Protective Effect of Potentilla glabra in UVB-Induced Photoaging Process

Anti-apoptotic, anti-inflammatory, and anti-melanogenic effects of the ethanol extract of Picrasma quassioides (D. Don) Benn

ETHNOPHARMACOLOGICAL RELEVANCE

Picrasma quassioides (D. Don) Benn is a vascular plant belonging to the genus Picrasma of Simaroubaceae family and grows in Korea, China, India, Taiwan, and Japan. Picrasma quassioides extract has been reported to have anti-inflammatory, anti-bacterial, and anti-cancer properties. Moreover, this plant has been also traditionally used to alleviate symptoms of eczema, atopic dermatitis, psoriasis, scabies, and boils in skin.

AIM OF THE STUDY

The Pq-EE has been reported in Chinese pharmacopoeia for its pharmacological effects on skin. However, the detailed mechanism on alleviating skin conditions is not understood. Hence, we investigated the skin improvement potential of Pq-EE against skin damage.

MATERIALS AND METHODS

We used the human keratinocyte cell line (HaCaT) and mouse melanoma cell line (B16F10) to study the effects of Pq-EE on the epidermis. Additionally, in vitro antioxidant assays were performed using a solution that included either metal ions or free radicals.

RESULTS

In colorimetric antioxidant assays, Pq-EE inhibited free radicals in a dose-dependent manner. The Pq-EE did not affect cell viability and promoted cell survival under UVB exposure conditions in the MTT assay. The Pq-EE downregulated the mRNA levels of apoptotic factors. Moreover, MMP1 and inflammatory cytokine iNOS mRNA levels decreased with Pq-EE treatment. With regard to protein levels, caspases and cleaved caspases were more powerfully inhibited by Pq-EE than UVB-irritated conditions. p53 and Bax also decreased with Pq-EE treatment. The melanin contents and secretion were decreased at nontoxic concentrations of Pq-EE. The pigmentation pathway genes also were inhibited by treatment with Pq-EE.

CONCLUSIONS

In summary, we suggest the cell protective potential of Pq-EE against UVB and ROS, indicating its use in UV-protective cosmeceutical materials.

Regulatory Mechanisms of Natural Active Ingredients and Compounds on Keratinocytes and Fibroblasts in Mitigating Skin Photoaging

Background

The mechanism underlying skin photoaging remains elusive because of the intricate cellular and molecular changes that contribute to this phenomenon, which have yet to be elucidated. In photoaging, the roles of keratinocytes and fibroblasts are vital for maintaining skin structure and elasticity. But these cells can get photo-induced damage during photoaging, causing skin morphological changes. Recently, the function of natural active ingredients in treating and preventing photoaging has drawn more attention, with researches often focusing on keratinocytes and fibroblasts.

Methods

We searched for studies published from 2007 to January 2024 in the Web of Science, PubMed, and ScienceDirect databases through the following keywords: natural plant, natural plant products or phytochemicals, traditional Chinese Medicine or Chinese herbal, plant extracts, solar skin aging, skin photoaging, and skin wrinkling. This review conducted the accordance of Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

Results

In total, 87 researches were included in this review (Figure 1). In keratinocytes, natural compounds may primarily regulate signal pathways such as the NF-κB, MAPK, PI3K/AKT, and Nrf2/ARE pathways, reducing inflammation and cellular damage, thus slowing skin photoaging. Additionally, in fibroblasts, natural active ingredients primarily promote the TGF-β pathway, inhibit MMPs activity, and enhance collagen synthesis while potentially modulating the mTOR pathway, thereby protecting the dermal collagen network and reducing wrinkle formation. Several trials showed that natural compounds that regulate keratinocytes and fibroblasts responses have significant and safe therapeutic effects.

Conclusion

The demand for natural product-based ingredients in sunscreen formulations is rising. Natural compounds show promising anti-photoaging effects by targeting cellular pathways in keratinocytes and fibroblasts, providing potential therapeutic strategies. However, comprehensive clinical studies are needed to verify their efficacy and safety in mitigating photoaging, which should use advanced pharmacological methods to uncover the complex anti-photoaging mechanisms of natural compounds.

