New perspectives on antiacne plant drugs: contribution to modern therapeutics

The efficacy of enoxolone in reducing erythema and pain after laser treatment: A randomized split-face pilot study

BACKGROUND

Enoxolone, derived from licorice, possesses potent anti-inflammatory, and antioxidant properties. However, its effectiveness in alleviating post-laser reactions has not been extensively studied.

AIMS

This randomized split-face pilot study aimed to evaluate the effects of enoxolone on skin following laser treatment.

PATIENTS/METHODS

Ten healthy subjects underwent non-ablative 1550 nm Er:Glass fractional laser treatment and then randomly applied a moisturizer without enoxolone on one side of the face and a dermo-cosmetic formular containing 2% enoxolone mixed with the same moisturizer on the other side. The erythema index (EI), clinician's erythema assessment (CEA), and pain scores were recorded at 30 min, 60 min, and 24 h posttreatment.

RESULTS

The group treated with enoxolone showed significantly lower EI and CEA compared to the control group at 24 h posttreatment. Additionally, pain scores were notably reduced in the enoxolone-treated group 30 min after treatment.

CONCLUSIONS

This study suggests that dermo-cosmetic formular containing 2% enoxolone is effective in reducing erythema and pain following laser treatment.

Isotretinoin self-nano-emulsifying drug delivery system: Preparation, optimization and antibacterial evaluation

Purpose

Isotretinoin (ITN) is a poorly water-soluble drug. The objective of this study was to design a successful liquid self-nanoemulsifying drug delivery system (L-SNEDDS) for ITN to improve its solubility, dissolution rate, and antibacterial activity.

Methods

According to solubility and emulsification studies, castor oil, Cremophor EL, and Transcutol HP were selected as system excipients. A pseudo ternary phase diagram was constructed to reveal the self-emulsification area. The developed SNEDDS were visually assessed, and the droplet size was measured. In vitro release studies and stability studies were conducted. The antimicrobial effectiveness against multiple bacterial strains, including Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and different accessory gene regulator (Agr) variants were investigated for the optimum ITN-loaded SNEDDS formulation.

Results

Characterization studies showed emulsion homogeneity and stability (%T 95.40-99.20, A graded) with low droplet sizes (31.87 ± 1.23 nm-115.47 ± 0.36 nm). It was found that the developed ITN-SNEDDS provided significantly a higher release rate (>96 % in 1 h) as compared to the raw drug (<10 % in 1 h). The in vitro antimicrobial activities of pure ITN and ITN-loaded SNEDDS demonstrated a remarkable inhibitory effect on bacterial growth with statistically significant findings (p < 0.0001) for all tested strains when treated with ITN-SNEDDS as compared to the raw drug.

Conclusion

These outcomes suggested that SNEDDS could be a potential approach for improving solubility, dissolution rates, and antibacterial activity of ITN.

Plants with cosmetic uses

The use of plants as a source of active principles for cosmetics has significantly increased in the last few years. Safety, compatibility with all types of skin, fewer side effects, and availability are among the advantages of herbal cosmetics above synthetic ingredients. The present review aims to explore the most important plants used in cosmetics. A literature search was carried out in several electronic databases with the following phrases: skincare and plants; cosmetics and plants; natural and cosmetics; and natural and skincare. Furthermore, more detailed filters such as clinical studies, meta-analyses, and systemic reviews were applied to positive results. Various plants and plant extracts currently used in skin care, scaring, whitening, and aging, as well as in sun protection, acne, eczema, and others, have been included in this review. The effectiveness of these plants is based mainly on preclinical research, and to a lesser extent on clinical studies. Some plant extracts or oils have been tested clinically, such as onions, aloe, and tea tree oil, more than other plant extracts. Despite many studies on natural products to improve dermal needs, proper clinical cosmeceutical trials are much fewer than expected. Therefore, more clinical trials are needed to evaluate appropriate efficacy. Furthermore, new formulation technologies might enhance the cosmeceutical benefits, but more work is warranted.

Antibacterial and Antiviral Properties of Pinus densiflora Essential Oil

The Korean mountains are home to the Korean red pine (Pinus densiflora). Pine needle oil has been used as a food additive and a traditional herbal medicine; however, any health-related properties of its trunk oil remain unknown. Herein, we assessed antibacterial and antiviral properties of essential oil extracted from the trunk of P. densiflora. Th extracted oil was hydrodistilled using a Clevenger apparatus and analyzed using gas chromatography-mass spectrometry. The antimicrobial activity of the oil was tested using the microbroth dilution technique against 10 bacterial species (6 g-positive and 4 g-negative) and fungi. The extract exerted strong antimicrobial activity against Vibrio parahaemolyticus, Bacillus cereus, Listeria monocytogenes, Propionibacterium acnes, and Malassezia furfur (minimum inhibitory concentration = 10 mL/L). Additionally, it exhibited dose-dependent activity against influenza virus A and feline coronavirus. Furthermore, among 20 identified constituents accounting for 98.7% of the oil contents, the major components included 3-cyclohexene-1-methanol (10.12%), 2-(4-methylcyclohexyl)-2-propanol (9.09%), fenchone (8.14%), O-isopropyltoluene (6.35%), and isothymol methyl ether (6.14%). The P. densiflora trunk essential oil showed antibacterial and antiviral activities that depended on its chemical composition and the microbial strains tested herein. The essential oil can be used as an antimicrobial agent and disinfectant.

Tea Tree Oil: Properties and the Therapeutic Approach to Acne-A Review

Acne vulgaris is an inflammatory dermatological pathology that affects mostly young people. However, it can also appear in adulthood, mainly in women. It has a high psychosocial impact, not only at the time of active lesions but also due to the consequences of lesions such as scarring and hyperpigmentation. Several factors are involved in the physiopathology of acne and the constant search for active ingredients is a reality, namely phytotherapeutic ingredients. Tea tree oil is an essential oil extracted from Melaleuca alternifolia (Maiden & Betch) Cheel with known antibacterial, anti-inflammatory, and antioxidant properties, making it a candidate for the treatment of acne. This review aims to describe the various properties of tea tree oil that make it a possible ingredient to use in the treatment of acne and to present several human studies that have evaluated the efficacy and safety of using tea tree oil in the treatment of acne. It can be concluded that tea tree oil has good antibacterial, anti-inflammatory, and antioxidant properties that result in a decrease in the number of inflammatory lesions, mainly papules, and pustules. However, given the diversity of study designs, it is not possible to draw concrete conclusions on the efficacy and safety of this oil in the treatment of acne.

