Acetyl zingerone: An efficacious multifunctional ingredient for continued protection against ongoing DNA damage in melanocytes after sun exposure ends

Prospective randomized double-blind comparative study of topical acetyl zingerone with tetrahexyldecyl ascorbate versus tetrahexyldecyl ascorbate alone on facial photoaging

BACKGROUND

Tetrahexydecyl ascorbate (THDA) is a lipophilic precursor to ascorbic acid that may be stabilized by acetyl zingerone (AZ). Studies have shown that the topical application of THDA may have photoprotective effects. Similarly, AZ has been shown to mitigate oxidative and inflammatory stress, thereby improving the appearance of photoaging.

AIMS

To examine the effects of THDA and AZ (THDA-AZ) on skin photoaging compared to THDA alone.

PATIENTS/METHODS

In this double-blind, randomized controlled trial, healthy individuals aged 30 to 65 were included and 44 participants were randomized to receive either THDA-AZ (THDA 5% + AZ 1%) or THDA only (THDA 5%) for 8 weeks. Facial photographs were taken at 0, 4, and 8 weeks to analyze wrinkle severity, pigment intensity, and redness intensity. A skin colorimeter was used to assess infraorbital pigmentation and erythema. Self-perception of skin and tolerability were assessed through questionnaires.

RESULTS

Average wrinkle severity was significantly decreased in the THDA-AZ group at Weeks 4 and 8 by 0.75% (p = 0.023) and 3.72% (p = 0.048), respectively, compared to the THDA group where wrinkle severity at Weeks 4 and 8 was increased by 7.88% and 4.48%, respectively. Facial pigment intensity was significantly decreased in the THDA-AZ group by 4.10% (p = 0.0002) at Week 8 compared to a 0.69% decrease in the THDA group. Facial redness intensity was decreased in the THDA-AZ group at Weeks 4 and 8 by 3.73% (p = 0.0162) and 14.25% (p = 0.045), respectively, compared to the THDA group where at Weeks 4 and 8 erythema increased by 27.5% and 8.34%, respectively. There were no significant differences in either group for infraorbital pigmentation or erythema.

CONCLUSIONS

Daily use of combined THDA and AZ may improve facial wrinkle severity, pigment intensity, and erythema to a greater extent than THDA. While THDA alone increases facial wrinkle severity and erythema, the addition of AZ reduces both.

Decoding the synergistic potential of MAZ-51 and zingerone as therapy for melanoma treatment in alignment with sustainable development goals

Melanoma, an invasive class of skin cancer, originates from mutations in melanocytes, the pigment-producing cells. Globally, approximately 132,000 new cases are reported each year, and in South Africa, the incidence stands at 2.7 per 100,000 people, signifying a worrisome surge in melanoma rates. Therefore, there is a need to explore treatment modalities that will target melanoma's signalling pathways. Melanoma metastasis is aided by ligand activity of transforming growth factor-beta 1 (TGF-β1), vascular endothelial growth factor-C (VEGF-C) and C-X-C chemokine ligand 12 (CXCL12) which bind to their receptors and promote tumour cell survival, lymphangiogenesis and chemotaxis. (3-(4-dimethylaminonaphthelen-1-ylmethylene)-1,3-dihydroindol-2-one) MAZ-51 is an indolinone-based molecule that inhibits VEGF-C induced phosphorylation of vascular endothelial growth factor receptor 3 (VEGFR-3). Despite the successful use of conventional cancer therapies, patients endure adverse side effects and cancer drug resistance. Moreover, conventional therapies are toxic to the environment and caregivers. The use of medicinal plants and their phytochemical constituents in cancer treatment strategies has become more widespread because of the rise in drug resistance and the development of unfavourable side effects. Zingerone, a phytochemical derived from ginger exhibits various pharmacological properties positioning it as a promising candidate for cancer treatment. This review provides an overview of melanoma biology and the intracellular signalling pathways promoting cell survival, proliferation and adhesion. There is a need to align health and environmental objectives within sustainable development goals 3 (good health and well-being), 13 (climate action) and 15 (life on land) to promote early detection of skin cancer, enhance sun-safe practices, mitigation of environmental factors and advancing the preservation of biodiversity, including medicinal plants. Thus, this review discusses the impact of cytostatic cancer drugs on patients and the environment and examines the potential use of phytochemicals as adjuvant therapy.

