Kaempferia parviflora Extract as a Potential Anti-Acne Agent with Anti-Inflammatory, Sebostatic and Anti-Propionibacterium acnes Activity

Research progress on the role of macrophages in acne and regulation by natural plant products

Acne vulgaris is one of the most common skin diseases. The current understanding of acne primarily revolves around inflammatory responses, sebum metabolism disorders, aberrant hormone and receptor expression, colonization by Cutibacterium acnes, and abnormal keratinization of follicular sebaceous glands. Although the precise mechanism of action remains incompletely understood, it is plausible that macrophages exert an influence on these pathological features. Macrophages, as a constituent of the human innate immune system, typically manifest distinct phenotypes across various diseases. It has been observed that the polarization of macrophages toward the M1 phenotype plays a pivotal role in the pathogenesis of acne. In recent years, extensive research on acne has revealed an increasing number of natural remedies exhibiting therapeutic efficacy through the modulation of macrophage polarization. This review investigates the role of cutaneous macrophages, elucidates their potential significance in the pathogenesis of acne, a prevalent chronic inflammatory skin disorder, and explores the therapeutic mechanisms of natural plant products targeting macrophages. Despite these insights, the precise role of macrophages in the pathogenesis of acne remains poorly elucidated. Subsequent investigations in this domain will further illuminate the pathogenesis of acne and potentially offer guidance for identifying novel therapeutic targets for this condition.

The circadian rhythm: A new target of natural products that can protect against diseases of the metabolic system, cardiovascular system, and nervous system

BACKGROUND

The treatment of metabolic system, cardiovascular system, and nervous system diseases remains to be explored. In the internal environment of organisms, the metabolism of substances such as carbohydrates, lipids and proteins (including biohormones and enzymes) exhibit a certain circadian rhythm to maintain the energy supply and material cycle needed for the normal activities of organisms. As a key factor for the health of organisms, the circadian rhythm can be disrupted by pathological conditions, and this disruption accelerates the progression of diseases and results in a vicious cycle. The current treatments targeting the circadian rhythm for the treatment of metabolic system, cardiovascular system, and nervous system diseases have certain limitations, and the identification of safer and more effective circadian rhythm regulators is needed.

AIM OF THE REVIEW

To systematically assess the possibility of using the biological clock as a natural product target for disease intervention, this work reviews a range of evidence on the potential effectiveness of natural products targeting the circadian rhythm to protect against diseases of the metabolic system, cardiovascular system, and nervous system. This manuscript focuses on how natural products restore normal function by affecting the amplitude of the expression of circadian factors, sleep/wake cycles and the structure of the gut microbiota.

KEY SCIENTIFIC CONCEPTS OF THE REVIEW

This work proposes that the circadian rhythm, which is regulated by the amplitude of the expression of circadian rhythm-related factors and the sleep/wake cycle, is crucial for diseases of the metabolic system, cardiovascular system and nervous system and is a new target for slowing the progression of diseases through the use of natural products. This manuscript provides a reference for the molecular modeling of natural products that target the circadian rhythm and provides a new perspective for the time-targeted action of drugs.

Macrophages in acne vulgaris: mediating phagocytosis, inflammation, scar formation, and therapeutic implications

Macrophages serve as a pivotal nexus in the pathogenesis of acne vulgaris, orchestrating both the elimination of Cutibacterium acnes (C. acnes) and lipid metabolic regulation while also possessing the capacity to exacerbate inflammation and induce cutaneous scarring. Additionally, recent investigations underscore the therapeutic potential inherent in macrophage modulation and challenge current anti-inflammatory strategies for acne vulgaris. This review distills contemporary advances, specifically examining the dual roles of macrophages, underlying regulatory frameworks, and emergent therapeutic avenues. Such nuanced insights hold the promise of guiding future explorations into the molecular etiology of acne and the development of more efficacious treatment modalities.

The updates and implications of cutaneous microbiota in acne

Acne is a chronic inflammatory skin disorder that profoundly impacts the quality of life of patients worldwide. While it is predominantly observed in adolescents, it can affect individuals across all age groups. Acne pathogenesis is believed to be a result of various endogenous and exogenous factors, but the precise mechanisms remain elusive. Recent studies suggest that dysbiosis of the skin microbiota significantly contributes to acne development. Specifically, Cutibacterium acnes, the dominant resident bacterial species implicated in acne, plays a critical role in disease progression. Various treatments, including topical benzoyl peroxide, systemic antibiotics, and photodynamic therapy, have demonstrated beneficial effects on the skin microbiota composition in acne patients. Of particular interest is the therapeutic potential of probiotics in acne, given its direct influence on the skin microbiota. This review summarizes the alterations in skin microbiota associated with acne, provides insight into its pathogenic role in acne, and emphasizes the potential of therapeutic interventions aimed at restoring microbial homeostasis for acne management.