Anti-Aging, Anti-Acne, and Cytotoxic Activities of Houttuynia cordata Extracts and Phytochemicals Analysis by LC-MS/MS

Although many biological properties of Houttuynia cordata have been found, its anti-aging and anti-acne effects have not yet been investigated. This study was aimed to evaluate the in vitro anti-aging and anti-acne activities of H. cordata extracts and their cytotoxic activities and phytochemicals analyzed with liquid chromatography with tandem mass spectrometry (LC-MS/MS). Dried aerial parts of H. cordata were given different extractions. The aqueous and ethanolic extracts obtained were named HCA and HCE, respectively, and used to screen total phenolic and flavonoid contents. In vitro anti-aging, skin-related antimicrobial, scanning electron microscopy (SEM), in vitro cytotoxic, and LC-MS/MS analyses were performed. The total phenolic contents of the HCA and HCE were 5.11 ± 0.25 and 27.02 ± 1.07 mg gallic acid equivalent (GAE)/g dry extract while their total flavonoid contents were 104.94 ± 5.16 and 571.86 ± 2.86 mg quercetin equivalent (QE)/g dry extract, respectively. The HCA and HCE inhibited the activities of collagenase (28.33–46.00%), elastase (30.00–34.33%), and hyaluronidase (93.87–98.72%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the HCA against Cutibacterium acnes DMST14916 were 5.77 and 5.77 mg/mL while those of the HCE were 2.47 and 2.47 mg/mL, respectively. Cell collapses of C. acnes after treatment with the extracts were observed with SEM. The HCE was not toxic to macrophages, keratinocytes, and fibroblasts up to 400 mg/mL. The HCA showed toxicity against macrophages at 62.5 mg/mL and both skin cells at 250 mg/mL. The main phytochemicals in the extracts were identified with LC-MS/MS. Phenolic compounds, flavonoids, and flavonoid derivatives in H. cordata extracts could be major phytochemicals to possess a broad spectrum of biological activities including antioxidant, antimicrobial, and anti-aging activities. The findings from this study showed that the HCE has potential anti-aging and anti-acne properties while having non-cytotoxic activities on the immune and skin cells. These results indicate that the extract is probably advantageous in the development of skincare cosmeceutics and beauty treatments.

Total Phenolic Content, Antioxidant Capacity and UV Radiation Protection Properties of Marigold (Calendula officinalis), Carrot (Daucus carota), Tomato (Solanum lycopersicum) and Hop (Humulus lupulus) Extracts

Total phenolic content using Folin–Ciocalteu method, antioxidant capacity by CUPRAC method and sun protection properties were measured for four different extracts of selected plants: marigold petals, carrot roots, tomato fruits and hop cones. Three types of extracts: water, oil and water-glycolic (1:4) were studied. Assessment of sun protection properties for extracts obtained from selected plants was first done by mathematical indication method and subsequently done spectrophotometrically. In a method of mathematical indication of UV protection based on absorption spectra, four parameters were determined regarding sun protection properties at different concentrations of selected plant extracts. Absorbance generally increased with an increase of concentration of extracts, but an expected increase of particular parameters was not obtained in all samples. The water-glycolic extract from hop cones was characterized by the highest content of phenolic compounds (among all studied samples) and high antioxidant activity. It also showed high radiation protection. Data for four parameters like UVA/UVB parameter, UVA1/UV parameter, SUI parameter and critical wavelength was generated, and the three first parameters were the highest for water and water-glycolic extracts of marigold. Among all plants, hop cones were characterized by the highest SPF for all types of extracts. SPF values increased with the concentration of extracts, but an increase of the weight of dried plants used to prepared extracts did not influence sun protection factor.

Antimicrobial Formulation of Chrysopogon zizanioides Essential Oil in an Emulsified Lotion for Acne

Acne is a skin condition arising from excess sebum production and microbial overgrowth within the pilosebaceous unit. Several commercial essential oils have shown promising activity against acne-related pathogens. Due to their volatility and thermal instability, the formulation of essential oils into commercial products remains a pharmaceutical challenge. Thus, this study aimed to develop a viable anti-acne topical treatment as an oil-in-water emulsified lotion to overcome these challenges. Chrysopogon zizanioides (vetiver) displayed noteworthy antimicrobial activity with a mean minimum inhibitory concentration of 0.14 mg/mL against Cutibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. Emulsified lotions containing C. zizanioides were developed through the hydrophilic-lipophilic balance approach. At tested hydrophilic-lipophilic balance values of 8, 9, and 10, C. zizanioides emulsified lotions displayed maximum stability at hydrophilic-lipophilic balance 9 with a minimum change in mean droplet size and polydispersity index of 20.61 and 33.33%, respectively, over 84 days. The C. zizanioides emulsified lotion at optimum hydrophilic-lipophilic balance 9 completely inhibited the growth of C. acnes and killed S. aureus, S. epidermidis, and S. pyogenes within 24 h. Additionally, the lotion retained antimicrobial activity against these test micro-organisms over the 84-day stability test period. Thus, the C. zizanioides emulsified lotion demonstrated physical stability and antimicrobial efficiency, making it an ideal natural product anti-acne treatment.

