Ginsenoside Rb1 and paeoniflorin inhibit transient receptor potential vanilloid-1-activated IL-8 and PGE2 production in a human keratinocyte cell line HaCaT

Study of the soothing effects of troxerutin in alleviating skin sensitivity

BACKGROUND

Transient receptor potential vanilloid 1 (TRPV1) is associated with skin sensitivity and mainly activated by capsaicin and heat. Interestingly, troxerutin can inhibit TRPV1 activation. However, its efficacy in reducing skin sensitivity remains undetermined.

AIMS

We evaluated the efficacy of troxerutin in alleviating skin sensitivity using clinical tests and in vitro experiments.

METHODS

For the in vitro experiment, HaCaT keratinocytes were pretreated with different concentrations of troxerutin, followed by incubation with 50 μM capsaicin for 1, 24, or 48 h. The gene and protein expressions of four inflammatory cytokines involved in skin irritation were determined. Among 35 Korean women with sensitive skin recruited for the clinical trial, 13 were involved in assessing the immediate soothing effects of 0.1% and 0.0095% troxerutin following capsaicin irritation, whereas 22 participated in evaluating the preventive soothing effect of 10% and 1% troxerutin over 4 weeks against capsaicin- and heat-induced irritation. We evaluated the soothing rate using skin redness, visual analog scale, and high temperature sensitive index as evaluation indices.

RESULTS

Troxerutin inhibited the mRNA and protein expressions of cytokines in capsaicin-treated keratinocytes. In the clinical study, 0.1% and 0.0095% troxerutin promptly alleviated capsaicin-induced skin redness, whereas 10% troxerutin notably decreased both the visual analog scale and high temperature sensitive index for capsaicin- and heat-related irritation. However, 1% troxerutin was only effective in reducing the visual analog scale in response to capsaicin irritation.

CONCLUSIONS

Troxerutin can inhibit TRPV1 activation in clinical and in vitro tests.

The traditional herbal medicines mixture, Banhasasim-tang, relieves the symptoms of irritable bowel syndrome via modulation of TRPA1, NaV1.5 and NaV1.7 channels

ETHNOPHARMACOLOGICAL RELEVANCE

The cause of irritable bowel syndrome (IBS), a functional gastrointestinal (GI) disorder, remains unclear. Banhasasim-tang (BHSST), a traditional herbal medicines mixture, mainly used to treat GI-related diseases, may have a potential in IBS treatment. IBS is characterized by abdominal pain as the main clinical symptom, which seriously affects the quality of life.

AIM OF THE STUDY

We conducted a study to evaluate the effectiveness of BHSST and its mechanisms of action in treating IBS.

MATERIALS AND METHODS

We evaluated the efficacy of BHSST in a zymosan-induced diarrhea-predominant animal model of IBS. Electrophysiological methods were used to confirm modulation of transient receptor potential (TRP) and voltage-gated Na⁺ (NaV) ion channels, which are associated mechanisms of action.

RESULTS

Oral administration of BHSST decreased colon length, increased stool scores, and increased colon weight. Weight loss was also minimized without affecting food intake. In mice administered with BHSST, the mucosal thickness was suppressed, making it similar to that of normal mice, and the degree of tumor necrosis factor-α was severely reduced. These effects were similar to those of the anti-inflammatory drug-sulfasalazine-and antidepressant-amitriptyline. Moreover, pain-related behaviors were substantially reduced. Additionally, BHSST inhibited TRPA1, NaV1.5, and NaV1.7 ion channels associated with IBS-mediated visceral hypersensitivity.

CONCLUSIONS

In summary, the findings suggest that BHSST has potential beneficial effects on IBS and diarrhea through the modulation of ion channels.

An overview of the effect of medicinal herbs on pain

This paper is typically intended to carefully collect and properly review the antinociceptive activities of medicinal plants. In this review article, by searching keywords of medicinal plants, pain, herbal medicine, antinociceptive, phytotherapy in databases of Web of Science, Scopus, Google Scholar, Springer, Wiley, Proquest, PubMed, Nature, Magiran, Emerald, SID, ISI, and some other indexing cites, or traditional books, desired articles were obtained until 2021. The title of medicinal plants was searched diligently in Persian and English. Ultimately, 270 articles were studied. The findings possibly indicated that several medicinal plants are among the most valuable plants that have antinociceptive activities. There efficiently are various antinociceptive compounds in medicinal plants. The antinociceptive activity of these specific compounds may be through their peculiar effects on the opioid system, cholinergic pathways, and stimulation of GABA receptors, with the peripheral and central antinociceptive mechanism. Antiinflammatory processes, inhibition of the synthesis, and the release of arachidonic acid, prostaglandins, phospholipase, nitric oxide, and cyclooxygenase-2 have been reported as analgesic mechanisms of some herbs. In a reasonable conclusion, our review thoughtfully provides a comprehensive summary of present data from some scientific studies on the common herbs with antinociceptive and antiinflammatory activities.

