Photoprotection by honeybush extracts, hesperidin and mangiferin against UVB-induced skin damage in SKH-1 mice

Photoprotection and Antiaging Activity of Extracts from Honeybush (Cyclopia sp.)-In Vitro Wound Healing and Inhibition of the Skin Extracellular Matrix Enzymes: Tyrosinase, Collagenase, Elastase and Hyaluronidase

Cyclopia sp. (honeybush) is an African shrub known as a rich source of polyphenols. The biological effects of fermented honeybush extracts were investigated. The influence of honeybush extracts on extracellular matrix (ECM) enzymes responsible for the skin malfunction and aging process-collagenase, elastase, tyrosinase and hyaluronidase-was analysed. The research also included assessment of the in vitro photoprotection efficiency of honeybush extracts and their contribution to the wound healing process. Antioxidant properties of the prepared extracts were evaluated, and quantification of the main compounds in the extracts was achieved. The research showed that the analysed extracts had a significant ability to inhibit collagenase, tyrosinase and hyaluronidase and a weak influence on elastase activity. Tyrosinase was inhibited effectively by honeybush acetone (IC₅₀ 26.18 ± 1.45 µg/mL), ethanol (IC₅₀ 45.99 ± 0.76 µg/mL) and water (IC₅₀ 67.42 ± 1.75 µg/mL) extracts. Significant hyaluronidase inhibition was observed for ethanol, acetone and water extracts (IC₅₀ were 10.99 ± 1.56, 13.21 ± 0.39 and 14.62 ± 0.21µg/mL, respectively). Collagenase activity was inhibited effectively by honeybush acetone extract (IC₅₀ 42.5 ± 1.05 μg/mL). The wound healing properties of the honeybush extracts, estimated in vitro in human keratinocytes (HaCaTs), were indicated for water and ethanol extracts. In vitro sun protection factor (SPF in vitro) showed medium photoprotection potential for all the honeybush extracts. The quantity of polyphenolic compounds was estimated with the use of high-performance liquid chromatography equipped with diode-array detection (HPLC-DAD), indicating the highest mangiferin contents in ethanol, acetone and n-butanol extracts, while in the water extract hesperidin was the dominant compound. The antioxidant properties of the honeybush extracts were estimated with FRAP (2,4,6-Tris(2-pyridyl)-s-triazine) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests, indicating their strong antioxidant activity, similar to ascorbic acid for the acetone extract in both tests. The wound healing abilities, estimation of SPF in vitro and the direct influence on selected enzymes (elastase, tyrosinase, collagenase and hyaluronidase) of the tested honeybush extracts were analysed for the first time, indicating a high potential of these well-known herbal tea for antiaging, anti-inflammation, regeneration and protection of the skin.

Natural polyphenols: a promising bioactive compounds for skin care and cosmetics

The physiological and morphological aspects of skin suffer from frequent change. Numerous internal and external factors have direct impact on inducing various skin problems like inflammation, aging, cancer, oxidative stress, hyperpigmentation etc. The use of plant polyphenols as a photo-ecting agent is gaining popularity nowadays. Polyphenols are known to enhance endogenic antioxidant system of skin thereby preventing various skin diseases. The biological activity of plant polyphenols is dependent on their physicochemical properties for overcoming the epidermal barriers to reach the specific receptor. Several evidences have reported the vital role polyphenols in mitigating adverse skin problems and reverting back the healthy skin condition. The interest in plant derived skin care products is emerging due to the changing notion of people to shift their focus towards use of plant-based products. The present review draws an attention to uncover the protective role of polyphenols in prevention of various skin problems. Several in vitro and in vivo studies have been summarized that claims the efficacious nature of plant extract having dermatological significance.

Anti-inflammatory and anti-aggregating effects of rangpur in the first trimester of growth: ultra-performance liquid chromatography-electrospray mass spectrometry profile and quantification of hesperidin

BACKGROUND

Citrus fruits are a rich source of valuable molecules, and their industrial processing produces bagasses, little explored to generate important by-products. These Citrus residues, including seeds and peels, also contain numerous pharmacologically important substances. To reduce the impact of these Citrus by-products, young, harvested fruits could be used as a functional supplemental food while another part is grown until maturity for industrial production. This study therefore aims to valorize rangpur (Citrus limonia) in the first 3 months of its growth by investigating and comparing its monthly chemical profiles using ultra-performance liquid chromatography-electrospray mass spectrometry (UPLC-ESI-MS) and its anti-inflammatory and antiplatelet activity.

RESULTS

Extracts obtained from the fruits harvested in November, December, and January, 2017 and 2018 (L221117, L161217, and L160118) showed different UPLC-ESI-MS profiles. Twenty-five of the 26 detected metabolites were identified as cyclitol, pyrrolidine betaine, aryl propanoyl esters, chlorogenic acids, flavonoids, coumarins, and limonoids. Quantification studies indicated an increased concentration of hesperidin from the younger fruits to the older fruits of the series. L160118 reduced nitrogen oxide (NOx), tumor necrosis factor alpha (TNF-α), and interleukin 6 (IL-6) levels more than other extracts. Their activity followed the same trends as the hesperidin concentration in each fruit. In contrast, the most promising antiplatelet activity was observed with the extracts from the two youngest fruits. This suggests combined effects of the chemical components found in these fruits' extracts.

CONCLUSION

The extracts obtained from these young fruits showed considerable anti-inflammatory and antiplatelet activity. Overall, young rangpur could be used as raw material to produce functional foods without producing any waste. © 2022 Society of Chemical Industry.

Hesperetin-Based Hydrogels Protect the Skin against UV Radiation-Induced Damage

UV radiation can cause damages, such as erythema, skin photoaging, and carcinogenesis. The adoption of protective measures against sun exposure is essential to prevent these damages, and the interest in using natural substances as an alternative for photoprotection is growing. Thus, hesperetin with antioxidant, anti-inflammatory, and anticancer properties is a promising substance to be used with photochemopreventive action and to protect the skin from damage induced by UV radiation. Therefore, the present study aimed to develop a topical formulation based on AAMVPC gel containing hesperetin and evaluate its photoprotective effect on the skin of rats exposed to UVA-UVB radiation. The animals were submitted to the irradiation protocol UVA-UVB, and at the end, erythema, lipid peroxidation, and activity of the antioxidant enzyme catalase and superoxide dismutase were evaluated. Additionally, it evaluated the activity of myeloperoxidase and histological changes. The formulation presented a rheological and spreadability profile suitable for cutaneous application. In vivo results demonstrated that the topical formulation of AAMVPC gel containing hesperetin at a concentration of 10% protected the skin from damage induced by UVA-UVB radiation, with the absence of erythema, lipid lipoperoxidation, and inflammation (low myeloperoxidase activity), and increased catalase and superoxide dismutase activities. The morphology and architecture of the dermo-epidermal tissue of these animals were like those observed under normal conditions (non-irradiated animals). Thus, the results showed that hesperetin was able to protect the animals' skin against UV radiation-induced skin damage and the protection mechanisms may be related to the antioxidant and anti-inflammatory properties of this natural product.

Theragra chalcogramma Hydrolysates, Rich in Gly-Leu-Pro-Ser-Tyr-Thr, Exerts Anti-Photoaging Potential via Targeting MAPK and NF-κB Pathways in SD Rats

Previous studies have revealed that excessive exposure to UV irradiation is the main cause of skin photoaging and the signaling pathways of MAPK and NF-κB are involved in this progression. The present study aims to investigate the anti-photoaging effects of low molecular weight hydrolysates from Theragra chalcogramma (TCH) and to clarify the underlying mechanism. The degradation of mechanical barrier functions in photoaged skin was substantially ameliorated after TCH administration; meanwhile, TCH significantly elevated the antioxidant capacity and suppressed the over-production of inflammatory cytokine IL-1β. Moreover, the histopathological deteriorations such as epidermal hyperplasia and dermal loss were significantly alleviated, along with the increase in procollagen type I content and decrease in MMP-1 activity (p < 0.05). Furthermore, TCH effectively blocked the MAPK and NF-κB signaling pathways through inhibition of the phosphorylation of p38, JNK, ERK, iκB, and p65 proteins. Collectively, these data indicate that TCH has potential as a novel ingredient for the development of anti-photoaging foods.