Antibacterial and Anti-Inflammatory Activities of Thymus vulgaris Essential Oil Nanoemulsion on Acne Vulgaris

Antibiotics are frequently used in acne treatment and their prolonged use has led to an emergence of resistance. This study aimed to investigate the use of natural antimicrobials as an alternative therapy. The antimicrobial and anti-inflammatory activities of five commonly used essential oils (EOs) (tea tree, clove, thyme, mentha and basil EOs), and their possible mechanisms of action against Cutibacterium acnes and Staphylococcus epidermidis, were explored. The effect of the most potent EO on membrane permeability was elucidated and its anti-inflammatory action, when formulated as nanoemulsion, was tested in an in vivo acne model. The in vitro studies showed that thyme EO had the most potent antimicrobial and antibiofilm activity, with phenolics and terpenoids as main antimicrobial constituents of EO. Thyme EO affected cell membrane permeability of both bacterial species, evident by the detection of the leakage of intracellular ions and membrane integrity by the leakage of nucleic acids. Morphological alteration in bacterial cells was confirmed by transmission electron microscopy. Thyme EO nanoemulsion led to the suppression of an inflammatory response in acne animal models along with a bacterial load decrease and positive histopathological changes. Collectively, thyme EO nanoemulsion showed potent antimicrobial and anti-inflammatory effects compared to the reference antibiotics, suggesting its effectiveness as a natural alternative in acne treatment.

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.

The Chemical Composition and Biological Activities of Essential Oil from Korean Native Thyme Bak-Ri-Hyang (Thymus quinquecostatus Celak.)

Thymus quinquecostatus Celak. (Korean name: bak-ri-hyang) is an important medicinal and aromatic herb in Korea, which is named for the spread of its fragrance over a distance of approximately 40 km. In traditional Korean systems of medicine, T. quinquecostatus has been used to treat cancer, constipation, hepatic disease, arteriosclerosis, poor circulation in women, constipation, and menstrual irregularities. At present, T. quinquecostatus is used only for ornamental and ground cover purposes. A literature search was conducted to retrieve information regarding the essential oil composition and biological properties of T. quinquecostatus from PubMed, Science Direct, Wiley, Springer, Taylor and Francis, Wiley, and other literature databases. T. quinquecostatus can be divided into different chemotypes, such as γ-terpinene, thymol, phenol, carvacrol, and geraniol, according to the presence of major components in its essential oil. Further, the essential oil from T. quinquecostatus has been reported to possess various therapeutic properties such as antioxidant, antimicrobial, anticancer, anti-inflammatory, analgesic, sleep prolonging, soothing, skin protection and whitening, anti-aging, anti-obesity, and anti-acne properties. In conclusion, this review will be helpful for utilizing the T. quinquecostatus plant in different industries including food, pharmaceuticals, pesticides, perfumery, and cosmetics.

Quercus suber: A Promising Sustainable Raw Material for Cosmetic Application

There is a drive within the cosmetic industry towards the development of more sustainable products, supported by consumer awareness of the environmental footprint. The cosmetic industry is rising to meet consumer demand by following practices, such as the use of by-products from agro-industrial waste. Quercus suber is a tree prevalent in the Mediterranean basin. The extraction of cork is considered sustainable, as this process does not harm the tree, and the amount of cork produced increases with the number of extractions. Beyond this, the cork industry produces by-products that are used to sustain the industry itself, such as cork powder, which is reused for generating energy. Additionally, cork and cork by-products contain bioactive compounds mainly with antioxidant activity that can be of use to the cosmetic industry, such as for antiaging, anti-acne, anti-inflammatory, and depigmenting cosmetic products. We provide the reader with an overview of the putative cosmetic applications of cork and its by-products as well as of their bioactive compounds. It is noteworthy that only a few cork-based cosmetic products have reached the market, namely antiaging and exfoliant products. Clearly, the use of cork upcycled cosmetic ingredients will evolve in the future considering the wide array of biological activities already reported.

Mask Acne in Skin of Color: A Significant Dermatological Condition Amidst the COVID-19 Pandemic

The COVID-19 pandemic has given rise to the need to use personal protective equipment such as masks, among healthcare professionals and the general public. Numerous facial dermatoses linked to the use of masks have been described, from which the term maskne or mask acne has emerged. Although prolonged mask usage has been necessary, and a vast majority of people develop various skin conditions, there is a lack of research on the effects of masks on skin. In this article, we review alterations in biochemical properties of skin associated with mask use in individuals with skin of color and the factors predisposing them to developing acne. Because masks are crucial in preventing the spread of COVID-19, we also elucidate some fundamental strategies such as gentle skin care measures, decreasing the duration of mask wear, and following appropriate protocols for mask re-use, which may prevent mask acne and its long-term effects.

Quercetin loaded cosm-nutraceutical electrospun composite nanofibers for acne alleviation: Preparation, characterization and experimental clinical appraisal

In the cosmeceutical field, it is essential to develop topical delivery systems which would allow drugs to create a depot and permeate within the skin. The aim of the present study was to develop composite nanofibers of polyvinyl alcohol/quercetin/essential oils using the electrospinning technique, and assess their efficiency in acne alleviation. Quercetin was chosen due to its anti-inflammatory, anti-oxidant, and antibacterial activities. Nanofibers were characterized for their morphology, ex-vivo deposition/permeation, physical/mechanical integrity, thermal properties, and chemical characteristics. In addition, the anti-bacterial efficacy was tested on Propionibacterium acne (P. acne), and a cytotoxicity assay was carried out. Lastly, an experimental clinical trial was conducted on acne patients, where the percentage reduction of inflammatory, non-inflammatory and total acne lesions was taken as evaluation criterion. Results showed that quercetin was successfully loaded into the nanofibers which were homogenously dispersed. They showed a reasonable skin deposition percentage of 28.24% ± 0.012, a significantly higher antibacterial efficacy against Propionibacterium acne than quercetin alone, and were utterly safe on skin fibroblastic cells. Upon clinical examination on acne patients, the nanofibers showed 61.2%, 14.7%, and 52.9% reduction of inflammatory, comedonal, and total acne lesions respectively, suggesting a promising topical anti-acne delivery system.