Acetyl zingerone ameliorates osteoarthritis by inhibiting chondrocyte programmed cell death

Osteoarthritis (OA) is a degenerative disease that ultimately leads to joint deformity. The pathogenesis of OA is believed to involve abnormal chondrocyte death, with ferroptosis serving a key role in chondrocyte damage. The present study investigated whether acetyl zingerone (AZ), a newly identified antioxidant derived from curcumin, can alleviate the progression of OA. To investigate this, the present study performed various experiments, including crystal violet staining, flow cytometry, immunofluorescence and western blot analysis. In addition, dual validation was performed using in vivo and in vitro experiments; a mouse OA model was constructed for the in vivo experiments, and chondrocytes were used for the in vitro experiments. Destabilization of the medial meniscus (DMM) surgery was performed to establish an OA model in mice and IL‑1β was used to induce an OA model in vitro. The results indicated that AZ may promote chondrocyte viability and the expression of extracellular matrix components. Furthermore, AZ reduced the occurrence of ferroptosis by promoting the expression of glutathione peroxidase 4, inhibiting cartilage destruction and osteophyte formation, and alleviating damage to articular cartilage caused by DMM surgery. Mechanistically, the activation of nuclear factor erythroid 2‑related factor 2 and heme oxygenase‑1 may be responsible for the anti‑ferroptosis effects of AZ on chondrocytes. These findings indicated that AZ may be considered a promising candidate for OA therapy.

Promising influences of zingerone against natural and chemical toxins: A comprehensive and mechanistic review

Zingerone is a flavor phytochemical present in ginger, a flowering plant belonging to the Zingiberaceae family used as a condiment and herbal remedy. It possesses anti-inflammatory, antioxidant, and anti-apoptotic properties and also exhibits protective effects against radiation, chemicals, biological toxins, and oxidative stress. The current comprehensive literature review was performed in order to assess the therapeutical and protective properties of zingerone against various chemical and natural toxins by considering the mechanisms of action. Extensive searches were performed on Scopus, Web of Science, PubMed, and Google Scholar databases. Zingerone lessens oxidative stress, inflammation, apoptosis, and oxidative DNA damage by increasing the activities of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPX). It prevents alginate production, which increases the cell's susceptibility to macrophages, serum, and antibiotics and dramatically lowers the generation of proinflammatory cytokines brought on by lipopolysaccharide (LPS). Cytokine production, MAPK, and NF-κB activation are all inhibited dose-dependently by zingerone. Zingerone also reduces 8-OHdG over-expression in the liver tissue and the expression of NADPH oxidase 4 (NOX4), inflammatory cytokines (e.g., IFN-γ, IL-17, IL-6, COX-2, TNF-α, and iNOS mRNA level), decreases macrophage inflammatory protein cytokines and eliminates free radicals. It also suppresses matrix metalloproteinase-2 (MMP-2) and MMP-9 during tumor progression, showing its anti-angiogenic activity. Strong radioprotective properties of zingerone are demonstrated against radiation-induced toxicity. The authors hope this review gives researchers some insight into conducting novel clinical and preclinical studies on pharmaceutical applications and the efficiency of zingerone in cancer treatment, and drug adverse effects.

Acetyl Zingerone: A Photostable Multifunctional Skincare Ingredient That Combats Features of Intrinsic and Extrinsic Skin Aging

The cumulative damage skin sustains from exposure to environmental stressors throughout life exerts significant effects on skin aging and cancer development. One of the main ways by which environmental stressors mediate their effects within skin is through induction of reactive oxygen species (ROS). In this review, we chronicle the multiple properties by which acetyl zingerone (AZ) as a skincare ingredient can benefit skin (1) by helping manage overproduction of ROS through multiple routes as an antioxidant, physical quencher and selective chelator, (2) by fortifying protection after UV exposure ends to prevent the type of epidermal DNA damage that correlates with development of skin cancer, (3) by modulating matrisome activity and nurturing the integrity of the extracellular matrix (ECM) within the dermis and (4) through its proficient ability to neutralize singlet oxygen, by stabilizing the ascorbic acid precursor tetrahexyldecyl ascorbate (THDC) in the dermal microenvironment. This activity improves THDC bioavailability and may blunt pro-inflammatory effects of THDC, such as activation of type I interferon signaling. Moreover, AZ is photostable and can sustain its properties during UV exposure, in contrast to α-tocopherol. All these properties of AZ translate into measurable clinical benefits to improve the visual appearance of photoaged facial skin and to strengthen the skin's own defenses against sun damage.

