Abietic acid inhibits UVB-induced MMP-1 expression in human dermal fibroblast cells through PPARα/γdual activation

Rosin: A comprehensive review on traditional uses, phytochemistry, and pharmacology

Rosin, a natural resin obtained from conifer trees, has a long history of use in traditional folk medicine for treating abscesses, wounds, carbuncles, and burns, etc. It has been employed in ancient Egypt, China, Nordic countries, and Turkey as a therapeutic remedy. This comprehensive review examines the traditional uses, phytochemistry, and pharmacology of rosin, and it provides a critical update on current knowledge of rosin and identifies potential therapeutic opportunities. The chemical composition of rosin is known to vary depending on factors such as botanical sources, geographical locations, and processing methods. Rosin acids, which account for over 90% of its primary chemical constituents, have been identified as the predominant compounds in rosin. Researchers have isolated approximately 50 compounds from rosin, with terpenoid rosin acids being the most prevalent. Furthermore, the review highlights the potential pharmacological activities of rosin and its constituents. Crude extracts and isolated rosin acids have demonstrated promising properties, including antimicrobial, anti-inflammatory, anti-tumor, insecticidal, wound healing, and anti-obesity effects. However, the review emphasizes that further research is needed, as existing studies are predominantly preliminary. Many of the reported bioactivities require further verification, and the underlying mechanisms of action remain largely unexplored. In conclusion, rosin has been extensively used in traditional medicine across different cultures, and its chemical composition has been confirmed to a significant extent. The pharmacological activities observed in crude extracts and isolated rosin acids support its traditional uses. Nevertheless, additional research is necessary to deepen our understanding of the pharmacological mechanisms underlying its effects.

Research progress of PPARγ regulation of cholesterol and inflammation in Alzheimer's disease

Peroxidase proliferator receptors (PPARs) are defined as key sensors and regulators of cell metabolism, transcription factors activated by ligands, involved in lipid, glucose and amino acid metabolism, participating in the processes of cell differentiation, apoptosis, inflammation regulation, and acute and chronic nerve damage. Among them, PPARγ is expressed in different brain regions and can regulate lipid metabolism, mitochondrial disorders, oxidative stress, and cell apoptosis. It has anti-inflammatory activity and shows neuroprotection. The regulation of Aβ levels in Alzheimer's disease involves cholesterol metabolism and inflammation, so this article first analyzes the biological functions of PPARγ, then mainly focuses on the relationship between cholesterol and inflammation and Aβ, and elaborates on the regulation of PPARγ on key proteins and the corresponding molecules, which provides new ideas for the treatment of AD.

Antioxidant activity of mycelia methanolic extracts of endophytic fungi BvFV and BvFIX isolated from leaves of Bauhinia variegata

Endophytes are considered an essential source of natural products. Skin is the body's largest organ; its primary function is the protection of other organs, and aging is one of the most relevant problems associated with this organ. UV radiation generates reactive oxygen species (ROS), which lead to skin degeneration and consequent aging. The main endogenous antioxidants that neutralize ROS are enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase, and glutathione reductase, and non-enzymatic antioxidants, such as glutathione and α-tocopherol. Nuclear receptors are involved in molecular mechanisms that control the aging process, especially peroxisome proliferator-activated receptors (PPAR), which regulate the function and expression of genes that modulate the balance between matrix metalloproteinases (MMP) activity and the expression of collagen. Some natural compounds, such as polyphenols, can activate PPAR and reduce the activation of MMP and collagen degradation. In this work, the antioxidant activity of the mycelia methanolic extracts of two endophytic fungi isolated from leaves of Bauhinia variegata, named BvFV and BvFIX, their action as PPAR agonists, and their effect on the activity of antioxidant defense system enzymes were evaluated. The mycelia methanolic extract of BvFV showed a weak agonist effect on PPARβ/δ, a high capability to inhibit lipid peroxidation, increased catalase activity, and increased superoxide dismutase activity by approximately 64%. In contrast, BvFIX increased catalase activity and increased superoxide dismutase activity in a dose-dependent manner, with an increase of 49.62% ± 7.87%, 56.64% ± 12.27%, and 240.46% ± 26.11% at concentrations of 25 µg/mL, 50 µg/mL and 100 µg/mL, respectively, in human dermal fibroblasts submitted to oxidative stress. These results suggest that the metabolites of the mycelia of endophytic fungi studied are promising to act in the chemoprevention of skin aging.

