Abietic Acid Has an Anti-Obesity Effect in Mice Fed a High-Fat Diet

Anticancer activities of natural abietic acid

Cancer is the main cause of death in the world. There are several therapies that are in practice for cancer cure including radiotherapy, chemotherapy, and surgery. Among the chemotherapies, natural products are considered comparable safe, easily available and cost effective. Approximately 60% of cancer approved FDA drugs are natural products including vinblastine, doxorubicin, and paclitaxel. These natural products have complex structures due to which they work against cancer through different molecular pathways, STAT3, NF-kB, PI3K/AKT/mTOR, cell cycle arrest, mitochondrial dependent pathway, extrinsic apoptosis pathway, autophagy, mitophagy and ferroptosis. AA is a natural abietane diterpenoid compound from Pinus palustris and Pimenta racemose var. grissea with different pharmacological activities including anti-inflammatory, anti-convulsant, anti-obesity and anti-allergic. Recently it has been reported with its anticancer activities through different molecular mechanisms including NF-kB, PI3K/AKT, call cycle arrest at G0/G1 phase, mitochondrial dependent pathway, extrinsic apoptosis pathway, AMPK pathway and ferroptosis pathways. The literature survey reveals that there is no review on AA anticancer molecular mechanisms, therefore in current review, we summarize the anticancer molecular mechanisms of AA.

Antiedematogenic and Analgesic Activities of Abietic Acid in Mice

Exacerbated inflammatory responses to harmful stimuli can lead to significant pain, edema, and other complications that require pharmacological intervention. Abietic acid (AA) is a diterpene found as a significant constituent in pine species, and evidence has identified its biological potential. The present study aimed to evaluate abietic acid's antiedematogenic and anti-inflammatory activity in mice. Swiss mice (Mus musculus) weighing 20-30 g were treated with AA at 50, 100, and 200 mg/kg. The central nervous system (CNS) effects were evaluated using open-field and rotarod assays. The antinociceptive and anti-inflammatory screening was assessed by the acetic acid and formalin tests. The antiedematogenic activity was investigated by measuring paw edema induced by carrageenan, dextran, histamine, arachidonic acid, and prostaglandin, in addition to using a granuloma model. The oral administration of abietic acid (200 mg/Kg) showed no evidence of CNS effects. The compound also exhibited significant antiedematogenic and anti-inflammatory activities in the carrageenan and dextran models, mostly related to the inhibition of myeloperoxidase (MOP) activity and histamine action and, to a lesser extent, the inhibition of eicosanoid-dependent pathways. In the granuloma model, abietic acid's effect was less expressive than in the acute models investigated in this study. In conclusion, abietic acid has analgesic and antiedematogenic activities related to anti-inflammatory mechanisms.

Abietic acid inhibits acetaminophen-induced liver injury by alleviating inflammation and ferroptosis through regulating Nrf2/HO-1 axis

Abietic acid has been known to exhibit anti-inflammatory activity. This study was designed to investigate the protective effects of abietic acid on acetaminophen (APAP)-induced liver injury. The data demonstrated that abietic acid significantly ameliorated APAP-induced liver pathological changes, TNF-α and IL-1β production. APAP could increase malondialdehyde (MDA) and Fe²⁺ levels, and decrease ATP and glutathione (GSH) levels, as well as glutathione peroxidase 4 (GPX4) and xCT expression. However, these changes induced by APAP were prevented by abietic acid, indicating abietic acid could inhibit APAP-induced ferroptosis. Furthermore, abietic acid inhibited APAP-induced NF-κB activation and increased the expression of Nrf2 and HO-1. Additionally, the inhibitory effects of abietic acid on APAP-induced liver injury were prevented in Nrf2^-/- mice. In vitro, the inhibition of abietic acid on APAP-induced inflammation and ferroptosis were reversed when Nrf2 was knockdown. In summary, abietic acidexhibited a therapeutic effectagainst liver injury by attenuating inflammation and ferroptosis.

Anti-Atopic Dermatitis Effects of Abietic Acid Isolated from Rosin under Condition Optimized by Response Surface Methodology in DNCB-Spread BALB/c Mice