Significance of Singlet Oxygen Molecule in Pathologies

Reactive oxygen species, including singlet oxygen, play an important role in the onset and progression of disease, as well as in aging. Singlet oxygen can be formed non-enzymatically by chemical, photochemical, and electron transfer reactions, or as a byproduct of endogenous enzymatic reactions in phagocytosis during inflammation. The imbalance of antioxidant enzymes and antioxidant networks with the generation of singlet oxygen increases oxidative stress, resulting in the undesirable oxidation and modification of biomolecules, such as proteins, DNA, and lipids. This review describes the molecular mechanisms of singlet oxygen production in vivo and methods for the evaluation of damage induced by singlet oxygen. The involvement of singlet oxygen in the pathogenesis of skin and eye diseases is also discussed from the biomolecular perspective. We also present our findings on lipid oxidation products derived from singlet oxygen-mediated oxidation in glaucoma, early diabetes patients, and a mouse model of bronchial asthma. Even in these diseases, oxidation products due to singlet oxygen have not been measured clinically. This review discusses their potential as biomarkers for diagnosis. Recent developments in singlet oxygen scavengers such as carotenoids, which can be utilized to prevent the onset and progression of disease, are also described.

The Role of Acetyl Zingerone and Its Derivatives in Inhibiting UV-Induced, Incident, and Delayed Cyclobutane Pyrimidine Dimers

Cyclobutane pyrimidine dimers (CPDs) are ultraviolet radiation (UV)-induced carcinogenic DNA photoproducts that lead to UV signature mutations in melanoma. Previously, we discovered that, in addition to their incident formation (iCPDs), UV exposure induces melanin chemiexcitation (MeCh), where UV generates peroxynitrite (ONOO^-), which oxidizes melanin into melanin-carbonyls (MCs) in their excited triplet state. Chronic MeCh and energy transfer by MCs to DNA generates CPDs for several hours after UV exposure ends (dark CPD, dCPDs). We hypothesized that MeCh and the resulting dCPDs can be inhibited using MeCh inhibitors, and MC and ONOO^- scavengers. Here, we investigated the efficacy of Acetyl Zingerone (AZ), a plant-based phenolic alkanone, and its chemical analogs in inhibiting iCPDs and dCPDs in skin fibroblasts, keratinocytes, and isogenic pigmented and albino melanocytes. While AZ and its methoxy analog, 3-(4-Methoxy-benzyl)-Pentane-2,4-dione (MBPD) completely inhibited the dCPDs, MBPD also inhibited ~50% of iCPDs. This suggests the inhibition of ~80% of total CPDs at any time point post UV exposure by MBPD, which is markedly significant. MBPD downregulated melanin synthesis, which is indispensable for dCPD generation, but this did not occur with AZ. Meanwhile, AZ and MBPD both upregulated the expression of nucleotide excision repair (NER) pathways genes including Xpa, Xpc, and Mitf. AZ and its analogs were non-toxic to the skin cells and did not act as photosensitizers. We propose that AZ and MBPD represent "next-generation skin care additives" that are safe and effective for use not only in sunscreens but also in other specialized clinical applications owing to their extremely high efficacy in blocking both iCPDs and dCPDs.

Oxidative Stress and Oocyte Cryopreservation: Recent Advances in Mitigation Strategies Involving Antioxidants

Oocyte cryopreservation is widely used in assisted-reproductive technology and animal production. However, cryopreservation not only induces a massive accumulation of reactive oxygen species (ROS) in oocytes, but also leads to oxidative-stress-inflicted damage to mitochondria and the endoplasmic reticulum. These stresses lead to damage to the spindle, DNA, proteins, and lipids, ultimately reducing the developmental potential of oocytes both in vitro and in vivo. Although oocytes can mitigate oxidative stress via intrinsic antioxidant systems, the formation of ribonucleoprotein granules, mitophagy, and the cryopreservation-inflicted oxidative damage cannot be completely eliminated. Therefore, exogenous antioxidants such as melatonin and resveratrol are widely used in oocyte cryopreservation to reduce oxidative damage through direct or indirect scavenging of ROS. In this review, we discuss analysis of various oxidative stresses induced by oocyte cryopreservation, the impact of antioxidants against oxidative damage, and their underlying mechanisms. We hope that this literature review can provide a reference for improving the efficiency of oocyte cryopreservation.