Natural Active Ingredients and TRPV1 Modulation: Focus on Key Chemical Moieties Involved in Ligand-Target Interaction

Diseases such as cancer, neurological pathologies and chronic pain represent currently unmet needs. The existing pharmacotherapeutic options available for treating these conditions are limited by lack of efficiency and/or side effects. Transient receptor potential vanilloid 1 ion channel emerged as an attractive therapeutic target for developing new analgesic, anti-cancer and antiepileptic agents. Furthermore, various natural ingredients were shown to have affinity for this receptor. The aim of this narrative review was to summarize the diverse natural scaffolds of TRPV1 modulators based on their agonistic/antagonistic properties and to analyze the structure-activity relationships between the ligands and molecular targets based on the results of the existing molecular docking, mutagenesis and in vitro studies. We present here an exhaustive collection of TRPV1 modulators grouped by relevant chemical features: vanilloids, guaiacols, phenols, alkylbenzenes, monoterpenes, sesquiterpenoids, alkaloids, etc. The information herein is useful for understanding the key structural elements mediating the interaction with TRPV1 and how their structural variation impacts the interaction between the ligand and receptor. We hope this data will contribute to the design of novel effective and safe TRPV1 modulators, to help overcome the lack of effective therapeutic agents against pathologies with high morbidity and mortality.

Optimized flow cytometric detection of transient receptor potential vanilloid-1 (TRPV1) in human hematological malignancies

The ectopic overexpression of transient receptor potential vanilloid-1 (TRPV1) has been detected in numerous solid cancers, including breast, prostate, pancreatic, and tongue epithelium cancer. However, the expression of TRPV1 in hematological malignancies remains unknown. Here we show through in silico analysis that elevated TRPV1 mRNA expression occurs in a range of hematological malignancies and presents an optimized flow cytometry method to rapidly assess TRPV1 protein expression for both cell lines and primary patient samples. Three anti-TRPV1 antibodies were evaluated for intracellular TRPV1 detection using flow cytometry resulting in an optimized protocol for the evaluation of TRPV1 in hematological malignant cell lines and patients' peripheral blood mononuclear cells (PBMC). Overexpression of TRPV1 was observed in THP-1 (acute monocytic leukemia) and U266B1 (multiple myeloma, MM), but not U937 (histiocytic lymphoma) compared to healthy PBMC. TRPV1 was also detected in all 49 patients including B-cell non-Hodgkin's lymphoma (B-NHL), MM, and others and 20 healthy controls. TRPV1 expression was increased in 8% of patients (MM = 2, B-NHL = 2). In conclusion, we provide an optimized flow cytometry method for routine expression analysis of clinical samples and show that TRPV1 is increased in a subset of patients with hematological malignancies.

Paeoniflorin inhibits proliferation and promotes autophagy and apoptosis of sweat gland cells

Axillary bromhidrosis is sweat excreted by apocrine glands in the armpits, mouth corners and other parts. The clinical manifestation includes excessive sweating and heavy odor, leading to the growth of bacteria and skin disease. The present study investigated the mechanism underlying the effect of paeoniflorin (PF) in the treatment of bromhidrosis. PF was injected into the feet of rats, and the foot skin was dissected for histological analysis. Primary human sweat gland cells (hSGCs) were isolated from patients with bromhidrosis. After 24 h treatment with PF or 3-methyladenine, the production of reactive oxygen species (ROS), autophagy, apoptosis, proliferation and cell cycle distribution were determined. PF induced nuclear pyknosis in rat SGCs. In vitro PF treatment inhibited cell proliferation with a 25% inhibitory concentration of 9.530 µM. Treatment with 9.530 µM PF for 24 h significantly increased apoptosis, ROS production and autophagy in hSGCs. PF promoted LC3B and Beclin 1 expression, but inhibited p62, phosphorylated (p)-PI3K and p-Akt expression. 3-methyladenine treatment reversed PF-induced changes in hSGCs. PF-induced inhibition of hSGC proliferation was associated with ROS production, apoptosis, and autophagy. These findings provide a basis for treating bromhidrosis.

The effects of herbal medicines on cancer therapy-induced oral mucositis: A literature review

Cancer therapy-induced oral mucositis (OM) is one of the most troublesome morbidities after radio-chemotherapy. Age, nutritional status, tumor type, oral hygiene, and treatment method are the determinants for OM incidence. In addition, oxygen-free radicals can act as a trigger for an inflammatory milieu that causes OM. Based on the debilitating nature of OM, finding a safe and inexpensive agent with anti-inflammatory, anti-microbial, and antioxidative properties can be valuable for this situation. Considering the harmful effects of some chemical agents, herbal medicine has been suggested as a potential alternative owing to unique properties such as safety, availability and low cost. Many studies have illustrated several pharmacological properties of herbal medicines in recent years, such as anti-inflammatory, anti-microbial, and antioxidative activities, which are essential factors in the palliation of cancer therapy-induced OM. This review aimed to evaluate herbal medicines' effects on cancer therapy-induced OM. According to this comprehensive review, it is concluded that medicinal plants and phytochemicals can be used as practical agents in the palliation of cancer therapy-induced OM without any serious side effects.