Anti-inflammatory, Antioxidative, and Moisturizing Effects of Oxyceros horridus Lour. Ethanol Extract in Human Keratinocytes via the p38 Signaling Pathway

Skin is the largest and outermost organ in the human body; it serves as a vital defense mechanism against various external threats. Therefore, it is crucial to maintain its health through protection against harmful substances and adequate moisture levels. This study investigates the anti-inflammatory, antioxidant, and moisturizing properties of Oxyceros horridus Lour. (Oh-EE) in human keratinocytes. Oh-EE demonstrates potent antioxidant activity and effectively protects against oxidative stress induced by external stimuli such as UVB radiation and H2O2. Additionally, it exhibits significant anti-inflammatory effects proven by its ability to downregulate the expression of pro-inflammatory cytokines, namely COX-2 and IL-6. The study also explores the involvement of the AP-1 pathway, highlighting the ability of Oh-EE to suppress the expression of p38 and its upstream regulator, MKK3/6, under UVB-induced conditions. Interestingly, Oh-EE can activate the AP-1 pathway in the absence of external triggers. Furthermore, Oh-EE enhances skin moisture by upregulating the expression of key genes involved in skin hydration, namely HAS3 and FLG. These findings underscore the potential of Oh-EE as a versatile ingredient in skincare formulations, providing a range of skin benefits. Further research is warranted to comprehensively understand the underlying mechanisms through which Oh-EE exerts its effects.

Anti-oxidative, anti-apoptotic, and anti-inflammatory activities of Connarus semidecandrus Jack ethanol extract in UVB-irradiated human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Connarus semidecandrus Jack (Family: connaraceae) is a medicinal plant known for its wide distribution throughout Southeast Asia. Renowned for its diverse therapeutic properties, it has been traditionally used for treating fever, skin irritation, and colic.

AIM OF THE STUDY

Numerous individuals suffer from skin issues, including wrinkles, hyperpigmentation, and inflammation, due to environmental factors. Although many drugs are available to treat skin problems, chemical drugs have many shortcomings and side effects. Therefore, natural products are attractive potential medicines for alleviating skin troubles. We recently showed that Connarus semidecandrus Jack ethanol extract (Cs-EE) has anti-alopecia potential. This paper aims to explore the potential skin-protective effects and underlying molecular mechanisms of Connarus semidecandrus Jack in UVB-induced human keratinocytes (HaCaT).

MATERIALS AND METHODS

Before utilization, Cs-EE was dissolved in dimethyl sulfoxide (DMSO) and was preserved at a temperature of -20 °C. The phytochemical constituents of Cs-EE were detected by gas chromatography-mass spectrometry analysis (GC-MS). Sequentially, HaCaT cells were exposed to varying concentrations of Cs-EE prior to ultraviolet B (UVB) irradiation. Evaluations of cellular responses in HaCaT cells, including assessments of cell viability, deoxyribonucleic acid (DNA) damage, and gene and protein expressions, were carried out. To explore the specific signaling pathway involved, we conducted a luciferase assay in addition to validating these pathways using Western blot analysis.

RESULTS

Nitric oxide (NO) and intracellular reactive oxygen species were decreased. Melanin production through the activation of melanocytes by α-melanocyte-stimulating hormone (MSH) was also inhibited by Cs-EE. Furthermore, the mRNA expression levels of key factors such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), MMP-1, MMP-3, and MMP-9 exhibited a remarkable decrease. In addition, the phosphorylation of TAK1 within the signaling cascade exhibited a decline, and the activities of the transcription factor AP-1 were decreased according to a luciferase reporter assay.

CONCLUSIONS

Taken together, these findings suggest that the anti-inflammatory, anti-aging, and anti-apoptotic effects of Cs-EE indicate the compound's potential usefulness as a natural component in pharmaceutical and cosmetic products.