Essential Oils and Their Individual Components in Cosmetic Products

The current consumer demands together with the international regulations have pushed the cosmetic industry to seek new active ingredients from natural renewable sources for manufacturing more eco-sustainability and safe products, with botanical extract being an almost unlimited source of these new actives. Essential oils (EOs) emerge as very common natural ingredients in cosmetics and toiletries as a result of both their odorous character for the design and manufacturing of fragrances and perfumes, and the many beneficial properties of their individual components (EOCs), e.g., anti-inflammatory, antimicrobial and antioxidant properties, and, nowadays, the cosmetic industry includes EOs or different mixtures of their individual components (EOCs), either as active ingredients or as preservatives, in various product ranges (e.g., moisturizers, lotions and cleanser in skin care cosmetics; conditioners, masks or antidandruff products in hair care products; lipsticks, or fragrances in perfumery). However, the unique chemical profile of each individual essential oil is associated with different benefits, and hence it is difficult to generalize their potential applications in cosmetics and toiletries, which often require the effort of formulators in seeking suitable mixtures of EOs or EOCs for obtaining specific benefits in the final products. This work presents an updated review of the available literature related to the most recent advances in the application of EOs and EOCs in the manufacturing of cosmetic products. Furthermore, some specific aspects related to the safety of EOs and EOCs in cosmetics will be discussed. It is expected that the information contained in this comprehensive review can be exploited by formulators in the design and optimization of cosmetic formulations containing botanical extracts.

Insights into the mechanism of Cymbopogan martinii essential oil in topical therapy of acne vulgaris

Aim: The present study investigated the essential oil of Cymbopogan martinii (palmarosa oil; PRO) as a potential topical therapy in acne vulgaris. Materials & methods: GC-MS profiling and biocompatibility studies of PRO were undertaken. The antimicrobial potential was assessed against Cutibacterium acnes. anti-inflammatory, antityrosinase activity and lipid peroxidation were also evaluated. Results: Geraniol was identified as the major phytoconstituent, and the oil was found to be safe for topical application. The minimum inhibitory concentration and minimum bactericidal concentration values were noted as 16 μl/ml. PRO reduced the cytokine levels of TNF-α, IL-12 and IL-8 and inhibited tyrosinase. A low concentration of the oil (up to 0.5 μl/ml) produced malondialdehyde levels equivalent to that of untreated cells. Conclusion: PRO may prove useful as a natural topical agent in the management of acne.

In-vitro antioxidant and antimicrobial studies of ethanolic plant extracts of P. granatum, O. stamineus, A. bilimbi, M. nigra, and E. longifolia

BACKGROUND

Acne is a serious skin problem that affects mostly adolescents. The topical and systematic therapies are effective but could lead to several side effects and the emergence of antibacterial resistance of the acne-causing bacteria. Plant resources have been used as traditional medicine for centuries and can be the alternative therapies for acne treatment. Antioxidants are compounds that can prevent or delay the oxidation of substrates when present in low concentrations. Antioxidants are usually involved in several mechanisms of action, including the inhibition of free radical generation, enhancement of the scavenging capacity against free radicals, and reducing power.

METHODS

In this study, three antioxidant assays, DPPH, ABTS, and FRAP were used to evaluate the antioxidant properties of the ethanolic extracts of five plant extracts (A. bilimbi, M. nigra, O. stamineus, P. granatum, and E. longifolia). Furthermore, the study aimed to identify the most potent plant extracts and their combination which could provide better antibacterial activities against acne-causing bacteria. Ethanolic extracts of A. bilimbi, O. stamineus, M. nigra, P. granatum, and E. longifolia were prepared by the Ultrasound-Assisted Extraction (UAE) technique. Their phytochemical contents were screened using several biochemical tests and GC-MS analysis.

RESULTS

The study found that only the extracts of P. granatum and O. stamineus exhibited good antioxidant activity using DPPH assay (82.37% and 81.72% μg/mL respectively) and in ABTS assay (87.25% and 88.85% μg/mL respectively); their observed FRAP values were 115.1667 ± 5.6182 and 41.3860 ± 2.4583 μg/mL, respectively. The preliminary antibacterial screening using the disc diffusion method showed that P. granatum and O. stamineus were the most potent extracts; hence, both extracts were combined at the ratios of 1:1, 1:2, and 2:1 to a total concentration of 400 mg/mL.

DISCUSSION

The antibacterial efficacy of the mixture was studied using the disc diffusion method and the MIC value was determined. Both S. aureus and S. epidermidis were sensitive to all the individual and combined extracts but C. acnes was resistant to all of them.

CONCLUSION

The antibacterial activity of the combined extracts against S. aureus showed a synergistic effect at the ratio of 2:1 with the inhibitory zone diameter of 18.00 ± 1.00 mm and MIC value of 12.5 mg/mL; however, antagonistic effects were observed against S. epidermidis while no effect was noted against C. acnes. Therefore, all the selected plant extracts exhibited antibacterial activities against certain bacteria and their effects may be enhanced by combining the plant extracts.

Nanotechnological Innovations Enhancing the Topical Therapeutic Efficacy of Quercetin: A Succinct Review

Nanotechnology is currently a hot topic in dermatology and nutraceutical/cosmeceutical delivery, owing to the advantages it provides in terms of enhancing the skin permeation of drugs, as well as increasing their therapeutic efficacy in the treatment of different dermatological diseases. There is also a great interest in the topical delivery of nutraceuticals; which are natural compounds with both therapeutic and cosmetic benefits, in order to overcome the side effects of topically applied chemical drugs. Quercetin is a key nutraceutical with topical antioxidant and anti-inflammatory properties which was reported to be effective in the treatment of different dermatological diseases, however, its topical therapeutic activity is hindered by its poor skin penetration. This review highlights the topical applications of quercetin, and summarizes the nanocarrier-based solutions to its percutaneous delivery challenges.