Capsaicin attenuates imiquimod-induced epidermal hyperplasia and cutaneous inflammation in a murine model of psoriasis

Psoriasis is one of the most common chronic inflammatory diseases that is characterized by well-defined erythematous plaques, with typical histopathological findings of lymphocytic infiltration and epidermal hyperplasia. Topical treatments of psoriasis are either associated with limited response or with side effects. Up to date, topicals targeting neuroimmune axis in psoriasis or psoriasiform dermatitis have not been explored. Here, we investigated whether percutaneous delivery of capsaicin could attenuate the pathological change of psoriasiform inflammation. Imiquimod-induced psoriasis-like murine model was used to evaluate therapeutic effects from topical application of capsaicin. An additional model of psoriasiform dermatitis induced by direct IL-23 injection was used to identify the level of action from capsaicin in this neuroimmune axis. Cutaneous inflammation was assessed by erythema level and ear thickness change. Key cytokines, infiltrating cells in the skin, and draining lymph node cells were investigated. The results showed that capsaicin administration obstructed the activation of IL-23/IL-17 pathway induced by imiquimod, presenting with significantly reduced psoriasiform dermatitis both in gross appearance and microscopic features. Tissue gene expression of psoriatic core cytokines induced by imiquimod (including IL-23, IL-17A, IL-22, TNF-α, and IL-6) were greatly decreased by capsaicin application. This protective effect from capsaicin could be hampered by direct intradermal injection of IL-23. CONCLUSION: Epicutaneous delivery of capsaicin on imiquimod-treated murine skin could significantly decrease expression of multiple inflammatory cytokines and the severity of prototypic change of psoriasiform inflammation. The beneficial effect imposed by capsaicin reinforces the neuroimmune contribution towards psoriasiform inflammation and provides a potential non-steroidal therapeutic alternative for topical treatment of psoriasiform dermatitis.

Natural compounds protect the skin from airborne particulate matter by attenuating oxidative stress

Particulate matter (PM) is a common indirect indicator of air pollution and threatens public health upon prolonged exposure, leading to oxidative stress, increasing the risk of develop respiratory and cardiovascular, as well as several autoimmune diseases and cancer. Nowadays, as a first line defense against PM, skin health attracted much attention. Our review summarized the skin damage mechanism induced by PM, including damage skin barrier directly, reactive oxygen species (ROS) accumulation, autophagy, and two canonical signaling pathways. Furthermore, ROS and oxidative stress have been considered pathogenesis centers, with essential skin damage roles. Extracts from plants and natural compounds which present high antioxidant capacity could be used to treat or protect against air pollution-related skin damage. We conclude the extracts reported in recent studies with protective effects on PM-mediated skin damage. Besides, the mechanism of extracts' positive effects has been revealed partially.

Total glucosides of paeony: A review of its phytochemistry, role in autoimmune diseases, and mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Paeoniae Radix Alba (PRA, called baishao in China), the root of Paeonia lactiflora Pall., has shown a rich medicinal value for more than 2000 years. PRA is used in local medicine and traditional medicine for autoimmune diseases associated with inflammation. At present, total glucosides of paeony (TGP), the main active ingredient of PRA, has been developed into a preparation for the treatment of autoimmune diseases, as TGP exhibits the effect of regulating immunity, anti-inflammatory, and analgesic effects.

AIM OF THE REVIEW

TGP was developed and applied to inflammation-related autoimmune diseases in modern clinical practice. Based on its application in traditional prescriptions, this article reviews PRA's botany and phytochemistry (including its extraction process and quality control), and discusses the clinical application and pharmacological research of TGP as an anti-inflammatory drug from the perspective of ethnopharmacology. Additionally, we review modern pharmacological and molecular-target research on TGP and discuss the mechanisms of TGP in treating autoimmune diseases. Through a systematic literature review, we also highlight the clinical efficacy of TGP in the treatment of immune diseases, and provide a reference for the continued scientific development and quality control of TGP so that its wider application and clinical value can be fully realized.

MATERIALS AND METHODS

Literature search was conducted through the Web of Science, Baidu Scholar, ScienceDirect, PubMed, CNKI, and WanFang DATA using the keywords "Total glucosides of paeony", "Paeonia lactiflora Pall. ", "Paeonia veitchii Lynch", "Paeoniae Radix Alba or white peony", "Paeoniae Radix Rubra or red peony", "Paeoniflorin", "Albiflorin", "Autoimmune diseases", and their combinations. In addition, information was collected from relevant textbooks, reviews, and documents.