Cathelicidin-NV from Nanorana ventripunctata effectively protects HaCaT cells, ameliorating ultraviolet B-induced skin photoaging

Cathelicidins are diverse effector molecules in the vertebrate immune system and are related to immune regulation, inflammatory response, wound healing, and blood vessel formation. However, little is known about their free radical scavenging ability, especially in vivo. In this study, a cathelicidin molecule (cathelicidin-NV, ARGKKECKDDRCRLLMKRGSFSYV) previously identified from the spot-bellied plateau frog (Nanorana ventripunctata) (Anura, Dicroglossidae, Dicroglossinae) by us was shown to alleviate ultraviolet B (UVB)-induced skin photoaging in mice. Cathelicidin-NV effectively suppressed cytotoxicity, DNA fragmentation, apoptosis and reduced the protein expression levels of JNK, c-Jun, and MMP-1, which are involved in the regulation of collagen degradation in HaCaT cells induced by UVB irradiation. Furthermore, cathelicidin-NV also scavenged UVB-induced intracellular reactive oxygen species (ROS). Taken together, cathelicidin-NV directly scavenged excessive intracellular ROS to protect HaCaT cells, and subsequently alleviated UVB-induced skin photoaging. This study extends reports on the antioxidant function of the cathelicidin family. In addition, the properties of cathelicidin-NV make it an excellent candidate for the prevention and treatment of UV-induced skin photoaging.

Promising Therapeutic Candidate for Myocardial Ischemia/Reperfusion Injury: What Are the Possible Mechanisms and Roles of Phytochemicals?

Percutaneous coronary intervention (PCI) is one of the most effective reperfusion strategies for acute myocardial infarction (AMI) despite myocardial ischemia/reperfusion (I/R) injury, causing one of the causes of most cardiomyocyte injuries and deaths. The pathological processes of myocardial I/R injury include apoptosis, autophagy, and irreversible cell death caused by calcium overload, oxidative stress, and inflammation. Eventually, myocardial I/R injury causes a spike of further cardiomyocyte injury that contributes to final infarct size (IS) and bound with hospitalization of heart failure as well as all-cause mortality within the following 12 months. Therefore, the addition of adjuvant intervention to improve myocardial salvage and cardiac function calls for further investigation. Phytochemicals are non-nutritive bioactive secondary compounds abundantly found in Chinese herbal medicine. Great effort has been put into phytochemicals because they are often in line with the expectations to improve myocardial I/R injury without compromising the clinical efficacy or to even produce synergy. We summarized the previous efforts, briefly outlined the mechanism of myocardial I/R injury, and focused on exploring the cardioprotective effects and potential mechanisms of all phytochemical types that have been investigated under myocardial I/R injury. Phytochemicals deserve to be utilized as promising therapeutic candidates for further development and research on combating myocardial I/R injury. Nevertheless, more studies are needed to provide a better understanding of the mechanism of myocardial I/R injury treatment using phytochemicals and possible side effects associated with this approach.

Promising Natural Products in New Drug Design, Development, and Therapy for Skin Disorders: An Overview of Scientific Evidence and Understanding Their Mechanism of Action

The skin is the largest organ in the human body, composed of the epidermis and the dermis. It provides protection and acts as a barrier against external menaces like allergens, chemicals, systemic toxicity, and infectious organisms. Skin disorders like cancer, dermatitis, psoriasis, wounds, skin aging, acne, and skin infection occur frequently and can impact human life. According to a growing body of evidence, several studies have reported that natural products have the potential for treating skin disorders. Building on this information, this review provides brief information about the action of the most important in vitro and in vivo research on the use of ten selected natural products in inflammatory, neoplastic, and infectious skin disorders and their mechanisms that have been reported to date. The related studies and articles were searched from several databases, including PubMed, Google, Google Scholar, and ScienceDirect. Ten natural products that have been reported widely on skin disorders were reviewed in this study, with most showing anti-inflammatory, antioxidant, anti-microbial, and anti-cancer effects as the main therapeutic actions. Overall, most of the natural products reported in this review can reduce and suppress inflammatory markers, like tumor necrosis factor-alpha (TNF-α), scavenge reactive oxygen species (ROS), induce cancer cell death through apoptosis, and prevent bacteria, fungal, and virus infections indicating their potentials. This review also highlighted the challenges and opportunities of natural products in transdermal/topical delivery systems and their safety considerations for skin disorders. Our findings indicated that natural products might be a low-cost, well-tolerated, and safe treatment for skin diseases. However, a larger number of clinical trials are required to validate these findings. Natural products in combination with modern drugs, as well as the development of novel delivery mechanisms, represent a very promising area for future drug discovery of these natural leads against skin disorders.

Mangiferin and Hesperidin Transdermal Distribution and Permeability through the Skin from Solutions and Honeybush Extracts (Cyclopia sp.)-A Comparison Ex Vivo Study

Polyphenolic compounds—mangiferin and hesperidin—are, among others, the most important secondary metabolites of African shrub Cyclopia sp. (honeybush). The aim of this study was to compare the percutaneous absorption of mangiferin and hesperidin from solutions (water, ethanol 50%, (v/v)) and extracts obtained from green and fermented honeybush (water, ethanol 50%, (v/v)). Research was performed with the Bronaugh cells, on human dorsal skin. The mangiferin and hesperidin distributions in skin layers (stratum corneum, epidermis, and dermis) and in acceptor fluid (in every 2, 4, 6, and 24 h) were evaluated by HPLC–Photodiode Array Coulometric and Coulometric Electrochemical Array Detection. The transdermal distribution of hesperidin was also demonstrated by fluorescence microscopy. Results indicated that mangiferin and hesperidin were able to cross the stratum corneum and penetrate into the epidermis and dermis. An advantage of hesperidin penetration into the skin from the water over ethanol solution was observed (451.02 ± 14.50 vs. 357.39 ± 4.51 ng/cm²), as well as in the mangiferin study (127.56 ± 9.49 vs. 97.23 ± 2.92 ng/cm²). Furthermore, mangiferin penetration was more evident from nonfermented honeybush ethanol extract (189.85 ± 4.11 ng/cm²) than from solutions. The permeation of mangiferin and hesperidin through the skin to the acceptor fluid was observed regardless of whether the solution or the honeybush extract was applied. The highest ability to permeate the skin was demonstrated for the water solution of hesperidin (250.92 ± 16.01 ng/cm²), while the hesperidin occurring in the extracts permeated in a very low capacity. Mangiferin from nonfermented honeybush ethanol extract had the highest ability to permeate to the acceptor fluid within 24 h (152.36 ± 8.57 ng/cm²).

Protective effects of GLHP from Gracilaria lemaneiformis against UVB-induced photodamage in human immortalized keratinocytes cells and BALB/c mice

Our previous study showed that the water-soluble heteropolysaccharide extracted from Gracilaria lemaneiformis (GLHP) has excellent anti-inflammation and anti-oxidant properties. This study explored the efficacy of GLHP against skin anti-photoaging in human immortalized keratinocytes (HaCaT) cells and BALB/c mice under UVB irradiation. Cell viability, antiapoptotic, reactive oxygen species (ROS) scavenging activity, mitochondrial membrane potential, and cell wound scratch assays were conducted, as well as assessment of inflammation markers and sun protection factors. The in vitro results showed that GLHP pretreatment significantly inhibited UVB-induced apoptosis, reversed the decrease of cell viability via downregulating the expression of apoptosis-related protein caspase-3, accelerated the migration of HaCaT cells, and promoted wound healing. Notably, the protective effect of GLHP may be associated with the scavenging of ROS and the decrease of mitochondrial membrane potential. Moreover, GLHP pretreatment significantly restrained the upregulation of iNOS (UVB-induced inflammation marker), suppressed the expression of P-ERK and NF-κB, and decreased the activity of MMPs, suggesting that it exerts the therapeutic effects by inhibiting the MAPK/NF-κB signal pathway. Results obtained after conducting the in vivo assay confirmed that GLHP could reverse the UVB-induced increase of epidermal thickness in BALB/c mice. In conclusion, this study shows that GLHP can be utilized as a safer resource in the manufacture of anti-aging cosmetics because it exerts excellent anti-photoaging effects.

