M-mediated drug resistance.

In vivo disposition and metabolism of madecassoside, a major bioactive constituent in Centella asiatica (L.) Urb

ETHNOPHARMACOLOGICAL RELEVANCE

Centella asiatica (L.) Urb. herb is frequently used in traditional Chinese medicine for many indications, such as traumatic injuries, keloid and scar. Madecassoside is the main active ingredient of this herb drug with higher content than other triterpenoid constituents. Understandings of pharmacokinetic profiles of madecassoside should be beneficial for its development as a therapeutic agent.

MATERIALS AND METHODS

Sprague-Dawley rats were intravenously and orally administered madecassoside (100 mg/kg), respectively. Plasma, heart, liver, spleen, lung, kidney, brain, bile, urine and feces were collected at the designed time points. Madecassoside concentrations in biological samples were determined by a sensitive and well-validated liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method. A liquid chromatography coupled with time-of-flight mass spectrometry (LC-TOF-MS) method was established to identify its major metabolites in feces. To further pursue the disposition characteristics of madecassoside in rats, the involvement of the hepatobiliary efflux transporters in biliary elimination were studied by combination with digoxin (P-glycoprotein inhibitor) or probenecid (multidrug resistance-associated protein inhibitor). A linked-rat model was also used to assess the role of enterohepatic circulation in the pharmacokinetics of madecassoside.

RESULTS

After a single oral dosing, madecassoside was widely distributed in heart, liver, spleen, lung and kidney of rats, and the levels of madecassoside in liver and kidney were relatively higher than other organs. The excretions of madecassoside in bile, urine and feces were 7.16% (0-12 h), 0.25% (0-72 h) and 24.68% (0-72 h), respectively. The findings suggested that madecassoside might excrete mainly by metabolites. The combination with either digoxin or probenecid significantly attenuated the excretion of madecassoside as parent from bile, indicating that P-glycoprotein and multidrug resistance-associated protein might contribute to the hepatobiliary elimination of madecassoside. The presence of enterohepatic circulation, as implied by double-humped profiles in plasma and tissue concentration-time curves, was confirmed by a linked-rat model. Furthermore, three metabolities of madecassoside were indentified in rat feces and the possible metabolic pathways were proposed.

CONCLUSIONS

These findings provide valuable information regarding in vivo process of madecassoside, and help us to recognize the efficacy and safety of madecassoside itself, the relevant herbs or herbal preparations.