Evaluation of the UVB-screening capacity and restorative effects exerted by farnesol gel on UVB-caused sunburn

Magnolia biondii flower extract attenuates UVB-induced skin damage through high-mobility group box protein B1

OBJECTIVE

Magnolia biondii, a plant containing many magnolian-like compounds in its flowers or buds, exhibits anti-inflammatory and antiallergic effects; however, no study has addressed its effect on alleviating ultraviolet light (UV)-induced skin damage. We thus aimed at studying the effects of M. biondii flower extract (MB) on UVB-induced skin damage and determine the relationship between cell damage and damage-associated molecular patterns (DAMPs).

METHODS

Reconstructed epidermal models and foreskin samples were selected to detect cellular reactions after UVB irradiation and MB treatment. MTT, haematoxylin-eosin and immunofluorescence staining were used to examine total viability, sunburned cells and expression and migration of DAMPs at 16 or 48 h. Prostaglandin E2 (PGE-2) and interleukin 8 (IL-8) levels were measured using enzyme-linked immunosorbent assays. A clinical UVB-damaged test was carried out on human arms subjected to MB pre- or post-treatment. Human skin probes were used to measure erythema, melanin, ITA° and transepidermal water loss (TEWL), while skin photos were captured using the VISIA system.

RESULTS

MB is rich in lignans such as magnolin, pinoresinol dimethyl ether and fargesin, and shows weak UV absorption at 280-320 nm. Coculturing with MB for 16 or 48 h after UVB irradiation improved the tissue viability and structure of Skinovo-Epi, and reduced the expression and migration of high mobility group box protein B1 (HMGB1) as well as the expression of IL-8 and PGE-2. In the excised foreskin treated with MB after UVB irradiation, the generation of 8-hidroxy-2-deoxyguanosine and nuclear transfer of HMGB1 were reduced. When pre-treated with MB for 3 days, UVB-induced skin erythema and ITA° were significantly decreased. When post-treated with MB for 5 days, a decrease in skin erythema, melanin and TEWL values and an increase in skin ITA° were observed.

CONCLUSIONS

Treatment with MB attenuated UVB-induced skin damage, such as erythema, pigmentation and skin barrier function, by improving the tissue viability and structure and reducing sunburned cells and skin inflammation. This effect may be related to DNA damage, which causes the migration of HMGB1 from the nucleus to the outside of the cell to induce skin inflammation.

Exploration of risk analysis and elimination methods for a Cr(VI)-removal recombinant strain through a biosafety assessment in mice

Though recombinant strains are increasingly recognized for their potential in heavy metal remediation, few studies have evaluated their safety. Moreover, biosafety assessments of fecal-oral pathway exposure at country as well as global level have seldom analyzed the health risks of exposure to microorganisms from a microscopic perspective. The present study aimed to predict the long-term toxic effects of recombinant strains by conducting a subacute toxicity test on the chromium-removal recombinant strain 3458 and analyzing the gut microbiome. The available disinfection methods were also evaluated. The results showed that strain 3458 induced liver damage and affected renal function and lipid metabolism at 1.0 × 1011 CFU/mL, which may be induced by its carrier strain, pET-28a. Strain 3458 poses the risk of increasing the number of pathogenic bacteria under prolonged exposure. When 500 mg L-1 chlorine-containing disinfectant or 250 mg L-1 chlorine dioxide disinfectant was added for 30 min, the sterilization rate exceeded 99.9 %. These findings suggest that existing wastewater disinfection methods can effectively sterilize strain 3458, ensuring its application value. The present study can serve a reference for the biosafety evaluation of the recombinant strain through exposure to the digestive tract and its feasibility for application in environmental pollution remediation.

Restoration of the Phenotype of Dedifferentiated Rabbit Chondrocytes by Sesquiterpene Farnesol

Osteoarthritis (OA) is a joint disorder characterized by the progressive degeneration of articular cartilage. The phenotype and metabolism behavior of chondrocytes plays crucial roles in maintaining articular cartilage function. Chondrocytes dedifferentiate and lose their cartilage phenotype after successive subcultures or inflammation and synthesize collagen I and X (COL I and COL X). Farnesol, a sesquiterpene compound, has an anti-inflammatory effect and promotes collagen synthesis. However, its potent restoration effects on differentiated chondrocytes have seldom been evaluated. The presented study investigated farnesol's effect on phenotype restoration by examining collagen and glycosaminoglycan (GAG) synthesis from dedifferentiated chondrocytes. The results indicated that chondrocytes gradually dedifferentiated through cellular morphology change, reduced expressions of COL II and SOX9, increased the expression of COL X and diminished GAG synthesis during four passages of subcultures. Pure farnesol and hyaluronan-encapsulated farnesol nanoparticles promote COL II synthesis. GAG synthesis significantly increased 2.5-fold after a farnesol treatment of dedifferentiated chondrocytes, indicating the restoration of chondrocyte functions. In addition, farnesol drastically increased the synthesis of COL II (2.5-fold) and GAG (15-fold) on interleukin-1β-induced dedifferentiated chondrocytes. A significant reduction of COL I, COL X and proinflammatory cytokine prostaglandin E2 was observed. In summary, farnesol may serve as a therapeutic agent in OA treatment.