Abietic acid ameliorates nephropathy progression via mitigating renal oxidative stress, inflammation, fibrosis and apoptosis in high fat diet and low dose streptozotocin-induced diabetic rats

BACKGROUND

Abietic acid (AA) has been reported to exhibit anti-inflammatory activity, however its protective effect against inflammation and its trigger factor i.e., oxidative stress and the related sequelae i.e., apoptosis and fibrosis in the kidney in diabetes mellitus (DM) is unknown.

PURPOSE

To identify the ability of AA to mitigate the inflammatory and inflammation-related insults to the kidney in DM.

METHODS & STUDY DESIGN

Adult male rats were induced type-2 DM by feeding with a high-fat diet for twelve weeks followed by injection with a single dose of streptozotocin (STZ) (30 mg/kg/bw) intraperitoneally at twelve weeks. Following DM confirmation, AA (10 and 20 mg/kg/day) was given orally for another four weeks. Then the fasting blood glucose (FBG) and renal profile were determined and oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) tests were performed. A day after the last treatment, rats were sacrificed and kidneys were harvested and subjected for histopathological and molecular biological analysis.

RESULTS

AA treatment was found to reduce the FBG, serum urea and creatinine levels (p < 0.05) while improving the OGTT and ITT (p < 0.05) in diabetic rats. Besides, AA treatment also mitigated kidney histopathological changes, reduces kidney oxidative stress as reflected by reduced levels of RAGE and Keap1 but increased levels of kidney antioxidants Nrf2, SOD, CAT, GPX, HO-1 & NQO-1 (p < 0.05). Additionally, AA treatment also decreases kidney inflammation (NF-kB p65, IL-1β, IL-6, TNF-α and iNOS) and fibrosis (TGF-β1 and GSK-3β) (p < 0/05). Kidney apoptosis decreased as reflected by decreased levels of Bax, caspase-3 and caspase-9 while its anti-apoptosis Bcl-2 protein levels increased (p < 0.05).

CONCLUSION

AA helps to mitigate nephropathy development in DM via counteracting oxidative stress, inflammation and apoptosis.

Abietic acid ameliorates psoriasis-like inflammation and modulates gut microbiota in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Abietic acid (AA), an antibacterial terpenoid, was initially isolated from rosin which has been used as a traditional Chinese medicine to treat psoriasis. In our previous works, we found that water-processed rosin (WPR) can alleviate imiquimod (IMQ)-induced psoriasis-like inflammation in mice. However, the efficacy of AA, the main component of WPR, against psoriasis remains unclear.

MATERIALS AND METHODS

In this study, we confirmed the anti-psoriasis efficacy of AA (40 mg/kg daily for 7 days) in IMQ-induced psoriasis-like inflammation BALB/c mouse model by the psoriasis area severity index (PASI), flow cytometry, ELISA, histopathological and immunohistochemical analysis. Furthermore, we detected the relative abundance of gut microbe using high-throughput 16S rRNA gene sequencing to validate whether AA modulate gut microbe.

RESULT

Oral administration of AA ameliorates IMQ-induced psoriasis-like skin inflammation through reducing PASI scores, regulating the balance of Th17/Treg cells in the mouse spleen, and downregulating the level of serum cytokines such as TNF-α, IL-17A, TGF-1β, and IL-23. 16S rRNA gene sequencing revealed that the relative abundance of gut bacteria related to inflammation, such as, Anaerotruncus and Christensenella at genus level were decreased, while Kurthia, Citrobacter, and Klebsiella at genus level were increased in AA group mice. Additionally, the correlation analysis illustrated that the key microbiota had a close relationship with the psoriasis-like inflammation related indexes.

CONCLUSION

AA might exert the anti-psoriasis effect via inhibiting Th17-related immune responses, hinting that it might be a candidate for treating psoriasis. Meanwhile, the alteration of intestinal microbiota by AA treatment is another possible explanation for the amelioration of imiquimod-induced psoriasis-like inflammation.