The Effects of Myrtle (Myrtus communis) and Clindamycin Topical Solution in the Treatment of Mild to Moderate Acne Vulgaris: A Comparative Split-Face Study

Objectives

Although Acne vulgaris is a chronic skin disease, which its standard treatment causes therapeutic limitations and some common adverse effects, medicinal plants can be effective in treatment with low adverse effects as combination therapy. Myrtle (Myrtus Communis) has some beneficial properties, which has been administered topically and orally for some skin diseases in Persian medicine. This study aimed to compare the efficacy and safety of Myrtle formula and 1% clindamycin topical solution.

Methods

This was a split-face clinical trial that was done on 55 patients with mild to moderate acne vulgaris for 16 weeks. The patients received topical Myrtle solution to the right side of the face (group 1) and clindamycin solution to the left side (group 2) twice daily for 12 weeks. All participants were examined for the acne severity index (ASI) and total acne lesions counting (TLC) at certain times during the study. Then, they stopped using them for four weeks. They also did not take the drug in the final four weeks of the study.

Results

Forty-eight patients completed the study for 16 weeks; 40 (83.2%) patients were female and the rest of them were male. The mean age and standard deviation were 25.62 ± 7.62 years. After 12 weeks, the percentage changes of comedones, inflammatory lesions, ASI and TLC were significantly reduced in both groups (p < 0.001). The percentage change of inflammatory lesions and ASI decrease was significantly higher in the group 1 (p = 0.03). There was no significant difference in the incidence of side effects between the two groups. There was a more significant decrease in sebum percentage change in the group 1 (p = 0.003).

Conclusion

Myrtle lotion was effective and safe for the treatment of mild to moderate acne vulgaris.

Anti-Inflammatory Activities of an Extract of In Vitro Grown Adventitious Shoots of Toona sinensis in LPS-Treated RAW264.7 and Propionibacterium acnes-Treated HaCaT Cells

Toona sinensis has been traditionally used to treat dysentery, enteritis, flatulence, and itchiness. However, the existence of anti-inflammatory effects of T. sinensis on Propionibacterium acnes-induced skin disease is unknown. In vitro cultures of plant cells and tissues produced under controlled conditions offer a continuous production platform for plant natural products including pigments and anti-inflammatory agents. In this study, we determine the anti-inflammatory activities of an extract of in vitro grown adventitious shoots of T. sinensis on P. acnes, the etiologic agent of skin inflammation. The extract of T. sinensis showed antioxidant and anti-inflammatory activity in LPS-treated RAW264.7 cells. It also had antibacterial activity and anti-inflammatory effects on P. acnes-treated HaCaT cells. In addition, these effects were regulated by suppression of the mitogen-activated protein kinase (MAPK) pathways. These results suggesting the potential application of adventitious shoots of T. sinensis grown with an in vitro proliferation system as a medicine for treating P. acnes-induced inflammatory skin disease.

Hop Extract: An Efficacious Antimicrobial and Anti-biofilm Agent Against Multidrug-Resistant Staphylococci Strains and Cutibacterium acnes

Bacteria belonging to Staphylococcus genus, in particular methicillin-resistant Staphylococcus aureus and multidrug-resistant Staphylococcus epidermidis, together with Cutibacterium acnes are the main strains involved in skin disease. The increase in multidrug-resistant bacteria has revived attention on natural compounds as alternative agents for the treatment management. Among these, hop extract, a hydroalcoholic solution obtained from experimental crops of Humulus lupulus L. variety cascade (hop), displays diverse biological properties including an antimicrobial one. The aim of this study was to evaluate the antimicrobial activity and the capacity to inhibit the biofilm formation of a characterized hop extract against S. aureus and S. epidermidis multidrug-resistant strains and against a C. acnes strain. The hop extract was characterized by (i) phytochemical analysis through a reversed-phase high-performance liquid chromatography (HPLC)-fluorimetric method, (ii) biocompatibility test with Artemia salina L., (iii) cytotoxicity against two cell lines, (iv) docking analysis, and (v) antimicrobial and antibiofilm activities by detection of zones inhibition, minimal inhibitory concentrations (MICs), biomass quantification, and cell viability. The hop extract was biocompatible and non-cytotoxic at all tested concentrations. HPLC analysis revealed significant levels of gallic acid, resveratrol, and rutin. This last compound was the most representative displaying a high affinity against PBP2a and KAS III (Ki values in the submicromolar range). The characterized hop extract showed a good antimicrobial action with MICs ranging from 1 to 16 μg/mL and was able to inhibit the biofilm formation of all tested strains, except for two S. aureus strains. The biofilm formed in presence of the hop extract was significantly reduced in most cases, even when present at a concentration of 1/4 MIC. The live/dead images showed a remarkable inhibition in the biofilm formation by hop extract with a weak killing action. Overall, the tested hop extract is a good candidate to further explore for its use in the prevention of infection particularly, by multidrug-resistant Gram-positive pathogens.

1H-NMR Metabolomics and LC-MS Analysis to Determine Seasonal Variation in a Cosmeceutical Plant Leucosidea sericea

Leucosidea sericea is an evergreen shrub belonging to the Rosaceae family with previous studies that indicated that L. sericea extracts exhibited strong anti-bacterial properties against Propionibacterium acnes, showing potential as a cosmeceutical. The plant is traditionally used as a vermifuge, as an astringent and to treat conjunctivitis. Commercial production is, however, not possible as no information is available on cultivation and the effect of external environmental factors such as seasonal variation on the medicinal properties of the plant. Seasonal variation was investigated and it was found that significant differences were observed between the anti-acne (P. acnes) activity of plant material collected in different seasons. The best activity was found in winter with a mean minimum inhibitory concentration (MIC) of 5.20 μg mL^–1 compared to spring at 26.04 μg mL^–1. A ¹H NMR-based untargeted metabolomic analysis was used to determine the differences in the chemical profiles of plant samples collected in different seasons. Principal component analysis (PCA) showed clear separation of the seasons and a supervised orthogonal partial least square discriminant analysis (OPLS-DA) was used to determine the compounds that differentiated the spring from the winter samples. The contribution plot indicated a strong positive association with the NMR regions from δ 1.2–1.6, 3.3–4.1, and 6.8–8.0 ppm indicative of a compound with an aromatic ring. Different LC-MS analyses were used in conjunction with a compound database, MAGMa and CSIFingerID, which led to the identification of the compound 2-(4-ethoxyphenyl)-5,6,7,8-tetramethoxy-4H-1-benzopyran-4-one and also confirmed the presence of tangeritin, rutin, quercetin glucoside, and kaempferol glucosides as well as several other compounds previously identified from the plant. This compound similar in structure to the anti-microbial flavonoid tangeritin, was only present in the winter samples. It is therefore recommended that seasonal variation be closely monitored during cultivation and commercial harvesting, and that winter is the preferred harvesting season to obtain the best anti-acne activity.

