Isolation of tyrosinase and melanogenesis inhibitory flavonoids from Juniperus chinensis fruits

Evaluation of the antioxidant and antityrosinase activities of Prosopis juliflora fruit extract as a novel multifunctional bioactive ingredient and its potential applicability in pro-ageing and skin colour harmonization cosmetic products

OBJECTIVE

Prosopis juliflora, commonly known as algaroba or mesquite, was introduced and has since proliferated throughout the semi-arid region of the Caatinga biome. Various studies have documented its properties, including antimicrobial, antioxidant, and antitumor activities, attributed to the presence of diverse secondary metabolites such as alkaloids, terpenoids, tannins, and flavonoids. The objective of this study was to evaluate the antioxidant and antityrosinase activities of P. juliflora fruit extract as a multifunctional active ingredient, and to develop cosmetic formulations containing this vegetal extract for potential applications in skincare products targeting pro-ageing and skin colour homogenization properties.

METHODS

The extraction process followed established protocols. Chemical characterization of the extract involved quantification of total flavonoids and phenolic compounds, along with Liquid Chromatography-Mass Spectrometry (LC-MS) analysis. In vitro antioxidant activity was assessed using different methods. Antityrosinase activity was determined by employing enzymatic assays. Cosmetic formulations containing Disodium EDTA, Phenoxyethanol (and) Ethylhexyl Glycerin, Distilled Water, Sodium Acrylates Copolymer Lecithin, Polyacrylamide (and) C13-14 Isoparaffin (and) Laureth-7, and 3.0% of the investigated plant extract were subjected to preliminary and accelerated stability tests.

RESULTS

The extract demonstrated a concentration of total flavonoids (1.71 ± 0.26 μg EQ/mg) and exhibited concentrations of phenolic compounds at 0.21 ± 0.01 mg EAG/g. Metabolites such as flavonoids and saponins were annotated, as well as some of their respective glycosidic derivatives. The extract showed antioxidant potential and the ability to inhibit the oxidation cascade in both the initiation and propagation phases. Moreover, the extract exhibited noteworthy inhibition of antityrosinase activity, presenting 62.48 ± 2.09 at a concentration of 30.00 mg/mL. The formulations were stable in accelerated stability tests over a 60-day period.

CONCLUSION

This research not only demonstrates scientifically by demonstrating the potential of a plant from the Caatinga biome with antioxidant and antityrosinase properties in the development of cosmetic products aimed at pro-ageing effects and skin colour harmonization, but also adds value to the P. juliflora production chain. This valorization encompasses various aspects which include environmental, social, and biodiversity responsibilities.

Ethanolic Extracts of Cupressaceae Species Conifers Provide Rapid Protection against Barium Chloride-Induced Cardiac Arrhythmia

Sudden cardiac death (SCD) is responsible for a high percentage of cardiovascular fatalities, with ventricular arrhythmias being the most common cause. Despite numerous clinically available antiarrhythmic drugs (AADs), AADs retain some undesirable arrhythmic effects, and their inappropriate use can lead to severe adverse reactions. The exploration of new therapeutic options against arrhythmias with fewer unreceptive effects is of utmost importance. The ethanolic extracts of seven Cupressaceae species, namely, Chamaecyparis obtusa, Juniperus chinensis (L.) Ant., Sabina chinensis (L.) Ant. cv. Kaizuca, Platycladus orientalis (L.) Franco, Juniperus sabina L., Fokienia hodginsii, and Juniperus chinensis 'Pyramidalis' were investigated for their pharmacological effects on barium chloride (BaCl2)-induced arrhythmia using normal II lead electrocardiogram (ECG) measurements in a mouse model. According to the ECG profiles, pretreatment with C. obtusa, P. orientalis, and J. sabina extracts provoked dose-dependent protection against BaCl2-induced arrhythmia, while pretreatment with the other four species and amiodarone did not exert cardioprotective effects. The treatment effects were confirmed using a rat model. The therapeutic effects of C. obtusa, P. orientalis, and J. sabina extracts on the M2 and M3 receptors but not the M1 receptor were mediated by the inhibition of the M2 receptor blocker (methoctramine tetrahydrochloride), M3 antagonist (4-DAMP), or M1 receptor blocker (pirenzepine dihydrochloride). This first-line evidence illustrates that certain Cupressaceae species possess active antiarrhythmic components. The first line of key findings revealed that active components of certain Cupressaceae species have cardioprotective effects, suggesting that these innovative phytochemicals have promising potential for preventing the occurrence of cardiac arrhythmia and reducing sudden cardiac death.