Open-Label Study to Evaluate the Efficacy of a Topical Anhydrous Formulation with 15% Pure Ascorbic Acid and Ginger as a Potent Antioxidant

Vitamin C is one of the naturally occurring antioxidants capable of reducing or preventing skin photoaging. Achieving a stable formulation with the optimal dose of ascorbic acid to ensure a biologically significant antioxidant effect is a challenge when developing cosmetic formulations. The objective of this study was to develop a stable formula in a non-aqueous media with 15% pure vitamin C supplemented with ginger and to study its efficacy, skin tolerance, and cosmetic assessment in 33 women. Vitamin C stability over time was determined via a high-performance liquid chromatography (HPLC) technique versus an aqueous option. Reactive oxygen species (ROS) determination was quantified to provide antioxidant effect. A 56-day in vivo study was performed to evaluate skin luminosity and hyperpigmentation reduction. Skin acceptability was verified by a dermatologist. The HPLC studies demonstrated a high stability of the anhydrous formula compared to an aqueous option. The in vitro studies showed a reduction in ROS of 93% (p-value < 0.0001). In vivo, luminosity increased by 17% (p-value < 0.0001) and skin tone became 10% more uniform (p-value < 0.007). Moreover, very good skin tolerance was determined as the dermatologist did not determine any clinical signs, and the subjects did not report any feelings of discomfort. We were able to develop an anhydrous formula of pure vitamin C that combines very good stability, consumer acceptance, and skin tolerance with a high level of efficacy.

Formation of Cyclobutane Pyrimidine Dimers after UVA Exposure (Dark-CPDs) Is Inhibited by an Hydrophilic Extract of Polypodium leucotomos

Exposure to sun and especially to ultraviolet radiation (UVR) exerts well known detrimental effects on skin which are implicated in malignancy. UVR induces production of cyclobutane pyrimidine dimers (CPDs), immediately during exposure and even hours after the exposure, these latter being called dark-CPDs, as consequence of the effects of different reactive species that are formed. Fernblock^® (FB), an aqueous extract of Polypodium leucotomos, has proven to have photoprotective and antioxidant effects on skin. The aim of our work was to investigate the potential photoprotective effect of FB against dark-CPD formation. Murine melanocytes (B16-F10) were exposed to UVA radiation and the production of dark-CPDs and different reactive oxygen and nitrogen species (ROS and RNS) was measured. Significant dark-CPD formation could be seen at 3 h after UVA irradiation, which was inhibited by the pre-treatment of cells with FB. Formation of nitric oxide, superoxide and peroxynitrite was increased after irradiation, consistent with the increased CPD formation. FB successfully reduced the production of these reactive species. Hence, these results show how dark-CPDs are formed in UVA irradiated melanocytes, and that FB acts as a potential antioxidant and ROS scavenger, preventing the DNA damage induced by sun exposure.

Standardized Terminalia chebula Fruit Extract: A Natural Ingredient That Provides Long-Lasting Antioxidant Protection and Reverses Visible Signs of Pollution-Induced Skin Damage

Background

Identification of long-lasting natural antioxidants to protect against and repair skin damage induced by exposure to environmental pollution is in high demand.

Objective

To investigate a standardized Terminalia chebula (TC) fruit extract for its long-lasting antioxidant and anti-inflammatory properties and its ability to reverse the visible signs of pollution-induced skin damage in an 8-week clinical study.

Material and Methods

Chemical and cell-based in vitro studies were performed to characterize long-lasting antioxidant and anti-inflammatory properties; a clinical study with subjects with normal to dry skin living in a high-pollution city for the previous 5 years was conducted to assess if a formulation containing 1% standardized TC fruit extract affected significant improvements in skin’s visible condition and appearance compared with its placebo.

Results

The standardized TC fruit extract provided longer-lasting and more efficient neutralization of reactive oxygen species (ROS) than tocopherol; treatment of keratinocytes with the fruit extract prior to being stressed with urban dust safeguarded against increases in intracellular ROS, inhibited release of inflammatory cytokines IL-6 and IL-8 and protected membrane lipids against peroxidation. A clinical study yielded statistically significant improvements in dermatologist scores and subject self-assessments for skin texture, hydration, tone, firmness and radiance as compared to its placebo.

Conclusion

These studies validate the use of this standardized TC fruit extract not only as a restorative to diminish visible signs of existing damage but also as a preventative to help defend skin against damages caused by chronic exposure to environmental pollution.