Antibacterial Activity Test of Ethanol Extract Pineapple (Ananas comosus (L.) Merr.) Peel against Growth of Propionibacterium acnes

Pineapple peel (Ananas comosus (L.) Merr.) is waste from the pineapple fruit. The purpose of this study was to determine the content of pineapple peel extract and to antibacterial activity in various concentrations effective in inhibiting the growth of Propionibacterium acnes. The pineapple peel extract is made by using the extraction method in the form of maceration. The method used in the inhibitory test using the three replication samples in each treatment group. The sample consisted of 10 treatment groups ie pineapple peel extract concentration 12.5%, 25%, 37.5%, 50%, 62.5%, 75%, 87.5%, and 100%, as well as positive and negative control. The results obtained from pineapple peel screening contain flavonoid and saponin compounds. The data analysis shows that pineapple peel extract concentrations of 50%, 62.5%, 75%, 87.5%, and 100% had inhibitory zones with the medium-strong category while clindamycin as the control has a strong inhibition zone. The conclusion of this research proves that pineapple peel extract has antibacterial power to P. acnes with effective concentration is 100% with the strong category.

Menopausal Acne - Challenges And Solutions

Although acne is a disease predominant in adolescence, it is being increasingly observed in adult life, including the menopausal period. The etiology of menopausal acne is multifactorial, with hormonal imbalance being the major culprit. There is a relative increase of androgens in the menopausal female that leads to clinical hyperandrogenism manifesting as acne, hirsutism and androgenetic alopecia. Other endocrine disorders including thyroid abnormalities, hyperprolactinemia and insulin resistance also play a role. Genetics, stress, dietary changes, lack of sleep and exercise and other lifestyle changes are implicated as trigger factors. Most menopausal women with isolated few acne lesions have normoandrogenic serum levels and do not require extensive investigations. However, baseline investigations including total testosterone are useful. Patients must also be evaluated for associated comorbidities such as obesity, diabetes, hypertension and dyslipidemia. A detailed history can help to exclude polycystic ovarian syndrome, late-onset congenital adrenal hyperplasia or medications as a cause of acne. The evaluation of menopausal acne and the approach to treatment depend on the severity of acne and associated features. In patients with mild acne without virilization, prolonged topical therapy is the mainstay of treatment. Though combined oral contraceptives are effective, they are relatively contraindicated in the postmenopausal period. Spironolactone is the first choice of therapy in the subset of patients that require oral anti-androgen therapy. Procedural treatment can be useful as it can also help in the treatment of associated acne scars and concomitant skin aging. It is also important to focus on lifestyle changes such as reducing stress, controlling obesity, having a healthy diet, exercise and proper skin care routine to reduce acne. The focus of this article is on the clinical presentation and management challenges of menopausal acne, which represents a special subtype of acne.

Subinhibitory concentrations of Honokiol reduce α-Hemolysin (Hla) secretion by Staphylococcus aureus and the Hla-induced inflammatory response by inactivating the NLRP3 inflammasome

Staphylococcus aureus (S. aureus) is one of the most serious human pathogens. α-Hemolysin (Hla) secreted by S. aureus is a key toxin for various infections. We herein report that Honokiol, a natural plant polyphenol, inhibits the secretion and hemolytic activity of staphylococcal Hla with concomitant growth inhibition of S. aureus and protection of S. aureus-mediated cell injury within subinhibitory concentrations. In parallel, Honokiol attenuates the staphylococcal Hla-induced inflammatory response by inhibiting NLRP3 inflammasome activation in vitro and in vivo. Consequently, the biologically active forms of the inflammatory cytokines IL-1β and IL-18 are reduced significantly in response to Honokiol in mice infected with S. aureus. Experimentally, we confirm that Honokiol binds to monomeric Hla with a modest affinity without impairing its oligomerization. Based on molecular docking analyses in silico, we make a theoretical discovery that Honokiol is located outside of the triangular region of monomeric Hla. The binding model restricts the function of the residues related to membrane channel formation, which leads to the functional disruption of the assembled membrane channel. This research creates a new paradigm for developing therapeutic agents against staphylococcal Hla-mediated infections.

Development of Novel Topical Cosmeceutical Formulations from Nigella sativa L. with Antimicrobial Activity against Acne-Causing Microorganisms

Acne vulgaris occurs due to the inflammation of sebaceous follicles in the skin. It is triggered by the activity of some bacterial species like Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis. Acquisition of antibiotic resistance by these microorganisms and adverse effects associated with the current treatment regimens necessitate the introduction of novel therapeutic agents for acne vulgaris. Thus, this study was undertaken to develop novel gel formulations from seeds of Nigella sativa L. and to evaluate the antibacterial potential against some acne-causing bacterial species. The antibacterial activity of seed extracts was initially screened against S. aureus and P. acnes by the agar well diffusion method. Thereafter, topical gels were formulated incorporating the ethyl acetate extract of seeds of N. sativa at three different concentrations. These topical formulations were subjected to antimicrobial activity studies while the stability was evaluated over a period of 30 days. All three formulations were capable of inhibiting the growth of S. aureus and P. acnes, with the highest antibacterial activity in the formulation comprising 15% of the seed extract. Interestingly, the antibacterial potency of this formulation against S. aureus surpassed the commercial synthetic product used as the positive control. Moreover, any alteration in color, odor, homogeneity, washability, consistency, and pH was not observed while the antibacterial potency was also retained during the storage period. The potent antibacterial activity in topical gel formulations developed from the ethyl acetate extract of N. sativa signposts their suitability as alternatives to existing antiacne agents in the management of acne vulgaris.