Essential oils extracted from nine different plants exhibit differential effects on skin antioxidation and elasticity

Essential oils derived from plants are major ingredients in the medical and cosmetic industry. Here, we evaluated nine types of plant essential oils to identify potential candidates with antioxidant and elasticity-enhancing properties. Seven essential oils showed at least 10% radical scavenging activity at the highest concentration. Essential oils extracted from Aster glehnii, Cinnamomum cassia, Citrus unshiu, Juniperus chinensis L., and Juniperus chinensis var. sargentii significantly enhanced fibroblast viability, and oils from Cit. unshiu, J. chinensis L., and J. chinensis var. sargentii significantly increased cell proliferation and migration. Expression of extracellular matrix proteins, including collagen 1, collagen 3, and elastin, were upregulated by J. chinensis L. and J. chinensis var. sargentii oil, which also significantly enhanced the contractile activity of skin cells in a three-dimensional gel contraction assay. The results suggest that J. chinensis L. and J. chinensis var. sargentii essential oils may be potential anti-wrinkling and anti-oxidative agents for future consideration of use in the medical and cosmetic industry.

Comparative transcriptome analysis of juniper branches infected by Gymnosporangium spp. highlights their different infection strategies associated with cytokinins

BACKGROUND

Gymnosporangium asiaticum and G. yamadae can share Juniperus chinensis as the telial host, but the symptoms are completely different. The infection of G. yamadae causes the enlargement of the phloem and cortex of young branches as a gall, but not for G. asiaticum, suggesting that different molecular interaction mechanisms exist the two Gymnosporangium species with junipers.

RESULTS

Comparative transcriptome analysis was performed to investigate genes regulation of juniper in responses to the infections of G. asiaticum and G. yamadae at different stages. Functional enrichment analysis showed that genes related to transport, catabolism and transcription pathways were up-regulated, while genes related to energy metabolism and photosynthesis were down-regulated in juniper branch tissues after infection with G. asiaticum and G. yamadae. The transcript profiling of G. yamadae-induced gall tissues revealed that more genes involved in photosynthesis, sugar metabolism, plant hormones and defense-related pathways were up-regulated in the vigorous development stage of gall compared to the initial stage, and were eventually repressed overall. Furthermore, the concentration of cytokinins (CKs) in the galls tissue and the telia of G. yamadae was significantly higher than in healthy branch tissues of juniper. As well, tRNA-isopentenyltransferase (tRNA-IPT) was identified in G. yamadae with highly expression levels during the gall development stages.

CONCLUSIONS

In general, our study provided new insights into the host-specific mechanisms by which G. asiaticum and G. yamadae differentially utilize CKs and specific adaptations on juniper during their co-evolution.

Quercetin 3-O-Galactoside Isolated from Limonium tetragonum Inhibits Melanogenesis by Regulating PKA/MITF Signaling and ERK Activation

Quercetin 3-O-galactoside (Q3G) is a common dietary flavanol that has been shown to possess several bioactivities, including anti-melanogenesis. However, how Q3G exerts its anti-melanogenic effect has not been studied. The current study, therefore aimed to investigate the anti-melanogenesis potential of Q3G and elucidate the underlying action mechanism in α-melanocyte-stimulating hormone (α-MSH)-induced hyperpigmentation model of B16F10 murine melanoma cells. Results showed that α-MSH stimulation significantly increased tyrosinase (TYR) and melanin production, which were significantly downregulated by Q3G treatment. The treatment with Q3G suppressed the transcriptional and protein expressions of melanogenesis-related enzymes TYR, tyrosinase related protein-1 (TRP-1), and TRP-2, along with the melanogenic transcription factor microphthalmia-associated transcription factor (MITF) in B16F10 cells. It was shown that Q3G downregulated MITF expression and suppressed its transcriptional activity by inhibiting the cAMP-dependent protein kinase A (PKA)-mediated activation of CREB and GSK3β. In addition, MAPK-regulated MITF activation signaling was also involved in the inhibition of melanin production by Q3G. The results suggest that the anti-melanogenic properties of Q3G rationalize further studies in vivo to confirm its action mechanism and consequent utilization as a cosmetic ingredient against hyperpigmentation.