The industrially important genus Kaempferia: An ethnopharmacological review

Kaempferia, a genus of the family Zingiberaceae, is widely distributed with more than 50 species which are mostly found throughout Southeast Asia. These plants have important ethnobotanical significance as many species are used in Ayurvedic and other traditional medicine preparations. This genus has received a lot of scholarly attention recently as a result of the numerous health advantages it possesses. In this review, we have compiled the scientific information regarding the relevance, distribution, industrial applications, phytochemistry, ethnopharmacology, tissue culture and conservation initiative of the Kaempferia genus along with the commercial realities and limitations of the research as well as missing industrial linkages followed by an exploration of some of the likely future promising clinical potential. The current review provides a richer and deeper understanding of Kaempferia, which can be applied in areas like phytopharmacology, molecular research, and industrial biology. The knowledge from this study can be further implemented for the establishment of new conservation strategies.

The Chemistry and the Anti-Inflammatory Activity of Polymethoxyflavonoids from Citrus Genus

Polymethoxyflavonoids (PMFs) are a large group of compounds belonging to the more general class of flavonoids that possess a flavan carbon framework decorated with a variable number of methoxy groups. Hydroxylated polymethoxyflavonoids (HPMFs), instead, are characterized by the presence of both hydroxyl and methoxy groups in their structural unities. Some of these compounds are the aglycone part in a glycoside structure in which the glycosidic linkage can involve the -OH at various positions. These compounds are particular to Citrus genus plants, especially in fruits, and they are present mainly in the peel. A considerable number of PMFs and HPMFs have shown promising biological activities and they are considered to be important nutraceuticals, responsible for some of the known beneficial effects on health associated with a regular consumption of Citrus fruits. Among their several actions on human health, it is notable that the relevant contribution in controlling the intracellular redox imbalance is associated with the inflammation processes. In this work, we aim to describe the status concerning the chemical identification and the anti-inflammatory activity of both PMFs and HPMFs. In particular, all of the chemical entities unambiguously identified by isolation and complete NMR analysis, and for which a biochemical evaluation on the pure compound was performed, are included in this paper.

Cannabidiol Inhibits Inflammation Induced by Cutibacterium acnes-Derived Extracellular Vesicles via Activation of CB2 Receptor in Keratinocytes

Background

Acne is a common inflammatory skin disease, while cannabidiol (CBD) is a representative non-psychoactive phytocannabinoid which has been proved to exert universal anti-inflammatory properties. This study aimed to explore the effect of CBD on acne inflammation induced by Cutibacterium acnes-derived extracellular vesicles (CEVs) in keratinocytes and reveal the underlying mechanisms.

Methods

Normal human epidermal keratinocytes (NHEKs) were stimulated by CEVs in the presence of CBD or vehicle. Interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α levels were examined by RT-PCR and ELISA. The expression of cannabinoid type-2 (CB2) receptor and transient receptor potential vanilloid type-1 (TRPV1) was detected by Western blotting. TNF-α levels in the presence of CB2 receptor antagonist (AM630) or TRPV1 antagonist (Capsazepine) were detected by RT-PCR. The activation of MAPK and NF-κB signaling pathways and the nuclear translocation of NF-κB p65 upon CBD treatment were analyzed by Western blotting and immunofluorescence assay, respectively.

Results

The expression of inflammatory cytokines (IL-6, IL-8 and TNF-α) in CEVs-stimulated NHEKs was suppressed by CBD. CB2 receptor expression was upregulated by CBD, whereas CEVs-promoted TRPV1 expression was downregulated by CBD. AM630 reversed TNF-α levels inhibited by CBD. Capsazepine exerted an inhibitory effect on CEVs-induced inflammation and had synergistic effect with CBD. The phosphorylation of ERK1/2 and NF-κB p65 and nuclear translocation of NF-κB p65 were induced by CEVs but reduced by CBD.