Gold Nanoparticles Synthesized Using Extracts of Cyclopia intermedia, Commonly Known as Honeybush, Amplify the Cytotoxic Effects of Doxorubicin

Cyclopia intermedia (C. intermedia) is an indigenous South African shrub used to prepare the popular medicinal honeybush (HB) tea. This plant contains high levels of mangiferin (MGF), a xanthonoid that was reported to have numerous biological activities, including anti-tumor activity. MGF and extracts that contain high concentrations of MGF, such as extracts from Mangifera indica L. or mango have been used to synthesize gold nanoparticles (AuNPs) using green nanotechnology. It has previously been shown that when AuNPs synthesized from M. indica L. extracts are used in combination with doxorubicin (DOX) and Ayurvedic medicine, the anti-tumor effects appear to be augmented. It has also been demonstrated that MGF used in combination with DOX resulted in enhanced anti-tumor effects. In this study, C. intermedia (HB) and MGF were used to synthesize HB-AuNPs and MGF-AuNPs, respectively. The physicochemical properties of the AuNPs were characterized by the UV-Visible Spectroscopy (UV-Vis), dynamic light scattering (DLS), Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD) and high-resolution transmission electron microscopy (HR-TEM). The cytotoxicity of HB-AuNPs and MGF-AuNPs were assessed on human colon (Caco-2), prostate (PC-3) and glioblastoma (U87) cancer cells; as well as normal breast epithelial (MCF-12A) cells using the MTT assay. Both HB-AuNPs and MGF-AuNPs demonstrated relatively low cytotoxicity in these cells. However, when these nanoparticles were used in combination with DOX, the cytotoxicity of DOX was significantly augmented.

Natural Xanthones and Skin Inflammatory Diseases: Multitargeting Mechanisms of Action and Potential Application

The pathogenesis of skin inflammatory diseases such as atopic dermatitis, acne, psoriasis, and skin cancers generally involve the generation of oxidative stress and chronic inflammation. Exposure of the skin to external aggressors such as ultraviolet (UV) radiation and xenobiotics induces the generation of reactive oxygen species (ROS) which subsequently activates immune responses and causes immunological aberrations. Hence, antioxidant and anti-inflammatory agents were considered to be potential compounds to treat skin inflammatory diseases. A prime example of such compounds is xanthone (xanthene-9-one), a class of natural compounds that possess a wide range of biological activities including antioxidant, anti-inflammatory, antimicrobial, cytotoxic, and chemotherapeutic effects. Many studies reported various mechanisms of action by xanthones for the treatment of skin inflammatory diseases. These mechanisms of action commonly involve the modulation of various pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor α (TNF-α), as well as anti-inflammatory cytokines such as IL-10. Other mechanisms of action include the regulation of NF-κB and MAPK signaling pathways, besides immune cell recruitment via modulation of chemokines, activation, and infiltration. Moreover, disease-specific activity contributed by xanthones, such as antibacterial action against Propionibacterium acnes and Staphylococcus epidermidis for acne treatment, and numerous cytotoxic mechanisms involving pro-apoptotic and anti-metastatic effects for skin cancer treatment have been extensively elucidated. Furthermore, xanthones have been reported to modulate pathways responsible for mediating oxidative stress and inflammation such as PPAR, nuclear factor erythroid 2-related factor and prostaglandin cascades. These pathways were also implicated in skin inflammatory diseases. Xanthones including the prenylated α-mangostin (2) and γ-mangostin (3), glucosylated mangiferin (4) and the caged xanthone gambogic acid (8) are potential lead compounds to be further developed into pharmaceutical agents for the treatment of skin inflammatory diseases. Future studies on the structure-activity relationships, molecular mechanisms, and applications of xanthones for the treatment of skin inflammatory diseases are thus highly recommended.

Skin photo-protection with phytochemicals against photo-oxidative stress, photo-carcinogenesis, signal transduction pathways and extracellular matrix remodeling-An overview

Excessive exposure of skin to UV radiation triggers the generation of oxidative stress, inflammation, immunosuppression, apoptosis, matrix-metalloproteases production, and DNA mutations leading to the onset of photo ageing and photo-carcinogenesis. At the molecular level, these changes occur via activation of several protein kinases as well as transcription pathways, formation of reactive oxygen species, and release of cytokines, interleukins and prostaglandins together. Current therapies available on the market only provide limited solutions and exhibit several side effects. The present paper provides insight into scientific studies that have elucidated the positive role of phytochemicals in counteracting the UV-induced depletion of antioxidant enzymes, increased lipid peroxidation, inflammation, DNA mutations, increased senescence, dysfunctional apoptosis and immune suppression. The contribution of phytochemicals to the downregulation of expression of oxidative-stress sensitive transcription factors (Nrf2, NF-Kb, AP-1 and p53) and protein kinases (MSK, ERK, JNK, p38 MAPK, p90RSK2 and CaMKs) involved in inflammation, apoptosis, immune suppression, extracellular matrix remodelling, senescence, photo ageing and photo-carcinogenesis, is also discussed. Conclusively, several phytochemicals hold potential for the development of a viable solution against UV irradiation-mediated photo ageing, photo-carcinogenesis and related manifestations.

Ultraviolet A protective potential of plant extracts and phytochemicals

Chronic exposure to solar radiation is related to an increased incidence of various skin disorders, including premature skin aging and melanoma and non-melanoma skin cancers. Ultraviolet (UV) photons in particular are responsible for skin damage. Solar UV photons mainly belong to UVA wavebands, however UVA radiation has been mostly ignored for a long time. At the cellular level, UVA photons mainly provoke indirect oxidative damage to biomolecules via the massive generation of unstable and highly reactive compounds. Human skin has several effective mechanisms that forestall, repair and eliminate damage caused by solar radiation. Regardless, some damage persists and can accumulate with chronic exposure. Therefore, conscious protection against solar radiation (UVB+UVA) is necessary. Besides traditional types of photoprotection such as sunscreen use, new strategies are being searched for and developed. One very popular protective strategy is the application of phytochemicals as active ingredients of photoprotection preparations instead of synthetic chemicals. Phytochemicals usually possess additional biological activities besides absorbing the energy of photons, and those properties (e.g. antioxidant, anti-inflammatory) magnify the protective potential of phytochemicals and extracts. Therefore, compounds of natural origin are in the interest of researchers as well as developers. In this review, only studies on UVA protection with well-documented experimental conditions are summarized. This article includes 17 well standardized plant extracts (Camellia sinensis (L.) Kuntze, Silybum marianum L. Gaertn., Punica granatum L., Polypodium aureum L., Vaccinium myrtillus L., Lonicera caerulea L., Thymus vulgaris L., Opuntia ficus-indica (L.) Mill., Morinda citrifolia L., Aloe vera (L.) Burm.f., Oenothera paradoxa Hudziok, Galinsoga parviflora Cav., Galinsoga quadriradiata Ruiz et Pavón, Hippophae rhamnoides L., Cola acuminata Schott & Endl., Theobroma cacao L. and Amaranthus cruentus L.) and 26 phytochemicals.