Novel Signposts on the Road from Natural Sources to Pharmaceutical Applications: A Combinative Approach between LC-DAD-MS and Offline LC-NMR for the Biochemical Characterization of Two Hypericum Species (H. montbretii and H. origanifolium)

The members of the genus Hypericum have great potential to develop functional uses in nutraceutical and pharmaceutical applications. With this in mind, we aimed to determine the chemical profiling and biological properties of different extracts (ethyl acetate, methanol and water) from two Hypericum species (H. montbretii and H. origanifolium). We combined two approaches (LC-DAD-MS and LC-NMR) to identify and quantify chemical compounds of the extracts. Antioxidant properties (free radical quenching, reducing power and metal chelating) and enzyme inhibitory effects (cholinesterase, tyrosinase, amylase and glucosidase) were determined as biological properties. The tested extracts were rich in caffeic acid derivatives and flavonoids, and among them, 3-caffeoyl quinic acid and myricetin-3-O-rhamnoside were found to be the main compounds. The total phenolic and flavonoid levels were determined to be 50.97-134.99 mg GAE/g and 9.87-82.63 mg RE/g, respectively. With the exception of metal chelating, the methanol and water extracts showed stronger antioxidant properties than the ethyl acetate extracts. However, different results were obtained for each enzyme inhibition assay, and in general, the ethyl acetate extracts present more enzyme-inhibiting properties than the water or methanol extracts. Results from chemical and biological analyses were combined using multivariate analysis, which allowed establishing relationships between composition and observed effects of the Hypericum extracts based on the extraction solvents. To gain more insights between chemical compounds and enzyme-inhibiting effects, we performed molecular docking analysis. We observed favorable interactions between certain compounds and the tested enzymes during our analysis, confirming the data obtained from the multivariate approach. In conclusion, the obtained results may shed light on the road from natural sources to functional applications, and the tested Hypericum species may be considered potential raw materials, with promising chemical constituents and biological activities.

In Silico Interactions of the Components from the Schinus terebinthifolius Extract with Human Tyrosinase

The anti-tyrosinase activity of the leaf extract of Schinus terebinthifolius, also known as Brazilian peppertree, was evaluated using multiple in silico approaches, such as molecular homology, molecular docking, MM-GBSA, molecular dynamics, MM-PBSA, QSAR, and skin permeability predictions. With these computational tools, the compounds that downregulate tyrosinase enzyme activity could be evaluated, and more potent molecules could be identified. The results indicated that various compounds, especially luteolin, are accountable for the anti-tyrosinase activity of S. terebinthifolius. For cosmetic application, further studies with luteolin are especially recommended, for having presented a good performance both in theoretical inhibition (30.92 kJ mol^-1 ) and skin permeability (LogKp=-6.62 cm^-1 ).

Insights on the Inhibitory Power of Flavonoids on Tyrosinase Activity: A Survey from 2016 to 2021

Tyrosinase is a multifunctional copper-containing oxidase enzyme that initiates melanin synthesis in humans. Excessive accumulation of melanin pigments or the overexpression of tyrosinase may result in skin-related disorders such as aging spots, wrinkles, melasma, freckles, lentigo, ephelides, nevus, browning and melanoma. Nature expresses itself through the plants as a source of phytochemicals with diverse biological properties. Among these bioactive compounds, flavonoids represent a huge natural class with different categories such as flavones, flavonols, isoflavones, flavan-3-ols, flavanones and chalcones that display antioxidant and tyrosinase inhibitor activities with a diversity of mechanistic approaches. In this review, we explore the role of novel or known flavonoids isolated from different plant species and their participation as tyrosinase inhibitors reported in the last five years from 2016 to 2021. We also discuss the mechanistic approaches through the different studies carried out on these compounds, including in vitro, in vivo and in silico computational research. Information was obtained from Google Scholar, PubMed, and Science Direct. We hope that the updated comprehensive data presented in this review will help researchers to develop new safe, efficacious, and effective drug or skin care products for the prevention of and/or protection against skin-aging disorders.