RESULTS

Approximately 15 compounds have been identified in TGP, of which paeoniflorin and albiflorin are the most common constituents. In recent years, studies have found that TGP and its main chemical components are effective in the treatment of autoimmune diseases, such as rheumatoid arthritis, psoriasis, oral lichen planus, and Sjogren's syndrome. TGP has a variety of pharmacological effects related to PRA traditional effects, including anti-organ-damage, anti-inflammatory, analgesic, antioxidant, cardiovascular, and nervous-system protection. Previously published reports on TGP treatment of autoimmune diseases have shown that TGP regulates intracellular pathways, such as the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathways. However, there is no standardized preparation method for TGP, and there is insufficient quality control of formulations. Many related pharmacological studies have not tested TGP components, and the validity of such pharmacological results requires further verification.

CONCLUSIONS

Modern pharmacological research on TGP is based on the traditional usage of PRA, and its folk medicinal value in the treatment of autoimmune diseases has now been verified. In particular, TGP has been developed into a formulation used clinically for the treatment of autoimmune diseases. The combination of TGP capsules and chemicals to treat autoimmune diseases has the effect of increasing efficacy and reducing toxicity. Based on further research on its preparation, quality control, and mechanisms of action, TGP is expected to eventually play a greater role in the treatment of autoimmune diseases.

A review on the pharmacokinetics of paeoniflorin and its anti-inflammatory and immunomodulatory effects

Increasing pharmacological evidence supports that paeoniflorin, a water-soluble monoterpene glycoside isolated from Paeonia lactiflora Pall. (Shaoyao in Chinese), has a wide range of medicinal properties including anti-inflammatory, antioxidant, antithrombotic, anticonvulsive, analgesic, cardioprotective, neuroprotective, hepatoprotective, antidepressant-like, antitumoral, and immune-regulatory activities; as well as enhancing cognition and attenuating learning impairment. In addition to pharmacodynamic studies, information on pharmacokinetics is also significant for the further development and utilization of paeoniflorin. The present review focuses on the absorption, distribution, metabolism, and excretion of paeoniflorin, especially main pharmacological activities of paeoniflorin on inflammation and immune function. According to the findings obtained both in vitro and in vivo, a broad application prospect has been opened for paeoniflorin. However, further studies are needed to clarity the direct molecular mechanisms and key targets underlying the beneficial effects of paeoniflorin on inflammation and immunity.

Paeoniflorin relieves LPS-induced inflammatory pain in mice by inhibiting NLRP3 inflammasome activation via transient receptor potential vanilloid 1

LPS has been widely used to induce inflammatory pain, attributing to production of inflammatory cytokines and sensitization of nociceptors. Paeoniflorin (PF) possesses anti-nociceptive property, but its effect on LPS-induced inflammatory pain has not been investigated. In this study, we aimed to investigate the analgesic effect of PF on an inflammatory pain mouse model and explore the underlying mechanisms. LPS-induced inflammatory pain model was established in C57BL/6J mice after PF treatment. Then, thermal hyperalgesia, neutrophil infiltration, inflammatory cytokine production, intracellular Ca²⁺ levels, PKC activity, transient receptor potential vanilloid 1 (TRPV-1) expression, NF-κB transcription, and NLPR3 inflammasome activation were assessed by thermal withdrawal latency, histopathology, ELISA, intracellular Ca²⁺ concentration, immunohistochemistry, and Western blot, separately. PF significantly relieved inflammatory pain and paw edema in mice with LPS-induced inflammatory pain. Additionally, PF inhibited neutrophil infiltration, inflammatory cytokine production (IL-1β, TNF-α, and IL-6), intracellular Ca²⁺ levels, and PKC activity as well as suppressed TRPV-1 expression, NF-κB transcription, and NLPR3 inflammasome activation in the footpad tissue samples. Importantly, capsaicin (TRPV-1 agonists) obviously reversed the pain-relieving effect of PF, suggesting the involvement of TRPV-1 in the analgesic activity of PF. Our results indicated PF ameliorated LPS-induced inflammation and pain in mice by inhibiting TRPV-1-mediated NLRP3 inflammasome activation. These findings suggest that PF can be as a potential pharmacological agent for inflammatory pain and thus deserves more attention and further investigation.