Pharmacological Activity of Honeybush (Cyclopia intermedia) in Boar Spermatozoa during Semen Storage and under Oxidative Stress

Simple Summary

Nowadays, pig breeding is mostly conducted by artificial insemination using diluted semen stored for 1 to 5 days. During semen handling and storage, sperm quality usually declines, mainly because of oxidative stress and bacterial contamination. As cheap and natural sources of antioxidants, medicinal plants have become an alternative to the most common additives used in semen extenders. In this regard, several indigenous plants from Southern Africa have shown pharmacological activity in different animal cell types, although their effects on sperm cells have not been explored extensively. In the present study, we tested the effects of honeybush (Cyclopia intermedia) aqueous extract as a preservative of boar semen during 5 days of storage and under induced oxidative stress. Overall, this plant extract enhanced several sperm quality parameters and did not show any toxic effects. Supplementation with honeybush extract was able to improve the preservative properties of a long-term semen extender, thus confirming the beneficial use of plant extracts as natural additives for boar sperm.

Abstract

In recent decades, an increasing number of ethnopharmacological studies have been dedicated to medicinal plants from South African fynbos. Among these plants, honeybush (Cyclopia spp.) has become a popular tea, mainly due to its healthy properties and caffeine-free status. The antioxidant, antimutagenic, and antimicrobial properties of this plant have been reported in several cell types, but its effects on reproductive function are still unknown. Here, we assessed the effects of honeybush (Cyclopia intermedia) on boar sperm parameters under induced oxidative stress (Fe²⁺/ascorbate) and during five days of semen storage at 17 °C without oxidative stress. In both experiments, four concentrations (200, 50, 12.5, and 3.125 µg/mL) of fermented honeybush were tested. Our results show that honeybush enhances sperm parameters, and no toxic effects were observed at any of the tested extract concentrations. Interestingly, honeybush (12.5 µg/mL) improved the sperm motility and kinetic parameters, preserved the plasma membrane integrity, and reduced the lipid peroxidation in the samples exposed to Fe²⁺/ascorbate (p < 0.05). In the stored samples, positive effects of honeybush on sperm parameters (motility, kinetics, acrosome, and mitochondria) were observed from 48 h until 120 h of semen storage (p < 0.05). Our results clearly show the protective effects of honeybush on sperm samples, thus promoting its use as a natural source of antioxidants for boar semen.

Protective effects of hesperidin and diosmin against acrylamide-induced liver, kidney, and brain oxidative damage in rats

Acrylamide (AA) is a heat-induced toxin formed during thermal processing of many commonly consumed foods, including meat products, French fries, potato crisps, bread, cereals, cookies, and coffee. There is thus potentially high dietary exposure of humans to AA, which can induce significant oxidative stress. Hesperidin (HS) and diosmin (DS) are flavone glycosides that have antioxidant properties. The aim of this study was to investigate the protective effects of HS and DS against AA toxicity. Fifty-six adult male Wistar albino rats were divided into seven groups. The first group was orally administered 0.5% (w/v) dimethyl sulfoxide (DMSO) and considered as the control group. The second and third groups were orally administered 10 mg/kg/day of HS or DS, respectively. The fourth group received 20 mg/kg/day of AA orally for 14 days. The fifth and sixth groups were given 10 mg/kg/day of HS or DS, respectively, followed by AA. The seventh group was given both HS and DS after AA administration. AA intoxication significantly (p ≤ 0.05) increased serum levels of liver function enzymes (ALT, AST, and ALP), kidney function products (urea and creatinine), oxidative DNA damage marker (OHdG), proinflammatory markers (TNF-α, IL-1β, and IL-6), lipid peroxidation marker (malondialdehyde), and nitric oxide (NO). On the other hand, it significantly (p ≤ 0.05) decreased levels of reduced glutathione (GSH) in the liver, kidney, and brain. The activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) in the liver, kidney, and brain tissues were also reduced. HS and DS supplementation prevented lipid peroxidation, normalized the serum parameters altered by AA, and enhanced the tissue concentrations and activities of antioxidant biomarkers. It could be concluded that HS and DS have potent protective effects against oxidative stress, lipid peroxidation, and DNA damage induced by AA toxicity in rats.

Oral supplementation of L-glutathione prevents ultraviolet B-induced melanogenesis and oxidative stress in BALB/c mice

Dietary antioxidant supplements such as L-glutathione have gained considerable attention in dermatology and cosmeceutical fields. L-glutathione possesses antiaging, antimelanogenic, antioxidant, and anticancer properties. This study aimed to investigate the inhibitory effects of L-glutathione on melanogenesis activity and oxidative stress in ultraviolet B (UVB)-irradiated BALB/c mice. Eighteen female BALB/c mice were randomly divided into 3 groups: a control group (n=6), a group without UVB irradiation and L-glutathione administration; a UVB irradiated group (n=6), a group irradiated with a UVB dose of 250 mJ/cm² for 3 min; and a treatment group (n=6), a group irradiated with UVB and treated with 100 mg/kg of L-glutathione by oral gavage. Treatment was given for 14 days, and UVB irradiation was given on days 9, 11, and 13. Oral L-glutathione significantly (P<0.05) reduced lipid peroxidation and elevated superoxide dismutase activity the and glutathione level. L-glutathione also inhibited melanin content and tyrosinase activity significantly (P<0.05) as compared with the UVB-irradiated group. Histopathological examination also showed that L-glutathione reduced the deposition of melanin pigment in the basal layer of the epidermis as compared with that in UVB-irradiated mice. All in all, the present study demonstrated that L-glutathione has the potential to be developed as a photoprotection agent against UVB-induced oxidative stress and melanogenesis.

Benefits of Hesperidin for Cutaneous Functions

Hesperidin is a bioflavonoid, with high concentration in citrus fruits. In addition to its well-known benefits for cardiovascular function, type II diabetes, and anti-inflammation, recent studies have demonstrated multiple benefits of hesperidin for cutaneous functions, including wound healing, UV protection, anti-inflammation, antimicrobial, antiskin cancer, and skin lightening. In addition, hesperidin enhances epidermal permeability barrier homeostasis in both normal young and aged skin. The mechanisms by which hesperidin benefits cutaneous functions are attributable to its antioxidant properties, inhibition of MAPK-dependent signaling pathways, and stimulation of epidermal proliferation, differentiation, and lipid production. Because of its low cost, wide availability, and superior safety, hesperidin could prove useful for the management of a variety of cutaneous conditions.

Defense potential of secondary metabolites in medicinal plants under UV-B stress

Ultraviolet-B (UV-B) radiation has, for many decades now, been widely studied with respect to its consequences on plant and animal health. Though according to NASA, the ozone hole is on its way to recovery, it will still be a considerable time before UV-B levels reach pre-industrial limits. Thus, for the present, excessive UV-B reaching the Earth is a cause for concern, and UV-B related human ailments are on the rise. Plants produce various secondary metabolites as one of the defense strategies under UV-B. They provide photoprotection via their UV-B screening effects and by quenching the reactive oxygen- and nitrogen species produced under UV-B influence. These properties of plant secondary metabolites (PSMs) are being increasingly recognized and made use of in sunscreens and cosmetics, and pharma- and nutraceuticals are gradually becoming a part of the regular diet. Secondary metabolites derived from medicinal plants (alkaloids, terpenoids, and phenolics) are a source of pharmaceuticals, nutraceuticals, as well as more rigorously tested and regulated drugs. These metabolites have been implicated in providing protection not only to plants under the influence of UV-B, but also to animals/animal cell lines, when the innate defenses in the latter are not adequate under UV-B-induced damage. The present review focuses on the defense potential of secondary metabolites derived from medicinal plants in both plants and animals. In plants, the concentrations of the alkaloids, terpenes/terpenoids, and phenolics have been discussed under UV-B irradiation as well as the fate of the genes and enzymes involved in their biosynthetic pathways. Their role in providing protection to animal models subjected to UV-B has been subsequently elucidated. Finally, we discuss the possible futuristic scenarios and implications for plant, animal, and human health pertaining to the defense potential of these secondary metabolites under UV-B radiation-mediated damages.