Target Proteins of Phloretin for Its Anti-Inflammatory and Antibacterial Activities Against Propionibacterium acnes-Induced Skin Infection

Phloretin is a natural chalcone with antibacterial and anti-inflammatory effects. This study investigated the anti-acne activity of phloretin against Propionibacterium acnes-induced skin infection and the potential target proteins of its anti-inflammatory and antibacterial effects. Phloretin potently inhibited the growth of P. acnes and P. acnes-induced Toll-like receptor (TLR) 2-mediated inflammatory signaling in human keratinocytes. Secreted embryonic alkaline phosphatase assay confirmed that the anti-inflammatory activity of phloretin is associated with the P. acnes-stimulated TLR2-mediated NF-κB signaling pathway. Phloretin significantly decreased the level of phosphorylated c-Jun N-terminal kinase (JNK), showing a binding affinity of 1.184 × 10⁻⁵ M⁻¹. We also found that phloretin binds with micromolar affinity to P. acnes β-ketoacyl acyl carrier protein (ACP) synthase III (KAS III), an enzyme involved in fatty acid synthesis. Conformation-sensitive native polyacrylamide gel electrophoresis showed that phloretin reduced KAS III-mediated 3-ketoacyl ACP production by over 66%. A docking study revealed that phloretin interacts with the active sites of JNK1 and KAS III, suggesting their involvement in P. acnes-induced inflammation and their potential as targets for the antibacterial activity of phloretin. These results demonstrate that phloretin may be useful in the prevention or treatment of P. acnes infection.

Hop Extract Acts as an Antioxidant with Antimicrobial Effects against Propionibacterium Acnes and Staphylococcus Aureus

Acne is associated with hyperkeratosis, elevated levels of skin sebum and growth of Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus). Furthermore, P. acnes promotes inflammation by inducing IL-6 production and oxidative stress. The aim of this study was to assess the antioxidant, anti-inflammatory and antibacterial potential of a hop-CO₂-extract with 50% humulone and lupulone. The susceptibility of P. acnes and S. aureus to the hop extract was tested by using the broth microdilution technique. The minimal inhibitory concentrations (MIC) for P. acnes and S. aureus were 3.1 and 9.4 µg/mL, respectively. In addition, the hop extract showed an antioxidative effect with a half maximal inhibitory concentration (IC₅₀) of 29.43 µg/mL as well as additional anti-inflammatory effects by reducing the IL-6 expression (IC₅₀: 0.8 µg/mL). In addition, a gel formulation with 0.3% hop extract (w/w) had antibacterial activity against P. acnes and S. aureus (inhibition zone value: 5.5 mm and 3 mm, respectively) which was significantly superior to the placebo gel. The positive control (a gel with the antibiotic clindamycin) showed an inhibition zone of 9 mm. Due to its antioxidant, anti-inflammatory and antibacterial effects hop extract might be a treatment option for acne-prone skin.

In Vitro Antimicrobial Activity of Essential Oils from Sardinian Flora against Cutibacterium (Formerly Propionibacterium) acnes and Its Enhancement by Chitosan

The in vitro antibacterial activity of some essential oils from Sardinian flora, both alone and in combination with chitosan, was investigated against a strain of Cutibacterium acnes, a bacterium involved in pathogenesis of acne. The composition of the essential oils was determined by gas chromatography and gas chromatography/mass spectrometry. The results of this investigation demonstrated that some of the oils examined, characterised by different chemical profiles, possessed some activity against C. acnes. Interestingly, this antibacterial effect was enhanced by sub-inhibitory concentrations of chitosan. These observations suggest the potential application of this synergy in the development of innovative topical formulations useful in the management of acne.

Origanum vulgare L. Essential Oil as a Potential Anti-Acne Topical Nanoemulsion-In Vitro and In Vivo Study

Antibiotics are often prescribed in acne treatment; however, Propionibacterium acnes and Staphylococcus epidermidis, the two of the major acne-associated bacteria, developed antibiotic resistance. Essential oils (EOs) present a natural, safe, efficacious and multifunctional alternative treatment. This study aimed to assess the potential anti-acne activity of selected seven EOs commonly used in Mediterranean folk medicine. Antimicrobial activity screening of these oils showed oregano to exhibit the strongest antimicrobial activity with minimum inhibitory concentration (MIC) of 0.34 mg/mL and minimum bactericidal concentration (MBC) of 0.67 mg/mL against P. acnes; and MIC of 0.67 mg/mL and MBC of 1.34 mg/mL against S. epidermidis. The composition of the most effective EOs (oregano and thyme) was determined using gas chromatography-mass spectrometry (GC-MS). Monoterpenoid phenols predominated oregano and thyme EO with thymol percentile 99 and 72, respectively. Thymol showed MIC 0.70 mg/mL against both P. acnes and S. epidermidis whereas MBC was 1.40 and 2.80 mg/mL against P. acnes and S. epidermidis, respectively. Moreover, oregano exhibited the strongest anti-biofilm effect against S. epidermidis with MBIC 1.34 mg/mL and killing dynamic time of 12 and 8 h against P. acnes and S. epidermidis, respectively. Oregano, the most effective EO, was formulated and tested as a nanoemulsion in an acne animal mouse model. The formulation showed superior healing and antimicrobial effects compared to the reference antibiotic. Collectively, our data suggested that oregano oil nanoemulsion is a potential natural and effective alternative for treating acne and overcoming the emerging antibiotic resistance.