A Comparative Study of Skin Changes in Different Species of Mice in Chronic Photoaging Models

This study aimed to design a novel mouse model of chronic photoaging. We used three different species of mice (C57BL/6J, ICR, and KM) to create a chronic photoaging model of the skin. The irradiation time was gradually increased for 40 consecutive days. The skins of the mice were removed on day 41 and subjected to staining to observe them for morphological changes. Immunohistochemistry was used to detect tumor necrosis factor-α (TNF-α) and p53 expression; superoxide dismutase (SOD) and malondialdehyde (MDA) were measured as well. Compared with C57BL/J mice, which showed hyperpigmentation, the irradiated skin of ICR and KM mice showed more obvious skin thickening and photoaging changes of the collagen and elastic fibers. KM mice had higher levels of inflammation, oxidative stress, and senescent cells. Compared with the 5-month-old KM mice, the photoaging changes of the 9-month-old KM mice were more pronounced, the SOD values were lower, and the MDA values were higher. In summary, KM mice have higher levels of abnormal elastic fibers, inflammation, cellular senescence, and oxidative stress than ICR mice, and are more suitable for studies related to chronic skin photoaging. C57BL/6J mice were found to be suitable for studies related to skin pigmentation due to photoaging.

Anti-Oxidative and Anti-Aging Effects of Ethanol Extract of the Officinal Breynia (Breynia vitis-idaea) In Vitro

The skin is the largest organ of the human body, and it is also the one most exposed to external environmental contaminants. The skin is the body's first defense against harmful environmental stimuli, including ultraviolet B (UVB) rays and hazardous chemicals. Therefore, proper care of the skin is required to prevent skin-related diseases and age-related symptoms. In this study, we analyzed anti-aging and anti-oxidative effects of Breynia vitis-idaea ethanol extract (Bv-EE) in human keratinocytes and dermal fibroblasts. The Bv-EE had free radical scavenging activity and decreased the mRNA expression of MMPs and COX-2 in H₂O₂- or UVB-treated HaCaT cells. The Bv-EE also inhibited AP-1 transcriptional activity and phosphorylation of c-Jun N-terminal kinase, extracellular signal-regulated kinase, and mitogen-activated protein kinase 14 (p38), which are major AP-1 activators upon H₂O₂ or UVB exposure. Furthermore, the promoter activity and mRNA expression of collagen type I (Col1A1) increased in HDF cells treated with Bv-EE, and Bv-EE recovered the collagen mRNA expression decreased by H₂O₂ or UVB exposure. These results suggest that Bv-EE has anti-oxidative effects by inhibiting the AP-1 signaling pathway, and shows anti-aging effects by upregulating collagen synthesis.

Natural Products for Cosmetic Applications

Natural products provide an interesting and largely unexplored source for the development of potential new cosmetic ingredients [...].

Modulation of Cytoskeleton, Protein Trafficking, and Signaling Pathways by Metabolites from Cucurbitaceae, Ericaceae, and Rosaceae Plant Families

One promising frontier within the field of Medical Botany is the study of the bioactivity of plant metabolites on human health. Although plant metabolites are metabolic byproducts that commonly regulate ecological interactions and biochemical processes in plant species, such metabolites also elicit profound effects on the cellular processes of human and other mammalian cells. In this regard, due to their potential as therapeutic agents for a variety of human diseases and induction of toxic cellular responses, further research advances are direly needed to fully understand the molecular mechanisms induced by these agents. Herein, we focus our investigation on metabolites from the Cucurbitaceae, Ericaceae, and Rosaceae plant families, for which several plant species are found within the state of Florida in Hillsborough County. Specifically, we compare the molecular mechanisms by which metabolites and/or plant extracts from these plant families modulate the cytoskeleton, protein trafficking, and cell signaling to mediate functional outcomes, as well as a discussion of current gaps in knowledge. Our efforts to lay the molecular groundwork in this broad manner hold promise in supporting future research efforts in pharmacology and drug discovery.

Potentilla paradoxa Nutt. Ethanol Extract Exhibits Anti-Inflammatory Effects by Suppression of the Src/NF-κB Signaling Pathway