Transient receptor potential vanilloid 1 promotes EGFR ubiquitination and modulates EGFR/MAPK signalling in pancreatic cancer cells

Transient receptor potential vanilloid-1 (TRPV1) was first identified in sensory neurons, where it was suggested as a therapeutic target for pain relief. Here, we show that TRPV1 is expressed in the pancreatic cancer cell line, PANC-1; that epidermal growth factor receptor (EGFR) expression is downregulated by overexpression or agonist-induced activation of TRPV1; and conversely, that EGFR expression is increased after silencing TRPV1. Furthermore, TRPV1 overexpression inhibits cell proliferation and significantly reduces the mRNA levels of two oncogenes, KRAS and AKT2. More importantly, TRPV1 downregulates EGFR levels by inducing EGFR ubiquitination and degradation, which modulate EGFR/MAPK signalling in pancreatic cancer cells. These results illustrate the regulation and mechanism of TRPV1 on EGFR in pancreatic cancer cells and may provide new ideas for the design of novel antitumor drugs targeting EGFR. SIGNIFICANCE OF THE STUDY: We investigated the effect and mechanism of TRPV1 on EGFR-mediated proliferation and transformation of pancreatic cancer cells, with the aim of providing new ideas and experimental evidence for the application of strategies that promote EGFR degradation to treat pancreatic cancer.

Inhibitory Effect of Galactooligosaccharide on Skin Pigmentation

To investigate the effects of ingestion of galactooligosaccharide (GOS) on skin pigmentation, we conducted cell experiments and clinical trials. The effect of GOS on melanin accumulation was assessed in vitro using B16F10 cells. Moreover, melanin and erythema indexes following GOS consumption were explored during a double-blind, randomized, and placebo-controlled study, which included subjects divided by stratified block randomization to placebo or GOS. No cytotoxicity was observed at 70 mg/mL or lower GOS in B16F10 melanoma cells. Melanin accumulation was inhibited at 14 mg/mL or higher GOS. Upon ultraviolet B (UVB) irradiation, the survival of HaCaT cells (control) was reduced to 69.0% lower than baseline. A protective effect of GOS was observed upon treatment with 14~35 mg/mL GOS; however at 70 mg/mL, cells showed 64% viability compared to control cells irradiated with UVB. Delta values (Δ melanin index), which indicate the difference from the baseline melanin level, were significantly different to placebo (P<0.01) after 8 weeks. In the GOS group, delta values (Δ erythema index), which indicate the difference from baseline erythema level, also significantly differed from the placebo group (P<0.05) after 8 weeks. Our results suggest that intake of prebiotic GOS inhibits skin pigmentation and may represent a novel nutritional approach for skin care.

Particulate Matter 2.5 Mediates Cutaneous Cellular Injury by Inducing Mitochondria-Associated Endoplasmic Reticulum Stress: Protective Effects of Ginsenoside Rb1

The prevalence of fine particulate matter-induced harm to the human body is increasing daily. The aim of this study was to elucidate the mechanism by which particulate matter 2.5 (PM_2.5) induces damage in human HaCaT keratinocytes and normal human dermal fibroblasts, and to evaluate the preventive capacity of the ginsenoside Rb1. PM_2.5 induced oxidative stress by increasing the production of reactive oxygen species, leading to DNA damage, lipid peroxidation, and protein carbonylation; this effect was inhibited by ginsenoside Rb1. Through gene silencing of endoplasmic reticulum (ER) stress-related genes such as PERK, IRE1, ATF, and CHOP, and through the use of the ER stress inhibitor tauroursodeoxycholic acid (TUDCA), it was demonstrated that PM_2.5-induced ER stress also causes apoptosis and ultimately leads to cell death; however, this phenomenon was reversed by ginsenoside Rb1. We also found that TUDCA partially restored the production of ATP that was inhibited by PM_2.5, and its recovery ability was significantly higher than that of ginsenoside Rb1, indicating that the process of ER stress leading to cell damage may also occur via the mitochondrial pathway. We concluded that ER stress acts alone or via the mitochondrial pathway in the induction of cell damage by PM_2.5, and that ginsenoside Rb1 blocks this process. Ginsenoside Rb1 shows potential for use in skin care products to protect the skin against damage by fine particles.

Enhancing Immunomodulatory Function of Red Ginseng Through Fermentation Using Bifidobacterium animalis Subsp. lactis LT 19-2

Removal of sugar moieties from ginsenosides has been proposed to increase their biological effects in various disease models. In order to identify strains that can increase aglycone contents, we performed a screening using bacteria isolated from the feces of infants focusing on acid tolerance and β-glucosidase activity. We isolated 565 bacteria and selected Bifidobacterium animalis subsp. lactis LT 19-2 (LT 19-2), which exhibited the highest β-glucosidase activity with strong acid tolerance. As red ginseng (RG) has been known to exert immunomodulatory functions, we fermented RG using LT 19-2 (FRG) and investigated whether this could alter the aglycone profile of ginsenosides and improve its immunomodulatory effect. FRG increased macrophage activity more potently compared to RG, demonstrated by higher TNF-α and IL-6 production. More importantly, the FRG treatment stimulated the proliferation of mouse splenocytes and increased TNF-α levels in bone marrow-derived macrophages, confirming that the enhanced immunomodulatory function can be recapitulated in primary immune cells. Examination of the molecular mechanism revealed that F-RG could induce phosphorylations of ERK, p38, JNK, and NF-κB. Analysis of the ginsenoside composition showed a decrease in Rb1, Re, Rc, and Rb3, accompanied by an increase in Rd, Rh1, F2, and Rg3, the corresponding aglycone metabolites, in FRG compared to RG. Collectively, LT 19-2 maybe used as a probiotic strain to improve the bioactivity of functional foods through modifying the aglycone/glycoside profile.

