Open Access

Antioxidant, anti‑inflammatory and anti‑fibrotic effects of Boswellia serrate gum resin in CCl4‑induced hepatotoxicity

  • Authors:
    • Heba M. Eltahir
    • Michael A. Fawzy
    • Elhussein M. Mohamed
    • Mahmoud A. Alrehany
    • Ahmed M. Shehata
    • Mekky M. Abouzied
  • View Affiliations

  • Published online on: December 19, 2019     https://doi.org/10.3892/etm.2019.8353
  • Pages: 1313-1321
  • Copyright: © Eltahir et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

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Abstract

The present study aims to investigate the potential antioxidant, anti‑inflammatory and anti‑fibrotic effects of Boswellia serrate (BS) gum resin against carbon tetrachloride (CCl4)‑induced liver damage. Four groups consisting of eight rats each were designated: Group I, normal healthy control; group II, CCl4‑induced liver fibrosis; group III, CCl4‑induced liver fibrosis followed by BS treatment daily for two weeks; and group IV, CCl4‑induced liver fibrosis followed by silymarin treatment daily for two weeks. Expression of tumor necrosis factor‑α (TNF‑α) and nuclear factor κB (NF‑κB), interleukin‑6 (IL‑6), transforming growth factor‑β (TGF‑β) and cyclooxygenase‑2 (COX‑2) were assessed, in addition to histopathological and fibrotic changes in liver tissues isolated from the rats. BS significantly ameliorated CCl4‑induced increases in serum aspartate (AST) and alanine transaminase (ALT) levels, reduced lactate dehydrogenase (LDH) activities in addition to restoring total bilirubin, triglyceride and albumin levels. BS treatment also alleviated oxidative stress and improved total antioxidant capacity in the liver, and reduced the expression of TNF‑α, NF‑κB, TGF‑β, IL‑6 and COX‑2. On a histopathological level, BS treatment also exhibited antifibrotic activity. In conclusion, these findings suggest that BS contains potentially hepatoprotective effects against CCl4‑induced liver injury via its antioxidant, anti‑inflammatory and antifibrotic characteristics.

Introduction

Liver damage resulting from multiple factors including drug misuse, alcohol abuse and pesticides represents a major international health problem (1). To tackle this problem investigations into the potential hepatoprotective properties of food, medicinal plants and their bioactive constituents is currently of upmost importance. Indeed, inflammation and reactive oxygen species (ROS)-induced oxidative stress are major players in the pathogenesis of many chronic diseases such as liver fibrosis (2). The huge diversity of compounds derived from natural products provides a rich source of potential therapeutic agents (3). Accumulating evidence supports the beneficial antioxidant effects of food-derived phenolic compounds on the health of the liver, by protecting against chemical-induced hepatotoxicity such as ethanol-induced liver injury (4). Carbon tetrachloride (CCl4)-intoxication is an animal model of oxidative stress-induced liver injury that is widely used for assessing the hepatoprotective capacity of prospective therapeutic agents (5).

One such agent, the Gum resin of Boswellia serrata (BS), has been used for centuries as a traditional remedy for a variety of ailments in Ayurvedic medicine. The anti-inflammatory, anti-atherogenic, and analgesic properties of BS have been recognized for centuries (6). Extracts from this gum resin have previously been demonstrated to target the humoral and adaptive immune response (7). In vitro studies have revealed that the boswellic acids, consisting of a group of pentacyclic triterpenoid compounds/acids, and their acetylated derivatives can inhibit the biosynthesis of pro-inflammatory mediators such as leukotrienes (8), which increase cell permeability. In particular, 3-acetyl-11-ketobeta-boswellic acid (AKBA) has been found to be a natural inhibitor of the transcription factor NF-κB, which is an important downstream mediator of cytokines during inflammation (9). These anti-inflammatory properties has been attributed to the boswellic acids (α, β and γ-boswellic acid), acetyl-β boswellic acid, 11-keto-β-boswellic acid and acetyl-11-keto-β-boswellic acid (10), which can also simultaneously reduce oxidative stress (11). This group of triterpenic acids have also been reported to exhibit anti-cancer properties, controlling cell proliferation, metastasis, invasion and migration by targeting cell signaling components, including MAPK, NF-κB, TNF-α and ERK1/2 (12,13).

The aim of the present study was to elucidate the potential hepatoprotective effects and the mechanism of action of BS in CCl4-induced hepatocellular damage rat models. These effects were biochemically and histologically assessed in addition to being compared with that of silymarin, a more well-known hepatoprotective compound (14).

Materials and methods

Chemicals and Plant Material

Chemicals used were all of analytical grade and were purchased from Sigma-Aldrich (Merck KGaA). BS oleo-gum resin utilized in the present study was a kind gift from Professor Dr H. P. T. Ammon, Department of Pharmacology, Institute of Pharmaceutical Sciences, University of Tuebingen, Germany (Tubingen, Germany).