Therapeutic Efficacy of Sesquiterpene Farnesol in Treatment of Cutibacterium acnes-Induced Dermal Disorders

Acne vulgaris is a highly prevalent skin disorder requiring treatment and management by dermatologists. Antibiotics such as clindamycin are commonly used to treat acne vulgaris. However, from both medical and public health perspectives, the development of alternative remedies has become essential due to the increase in antibiotic resistance. Topical therapy is useful as a single or combined treatment for mild and moderate acne and is often employed as maintenance therapy. Thus, the current study investigated the anti-inflammatory, antibacterial, and restorative effects of sesquiterpene farnesol on acne vulgaris induced by Cutibacterium acnes (C. acnes) in vitro and in a rat model. The minimum inhibitory concentration (MIC) of farnesol against C. acnes was 0.14 mM, and the IC50 of 24 h exposure to farnesol in HaCaT keratinocytes was approximately 1.4 mM. Moreover, 0.8 mM farnesol exhibited the strongest effects in terms of the alleviation of inflammatory responses and abscesses and necrotic tissue repair in C.acnes-induced acne lesions; 0.4 mM farnesol and clindamycin gel also exerted similar actions after a two-time treatment. By contrast, nearly doubling the tissue repair scores, 0.4 mM farnesol displayed great anti-inflammatory and the strongest reparative actions after a four-time treatment, followed by 0.8 mM farnesol and a commercial gel. Approximately 2-10-fold decreases in interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, found by Western blot analysis, were predominantly consistent with the histopathological findings and tissue repair scores. The basal hydroxypropyl methylcellulose (HPMC) gel did not exert anti-inflammatory or reparative effects on rat acne lesions. Our results suggest that the topical application of a gel containing farnesol is a promising alternative remedy for acne vulgaris.

Enhancement of Rotator Cuff Healing with Farnesol-Impregnated Gellan Gum/Hyaluronic Acid Hydrogel Membranes in a Rabbit Model

Most rotator cuff (RC) tears occur at the bone–tendon interface and cause disability and pain. Farnesol, a sesquiterpene compound, can exert antioxidative and anti-inflammatory effects and promote collagen synthesis. In this rabbit model, either commercial SurgiWrap membrane or hydrogel membranes containing various compositions of gellan gum, hyaluronic acid, and farnesol (hereafter GHF membranes) were applied to the tear site, and the repair of the cuff was examined 2 and 3 weeks afterward. The designed membranes swelled rapidly and adsorbed onto the tear site more readily and closely than the SurgiWrap membrane. The membranes degraded slowly and functioned as both a barrier and a vehicle of slow farnesol release during the repair period. Farnesol enhanced collagen production in myoblasts and tenocytes, and interleukin 6 and tumor necrosis factor α levels were modulated. Gross observations and histological examinations indicated that the GHF membranes impregnated with 4 mM farnesol resulted in superior RC repair. In sum, the slow release of farnesol from hydrogel membranes can be beneficial in the repair of RC injuries.

Farnesol-Loaded Liposomes Protect the Epidermis and Dermis from PM2.5-Induced Cutaneous Injury

Particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5) increases oxidative stress through free radical generation and incomplete volatilization. In addition to affecting the respiratory system, PM2.5 causes aging- and inflammation-related damage to skin. Farnesol (Farn), a natural benzyl semiterpene, possesses anti-inflammatory, antioxidative, and antibacterial properties. However, because of its poor water solubility and cytotoxicity at high concentrations, the biomedical applications of Farn have been limited. This study examined the deleterious effects of PM2.5 on the epidermis and dermis. In addition, Farn-encapsulated liposomes (Lipo-Farn) and gelatin/HA/xanthan gel containing Lipo-Farn were prepared and applied in vivo to repair and alleviate PM2.5-induced damage and inflammation in skin. The prepared Lipo-Farn was 342 ± 90 nm in diameter with an encapsulation rate of 69%; the encapsulation significantly reduced the cytotoxicity of Farn. Lipo-Farn exhibited a slow-release rate of 35% after 192 h of incubation. The half-maximal inhibitory concentration of PM2.5 was approximately 850 μg/mL, and ≥400 μg/mL PM2.5 significantly increased IL-6 production in skin fibroblasts. Severe impairment in the epidermis and hair follicles and moderate impairment in the dermis were found in the groups treated with post-PM2.5 and continuous subcutaneous injection of PM2.5. Acute and chronic inflammation was observed in the skin in both experimental categories in vivo. Treatment with 4 mM Lipo-Farn largely repaired PM2.5-induced injury in the epidermis and dermis, restored injured hair follicles, and alleviated acute and chronic inflammation induced by PM2.5 in rat skin. In addition, treatment with 4 mM pure Farn and 2 mM Lipo-Farn exerted moderate reparative and anti-inflammatory effects on impaired skin. The findings of the current study indicate the therapeutic and protective effects of Lipo-Farn against various injuries caused by PM2.5 in the pilosebaceous units, epidermis, and dermis of skin.

Reparative and toxicity-reducing effects of liposome-encapsulated saikosaponin in mice with liver fibrosis

Saikosaponin d (SSd), a primary active component of the Chinese herb Bupleurum falcatum, has antitumor and antiliver fibrosis effects. However, the toxicity of SSd at high doses can induce conditions such as metabolic disorders and hemolysis in vivo, thus hampering its clinical use. The present study investigated the toxicity-reducing effects of liposome encapsulation of pure SSd and the therapeutic action of SSd-loaded liposomes (Lipo-SSd) in liver fibrosis in vitro and in vivo. Lipo-SSd (diameter, 31.7 ± 7.8 nm) was prepared at an entrapment efficiency of 94.1%. After 10-day incubation, a slow release profile of 56% SSd from Lipo-SSd was observed. The IC₅₀ of SSd on hepatic stellate cells was approximately 2.9 μM. Lipo-SSd exhibited much lower cytotoxicity than did pure SSd. In the in vivo toxicity assay, Lipo-SSd significantly increased mice survival rate and duration compared with pure SSd at the same dose. These in vitro and in vivo data indicate that liposomal encapsulation can reduce the cytotoxicity of SSd. The histopathological analysis results demonstrated that in mice with thioacetamide-induced liver fibrosis, Lipo-SSd exerted more obvious fibrosis- and inflammation-alleviating and liver tissue-reparative effects than did pure SSd; these effects are potentially attributable to the sustained release of SSd. In conclusion, Lipo-SSd fabricated here have antiliver fibrosis effects and lower toxicity compared with that of pure SSd.

Phloroglucinol Attenuates Ultraviolet B-Induced 8-Oxoguanine Formation in Human HaCaT Keratinocytes through Akt and Erk-Mediated Nrf2/Ogg1 Signaling Pathways

Ultraviolet B (UVB) radiation causes DNA base modifications. One of these changes leads to the generation of 8-oxoguanine (8-oxoG) due to oxidative stress. In human skin, this modification may induce sunburn, inflammation, and aging and may ultimately result in cancer. We investigated whether phloroglucinol (1,3,5-trihydroxybenzene), by enhancing the expression and activity of 8-oxoG DNA glycosylase 1 (Ogg1), had an effect on the capacity of UVB-exposed human HaCaT keratinocytes to repair oxidative DNA damage. Here, the effects of phloroglucinol were investigated using a luciferase activity assay, reverse transcription-polymerase chain reactions, western blot analysis, and a chromatin immunoprecipitation assay. Phloroglucinol restored Ogg1 activity and decreased the formation of 8-oxoG in UVB-exposed cells. Moreover, phloroglucinol increased Ogg1 transcription and protein expression, counteracting the UVB-induced reduction in Ogg1 levels. Phloroglucinol also enhanced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) as well as Nrf2 binding to an antioxidant response element located in the Ogg1 gene promoter. UVB exposure inhibited the phosphorylation of protein kinase B (PKB or Akt) and extracellular signal-regulated kinase (Erk), two major enzymes involved in cell protection against oxidative stress, regulating the activity of Nrf2. Akt and Erk phosphorylation was restored by phloroglucinol in the UVB-exposed keratinocytes. These results indicated that phloroglucinol attenuated UVB-induced 8-oxoG formation in keratinocytes via an Akt/Erk-dependent, Nrf2/Ogg1-mediated signaling pathway.