Shedding Light on the Effects of Calorie Restriction and its Mimetics on Skin Biology

During the aging process of an organism, the skin gradually loses its structural and functional characteristics. The skin becomes more fragile and vulnerable to damage, which may contribute to age-related diseases and even death. Skin aging is aggravated by the fact that the skin is in direct contact with extrinsic factors, such as ultraviolet irradiation. While calorie restriction (CR) is the most effective intervention to extend the lifespan of organisms and prevent age-related disorders, its effects on cutaneous aging and disorders are poorly understood. This review discusses the effects of CR and its alternative dietary intake on skin biology, with a focus on skin aging. CR structurally and functionally affects most of the skin and has been reported to rescue both age-related and photo-induced changes. The anti-inflammatory, anti-oxidative, stem cell maintenance, and metabolic activities of CR contribute to its beneficial effects on the skin. To the best of the author’s knowledge, the effects of fasting or a specific nutrient-restricted diet on skin aging have not been evaluated; these strategies offer benefits in wound healing and inflammatory skin diseases. In addition, well-known CR mimetics, including resveratrol, metformin, rapamycin, and peroxisome proliferator-activated receptor agonists, show CR-like prevention against skin aging. An overview of the role of CR in skin biology will provide valuable insights that would eventually lead to improvements in skin health.

CO2 lattice laser reverses skin aging caused by UVB

The carbon dioxide (CO₂) lattice laser has been successfully used to treat facial skin photoaging induced by UV light. In this study, we analyzed the effect of CO₂ lattice laser irradiation on skin photoaging, and investigated the underlying mechanisms. Our results demonstrate that the laser promoted collagen synthesis and proliferation of primary human skin fibroblasts, inhibited cell senescence, and induced expression of superoxide dismutase (SOD) and the signaling protein SMAD3. In addition, this laser reversed cell cycle arrest and fibroblast apoptosis induced by UVB irradiation, and restored fibroblast proliferation inhibited by SMAD3 silencing. Using a rat model of photoaging, our results show that the laser increased collagen expression and dermal thickness, demonstrating that the CO₂ lattice laser has a profound therapeutic effect on photoaged skin. Together, our in vitro and in vivo data show that the CO₂ lattice laser can reverse the skin aging caused by UVB, and indicate that this effect is mediated through SMAD3.

Anti-psoriasis effect of water-processed rosin in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Rosin, an exudate of conifer trees such as Pinus masscnlana (Pinaceae), has been used to treat psoriasis for nearly two thousand years in China despite its so far undefined pharmacology. Unfortunately, the rosin intoxication is noted from time to time, but the water-boiled rosin (WBR) has been documented to be safer. This study was performed to evaluate the in vivo anti-psoriasis efficacy of WBR.

MATERIALS AND METHODS

The main phytochemicals in WBR were quantified by high performance liquid chromatography (HPLC). WBR was evaluated in the imiquimod-induced psoriasis-like inflammation mouse model for its anti-psoriasis effect at 130, 260, and 390 mg/kg, which were set according to the dose used for patients. Through a combination of q-PCR, flow cytometry, and histopathological and immunohistochemical (IHC) analysis, the in vivo efficacy was assessed in terms of the psoriasis area severity index (PASI), epidermal keratinocyte proliferation, Th1 and Th17 cell numbers in spleen, and mRNA expressions of inflammatory cytokines.

RESULT

Oral administration of WBR ameliorates the psoriasis-like dermatitis in the imiquimod-generated mouse model. In particular, WBR given at 260 or 390 mg/kg significantly restores the normal keratinization of dorsal lesion if compared with the untreated psoriatic mice. Such an effect was addressed to correlate to the Th1/Th17 cell reduction in spleen and the suppressed expression of IL-17A, IL-17F, IL-22, IL-23, TNF-α, K17, and proliferating cell nuclear antigen (PCNA) after the WBR administration.

CONCLUSION

WBR is effective in the imiquimod-induced psoriasis-like inflammation mouse model with the efficacy arising from its proliferation inhibition of Th1/Th17 cells and epidermal keratinocytes via the down-regulation of the relevant inflammatory cytokines such as IL-23, IL-17A, and IL-17F. Collectively, WBR harvested and processed in the traditional manner is an efficacious psoriasis-treating agent.