Conclusion

The results indicated that CBD could inhibit inflammation induced by CEVs in NHEKs, which was mediated by activation of CB2 receptor and enhanced by the TRPV1 antagonist, through inactivation of the MAPK and NF-κB signaling pathways. CBD might be a potential novel strategy for acne treatment in the future.

Kaempferia parviflora Rhizome Extract as Potential Anti-Acne Ingredient

Kaempferia parviflora (Black ginger) is used widely in medical fields as an anti-microorganism and anti-inflammation. In this study, the aim was to evaluate the in vitro and in vivo anti-acne efficacy of black ginger extract. The results indicate that the methanol and ethanol extracts showed the highest total phenolic contents, without a significant difference, whereas the n-hexane extract showed the highest total flavonoid content. Nine flavones were detected using UPLC−QTOF−MS, and the ethyl acetate extract showed the highest amount of 5,7-dimethoxyflavone (DMF) according to HPLC. Antibacterial activity against Staphylococcus aureus, S. epidermidis, and Cutibacterium acnes was observed. All the extracts showed antimicrobial activity against C. acnes, revealing MICs in the range of 0.015 to 0.030 mg/mL, whereas the ethyl acetate extract inhibited the growth of S. epidermidis with a MIC of 3.84 mg/mL. In addition, the ethyl acetate extract showed the highest activity regarding nitric oxide inhibition (IC50 = 12.59 ± 0.35 µg/mL). The ethyl acetate extract was shown to be safe regarding cell viability at 0.1 mg/mL. The anti-acne efficacy was evaluated on volunteers. The volunteers were treated in two groups: one administered a 0.02% ethyl acetate extract gel-cream (n = 9) and one administered a placebo (n = 9) for 6 weeks. The group treated with the gel-cream containing the extract showed 36.52 and 52.20% decreases in acne severity index (ASI) after 4 and 6 weeks, respectively, and 18.19 and 18.54% decreases in erythema, respectively. The results suggest that K. parviflora could be a potent active ingredient in anti-inflammatory and anti-acne products.

Suppression of Cutibacterium acnes-Mediated Inflammatory Reactions by Fibroblast Growth Factor 21 in Skin

Cutibacterium acnes (C. acnes) is a common commensal bacterium that is closely associated with the pathogenesis of acne. Fibroblast growth factor 21 (FGF21), as a favorable regulator of glucose and lipid metabolism and insulin sensitivity, was recently shown to exert anti-inflammatory effects. The role and mechanism of FGF21 in the inflammatory reactions induced by C. acnes, however, have not been determined. The present study shows that FGF21 in the dermis inhibits epidermal C. acnes-induced inflammation in a paracrine manner while it functions on the epidermal layer through a receptor complex consisting of FGF receptor 1 (FGFR1) and β-Klotho (KLB). The effects of FGF21 in heat-killed C. acnes-induced HaCaT cells and living C. acnes-injected mouse ears were examined. In the presence of C. acnes, FGF21 largely counteracted the activation of Toll-like receptor 2 (TLR2), the downstream nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways induced by C. acnes. FGF21 also significantly reduced the expression of proinflammatory cytokines, including interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α. Taken together, these findings indicate that FGF21 suppresses C. acnes-induced inflammation and might be used clinically in the management and treatment of acne.

Bee Venom and Its Major Component Melittin Attenuated Cutibacterium acnes- and IGF-1-Induced Acne Vulgaris via Inactivation of Akt/mTOR/SREBP Signaling Pathway

Acne vulgaris is the most common disease of the pilosebaceous unit. The pathogenesis of this disease is complex, involving increased sebum production and perifollicular inflammation. Understanding the factors that regulate sebum production is important in identifying novel therapeutic targets for the treatment of acne. Bee Venom (BV) and melittin have multiple effects including antibacterial, antiviral, and anti-inflammatory activities in various cell types. However, the anti-lipogenic mechanisms of BV and melittin have not been elucidated. We investigated the effects of BV and melittin in models of Insulin-like growth factor-1 (IGF-1) or Cutibacterium acnes (C. acnes)-induced lipogenic skin disease. C. acnes or IGF-1 increased the expression of sterol regulatory element-binding protein-1 (SREBP-1) and proliferator-activated receptor gamma (PPAR-γ), transcription factors that regulate numerous genes involved in lipid biosynthesis through the protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/SREBP signaling pathway. In this study using a C. acnes or IGF-1 stimulated lipogenic disease model, BV and melittin inhibited the increased expression of lipogenic and pro-inflammatory factor through the blockade of the Akt/mTOR/SREBP signaling pathway. This study suggests for the first time that BV and melittin could be developed as potential natural anti-acne agents with anti-lipogenesis, anti-inflammatory, and anti-C. acnes activity.