Inflammation is an immune response that protects against harmful stimuli. However, severe inflammation can cause many diseases, such as diabetes, cancer, and arthritis. In this study, we examined the anti-inflammatory efficacy and mechanism of Potentilla paradoxa Nutt. ethanol extract (Pp-EE) as a new strategy for controlling the inflammatory response. Cellular activities and the molecular target of Pp-EE were identified in RAW264.7 cells and HEK293T cells. The effect of Pp-EE was analyzed using the Griess assay, the luciferase assay, reverse transcription-polymerase chain reaction, and Western blotting. To evaluate the in vivo effects, an HCl/EtOH-induced gastritis mouse model was used. NO production and pro-inflammatory gene (iNOS, COX-2, and TNF-α) mRNA levels were decreased by Pp-EE in a concentration-dependent manner without showing cytotoxicity. The activation of the transcription factor, particularly NF-κB, was effectively suppressed by Pp-EE. It was also found that Pp-EE directly inhibits the activation of Src in lipopolysaccharide (LPS)-treated RAW264.7 cells and in Src-overexpressed HEK293 cells by Western blotting analysis and cellular thermal shift assay. Experiments in the gastritis mouse model indicated that Pp-EE suppresses HCl/EtOH-induced gastric lesions, the expression levels of COX-2, IL-6, and TNF-α, and the phosphorylation of p65, p50, and Src. Taken together, these results suggest that Pp-EE can be applied as an anti-inflammatory remedy with a Src/NF-κB inhibitory property.

In Vitro Anti-Photoaging and Skin Protective Effects of Licania macrocarpa Cuatrec Methanol Extract

The Licania genus has been used in the treatment of dysentery, diabetes, inflammation, and diarrhea in South America. Of these plants, the strong anti-inflammatory activity of Licania macrocarpa Cuatrec (Chrysobalanaceae) has been reported previously. However, the beneficial activities of this plant on skin health have remained unclear. This study explores the protective activity of a methanol extract (50-100 μg/mL) in the aerial parts of L. macrocarpa Cuatrec (Lm-ME) and its mechanism, in terms of its moisturizing/hydration factors, skin wrinkles, UV radiation-induced cell damage, and radical generation (using RT/real-time PCR, carbazole assays, flowcytometry, DPPH/ABTS, and immunoblotting analysis). The anti-pigmentation role of Lm-ME was also tested by measuring levels of melanin, melanogenesis-related genes, and pigmentation-regulatory proteins. Lm-ME decreased UVB-irradiated death in HaCaT cells by suppressing apoptosis and inhibited matrix metalloproteinases 1/2 (MMP1/2) expression by enhancing the activity of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. It was confirmed that Lm-ME displayed strong antioxidative activity. Lm-ME upregulated the expression of hyaluronan synthases-2/3 (HAS-2/3) and transglutaminase-1 (TGM-1), as well as secreted levels of hyaluronic acid (HA) via p38 and JNK activation. This extract also significantly inhibited the production of hyaluronidase (Hyal)-1, -2, and -4. Lm-ME reduced the melanin expression of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein-1/2 (TYRP-1/2) in α-melanocyte-stimulating hormone (α-MSH)-treated B16F10 cells via the reduction of cAMP response element-binding protein (CREB) and p38 activation. These results suggest that Lm-ME plays a role in skin protection through antioxidative, moisturizing, cytoprotective, and skin-lightening properties, and may become a new and promising cosmetic product beneficial for the skin.

Antioxidant Capacity of Potentilla paradoxa Nutt. and Its Beneficial Effects Related to Anti-Aging in HaCaT and B16F10 Cells

Skin aging is a natural process influenced by intrinsic and extrinsic factors, and many skin anti-aging strategies have been developed. Plants from the genus Potentilla has been used in Europe and Asia to treat various diseases. Potentilla paradoxa Nutt. has been used as a traditional medicinal herb in China and has recently been shown to have anti-inflammatory effects. Despite the biological and pharmacological potential of Potentilla paradoxa Nutt., its skin anti-aging effects remain unclear. Therefore, this study evaluated the free radical scavenging, moisturizing, anti-melanogenic, and wound-healing effects of an ethanol extract of Potentilla paradoxa Nutt. (Pp-EE). Pp-EE was found to contain phenolics and flavonoids and exhibits in vitro antioxidant activities. α-Linolenic acid was found to be a major component of Pp-EE on gas chromatography-mass spectrometry. Pp-EE promoted the expression of hyaluronic acid (HA) synthesis-related enzymes and suppressed the expression of HA degradation-related enzymes in keratinocytes, so it may increase skin hydration. Pp-EE also showed inhibitory effects on the production and secretion of melanin in melanocytes. In a scratch assay, Pp-EE improved skin wound healing. Taken together, Pp-EE has several effects that may delay skin aging, suggesting its potential benefits as a natural ingredient in cosmetic or pharmaceutical products.