In-feed resin acids reduce matrix metalloproteinase activity in the ileal mucosa of healthy broilers without inducing major effects on the gut microbiota

The chicken gut is constantly exposed to harmful molecules and microorganisms which endanger the integrity of the intestinal wall. Strengthening intestinal mucosal integrity is a key target for feed additives that aim to promote intestinal health in broilers. Recently, dietary inclusion of resin-based products has been shown to increase broiler performance. However, the mode of action is still largely unexplored. Coniferous resin acids are known for their anti-microbial, anti-inflammatory and wound-healing properties, all properties that might support broiler intestinal health. In the current study, the effect of pure resin acids on broiler intestinal health was explored. Ross 308 broilers were fed a diet supplemented with coniferous resin acids for 22 days, after which the effect on both the intestinal microbiota as well as on the intestinal tissue morphology and activity of host collagenases was assessed. Dietary inclusion of resin acids did not alter the morphology of the healthy intestine and only minor effects on the intestinal microbiota were observed. However, resin acids-supplementation reduced both duodenal inflammatory T cell infiltration and small intestinal matrix metalloproteinase (MMP) activity towards collagen type I and type IV. Reduced breakdown of collagen type I and IV might indicate a protective effect of resin acids on intestinal barrier integrity by preservation of the basal membrane and the extracellular matrix. Further studies are needed to explore the protective effects of resin acids on broiler intestinal health under sub-optimal conditions and to elaborate our knowledge on the mechanisms behind the observed effects.

Abietic acid attenuates IL-1β-induced inflammation in human osteoarthritis chondrocytes

Abietic acid has been reported to have anti-inflammatory activity. However, whether abietic acid has anti-inflammatory effects against osteoarthritis (OA) remains unclear. The present study aimed to measure the anti-inflammatory effects of abietic acid on OA in vitro. Human osteoarthritis chondrocytes were pretreated with abietic acid 1 h before IL-1β treatment. The results showed that treatment of abietic acid significantly inhibited IL-1β-induced TNF-α, NO, PGE2 production, and COX-2 expression. Abietic acid also concentration-dependently suppressed MMP1, MMP3, and MMP13 production induced by IL-1β. Moreover, the increased phosphorylation levels of NF-κB p65 and IκBα were inhibited by the treatment of abietic acid. We also found that the expression of PPAR-γ was increased by abietic acid. The inhibition of abietic acid on TNF-α, NO, and PGE2 production were reversed by GW9662, the inhibitor of PPAR-γ. In conclusion, the study elucidated abietic acid suppressed IL-1β-induced inflammation in human osteoarthritis chondrocytes by activating PPAR-γ.

The Anti-Wrinkle Mechanism of Melatonin in UVB Treated HaCaT Keratinocytes and Hairless Mice via Inhibition of ROS and Sonic Hedgehog Mediated Inflammatory Proteins

Though melatonin is known to improve ultraviolet B (UVB)-induced oxidative damage and inflammatory conditions via the blockade of the nuclear factor (NF)-κB, interleukin (IL)-6, there is no report on the anti-wrinkle effect of melatonin to date. Hence in the present study, the anti-wrinkle mechanism of melatonin was elucidated in UVB treated HaCaT keratinocytes and hairless mice. Herein melatonin protected against a radical initiator tert-Butyl hydroperoxide (t-BOOH) induced reactive oxygen species (ROS) production, matrix metalloprotease 1 (MMP-1), pro-collagen and cytotoxicity in HaCaT keratinocytes. Additionally, melatonin suppressed the expression of sonic hedgehog (SHH) and GLI1 for hedgehog signaling and p-NF-κB, cyclooxygenase (COX-2), phospho-extracellular signal-regulated kinase-1 (p-ERK) for inflammatory responses in UVB treated HaCaT keratinocytes. Furthermore, melatonin protected skin from wrinkle formation, transdermal water loss in hairless mice irradiated by UVB for 8 weeks. Notably, melatonin prevented against epidermal thickness and dermal collagen degradation in UVB irradiated hairless mice by Hematoxylin and Eosin and Masson’s trichrome staining. Taken together, these findings suggest that melatonin reduces wrinkle formation via inhibition of ROS/SHH and inflammatory proteins such as NF-κB/COX-2/ERK/MMP1.