Euphorbia characias: Phytochemistry and Biological Activities

The aim of this review is to summarize all the compounds identified and characterized from Euphorbia characias, along with the biological activities reported for this plant. Euphorbia is one of the greatest genera in the spurge family of Euphorbiaceae and includes different kinds of plants characterized by the presence of milky latex. Among them, the species Euphorbia characias L. is an evergreen perennial shrub widely distributed in Mediterranean countries. E. characias latex and extracts from different parts of the plant have been extensively studied, leading to the identification of several chemical components such as terpenoids, sterol hydrocarbons, saturated and unsaturated fatty acids, cerebrosides and phenolic and carboxylic acids. The biological properties range between antioxidant activities, antimicrobial, antiviral and pesticidal activities, wound-healing properties, anti-aging and hypoglycemic properties and inhibitory activities toward target enzymes related to different diseases, such as cholinesterases and xanthine oxidase. The information available in this review allows us to consider the plant E. characias as a potential source of compounds for biomedical research.

Skin hyperpigmentation and its treatment with herbs: an alternative method

Background

With an increasing number of patients, those who are facing a lot of skin-related complaints, often referred to as skin of pigmentation patients, are on the rise. Among all the most common complaints in patients with skin of color is hyperpigmentation. So, there is need of herbal formulation for treatment of hyperpigmentation.

Main body

This review article addresses the different types of hyperpigmentation, causes, and its treatment with herbs for the management of the skin hyperpigmentation. As uneven pigmentation of skin or hyperpigmentation is a common skin condition, which occurs when the skin produces more melanin. This can make spots or patches of skin appear darker than surrounding areas. Some forms of hyperpigmentation with post-inflammatory, melasma, and sun spots are more likely to affect areas of face, arms, and legs due to sun exposure and injury. Although the availability of multiple treatments for the condition which leads to some adverse effects, hyperpigmentation continues to present skin care management challenges for dermatologists.

Conclusion

Some plants and phytoconstituents, e.g., Azadirachta indica, Glycyrrhiza glabra, Panax ginseng and genistein, ellagic acids, quercetin, are very useful in herbal cosmetic as anti-hyperpigmentry agents in cosmetic industries. Some of flavonoids and triterpenoids present in plants also show their effect as antioxidant and skin whitening agents. It is expected that this review will compile and improve the existing knowledge on the potential utilization of herbs for the treatment of skin hyperpigmentation.

The regulation of protein kinase casein kinase II by apigenin is involved in the inhibition of ultraviolet B-induced macrophage migration inhibitory factor-mediated hyperpigmentation

Ultraviolet (UV) radiation elicits melanogenesis and pigmentation in the skin. Apigenin (4',5,7-trihydroxyflavone [AGN]) is a plant flavone contained in various herbs, fruits, and vegetables. We herein investigated antimelanogenic properties of AGN and the molecular mechanisms of the action of AGN. In UVB-treated mice, AGN inhibited cutaneous hyperpigmentation and macrophage migration inhibitory factor (MIF) expression as a melanogenesis-related key factor. In mouse keratinocytes, AGN inhibited the expression of MIF and also the related factors (e.g., stem cell factor and proteinase-activated receptor 2) induced by MIF. In addition to ellagic acid as a casein kinase II (CK2) inhibitor, AGN suppressed CK2 enzymatic activity and UVB-induced CK2 expression and subsequent phosphorylation of IκB and MIF expression. These results suggest that AGN inhibits UVB-induced hyperpigmentation through the regulation of CK2-mediated MIF expression in keratinocytes.

Natural and Bioinspired Phenolic Compounds as Tyrosinase Inhibitors for the Treatment of Skin Hyperpigmentation: Recent Advances

One of the most common approaches for control of skin pigmentation involves the inhibition of tyrosinase, a copper-containing enzyme which catalyzes the key steps of melanogenesis. This review focuses on the tyrosinase inhibition properties of a series of natural and synthetic, bioinspired phenolic compounds that have appeared in the literature in the last five years. Both mushroom and human tyrosinase inhibitors have been considered. Among the first class, flavonoids, in particular chalcones, occupy a prominent role as natural inhibitors, followed by hydroxystilbenes (mainly resveratrol derivatives). A series of more complex phenolic compounds from a variety of sources, first of all belonging to the Moraceae family, have also been described as potent tyrosinase inhibitors. As to the synthetic compounds, hydroxycinnamic acids and chalcones again appear as the most exploited scaffolds. Several inhibition mechanisms have been reported for the described inhibitors, pointing to copper chelating and/or hydrophobic moieties as key structural requirements to achieve good inhibition properties. Emerging trends in the search for novel skin depigmenting agents, including the development of assays that could distinguish between inhibitors and potentially toxic substrates of the enzyme as well as of formulations aimed at improving the bioavailability and hence the effectiveness of well-known inhibitors, have also been addressed.