Cytoprotective Effects of Mangiferin and Z-Ligustilide in PAH-Exposed Human Airway Epithelium in Vitro

According to World Health Organisation (WHO) air pollution increases the risk of cardiovascular disorders, respiratory diseases, including COPD, lung cancer and acute respiratory infections, neuro-degenerative and other diseases. It is also known that various phytochemicals may mitigate such risks. This study tested if phytochemicals mangiferin (MNG) and Z-ligustilide (Z-LG) may protect PAH-exposed human lung bronchial epithelial cells (BEAS-2B). Organic PAH extract was obtained from the urban fine PM with high benzo(a)pyrene content collected in Eastern European mid-sized city during winter heating season. Cell proliferation traits and levels of intracellular oxidative stress were examined. Effect of MNG (0.5 µg/mL) alone or in combination with PAH on bronchial epithelium wound healing was evaluated. Both phytochemicals were also evaluated for their antioxidant properties in acellular system. Treatment with MNG produced strong cytoprotective effect on PAH-exposed cells (p < 0.01) while Z-LG (0.5 µg/mL) exhibited strong negative effect on cell proliferation in untreated and PAH-exposed cells (p < 0.001). MNG, being many times stronger antioxidant than Z-LG in chemical in vitro assays (p < 0.0001), was also able to decrease PAH-induced oxidative stress in the cell cultures (p < 0.05). Consequently MNG ameliorates oxidative stress, speeds up wound healing process and restores proliferation rate in PAH-exposed bronchial epithelium. Such protective effects of MNG in air pollution affected airway epithelium stimulate further research on this promising phytochemical.

Inhibition of autophagy via activation of PI3K/Akt/mTOR pathway contributes to the protection of hesperidin against myocardial ischemia/reperfusion injury

Hesperidin has been reported to attenuate myocardial ischemia/reperfusion (I/R) injury; however, its effect on autophagy during myocardial I/R and the underlying mechanism remains unknown. The present study aimed to investigate whether hesperidin inhibited I/R-induced excessive myocardial autophagy through activating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway. Male adult rats were pretreated with hesperidin for a total of 3 days prior to ischemia in the absence or presence of LY294002, a PI3K inhibitor, and then subjected to ischemia for 30 min followed by reperfusion for 4 h. Myocardial infarct size was measured by Evans blue/triphenyltetrazolium chloride staining. Hematoxylin and eosin staining was used for observing the histological changes in the heart, and the serum levels of creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) were measured by enzyme-linked immunosorbent assay. Additionally, the protein levels of light chain (LC) 3II, Beclin1, phosphorylated (p)-mTOR, p-Akt and p-PI3K were determined by western blot analysis. Hesperidin pretreatment significantly decreased the myocardial infarct size, myocardial damage and serum levels of CK-MB and cTnI. Furthermore, the expression levels of LC3II and Beclin1 were significantly downregulated and the expression levels of p-mTOR, p-Akt and p-PI3K were markedly upregulated by hesperidin. However, the aforementioned effects as a result of hesperidin were significantly reversed by the presence of LY294002. These results demonstrated that hesperidin reduced myocardial I/R injury by suppressing excessive autophagy. Activation of the PI3K/Akt/mTOR pathway contributed to the inhibitory effect of hesperidin on excessive autophagy.

Inhibition of UVB-induced pro-inflammatory cytokines and MMP expression by Zanthoxylum rhetsa bark extract and its active constituent hesperidin

The antiphoto aging property of Zanthoxylum rhetsa obtained from Pangkor Island, Malaysia, was evaluated. Solvent fractions of different polarity obtained from the methanolic extract of the bark material were initially tested for anticollagenase and antielastase activities. The ethyl acetate fraction showed bioactivity against the protease enzymes. Hence, it was subjected to further purification via column chromatography, to yield a major constituent, hesperidin. Subsequently, the ethyl acetate fraction and hesperidin were tested for their effects against UVB-induced cytotoxicity and expressions of inflammatory cytokines (IL-6, IL-1β, and TNF-α), NF-κB, and MMPs (MMP1, 3, and 9) in human dermal fibroblasts (HDF). Both fraction and pure compound prevented UVB-induced cytotoxicity in HDF cells, in a dose dependent manner. Moreover, the ethyl acetate fraction inhibited the increase of pro-inflammatory cytokines induced by UVB to a level similar to the control (without UV treatment). Additionally, the fraction significantly inhibited the expressions of NF-κB, MMP 1, MMP 3, and MMP 9 in HDF cells treated with UVB. Similar effects were observed with hesperidin. The results obtained suggested that the ethyl acetate fraction of Z. rhetsa and its bioactive constituent, hesperidin, have the potential to be used as active ingredients in sunscreen and antiphoto aging formulations.

Protective effects of fermented honeybush (Cyclopia intermedia) extract (HU-018) against skin aging: a randomized, double-blinded, placebo-controlled study

BACKGROUND

Oxidative stress and photodamage resulting from ultraviolet radiation exposure play key roles in skin aging. Fermented Cyclopia intermedia, which is used to brew honeybush tea, exerts antioxidant and anti-wrinkle effects by inhibiting reactive oxygen species production and downregulating matrix metalloproteinase activity.

OBJECTIVES

This randomized, double-blinded, placebo-controlled study aimed to evaluate the efficacy and safety of fermented honeybush (Cyclopia intermedia) extract (HU-018) for skin rejuvenation.

METHODS

120 Korean subjects with crow's feet wrinkles were randomized to receive either low-dose extract (400 mg/day), high-dose extract (800 mg/day), or placebo (negative control, only dextran) for 12 weeks. Wrinkles were evaluated using JANUS^® and PRIMO pico^®. Skin elasticity, hydration and transepidermal water loss were measured.

RESULTS

Global skin wrinkle grade was significantly improved in both low-dose and high-dose groups compared to placebo group, as well as for skin hydration and elasticity. Both the low- and high-dose groups showed significantly decreased TEWL compared to the placebo group. There were no adverse effects during the entire study period.

CONCLUSION

Our data indicate that HU-018 is effective for improving skin wrinkles, elasticity, and hydration. Therefore, daily supplementation with fermented honeybush could be helpful for protecting against skin aging.

Total phenylethanoid glycosides and magnoloside IafromMagnolia officinalisvar.bilobafruits inhibit ultraviolet B-induced phototoxicity and inflammation through MAPK/NF-κB signaling pathways

Magnolia officinalisvar.bilobais used as a traditional medicine in China and as a food additive in the United Kingdom and the European Union.

Echinacoside Alleviates UVB Irradiation-Mediated Skin Damage via Inhibition of Oxidative Stress, DNA Damage, and Apoptosis

Ultraviolet B (UVB) irradiation has been known to cause skin damage, which is associated with oxidative stress, DNA damage, and apoptosis. Echinacoside is a phenylethanoid glycoside isolated from Herba Cistanches, which exhibits strong antioxidant activity. In this study, we evaluate the photoprotective effect of echinacoside on UVB-induced skin damage and explore the potential molecular mechanism. BALB/c mice and HaCaT cells were treated with echinacoside before UVB exposure. Histopathological examination was used to evaluate the skin damage. Cell viability, lactate dehydrogenase (LDH) levels, antioxidant enzyme activities, reactive oxygen species (ROS) generation, DNA damage, and apoptosis were measured as well. Western blot was used to measure the expression of related proteins. The results revealed that pretreatment of echinacoside ameliorated the skin injury; attenuated oxidative stress, DNA damage, and apoptosis caused by UVB exposure; and normalized the protein levels of ATR, p53, PIAS3, hnRNP K, PARP, and XPA. To summarize, echinacoside is beneficial in the prevention of UVB-induced DNA damage and apoptosis of the skin in vivo and in vitro.