Early Effects of Rhodomyrtone on Membrane Integrity in Methicillin-Resistant Staphylococcus aureus

Strong evidence of high potency of rhodomyrtone as a promising antibacterial agent against pathogenic gram-positive bacteria has been clearly demonstrated in our previous work. The aim of this study was to provide insight into early action of rhodomyrtone, an acylphloroglucinol, on membrane damage in multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA). Early effects of rhodomyrtone on the bacterial membrane integrity were detected in a time-course study. Flow cytometry revealed a reduction in green fluorescent emission and increase in uptake of propidium iodide in rhodomyrtone-treated bacterial cells in a concentration- and time-dependent manner. Disruption of cytoplasmic membrane was further monitored by measuring cellular adenosine triphosphate (ATP) and potassium ion (K⁺). Leakage of both ATP and K⁺ and significant decrease in intracellular ATP in MRSA were observed following treatment. Pronounced changes in the bacterial ultrastructure and morphology were confirmed by transmission electron microscopy and scanning electron microscopy. Bacterial cell disruption, holes in cell surface, and bulge formations were noted in rhodomyrtone-treated cells. In this study, we provided relevant data to clarify that rhodomyrtone is a bacterial cell membrane-damaging agent. A possible early effect of this novel compound involves bacterial membrane disruption.

Rhinacanthin C Alleviates Amyloid-β Fibrils' Toxicity on Neurons and Attenuates Neuroinflammation Triggered by LPS, Amyloid-β, and Interferon-γ in Glial Cells

Neuroinflammation plays a central role in the pathophysiology of Alzheimer's disease (AD). Compounds that suppress neuroinflammation have been identified as potential therapeutic targets for AD. Rhinacanthin C (RC), a naphthoquinone ester found in Rhinacanthus nasutus Kurz (Acanthaceae), is currently proposed as an effective molecule against inflammation. However, the exact role of RC on neuroinflammation remains to be elucidated. In the present study, we investigated RC effect on modulating lipopolysaccharides (LPS), amyloid-β peptide (Aβ), or interferon-γ- (IFN-γ-) evoked pathological events in neurons and glia. Our findings demonstrated that RC prevented Aβ-induced toxicity in rat hippocampal neurons and attenuated LPS-activated nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression, and NF-κB signaling in rat glia. Likewise, RC suppressed LPS-induced neuroinflammation by reducing NO production and iNOS, IL-1β, CCL-2, and CCL-5 mRNA levels in rat microglia. Further studies using BV-2 microglia revealed that RC inhibited LPS-, Aβ-, and IFN-γ-stimulated IL-6 and TNF-α secretion. Of note, NF-κB and ERK activation was abrogated by RC in BV-2 cell response to Aβ or IFN-γ. Moreover, RC protected neurons from Aβ-stimulated microglial conditioned media-dependent toxicity. Collectively, these data highlight the beneficial effects of RC on neuroprotection and support the therapeutic implications of RC to neuroinflammation-mediated conditions.

Development and Sequential Analysis of a New Multi-Agent, Anti-Acne Formulation Based on Plant-Derived Antimicrobial and Anti-Inflammatory Compounds

The antibacterial and anti-inflammatory potential of natural, plant-derived compounds has been reported in many studies. Emerging evidence indicates that plant-derived essential oils and/or their major compounds may represent a plausible alternative treatment for acne, a prevalent skin disorder in both adolescent and adult populations. Therefore, the purpose of this study was to develop and subsequently analyze the antimicrobial activity of a new multi-agent, synergic formulation based on plant-derived antimicrobial compounds (i.e., eugenol, β-pinene, eucalyptol, and limonene) and anti-inflammatory agents for potential use in the topical treatment of acne and other skin infections. The optimal antimicrobial combinations selected in this study were eugenol/β-pinene/salicylic acid and eugenol/β-pinene/2-phenoxyethanol/potassium sorbate. The possible mechanisms of action revealed by flow cytometry were cellular permeabilization and inhibition of efflux pumps activity induced by concentrations corresponding to sub-minimal inhibitory (sub-MIC) values. The most active antimicrobial combination represented by salycilic acid/eugenol/β-pinene/2-phenoxyethanol/potassium sorbate was included in a cream base, which demonstrated thermodynamic stability and optimum microbiological characteristics.

Honokiol inhibits EMT-mediated motility and migration of human non-small cell lung cancer cells in vitro by targeting c-FLIP

AIM

Honokiol (HNK) is a natural compound isolated from the magnolia plant with numerous pharmacological activities, including inhibiting epithelial-mesenchymal transition (EMT), which has been proposed as an attractive target for anti-tumor drugs to prevent tumor migration. In this study we investigated the effects of HNK on EMT in human NSCLC cells in vitro and the related signaling mechanisms.

METHODS

TNF-α (25 ng/mL) in combination with TGF-β1 (5 ng/mL) was used to stimulate EMT of human NSCLC A549 and H460 cells. Cell proliferation was analyzed using a sulforhodamine B assay. A wound-healing assay and a transwell assay were performed to examine cell motility. Western blotting was used to detect the expression levels of relevant proteins. siRNAs were used to knock down the gene expression of c-FLIP and N-cadherin. Stable overexpression of c-FLIP L (H157-FLIP L) or Lac Z (H157-Lac Z) was also performed.

RESULTS

Treatment with TNF-α+TGF-β1 significantly enhanced the migration of A549 and H460 cells, increased c-FLIP, N-cadherin (a mesenchymal marker), snail (a transcriptional modulator) and p-Smad2/3 expression, and decreased IκB levels in the cells; these changes were abrogated by co-treatment with HNK (30 μmol/L). Further studies demonstrated that expression level of c-FLIP was highly correlated with the movement and migration of NSCLC cells, and the downstream effectors of c-FLIP signaling were NF-κB signaling and N-cadherin/snail signaling, while Smad signaling might lie upstream of c-FLIP.

CONCLUSION

HNK inhibits EMT-mediated motility and migration of human NSCLC cells in vitro by targeting c-FLIP, which can be utilized as a promising target for cancer therapy, while HNK may become a potential anti-metastasis drug or lead compound.