Abietic acid (AA) is known to have beneficial effects on inflammation, photoaging, osteoporosis, cancer, and obesity; however, its efficacy on atopic dermatitis (AD) has not been reported. We investigated the anti-AD effects of AA, which was newly isolated from rosin, in an AD model. To achieve this, AA was isolated from rosin under conditions optimized by response surface methodology (RSM), and its effects on cell death, iNOS-induced COX-2 mediated pathway, inflammatory cytokine transcription, and the histopathological skin structure were analyzed in 2,4-dinitrochlorobenzene (DNCB)-treated BALB/c mice after treatment with AA for 4 weeks. AA was isolated and purified through isomerization and reaction-crystallization under the condition (HCl, 2.49 mL; reflux extraction time, 61.7 min; ethanolamine, 7.35 mL) established by RSM, resulting in AA with a purity and extraction yield of 99.33% and 58.61%, respectively. AA exhibited high scavenging activity against DPPH, ABTS, and NO radicals as well as hyaluronidase activity in a dose-dependent manner. The anti-inflammatory effects of AA were verified in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages through amelioration of the inflammatory response, including NO production, iNOS-induced COX-2 mediated pathway activation, and cytokine transcription. In the DNCB-treated AD model, the skin phenotypes, dermatitis score, immune organ weight, and IgE concentration were significantly ameliorated in the AA cream (AAC)-spread groups compared to the vehicle-spread group. In addition, AAC spread ameliorated DNCB-induced deterioration of skin histopathological structure through the recovery of the thickness of the dermis and epidermis and the number of mast cells. Furthermore, activation of the iNOS-induced COX-2 mediated pathway and increased inflammatory cytokine transcription were ameliorated in the skin of the DNCB+AAC-treated group. Taken together, these results indicate that AA, newly isolated from rosin, exhibits anti-AD effects in DNCB-treated AD models, and has the potential to be developed as a treatment option for AD-related diseases.

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.

Metabolomic comparison between natural Huaier and artificial cultured Huaier

Vanderbylia robiniophila (Murrill) B.K. (Huaier) is a kind of higher fungal fruiting body parasitic on the trunk of Sophora japonica and Robinia pseudoacacia L.. As a traditional Chinese medicine with a history of more than 1600 years, Huaier has attracted wide attention for its excellent anticancer activity. A systematic study on the metabolome differences between natural Huaier and artificial cultured Huaier was conducted using liquid chromatography-mass spectrometry in this study. Principal component analysis and orthogonal projection on latent structure-discriminant analysis results showed that cultured Huaier evidently separated and individually separated from natural Huaier, indicating metabolome difference between natural Huaier and cultured Huaier. Hierarchical clustering analysis was further performed to cluster the differential metabolites and samples based on their metabolic similarity. The higher content of amino acids, alkaloids and terpenoids in natural Huaier makes it an excellent choice as a traditional Chinese medicine for anti-cancer or nutritional supplementation. The results of the Bel-7402 and A549 cells cytotoxicity test showed that the anticancer activity of natural Huaier was better than that of cultured Huaier. This may be due to the difference in chemical composition, which makes the anticancer activity of natural and cultured Huaier different.

Growth Inhibition and Apoptotic Effect of Pine Extract and Abietic Acid on MCF-7 Breast Cancer Cells via Alteration of Multiple Gene Expressions Using In Vitro Approach

In vitro anti-proliferative activity of Pinus palustris extract and its purified abietic acid was assessed against different human cancer cell lines (HepG-2, MCF-7 and HCT-116) compared to normal WI-38 cell line. Abietic acid showed more promising IC50 values against MCF-7 cells than pine extract (0.06 µg/mL and 0.11 µM, respectively), with insignificant cytotoxicity toward normal fibroblast WI-38 cells. Abietic acid triggered both G2/M cell arrest and subG0-G1 subpopulation in MCF-7, compared to SubG0-G1 subpopulation arrest only for the extract. It also induced overexpression of key apoptotic genes (Fas, FasL, Casp3, Casp8, Cyt-C and Bax) and downregulation of both proliferation (VEGF, IGFR1, TGF-β) and oncogenic (C-myc and NF-κB) genes. Additionally, abietic acid induced overexpression of cytochrome-C protein. Furthermore, it increased levels of total antioxidants to diminish carcinogenesis and chemotherapy resistance. P. palustris is a valuable source of active abietic acid, an antiproliferative agent to MCF-7 cells through induction of apoptosis with promising future anticancer agency in breast cancer therapy.

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.

Abietic acid suppresses non-small-cell lung cancer cell growth via blocking IKKβ/NF-κB signaling

Background: Abietic acid (AA) is one of the terpenoids, which are multifunctional natural compounds. It has been reported that AA possesses favorable therapeutic effects on inflammation and obesity.

Method: In the present study, we determined the inhibitory effect of AA on the proliferation and growth of non-small-cell lung cancer (NSCLC) cell lines for the first time. Then, flow cytometry and Western blot analysis were applied to determine the cell apoptosis and cell cycle. Finally, surface plasmon resonance, molecular docking and molecular dynamics (MD) simulation were performed to explore the underlying molecular mechanisms.

Results: In vitro experiments indicated that AA displays significant anti-proliferative, cell cycle arresting and pro-apoptotic activities. Mechanistically, AA abrogated tumor necrosis factor-α induced phosphorylation of IκB kinase (IKKα/β) (Ser176/180) and IkBα (Ser32), and inhibited the nuclear translocation of nuclear factor‐κB. Moreover, we found that the activities of AA against NSCLC cells were mediated by its IKKβ inhibition. Molecular docking and MD simulations demonstrated that the mechanism of action between AA and IKKβ was through hydrophobic interactions.