Histological observation of hairless mice skin after exposure to Simulated Solar Light: Comparison between the histological findings with different methodologies and 3R principle correlations

BACKGROUND

Albino hairless mouse (AHM) has been used as a biological model in photodermatology. However, the experimental landscape is diverse to follow and need particular attention.

PURPOSE

Irradiation parameters were investigated for the development of a protocol to assess alterations in the AHM skin using Simulated Solar Light (SSL). The present study was compared with published articles (last 15 years) according to irradiation protocols, morphological findings to minimize animal suffering and UV exposure.

MATERIALS AND METHODS

Three groups: Control (G1), experimental - sunburn (G2) and skin photodamage assay (G3). G2 were immobilized and exposed to SSL once for 15, 30 and 45min. G3 were exposed to SSL, without immobilization, for 15min once a day for one week. The dorsal skin was analyzed using hematoxylin and eosin technique.

RESULTS

G2 displayed different sunburn degrees. Based on the profile of the observed morphological alterations, a 15min irradiation was chosen as the exposure time to expose G3, without immobilization, for 5 consecutive days.

CONCLUSION

These conditions produced the same morphological changes in the AHM with a shorter solar exposure time, without immobilizing the animals but using environmental exposure fluences, conforming to 3R (reduction - refinement - replacement) recommendations.

Health-promoting effects of the citrus flavanone hesperidin

Hesperidin, a member of the flavanone group of flavonoids, can be isolated in large amounts from the rinds of some citrus species. Considering the wide range of pharmacological activities and widespread application of hesperidin, this paper reviews preclinical and clinical trials of hesperidin and its related compounds, including their occurrence, pharmacokinetics, and some marketed products available. Preclinical studies and clinical trials demonstrated therapeutical effects of hesperidin and its aglycone hesperetin in various diseases, such as neurological disorders, psychiatric disorders, and cardiovascular diseases and others, due to its anti-inflammatory, antioxidant, lipid-lowering, and insulin-sensitizing properties.

In Vitro Chemopreventive Properties of Green Tea, Rooibos and Honeybush Extracts in Skin Cells

The chemopreventive properties of the herbal teas rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) have been demonstrated on mouse skin in vivo but the underlying mechanisms are not clear. The aim of the current study was to determine the anti-proliferative and pro-apoptotic activity of methanol and aqueous extracts of rooibos and two Cyclopia species in different skin cells, using green tea (Camellia sinensis) as a benchmark. Extracts were also characterised for their major individual polyphenols by high performance liquid chromatography and spectroscopically for the total polyphenol (TP) groups. The methanol extract of rooibos, containing higher levels of polyphenols than its aqueous extract, displayed similar activity to green tea as it selectively targeted premalignant cells by inhibiting cell proliferation at lower concentrations whilst inducing apoptosis via membrane depolarisation at higher concentrations. Specific roles of the major rooibos dihydrochalcones and flavanol/proanthocyanidin-type (FLAVA) compounds are likely to be involved. The aqueous extracts of the Cyclopia species were more active against cell proliferation and at inducing apoptosis which was associated with a higher FLAVA content and a reduced TP/FLAVA ratio. In contrast, their methanol extracts exhibited a cytoprotective effect against apoptosis which was related to their monomeric xanthone and flavanone content. The underlying chemopreventive properties of green tea and the herbal teas appear to be associated with diverse and complex monomeric/polymeric polyphenolic cell interactions.

Baicalein Protects Human Skin Cells against Ultraviolet B-Induced Oxidative Stress

Baicalein (5,6,7-trihydroxy-2-phenyl-chromen-4-one) is a flavone, a type of flavonoid, originally isolated from the roots of Scutellaria baicalensis. This study evaluated the protective effects of baicalein against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) radiation in a human keratinocyte cell line (HaCaT). Baicalein absorbed light within the wavelength range of UVB. In addition, baicalein decreased the level of intracellular reactive oxygen species (ROS) in response to UVB radiation. Baicalein protected cells against UVB radiation-induced DNA breaks, 8-isoprostane generation and protein modification in HaCaT cells. Furthermore, baicalein suppressed the apoptotic cell death by UVB radiation. These findings suggest that baicalein protected HaCaT cells against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging ROS.

Anti-Inflammatory Effects of Aspalathus linearis and Cyclopia spp. Extracts in a UVB/Keratinocyte (HaCaT) Model Utilising Interleukin-1α Accumulation as Biomarker

Ultraviolet B (UVB) radiation is one of the major predisposing risk factors of skin cancer. The anticancer and photoprotective effects of unoxidized rooibos (Aspalathus linearis) and honeybush (Cyclopia) herbal teas, containing high levels of dihydrochalones and xanthones, respectively, have been demonstrated in skin cancer models in vivo. In the current study, the anti-inflammatory effects of methanol and aqueous extracts of these herbal teas were investigated in a UVB/HaCaT keratinocyte model with intracellular interleukin-1α (icIL-1α) accumulation as a biomarker. Extracts of green tea (Camellia sinensis) served as benchmark. Both extracts of green tea and rooibos, as well as the aqueous extract of C. intermedia, enhanced UVB-induced inhibition of cell viability, proliferation and induction of apoptosis, facilitating the removal of icIL-1α. The underlying mechanisms may involve mitochondrial dysfunction exhibiting pro-oxidant responses via polyphenol-iron interactions. The methanol extracts of honeybush, however, protected against UVB-induced reduction of cell growth parameters, presumably via antioxidant mechanisms that prevented the removal of highly inflamed icIL-1α-containing keratinocytes via apoptosis. The dual antioxidant and/or pro-oxidant role of the polyphenolic herbal tea constituents should be considered in developing preventive strategies against UVB-induced skin carcinogenesis. The indirect removal of UVB damaged keratinocytes by herbal tea extracts via apoptosis may find application in the prevention of photo-induced inflammation.

Anti-wrinkle effects of Sargassum muticum ethyl acetate fraction on ultraviolet B-irradiated hairless mouse skin and mechanistic evaluation in the human HaCaT keratinocyte cell line

The present study investigated the photoprotective properties of the ethyl acetate fraction of Sargassum muticum (SME) against ultraviolet B (UVB)‑induced skin damage and photoaging in a mouse model. HR‑1 strain hairless male mice were divided into three groups: An untreated control group, a UVB‑irradiated vehicle group and a UVB‑irradiated SME group. The UVB‑irradiated mice in the SME group were orally administered with SME (100 mg/kg body weight in 0.1 ml water per day) and then exposed to radiation at a dose of 60‑120 mJ/cm2. Wrinkle formation and skin damage were evaluated by analysis of skin replicas, epidermal thickness and collagen fiber integrity in the dermal connective tissue. The mechanism underlying the action of SME was also investigated in the human HaCaT keratinocyte cell line following exposure of the cells to UVB at a dose of 30 mJ/cm2. The protein expression levels and activity of matrix metalloproteinase‑1 (MMP‑1), and the binding of activator protein‑1 (AP‑1) to the MMP‑1 promoter were assessed in the HaCaT cells using western blot analysis, an MMP‑1 fluorescent assay and a chromatin immune‑precipitation assay, respectively. The results showed that the mean length and depth of the wrinkles in the UVB‑exposed hairless mice were significantly improved by oral administration of SME, which also prevented the increase in epidermal thickness triggered by UVB irradiation. Furthermore, a marked increase in collagen bundle formation was observed in the UVB‑treated mice with SME administration. SME pretreatment also significantly inhibited the UVB‑induced upregulation in the expression and activity of MMP‑1 in the cultured HaCaT keratinocytes, and the UVB‑enhanced association of AP‑1 with the MMP‑1 promoter. These results suggested that SME may be useful as an anti-photoaging resource for the skin.