[6]-gingerol and [6]-shogaol, active ingredients of the traditional Japanese medicine hangeshashinto, relief oral ulcerative mucositis-induced pain via action on Na+ channels

The traditional Japanese herbal medicine hangeshashinto (HST) has beneficial effects for the treatment of oral ulcerative mucositis (OUM) in cancer patients. However, the ingredient-based mechanism that underlies its pain-relieving activity remains unknown. In the present study, to clarify the analgesic mechanism of HST on OUM-induced pain, we investigated putative HST ingredients showing antagonistic effects on Na⁺ channels in vitro and in vivo. A screen of 21 major ingredients using automated patch-clamp recordings in channel-expressing cells showed that [6]-gingerol and [6]-shogaol, two components of a Processed Ginger extract, considerably inhibited voltage-activated Na⁺ currents. These two ingredients inhibited the stimulant-induced release of substance P and action potential generation in cultured rat sensory neurons. A submucosal injection of a mixture of [6]-gingerol and [6]-shogaol increased the mechanical withdrawal threshold in healthy rats. In a rat OUM model, OUM-induced mechanical pain was alleviated 30min after the swab application of HST despite the absence of anti-bacterial and anti-inflammatory actions in the OUM area. A swab application of a mixture of [6]-gingerol and [6]-shogaol induced sufficient analgesia of OUM-induced mechanical or spontaneous pain when co-applied with a Ginseng extract containing abundant saponin. The Ginseng extract demonstrated an acceleration of substance permeability into the oral ulcer tissue without an analgesic effect. These findings suggest that Na⁺ channel blockage by gingerol/shogaol plays an essential role in HST-associated analgesia of OUM-induced pain. This pharmacological mechanism provides scientific evidence supporting the use of this herbal medicine in patients suffering from OUM-induced pain.

The skin-depigmenting potential of Paeonia lactiflora root extract and paeoniflorin: in vitro evaluation using reconstructed pigmented human epidermis

OBJECTIVE

The roots of the herb Paeonia lactiflora ('White Peony') are used in association with other herbs in traditional clinical cosmetic practice in China as oral treatment for skin pigmentary disorders, such as brown or dark pigmentary spots. However, the skin-depigmenting potential of Paeonia lactiflora root extract and its main ingredient paeoniflorin has been scarcely investigated by topical application. The purpose of this study was to evaluate the efficacy of Paeonia lactiflora root extract and paeoniflorin as skin whitening agent in cosmetic application.

METHODS

Paeonia lactiflora root extract (containing 53.25% of paeoniflorin) and paeoniflorin (97% purity) were applied topically on reconstructed pigmented human epidermis model, a three-dimensional (3D) human skin equivalent, showing morphological and functional characteristics similar to those of in vivo human skin. Two specific methods were used for quantifying melanin inside the reconstructed pigmented epidermis: Fontana-Masson staining (2D quantification) and multiphoton microscopy (3D quantification).

RESULTS

Compared to vehicle (dimethyl sulfoxide DMSO), a significant decrease in 2D and 3D melanin content was observed after topical application on reconstructed pigmented epidermis of Paeonia lactiflora extract at 300 μg mL(-1) (-28% and -27%, respectively) and paeoniflorin at 120 μg mL(-1) /250 μM (-30% and -23%, respectively), which is in the same order of magnitude as the positive reference 4-n-butylresorcinol at 83 μg mL(-1) /500 μM (-26% and -40%, respectively).

CONCLUSION

These results demonstrate, for the first time, the depigmenting potential of paeoniflorin and thus the potential interest of using Paeonia lactiflora root extracts containing paeoniflorin in cosmetic or dermatological applications for reducing the severity of some hyperpigmented skin disorders.

Identification of nuclear factor-κB inhibitors and β2 adrenergic receptor agonists in Chinese medicinal preparation Fuzilizhong pills using UPLC with quadrupole time-of-flight MS

INTRODUCTION

Fuzilizhong Pills (FZLZ), a modified form of a famous traditional Chinese medicine (TCM) Lizhong Wan in Treatise on Febrile Diseases and consisting of Panax ginseng C.A.Mey. (Ren Shen), Aconitum carmichaelii Debx. (Fu Zi, Zhi), Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat. or Glycyrrhiza glabra L. (Gan Cao), Atractylodes macrocephala Koidz. (Bai Zhu) and Zingiber offcinale Rosc. (Gan Jiang), show strong clinical therapeutic effects for dyspnea and pulmonary oedema. However, the bioactive compounds are still unclear. In this study, FZLZ was analysed using a rapid detection method to identify its anti-inflammatory and spasmolytic constituents.