Eupatilin with PPARα agonistic effects inhibits TNFα-induced MMP signaling in HaCaT cells

Eupatilin (5,7-dihydroxy-3,4,6-trimethoxyflavone) is a flavonoid compound exhibiting several beneficial biological activities, including neuroprotection, anti-cancer, antinociception, chondroprotection, anti-oxidation, and anti-inflammation. Our previous study demonstrated that eupatilin specifically activates peroxisome proliferator-activated receptor alpha (PPARα) through direct binding. The PPAR subfamily includes ligand-dependent transcription factors that consist of three isotypes: PPARα, PPARβ/δ, and PPARγ. All isotypes are involved in inflammation, epidermal proliferation/differentiation and skin barrier function. Among them, PPARα regulates lipid and glucose metabolism and skin homeostasis. In this study, we confirm that the ability of eupatilin as a PPARα activator significantly inhibited tumor necrosis factor-alpha (TNFα)-induced matrix metalloproteinase (MMP)-2/-9 expression and proteolytic activity in HaCaT human epidermal keratinocytes. Furthermore, we found that eupatilin subsequently suppressed IκBα phosphorylation, blocked NF-κB p65 nuclear translocation and down-regulated MAPK/AP-1 signaling via PPARα activation. Taken together, our data suggest that eupatilin inhibits TNFα-induced MMP-2/-9 expression by suppressing NF-κB and MAPK⁄AP-1 pathways via PPARα. Our findings suggest the usefulness of eupatilin for preventing skin aging.

Resveratrol-Enriched Rice Attenuates UVB-ROS-Induced Skin Aging via Downregulation of Inflammatory Cascades

The skin is the outermost protective barrier between the internal and external environments in humans. Chronic exposure to ultraviolet (UV) radiation is a major cause of skin aging. UVB radiation penetrates the skin and induces ROS production that activates three major skin aging cascades: matrix metalloproteinase- (MMP-) 1-mediated aging; MAPK-AP-1/NF-κB-TNF-α/IL-6, iNOS, and COX-2-mediated inflammation-induced aging; and p53-Bax-cleaved caspase-3-cytochrome C-mediated apoptosis-induced aging. These mechanisms are collectively responsible for the wrinkling and photoaging characteristic of UVB-induced skin aging. There is an urgent requirement for a treatment that not only controls these pathways to prevent skin aging but also avoids the adverse effects often encountered when applying bioactive compounds in concentrated doses. In this study, we investigated the efficacy of genetically modified normal edible rice (NR) that produces the antiaging compound resveratrol (R) as a treatment for skin aging. This resveratrol-enriched rice (RR) overcomes the drawbacks of R and enhances its antiaging potential by controlling the abovementioned three major pathways of skin aging. RR does not exhibit the toxicity of R alone and promisingly downregulates the pathways underlying UVB-ROS-induced skin aging. These findings advocate the use of RR as a nutraceutical for antiaging purposes.

Abietic acid attenuates allergic airway inflammation in a mouse allergic asthma model

Abietic acid (AA), one of the terpenoids isolated from Pimenta racemosa var. grissea, has been reported to have anti-inflammatory and immunomodulatory effects. However, the anti-allergic effects of AA remain unclear. The aim of this study was to investigate the anti-allergic effects of AA in an ovalbumin (OVA)-induced asthma murine model. The model of mouse asthma was established by induction of OVA. AA (10, 20, 40mg/kg) was administered by oral gavage 1h after the OVA treatment on days 21 to 23. At 24h after the last challenge, bronchoalveolar lavage fluid (BALF) and lung tissues were collected to assess pathological changes, cytokines production, and NF-κB expression. The results showed that AA attenuated lung histopathologic changes, inflammatory cells infiltration, and bronchial hyper-responsiveness. AA also inhibited OVA-induced the nitric oxide (NO), IL-4, IL-5, IL-13, and OVA-specific IgE production, as well as NF-κB activation. In conclusion, the current study demonstrated that AA exhibited protective effects against OVA-induced allergic asthma in mice and the possible mechanism was involved in inhibiting NF-κB activation.