The potential role of polyphenols in the modulation of skin cell viability by Aspalathus linearis and Cyclopia spp. herbal tea extracts in vitro

OBJECTIVES

The relationship between polyphenol constituents, antioxidant properties of aqueous and methanol extracts of green tea (Camellia sinensis), the herbal teas, rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.), against skin cell viability was investigated in vitro.

METHODS

The effect of extracts, characterised in terms of polyphenol content and antioxidant properties, on cell viability of premalignant, normal and malignant skin cells was determined.

KEY FINDINGS

Phenolic composition, particularly high levels of potent antioxidants, of rooibos and green tea methanol extracts was associated with a strong reduction in cell viability specifically targeting premalignant cells. In contrast, the aqueous extracts of Cyclopia spp. were more effective in reducing cell viability. This correlated with a relatively high flavanol/proanthocyanidin content and ABTS radical cation scavenging capacity. The major green tea flavanol (epigallocatechin gallate) and rooibos dihydrochalcone (aspalathin) exhibited differential effects against cell viability, while the major honeybush xanthone (mangiferin) and flavanone (hesperidin) lacked any effect presumably due to a cytoprotective effect. The underlying mechanisms against skin cell viability are likely to involve mitochondrial dysfunction resulting from polyphenol-iron interactions.

CONCLUSIONS

The polyphenol constituents and antioxidant parameters of herbal tea extracts are useful tools to predict their activity against skin cell survival in vitro and potential chemopreventive effects in vivo.

Herbal extracts, lichens and biomolecules as natural photo-protection alternatives to synthetic UV filters. A systematic review

Besides the unquestionable positive effects of solar exposure for human health, UV rays have been widely investigated for toxicology aspects related to excessive UVB and UVA doses, which involve sunburns, skin aging, DNA skin damage and tumorigenesis. At present, synthetic and mineral sunscreens are used to protect against these damages but several natural molecules can provide UV protection, including also synergic effect or enhanced photo stability. Although a large number of herbal extracts and plant origin molecules can deserve potential applications, most of the study reported utilizes different method and different strategies of investigation, making thus difficult to understand the real versus claimed potential. This is possibly one of the reasons why, beside the large body of literature there are no officially approved natural commercial sun-filter but a consistent number of commercially available solar products (sunscreen) on the market that contain herbal derivatives. In this review we have evaluated the papers appeared in the last 15years and we have critically collected the most significant data. Several databases, namely Scifinder, Pubmed, Google Scholar, ISI-Web of Science and Scopus, were used as literature sources; excluding patents and symposium or congress papers. Only articles in the English language have been selected. New formulation, new skin delivery systems, skin penetration enhancers and boosters are most likely the next frontier of investigation in order to better understand the role of whole herbal extracts in exerting their photo protective activity.

Mangiferin: A xanthonoid with multipotent anti-inflammatory potential

Over the last era, small molecules sourced from different plants have gained attention for their varied and long-term medicinal benefits. Their advantageous therapeutic effects in diverse pathological complications lead researchers to give an ever-increasing emphasis on them and discover their novel therapeutic potentials. Among these, the heat stable, xanthonoid group of organic molecules has gained special importance with distinctive regards to the bioactive molecule mangiferin due to its solubility in water. Mangiferin, a yellow polyphenol having C-glycosyl xanthone structure, is widely present in different edible sources like mango, and possesses numerous biological activities. Extensive research with this molecule shows its antioxidant, anti-inflammatory, antidiabetic, anticancer, antimicrobial, analgesic, and immunomodulatory properties. Thus, it provides protection against a wide range of physiological disorders. The C-glucosyl linkage and polyhydroxy groups in mangiferin's structure contribute essentially to its free radical-scavenging activity. Moreover, its ability in regulating various transcription factors like NF-κB, Nrf-2, etc. and modulating the expression of different proinflammatory signaling intermediates like tumor necrosis factor-α, COX-2, etc. contribute to its anti-inflammatory, anticancer, and antidiabetic potentials. In this comprehensive article, information has been provided about the sources, chemical structure, metabolism, and different biological activities of mangiferin with special emphasis on the underlying cellular signal transduction pathways. Insights into an in-depth assessment of mangiferin's anti-inflammatory therapeutic potential have also been discussed in detail. On an overall perspective, this review aims to stage mangiferin's diversified therapeutic applications and its emerging possibility as a promising drug in future based on its anti-inflammatory property. © 2016 BioFactors, 42(5):459-474, 2016.

Polyphenols and Sunburn

Polyphenols are antioxidant molecules found in many foods such as green tea, chocolate, grape seeds, and wine. Polyphenols have antioxidant, anti-inflammatory, and antineoplastic properties. Growing evidence suggests that polyphenols may be used for the prevention of sunburns as polyphenols decrease the damaging effects of ultraviolet A (UVA) and ultraviolet B (UVB) radiation on the skin. This review was conducted to examine the evidence for use of topically and orally ingested polyphenols in prevention of sunburns. The PubMed database was searched for studies that examined polyphenols and its effects on sunburns. Of the 27 studies found, 15 met the inclusion criteria. Seven studies were conducted on human subjects and eight on animals (mice and rats). Eleven studies evaluated the effects of topical polyphenols, two studies examined ingested polyphenols, and two studies examined both topical and ingested polyphenols. Polyphenol sources included the following plant origins: green tea, white tea, cocoa, Romanian propolis (RP), Calluna vulgaris (Cv), grape seeds, honeybush, and Lepidium meyenii (maca). Eight studies examined green tea. Overall, based on the studies, there is evidence that polyphenols in both oral and topical form may provide protection from UV damage and sunburn, and thus are beneficial to skin health. However, current studies are limited and further research is necessary to evaluate the efficacy, mechanism of action, and potential side effects of various forms and concentrations of polyphenols.

Mangiferin inhibits macrophage classical activation via downregulating interferon regulatory factor 5 expression

Mangiferin is a natural polyphenol and the predominant effective component of Mangifera indica Linn. leaves. For hundreds of years, Mangifera indica Linn. leaf has been used as an ingredient in numerous traditional Chinese medicine preparations for the treatment of bronchitis. However, the pharmacological mechanism of mangiferin in the treatment of bronchitis remains to be elucidated. Macrophage classical activation is important role in the process of bronchial airway inflammation, and interferon regulatory factor 5 (IRF5) has been identified as a key regulatory factor for macrophage classical activation. The present study used the THP-1 human monocyte cell line to investigate whether mangiferin inhibits macrophage classical activation via suppressing IRF5 expression in vitro. THP-1 cells were differentiated to macrophages by phorbol 12-myristate 13-acetate. Macrophages were polarized to M1 macrophages following stimulation with lipopolysaccharide (LPS)/interferon-γ (IFN-γ). Flow cytometric analysis was conducted to detect the M1 macrophages. Reverse transcription-quantitative polymerase chain reaction was used to investigate cellular IRF5 gene expression. Levels of proinflammatory cytokines and IRF5 were assessed following cell culture and cellular homogenization using enzyme-linked immunosorbent assay. IRF5 protein and nuclei co-localization was performed in macrophages with laser scanning confocal microscope immunofluorescence analysis. The results of the present study demonstrated that mangiferin significantly inhibits LPS/IFN-γ stimulation-induced classical activation of macrophages in vitro and markedly decreases proinflammatory cytokine release. In addition, cellular IRF5 expression was markedly downregulated. These results suggest that the inhibitory effect of mangiferin on classical activation of macrophages may be exerted via downregulation of cellular IRF5 expression levels.