Farnesol-Containing Macromolecular Systems for Antibiofilm Strategies

Farnesol is a natural sesquiterpenoid and an interesting quorum-sensing molecule. Its insolubility in water is the biggest obstacle to its application for bacterial biofilm treatments since it compromises the bioavailability. Recently, an increasing interest in farnesol encapsulation or loading in polymeric materials may be noted due to the prolonged action of the active macromolecular systems. In this short review, we present an overview of methods leading to improved interactions between farnesol and microbial biofilms.

P1G10, the Proteolytic Fraction from Vasconcellea cundinamarcensis, Stimulates Tissue Repair after Acute Exposure to Ultraviolet B Radiation

BACKGROUND

P1G10 is a cysteine proteolytic fraction from Vasconcellea cundinamarcensis latex, obtained by chromatographic separation on Sephadex-G10 and ultrafiltration. This fraction enhances healing in different models of skin lesions, and displays a protective/healing effect against gastric ulcers, where it was suggested an antioxidant role.

METHODS

We evaluated here the effect of topical treatment with P1G10, in mice lesions induced by UVB.

RESULTS

After single exposure to 2.4 J cm-2 UVB, P1G10 reduced erythema, increased cellularity of hypodermis, enhanced MPO activity and IL1β, and inhibited COX2 levels. These results point to an anti-inflammatory effect by P1G10. This fraction displayed antioxidant activity by reversing the depletion of glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and reducing the catalase activity increased by UVB. These changes may be related to a reduction in MDA observed in groups treated with P1G10. P1G10 also inhibited MMP-9, caspase-3 and pkat while increasing p53 levels.

Antiaging and smoothness-improving properties of farnesol-based facial masks on rat skin exposed to ultraviolet B

BACKGROUND

Farnesol is an acyclic sesquiterpene presents in various natural sources including fruits, vegetables, and herbs. In this study, we successfully prepared a farnesol-containing gel with ultraviolet B-screening and skin-repairing capabilities. Furthermore, the advantageous potential of farnesol-containing facial masks for UVB-caused sunburnt skin was evaluated.

AIMS

Thus, the objectives of this study are to design and prepare optimal facial masks possessing collagen production and smoothness-enhancing capabilities for the skin.

METHODS

A series of formulations consisting of hydroxypropyl methylcellulose, hyaluronan, and farnesol were used to prepare the facial masks. The effects of the facial masks on collagen production by skin fibroblasts in vitro were examined. The effects of the prepared masks on collagen synthesis, smoothness, and inflammation of the skin were further evaluated in vivo using two modes (mask administration interspersed with UVB exposure and mask administration after UVB exposure) of a rat model.

RESULTS

Facial masks containing both 0.3 and 0.8 mM farnesol improved skin smoothness and enhanced collagen content and arrangement in the skin of rats with mask administration interspersed with and after UVB exposure. The masks containing 0.8 mM farnesol exerted the greatest effects on collagen production/arrangement and smoothness improvement in vivo model. Histopathologically observed inflammation was alleviated, and interleukin (IL)-6 was decreased in the 0.8 mM farnesol-containing facial mask-covered skin compared with that without facial masks.

CONCLUSIONS

The farnesol-containing facial masks prepared in this study may have collagen production-increasing, smoothness-improving, and anti-inflammatory properties for UVB-caused sunburn; thus, farnesol is potentially a beneficial component in facial masks.

Liposome-encapsulated farnesol accelerated tissue repair in third-degree burns on a rat model

Third-degree or full-thickness burns refer to lesions that extend to the epidermis, dermis, and subcutaneous tissue. The pathophysiology of burn wounds is characterized by tissue inflammation, edema, and hypertrophic scarring. Farnesol is a natural 15-carbon organic compound that possesses many biological effects. We have previously demonstrated that farnesol gel exerts restorative actions on ultraviolet B (UVB)-caused sunburn in vivo. The in vitro results revealed that liposomal farnesol from 0.04mM to 0.8mM significantly enhanced collagen production by murine skin fibroblasts, whereas liposomal farnesol at high (0.8mM) and low concentration (0.04mM) did not show any suppressions on skin fibroblast proliferation. We treated third-degree burns on a rat model with a formulated gel composed of various ratios of 2% hydroxypropyl methylcellulose (HPMC) and 4mM liposomal farnesol for 7 and 14 days. On days 7 and 14 post wounding, histopathological observations revealed that the HPMC:farnesol gel ratios of 1:2 and 2:1 exerted the greatest tissue-repairing effects on the skin after third-degree burns compared with skin untreated or treated with a commercial burn gel and HPMC alone. These findings were consistent with the in vivo quantitative collagen-producing assay, wound healing scoring, and IL-6 Western blot results. These findings demonstrated that the fabricated liposomal farnesol gel is potentially able to promote wound healing after third-degree burns.