Anti-Acne Vulgaris Potential of the Ethanolic Extract of Mesua ferrea L. Flowers

Acne vulgaris is a common chronic inflammatory skin disease. In the present study, we reported the anti-acne vulgaris effect of the Mesua ferrea (M. ferrea) flower extract. The extract was evaluated for three anti-acne-causing bacteria properties including Cutibacterium acnes (C. acnes), Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus). The results indicated that the M. ferrea flower extract could be considered as the bactericidal agent against S. epidermidis and S. aureus with MIC values of 0.78 and 6.25 mg mL−1 and MBC values of 1.56 and 12.50 mg mL−1 and the bacteriostatic agent against C. acnes with MIC and MBC values of 3.12 and 25.00 mg mL−1, respectively. The extract at a concentration of 25 µg mL−1 also presented potent anti-inflammatory activity with a significant decrease of nitric oxide (NO) and tumor necrosis factor (TNF)-α productions in RAW 264.7 macrophage cells stimulated by LPS. In addition, the extract showed moderate to weak anti-oxidative capacities against DPPH, ABTS, FRAP and NO assays and also showed weak anti-tyrosinase activity. M. ferrea flower extract may serve as the alternative natural anti-acne formulations.

Anti-psoriatic and anti-inflammatory effects of Kaempferia parviflora in keratinocytes and macrophage cells

Kaempferia parviflora (KP) has been used as folk medicine for curing various conditions, including anti-inflammatory diseases. However, anti-psoriatic effects in an aspect of suppression of NF-κB activation have not been explored. Therefore, our current study aimed to elucidate the anti-inflammation of KP in lipopolysaccharide (LPS)-induced RAW264.7 cells and anti-psoriatic effects of KP in cytokine-induced human keratinocytes, HaCaT cells. We discovered that KP extract significantly suppressed LPS-induced inflammation at both gene expression and protein production. Specifically, dramatic reduction of nitric oxide (NO) was explored by using Griess method. Consistently, data from RT-qPCR, ELISA, and western blot analysis confirmed that crucial inflammatory and psoriatic markers including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, IL-17, IL-22, and IL-23 were significantly decreased by the action of KP. These events were associated with the results from immunofluorescence study and western blot analysis where the activation of NF-κB upon LPS stimulation was clearly inhibited by KP through its ability to suppress IκB-α degradation resulting in inhibition of NF-κB nuclear translocation. Furthermore, KP extract significantly inhibited LPS-stimulated phosphorylation of ERK1/2, JNK, and p38 in a dose-dependent manner, along with inhibition of ERK1/2 activation in both TNF-α- and EGF-induced HaCaT cells. Interestingly, HaCaT cells exposed to 15 μg/mL of KP also exhibited significant decrease of cell migration and proliferation. Our results revealed that KP extract has a potential to be developed as a promising agent for treating inflammation and psoriasis, in part through targeting the proliferation and the NF-κB pathways.

Anti-acne vulgaris effects of chlorogenic acid by anti-inflammatory activity and lipogenesis inhibition

Chlorogenic acid (CGA) exhibits substantial biological function in antioxidant, antibacterial, anti-lipogenesis and anti-inflammatory activities. Increased sebum production and inflammation are considered important for the development of acne. However, the therapeutic effects of CGA on acne vulgaris remain unexplored. In this study, to assess the effects and underlying mechanisms of CGA on acne, a model of skin inflammation in ears of ICR mouse induced by living Propionibacterium acnes was used. 24 hours after 1.0 × 107 CFU, P. acnes were intradermally injected into the ears of the ICR mouse. 1, 5 and 10 mg of CGA mixed with vaseline were applied to the surface of the skin every 12 hours for 3 days. Then, skin inflammation in the ears was assessed and the change of SREBP1 and TNF-α expression was analysed after CGA treatment. The mechanisms of CGA in anti-inflammatory activity and lipogenesis were also studied in primary sebocytes and HaCaT cells. We found that CGA treatment effectively rescued ear swelling, redness and erythema skin in ears of ICR mouse induced by P. acnes and significantly downregulated the expression of inflammatory cytokines by reducing the activity of the NF-κB signalling pathway. Furthermore, CGA could inhibit lipogenesis at the protein secretion and transcription level by decreasing the AKT/mTOR/SREBP signalling pathway. Our findings suggest that CGA could become a potential alternative drug for the treatment of acne vulgaris.