Tetrahexyldecyl Ascorbate (THDC) Degrades Rapidly under Oxidative Stress but Can Be Stabilized by Acetyl Zingerone to Enhance Collagen Production and Antioxidant Effects

Tetrahexyldecyl Ascorbate (THDC) is an L-ascorbic acid precursor with improved stability and ability to penetrate the epidermis. The stability and transdermal penetration of THDC, however, may be compromised by the oxidant-rich environment of human skin. In this study, we show that THDC is a poor antioxidant that degrades rapidly when exposed to singlet oxygen. This degradation, however, was prevented by combination with acetyl zingerone (AZ) as a stabilizing antioxidant. As a standalone ingredient, THDC led to unexpected activation of type I interferon signaling, but this pro-inflammatory effect was blunted in the presence of AZ. Moreover, the combination of THDC and AZ increased expression of genes associated with phospholipid homeostasis and keratinocyte differentiation, along with repression of MMP1 and MMP7 expression, inhibition of MMP enzyme activity, and increased production of collagen proteins by dermal fibroblasts. Lastly, whereas THDC alone reduced viability of keratinocytes exposed to oxidative stress, this effect was completely abrogated by the addition of AZ to THDC. These results show that AZ is an effective antioxidant stabilizer of THDC and that combination of these products may improve ascorbic acid delivery. This provides a step towards reaching the full potential of ascorbate as an active ingredient in topical preparations.

How Tryptophan Oxidation Arises by "Dark" Photoreactions from Chemiexcited Triplet Acetone

Dioxetane intermediates readily decompose to chemiluminescent triplet carbonyls, giving rise to what has been paradoxically called photochemistry in the dark. In this issue of Photochemistry and Photobiology, Bechara et al. report on mechanistic advances in such a reaction. With the use of horseradish peroxidase for isobutyraldehyde-derived triplet acetone, light emission from acetone and singlet oxygen can be quenched. The experiments reveal that the reaction depends on oxygen and the amino acid. The analysis reveals that free tryptophan is a target of this form of "carbonyl stress," with the efficient formation of mono-, bi- and tricyclic compounds (N-formylkynurenine, indoline, 1λ² -indole and 3H-indoles).

Appropriate Technologies to Accompany Sunscreens in the Battle Against Ultraviolet, Superoxide, and Singlet Oxygen

The interaction of ultraviolet radiation with biological matter results in direct damage such as pyrimidine dimers in DNA. It also results in indirect damage provoked by the production of reactive oxygen species (ROS) catalyzed by photosensitizers. Photosensitizers can be endogenous (e.g., tryptophan) or exogenous (e.g., TiO₂ and other photostable UVA sunscreens). Direct damage triggers an inflammatory response and the oxidative and proteolytic bursts that characterize its onset. The inflammatory reaction multiplies the effects of one single photon. Indirect damage, such as the peroxidative cascade in membrane lipids, can extend to thousands of molecular modifications per absorbed photon. Sunscreens should therefore be formulated in the presence of appropriate antioxidants. Superoxide and singlet oxygen are the main ROS that need to be tackled: this review describes some of the molecular, biochemical, cellular, and clinical consequences of exposure to UV radiation as well as some results associated with scavengers and quenchers of superoxide and singlet oxygen, as well as with inhibitors of singlet oxygen production.

Randomized double-blind vehicle controlled study of the effects of topical acetyl zingerone on photoaging

OBJECTIVE

Acetyl zingerone (AZ), a derivative of the phytochemical zingerone from Zingiber officinale (ginger), is a novel compound that is purported to have antiaging properties. The objective of this clinical study was to assess the role of acetyl zingerone in its ability to improve the appearance of facial skin wrinkles, redness, pigmentation, and photoaging was assessed.

METHODS

Thirty-one healthy participants (age 44 ± 7 years) were randomized in blinded fashion to apply either 1% AZ or placebo, consisting of the vehicle base cream, to the full face twice daily for 8 weeks with a total of 3 visits. Signs of photoaging, including wrinkles, dyspigmentation, and redness were assessed with facial image analysis photography and software.

RESULTS

There was a significant decrease in average wrinkle severity (P = .019; Mean=-25.7% change), total wrinkle volume (P = .003; Mean=-30.1% change), pigment intensity (P = .021; Mean=-25.6% change), and redness intensity (P = .035; Mean=-20.7% change) in the AZ group by 8 weeks compared with the placebo. No significant itching, burning, or stinging was noted by study participants. There was also no significant difference between both groups in the clinical assessment of scaling, erythema, hypopigmentation, or hyperpigmentation.

CONCLUSIONS AND RELEVANCE

Topical AZ improves photodamage and decreases the appearance of wrinkles, dyspigmentation, and redness intensity when compared to placebo (vehicle) formulation. Acetyl zingerone is well tolerated with daily use.