Conclusion: Our data indicate that AA could be a promising lead compound for the discovery of novel IKKβ inhibitors and potential agents for the treatment of NSCLC.

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.

The Inhibitory Effect of Abietic Acid on Melanoma Cancer Metastasis and Invasiveness In Vitro and In Vivo

Melanoma cell metastasis is the primary cause of patient death. Thus, various treatment strategies have been developed to prevent metastasis. Abietic acid (AA) is an organic compound commonly found in trees. This study is aimed to investigate the antimetastatic activity of AA in B16F10-xenografted C57BL/6 mice and assess the anticancer activity of AA in combination with Taxol in melanoma cells. AA effectively reduced the formation of lung metastases by approximately 92.8%. AA treatment inhibited migratory potential ([Formula: see text]), invasion ([Formula: see text]), and motility ([Formula: see text]) of highly metastatic B16F10 melanoma cells in vitro. Zymography revealed that AA reduced the proteinase activities of matrix metalloproteinase-2 and urokinase-type plasminogen activator. Molecular analyses showed that AA reduced Akt phosphorylation and activating protein-1 DNA-binding activity by Western blot and electrophoretic mobility shift assay (EMSA), respectively. In summary, AA effectively inhibited B16F10 lung metastasis, and 50[Formula: see text][Formula: see text]M AA did not affect the viability of B16F10 cells. AA improved the efficacy of Taxol and demonstrated strong anticancer activity on melanoma cells. These results suggested that AA could be used as an antimetastatic agent or as an adjuvant for anticancer therapy.

Regulation of liver cell glucose homeostasis by dehydroabietic acid, abietic acid and squalene isolated from balsam fir (Abies balsamea (L.) Mill.) a plant of the Eastern James Bay Cree traditional pharmacopeia

In our previous study, Abies balsamea (L.) Mill., a plant used in Cree traditional medicine, had a strong effect on the regulation of glucose homeostasis in liver cells. This study aimed to isolate and identify its active constituents using a bioassay-guided fractionation approach as well as to elucidate their mechanism(s) of action. The effect of the crude extract and its constituents was evaluated on the activity of Glucose-6-Phosphatase (G6Pase) and Glycogen Synthase (GS) and phosphorylation of three kinases, AMP-activated protein kinase (AMPK), Akt and Glycogen Synthase Kinase-3 (GSK-3). Three compounds, abietic acid, dehydroabietic acid and squalene, were isolated from the most active fraction in the bioassays (hexane). The compounds were able to decrease the activity of G6Pase and to stimulate GS. Their effect on G6Pase activity involved both Akt and AMPK phosphorylation with significant correlations between insulin-dependent and -independent pathways and the bioassay. In addition, the compounds were able to stimulate GS through GSK-3 phosphorylation with a significant correlation between the signaling pathway and the bioassay. Dehydroabietic acid stood out for its strongest effect in all the experiments close to that of the crude extract. These compounds may have potential applications in the treatment of type 2 diabetes and insulin resistance.

HDAC3 interacts with sumoylated C/EBPα to negatively regulate the LXRα expression in rat hepatocytes

The expression changes of liver X receptor alpha (LXRα), histone deacetylase 3 (HDAC3) and CCAAT/enhancer binding protein alpha (C/EBPα) were detected in liver tissues of our high-fat-diet E3 rat model. The aim of this study is to pinpoint the molecular mechanism of HDAC3 and C/EBPα to orchestrate LXRα expression in hepatocytes. We confirmed that LXRα and its target genes were negatively regulated by HDAC3 in stable expressed clones with pEGFP-Hdac3 or shRNA-Hdac3 vector. However, transient pEGFP-C/EBPα plasmid transfection showed an upregulation of LXRα expression and C/EBPα enhanced LXRα promoter activity in a dose-dependent manner in CBRH-7919 cells. By using 5'-serial deletion reporter analysis, we identified that fragment from -2881 to -1181bp of LXRα promoter was responsible for C/EBPα binding to the promoter, especially CBS1 and CBS4 were identified essentially by using ChIP and luciferase reporter assay. Co-IP, qRT-PCR and ChIP revealed that HDAC3 interacted with C/EBPα co-regulated LXRα expression. Sumoylation of C/EBPα at lysine 159 was detected in CBRH-7919 cells with transient overexpressed C/EBPα, and Co-IP assay detected that sumoylated C/EBPα interacted with more HDAC3 than C/EBPα K159L mutant. Luciferase reporter assay demonstrated that C/EBPα participated in HDAC3-repressed LXRα transcription, and HDAC3 was involved in sumoylated C/EBPα-inactivated LXRα activity. Luciferase reporter assay demonstrated that sumoylation of C/EBPα by SUMO-1 directly reversed the activation of C/EBPα on LXRα promoter. The results suggested that HDAC3 interacts with sumoylated C/EBPα to negatively regulate the LXRα expression.