Hesperidin, A Popular Antioxidant Inhibits Melanogenesis via Erk1/2 Mediated MITF Degradation

Regulation of melanogenesis has been the focus of treatment for hyperpigmentary skin disorders. Although hesperidin is one of the most well-known, naturally occurring flavonoids with antioxidant and anti-inflammatory effect, its anti-melanogenic effect is not known. The present study aims to determine the anti-melanogenic effect of hespiridin as well as its underlying molecular mechanisms. Melanin contents were measured in normal human melanocytes and B16F10 melanoma cells. Protein and mRNA levels of tyrosinase, microphthalmia-associated transcription factor (MITF), tyrosinase related protein-1 (TRP-1) and TRP-2 were determined. Melanogenesis-regulating signals were examined. In results, hesperidin strongly inhibited melanin synthesis and tyrosinase activity. Hesperidin decreased tyrosinase, TRP-1, and TRP-2 protein expression but increased phospho-extracellular signal-regulated kinase 1/2 (p-Erk1/2) expression. Specific inhibitor of Erk1/2 or proteasome inhibitor reversed the inhibition of melanogenesis induced by hesperidin. Taken together, hesperidin, a popular antioxidant, stimulated Erk1/2 phosphorylation which subsequently degraded MITF which resulted in suppression of melanogenic enzymes and melanin synthesis.

Protective effects of flavonoids against microbes and toxins: The cases of hesperidin and hesperetin

Many plants produce flavonoids as secondary metabolites. These organic compounds may be involved in the defense against plant-threatening factors, such as microbes and toxins. Certain flavonoids protect their origin source against plant pathogens, but they also exhibit potential healthy properties in human organisms. Hesperidin (Hsd) and its aglycone, hesperetin (Hst), are two flavonoids from the Citrus species that exhibit various biological properties, including antioxidant, antiinflammatory and anticancer effects. Recent studies indicated that Hst and Hsd possess antimicrobial activity. Although the exact mechanisms behind their antimicrobial properties are not fully understood, several mechanisms such as the activation of the host immune system, bacterial membrane disruption, and interference with microbial enzymes, have been proposed. Hsd and Hst may also have protective effects against toxicity induced by various agents. These natural substances may contribute to the protection of cells and tissues through their antioxidant and radical scavenging activities. This review discusses the protective activities of Hsd and Hst against microbes and several toxicities induced by oxidants, chemicals, toxins, chemotherapy and radiotherapy agents, which were reported in vitro and in vivo. Furthermore, the probable mechanisms behind these activities are discussed.

The combination of red palm oil and rooibos show anti-inflammatory effects in rats

BACKGROUND

Red palm oil (RPO) and rooibos have been shown to exhibit cardioprotective properties. RPO is rich in essential fatty acids and fat soluble antioxidants while rooibos contains polyphenolic compounds with a unique composition of flavonoids. They exert their biological effects in different cellular compartments. Therefore the combination of these two natural food compounds has the potential to enhance the spectrum of available dietary antioxidants in different cellular compartments, which could result in an enhanced protection against certain pathological conditions such as inflammation.

METHODS

Male Wistar rats weighing 150-200 g were supplemented with RPO, rooibos or their combination for 28 days. The Langendorff system and the lipoposaccharide (LPS)-induced inflammatory model were used to establish if RPO and rooibos, when supplemented alone or in combination, will reverse the negative effects of LPS on cardiac function at baseline. The effect of dietary intervention was also investigated on modulation of pro-inflammatory and anti-inflammatory cytokines in plasma and myocardial tissue.

RESULTS AND DISCUSSION

The LPS resulted in induction of systemic inflammation as evidenced by increased levels of IL-1β in plasma of LPS-treated rats compared to their non-treated control counterparts. Dietary supplementation and LPS treatment did not have an effect on baseline cardiac functional parameters. However, the elevation of IL-1β levels in plasma of LPS-induced rats consuming either RPO or rooibos alone were paralleled with increased levels of the anti-inflammatory cytokine, IL-10. The combination of rooibos and RPO was associated with enhanced endogenous production of myocardial IL-10 in LPS-induced rats.

CONCLUSION

The results of this study indicate that RPO and rooibos when supplemented individually showed anti-inflammatory effect at systemic level while their combination exhibited an enhanced anti-inflammatory effect in the myocardial tissue. Therefore, the findings in the current study argue that the combination of these two natural food substances could be beneficial in clinically relevant conditions where inflammation plays a role.

Anti-wrinkle effects of fermented and non-fermented Cyclopia intermedia in hairless mice

Background

The fermented leaves and stems of Cyclopia intermedia are used to brew honeybush tea, an herbal tea indigenous to South Africa with reported anti-wrinkle effects. Wrinkle formation caused by photoaging clearly involves changes in extracellular matrix components and mechanical properties of the skin.

Methods

The inhibitory effects of honeybush extract and fermented honeybush on wrinkle formation were determined by analyzing skin replicas, histologically examining epidermal thickness, and identifying damage to collagen fibers.

Results

Honeybush extract and fermented honeybush reduced the length and depth of skin winkles caused by UV irradiation and inhibited thickening of the epidermal layer, in addition to suppressing collagen tissue breakdown reactions, indicating its potential use as a skin wrinkle prevention agent.

Conclusions

This in vivo study demonstrates that honeybush produces significant anti-wrinkle effects and is therefore of interest in anti-aging skin care products.

Fucodiphlorethol G Purified from Ecklonia cava Suppresses Ultraviolet B Radiation-Induced Oxidative Stress and Cellular Damage

Fucodiphlorethol G (6’-[2,4-dihydroxy-6-(2,4,6-trihydroxyphenoxy)phenoxy]biphenyl-2,2’,4,4’,6-pentol) is a compound purified from Ecklonia cava, a brown alga that is widely distributed offshore of Jeju Island. This study investigated the protective effects of fucodiphlorethol G against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) irradiation. Fucodiphlorethol G attenuated the generation of 2, 2-diphenyl-1-picrylhydrazyl radicals and intracellular reactive oxygen species in response to UVB irradiation. Fucodiphlorethol G suppressed the inhibition of human keratinocyte growth by UVB irradiation. Additionally, the wavelength of light absorbed by fucodiphlorethol G was close to the UVB spectrum. Fucodiphlorethol G reduced UVB radiation-induced 8-isoprostane generation and DNA fragmentation in human keratinocytes. Moreover, fucodiphlorethol G reduced UVB radiation-induced loss of mitochondrial membrane potential, generation of apoptotic cells, and active caspase-9 expression. Taken together, fucodiphlorethol G protected human keratinocytes against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging reactive oxygen species.

Photoprotection of Buddleja cordata extract against UVB-induced skin damage in SKH-1 hairless mice

Background

In recent years, there has been considerable interest in using botanical agents to prevent skin damage resulting from solar UV-irradiation. Buddleja cordata is a plant that is known as “tepozan”. Some people in Mexico use the leaves of this plant to treat tumours, abscesses, sores and burns. The purpose of this study is to investigate the photoprotective properties of Buddleja cordata methanolic extract (BCME) against UVB-induced skin damage in SKH-1 hairless mice at the macroscopic and histological levels.

Methods

BCME was characterised to determine its spectroscopic, chromatographic and antioxidant (DPPH, superoxide and hydroxyl radicals) properties. To conduct the photoprotection studies, BCME was applied topically to the skin of SKH-1 mice before acute exposure to UVB for 10 minutes. The murine skin samples were used for macroscopic and histological studies to assess tissue damage. Penetration of active components of BCME into stratum corneum on the dorsal area of mice was investigated in vivo by the tape stripping method. Moreover, genotoxicity of BCME was evaluated in a Vicia faba cell root micronucleus model.

Results

BCME displayed absorbance over the entire UVB spectrum, and its principal components included verbascoside and linarin. BCME exhibited antioxidant activity and significantly scavenged hydroxyl radicals. BCME reduced erythema, sunburn cell production, vessel congestion and epidermal thickening of UVB irradiated mouse skin. BCME penetrate the skin of mice. BCME did not exhibit genotoxic activity in the micronucleus test.

Conclusion

The topical administration of BCME protected against acute UVB-induced damage in mouse SKH-1 skin, and our results suggest that BCME may potentially prevent photodamage.