OBJECTIVE

To develop a simple screening method to detect the anti-inflammatory and spasmolytic constituents of FZLZ.

METHODS

Ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry combined with dual-bioactive (NF-κB and β2 -adrenergic receptor) luciferase reporter assay systems was employed.

RESULTS

Two β2 -adrenergic receptor agonists (salsolinol and higeramine) and three terpenoidal analogues of NF-κB inhibitors such as ginsenosides derivatives, triperpenoids derivatives and diester-diterpenoid aconitum alkaloid derivatives were characterised. Mesaconitine, flaconitine, ginsenosides Rb2, Rf, Rg2, F1 and Ro were considered to be new NF-κB inhibitors. Furthermore, IL-8 detection by enzyme linked immunosorbent assay confirmed the anti-inflammatory effects of the potential NF-κB inhibitors.

CONCLUSION

Compared with conventional fingerprints, activity-integrated fingerprints that contain both chemical and bioactive details offer a more comprehensive understanding of the chemical composition of plant materials. This strategy clearly demonstrated that dual bioactivity-integrated fingerprinting is a powerful tool for the improved screening and identification of potential dual-target lead compounds in complex herbal medicines.

Biochemical basis of cancer chemoprevention and/or chemotherapy with ginsenosides (Review)

Cancer still imposes a global threat to public health. After decades of research on cancer biology and enormous efforts in developing anticancer therapies, we now understand that the majority of cancers can be prevented. Bioactive phytochemicals present in edible plants have been shown to reduce the risk of various types of cancer. Ginseng (Panax ginseng C.A. Meyer), which contains a wide variety of saponins, known as ginsenosides, is an age-old remedy for human ailments, including cancer. Numerous laboratory-based studies have revealed the anticancer properties of ginsenosides, which compel tumor cells to commit suicide, arrest the proliferation of cancer cells in culture and inhibit experimentally-induced tumor formation in laboratory animals. Ginsenosides have been reported to inhibit tumor angiogenesis, as well as the invasion and metastasis of various types of cancer cells. Moreover, ginsenosides as combination therapy enhance the sensitivity of chemoresistant tumors to clinically used chemotherapeutic agents. This review sheds light on the molecular mechanisms underlying the cancer chemopreventive and/or chemotherapeutic activity of ginsenosides and their intestinal metabolites with particular focus on the modulation of cell signaling pathways associated with oxidative stress, inflammation, cell proliferation, apoptosis, angiogenesis and the metastasis of cancer cells.

Opportunistic activation of TRP receptors by endogenous lipids: exploiting lipidomics to understand TRP receptor cellular communication

Transient receptor potential channels (TRPs) form a large family of ubiquitous non-selective cation channels that function as cellular sensors and in many cases regulate intracellular calcium. Identification of the endogenous ligands that activate these TRP receptors is still under intense investigation with the majority of these channels still remaining "orphans." That these channels respond to a variety of external stimuli (e.g. plant-derived lipids, changes in temperature, and changes in pH) provides a framework for their abilities as cellular sensors, however, the mechanism of direct activation is still under much debate and research. In the cases where endogenous ligands (predominately lipids) have shown direct activation of a channel, multiple ligands have been shown to activate the same channel suggesting that these receptors are "promiscuous" in nature. Lipidomics of a growing class of endogenous lipids, N-acyl amides, the most famous of which is N-arachidonoyl ethanolamine (the endogenous cannabinoid, Anandamide) is providing a novel set of ligands that have been shown to activate some members of the TRP family and have the potential to deorphanize many more. Here it is argued that activation of TRPV receptors, a subset of the larger family of TRPs, by multiple endogenous lipids that are structurally analogous is a model system to drive our understanding that many TRP receptors are not promiscuous, but are more characteristically "opportunistic" in nature; exploiting the structural similarity and biosynthesis of a narrow range of analogous endogenous lipids. In addition, this manuscript will compare the activation properties of TRPC5 to the activity profile of an "orphan" lipid, N-palmitoyl glycine; further demonstrating that lipidomics aimed at expanding our knowledge of the family of N-acyl amides has the potential to provide novel avenues of research for TRP receptors.

Transient receptor potential vanilloid-1 participates in the inhibitory effect of ginsenoside Rg1 on capsaicin-induced interleukin-8 and prostaglandin E2 production in HaCaT cells

OBJECTIVES

Ginsenoside Rg1 (GRg1), one of the major active constituents of Panax notoginseng, has shown anti-inflammatory and antinocioceptic activity, but its role in keratinocytes needs further study. We have examined the inhibitory effect of GRg1 on transient receptor potential vanilloid-1 (TRPV1) activation in keratinocyte HaCaT cells and explored its involved mechanism.