Discovery and Development of Inflammatory Inhibitors from 2-Phenylchromonone (Flavone) Scaffolds

Flavonoids are compounds based on a 2-phenylchromonone scaffold. Flavonoids can be divided into flavonoids, flavonols, dihydroflavones, anthocyanins, chalcones and diflavones according to the oxidation degree of the central tricarbonyl chain, the connection position of B-ring (2-or 3-position), and whether the tricarbonyl chain forms a ring or not. There are a variety of biological activities about flavonoids, such as anti-inflammatory activity, anti-oxidation and anti-tumor activity, and the antiinflammatory activity is apparent. This paper reviews the anti-inflammatory activities and mechanisms of flavonoids and their derivatives reported in China and abroad from 2011 till date (2011-2020), in order to find a good drug scaffold for the study of anti-inflammatory activities.

Inhibitory effect of the antimicrobial peptide BLP-7 against Propionibacterium acnes and its anti-inflammatory effect on acne vulgaris

Propionibacterium acnes (P. acnes) is a Gram-positive commensal bacterium, which is involved in the pathogenesis and inflammation of acne vulgaris. An antimicrobial peptide named bombinin-like peptide 7 (BLP-7), which was determined from Bombina orientalis, has been shown to possess certain antibacterial activity. This study was carried out with synthesized BLP-7 on the basis of the antimicrobial and anti-inflammatory activities against P. acnes in vitro and in vivo. The minimal inhibitory concentration (MIC) of BLP-7 against P. acnes is 5 μM. And BLP-7 exhibits strong resistance to heat, pH and salt concentration, but no significant cytotoxicity to normal human epidermal keratinocytes (NHEKs). Using the co-culture of P. acnes and NHEKs, this study demonstrated that BLP-7 significantly reduced the production of interleukin (IL)-8 and granulocyte-macrophage colony stimulating factor (GM-CSF), as well as the expression of these two pro-inflammatory cytokines at the transcriptional level. In a separate study, using the rat ear edema model, BLP-7 significantly suppressed P. acnes-induced skin inflammation, reducing the ear thickness by 54.21% of the negative control group. These results suggest that due to its anti-P. acnes and anti-inflammatory activities, BLP-7 could be used as a potential anti-acne agent.

Recent Advances in Kaempferia Phytochemistry and Biological Activity: A Comprehensive Review

Background: Plants belonging to the genus Kaempferia (family: Zingiberaceae) are distributed in Asia, especially in the southeast region, and Thailand. They have been widely used in traditional medicines to cure metabolic disorders, inflammation, urinary tract infections, fevers, coughs, hypertension, erectile dysfunction, abdominal and gastrointestinal ailments, asthma, wounds, rheumatism, epilepsy, and skin diseases. Objective: Herein, we reported a comprehensive review, including the traditional applications, biological and pharmacological advances, and phytochemical constituents of Kaempheria species from 1972 up to early 2019. Materials and methods: All the information and reported studies concerning Kaempheria plants were summarized from library and digital databases (e.g., Google Scholar, Sci-finder, PubMed, Springer, Elsevier, MDPI, Web of Science, etc.). The correlation between the Kaempheria species was evaluated via principal component analysis (PCA) and agglomerative hierarchical clustering (AHC), based on the main chemical classes of compounds. Results: Approximately 141 chemical constituents have been isolated and reported from Kaempferia species, such as isopimarane, abietane, labdane and clerodane diterpenoids, flavonoids, phenolic acids, phenyl-heptanoids, curcuminoids, tetrahydropyrano-phenolic, and steroids. A probable biosynthesis pathway for the isopimaradiene skeleton is illustrated. In addition, 15 main documented components of volatile oils of Kaempheria were summarized. Biological activities including anticancer, anti-inflammatory, antimicrobial, anticholinesterase, antioxidant, anti-obesity-induced dermatopathy, wound healing, neuroprotective, anti-allergenic, and anti-nociceptive were demonstrated. Conclusions: Up to date, significant advances in phytochemical and pharmacological studies of different Kaempheria species have been witnessed. So, the traditional uses of these plants have been clarified via modern in vitro and in vivo biological studies. In addition, these traditional uses and reported biological results could be correlated via the chemical characterization of these plants. All these data will support the biologists in the elucidation of the biological mechanisms of these plants.