METHODS

HEK 293T cells over-expressing exogenous TRPV1 were constructed and named HEK 293T-TRPV1 cells. The effects of GRg1 on production of interleukin-8 (IL-8) and prostaglandin E(2) (PGE(2) ), calcium influx, the expression of cyclooxygenase-2 (COX-2) and nuclear factor-κB (NF-κB) transcriptional activity in HEK 293T-TRPV1 and HaCaT cells were examined by ELISA, Fluo 3-AM fluorescence probe, Western blot and Dual-Luciferase Reporter Assay, respectively.

KEY FINDINGS

The results showed that GRg1 blocked intracellular calcium by both capsaicin and proton activation in a TRPV1-dependent manner. Furthermore, GRg1 inhibited the expression of COX-2 and NF-κB transcriptional activity induced by capsaicin in keratinocytes. The inhibitory effect of GRg1 was similar to capsazepine, an antagonist of TRPV1. More importantly, GRg1 dose-dependently inhibited capsaicin-induced PGE(2) and IL-8 secretion in HaCaT cells and HEK 293T-TRPV1 cells.

CONCLUSIONS

These data showed that GRg1 could inhibit TRPV1 mediated responses in HaCaT cells, indicating that GRg1 acted as a TRPV1 antagonist.

Paeoniflorin inhibits function of synoviocytes pretreated by rIL-1α and regulates EP4 receptor expression

ETHNOPHARMACOLOGICAL RELEVANCE

To investigate the effect of the Paeoniflorin (Pae), a main active component of total glucosides of paeony (TGP) extracted from the root of Paeonia lactiflora, on regulation of synoviocytes cultured from rats collagen-induced arthritis (CIA) in vitro.

MATERIALS AND METHODS

CIA was induced in male Sprague-Dawley rats immunized with chicken type II collagen (CCII) in Freund's complete adjuvant. The levels of interleukin-1 (IL-1), tumor necrosis factor α (TNF-α), prostaglandin E(2) (PGE(2)) and cyclic adenosine monophosphate (cAMP) were measured by radioimmunoassay. The proliferation responses was determined by the 3-(4,5-2dimethylthiazal-2yl) 2,5-diphenyltetrazoliumbromide (MTT) assay. Expression of E-prostanoid (EP(4)) receptor was detected by Western blotting technique.

RESULTS

Treatment of Pae (2.5, 12.5, 62.5 μg/ml) significantly decreased the production of IL-1 and TNF-α. Recombinant interleukin-1 (rIL-1α) (10 ng/ml) apparently stimulated synoviocyte, thymocyte and splenocyte proliferation, and Pae (12.5, 62.5 μg/ml) inhibited abnormal proliferation responses stimulated by rIL-1α. Moreover, rIL-1α time- and concentration-dependently increased production of PGE(2). The production of PGE(2) produced by synoviocytes from CIA rats significantly inhibited by administration of Pae (12.5, 62.5 μg/ml). rIL-1α (10 ng/ml) decreased cAMP of synoviocytes cells treated for 24h. Similarly rIL-1α (0.1, 1, 10 ng/ml) induced a concentration-dependent decrease in the production of cAMP at 24h. Pae (12.5, 62.5 μg/ml) increased the production of cAMP in synoviocytes. The immunoblot, Pae (12.5, 62.5 μg/ml) apparently increased the expression of EP(4) receptor in synoviocytes stimulated by rIL-1α (10 ng/ml).

CONCLUSIONS

The present study indicates that Pae might exert its anti-inflammatory effects through suppressing synoviocytes function and regulating immune cells responses in CIA rats, which might be associated with its ability to up-regulate the E-prostanoid (EP(4)) receptor protein expression and modulate intracellular cAMP level.

Effects of Panax ginseng on tumor necrosis factor-α-mediated inflammation: a mini-review

Panax ginseng is one of the most commonly used Chinese medicines in China, Asia and Western countries. The beneficial effects of ginseng have been attributed to the biological activities of its constituents, the ginsenosides. In this review, we summarize recent publications on the anti-inflammatory effects of ginseng extracts and ginsenosides on cellular responses triggered by different inducers including endotoxin, tumor necrosis factor-alpha (TNF-α), interferon-gamma and other stimuli. Proinflammatory cytokines, chemokines, adhesion molecules and mediators of inflammation including inducible nitric oxide synthase, cyclooxygenase-2 and nitric oxide orchestrate the inflammatory response. Ginseng extracts and ginsenosides including Rb₁, Rd, Rg₁, Rg₃, Rh₁, Rh₂, Rh₃ and Rp₁ have been reported to have anti-inflammatory properties in different studies related to inflammation. Ginsenosides inhibit different inducers-activated signaling protein kinases and transcription factor nuclear factor-kappaB leading to decreases in the production of cytokines and mediators of inflammation. The therapeutic potential of ginseng on TNF-α-mediated inflammatory diseases is also discussed. Taken together, this summary provides evidences for the anti-inflammatory effects of ginseng extracts and ginsenosides as well as the underlying mechanisms of their effects on inflammatory diseases.