Animals and experimental design

Experiments on animals were performed in accordance with the international ethical guidelines for animal care of the United States Naval Medical Research Centre, Unit no. 3, Abbaseya, Cairo, Egypt, accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International. The adopted guidelines were in agreement with ‘Principles of Laboratory Animals Care’ (NIH Publication no. 85-23, revised 1985). The study protocol was approved by The Research Ethics Committee of the Faculty of Pharmacy, Minya University (Minya, Egypt).

A total of 32 male Wistar rats (age, 7–8 weeks old; average body weight, 250±25 g) were obtained from the Animal House of Assiut University were utilized in the experimental procedures. All animals received professional care and were kept with a 12-h light/dark cycle at 20°C and 45% relative humidity and had free access to water and food. Animals were randomly divided into four test groups of eight rats each, with the experimental procedures described as follows: i) Normal control group, which received two intraperitoneal (i.p.) injections of olive oil per week for six weeks; ii) CCl4-treated group, in which liver fibrosis was induced by an i.p. injection of CCl4 (1 ml/kg 40% CCl4, diluted in olive oil) twice weekly for 6 weeks (15); iii) BS treatment group, in which the rats received a daily i.p. injection of BS (150 mg/kg body weight) for an additional two weeks directly after the end of the six-week CCl4 treatment (16); and iv) Silymarin treatment group, in which the rats received a daily oral dose of silymarin (100 mg/kg body weight per oral gavage) for two weeks directly after the end of the six week CCl4 treatment. At the end of the 8th week, rats deeply anaesthetized by i.p. injection of 100 mg/kg ketamine and 20 mg/kg xylazine were sacrificed by cervical dislocation.

Sample collection

To perform the biochemical analysis, 5 ml of blood were collected from animals that were deeply anesthetized by intraperitoneal injections of 100 mg/kg ketamine and 20 mg/kg xylazine by cardiac puncture. The blood samples were subsequently centrifuged (1,000 × g, 20 min at room temperature) with the subsequent serum isolated. Liver tissues were excised rapidly for histological investigation and RNA isolation. A buffer with the following composition was used for tissue homogenization for further protein analysis: 20 mM Tris, 100 mM NaCl, 1 mM EDTA and 0.5% Triton X-100 supplemented with protease inhibitors mix. Biuret reagent (Bio-Rad laboratories, Inc.) was used to estimate the protein content of homogenates, using bovine serum albumin as standard (Sigma-Aldrich; Merck KGaA). Homogenized tissue samples were stored at −70°C until use.

Detection of nuclear NF-κB expression by western blot analysis

Preparation of nuclear samples was performed using Nuclear Extraction Kit (cat. no. ab113474; Abcam) according to manufacturer's protocol. A total of 50 µg of nuclear protein from each liver sample were used for western blot analysis according the protocol previously described by Abouzied et al (17). Briefly, protein samples were separated by 10% SDS-PAGE and then transferred to Hybond™ nylon membranes. Membranes were blocked for 2 h at room temperature in 5% non-fat milk diluted in TBS supplemented with 0.05% Tween-20 buffer followed by an overnight incubation at 4°C with mouse monoclonal primary antibodies against rat NF-κB p65 (1:2,000, cat. no. TA336457; Origene Technologies, Inc.) and β-actin (1:2,000; cat. no. TA310155; OriGene Technologies, Inc.). Alkaline phosphatase-conjugated goat anti-mouse immunoglobulins (cat. no. AP32278AP-N; Origene Technologies, Inc.) were diluted 1:5,000 in the 10X diluted blocking buffer and used as a secondary antibody that was used for incubating the membranes for 2 h at room temperature. Visualization of protein bands was achieved by incubating the membranes with alkaline phosphatase buffer containing the substrate 1-step™ NBT/BCIP substrate solution (cat. no. 34042; Thermo Fisher Scientific, Inc.). Color reactions were stopped by rinsing the membranes with stop buffer (10 mM Tris-Cl, pH 6.0, 5 mM EDTA). Visualized bands were analyzed using ImageJ software (version 2.0.0; National Institutes of Health).

RNA extraction and reverse transcription-polymerase chain reaction (RT-PCR) for TNF-α

Total RNA was isolated from freshly dissected tissues using total RNA Kit (Hangzhou Bioer Co., Ltd.) according to manufacturer's protocol. The amount of isolated RNA was quantified by measuring absorbance at 260 nm. RT-PCR was performed using RevertAid RT reverse transcription kit (Thermo Fisher Scientific, Inc.) according to manufacturer's protocols. For the amplification of TNF-α, the following synthetic oligonucleotides were used: TNF-α forward, 5′-CAGCAGATGGGCTGTACCTT-3′ and reverse, 5′-AAGTAGACCTGCCCGGACTC-3′; and GAPDH forward, 5′-AGATCCACAACGGAT-3′ and reverse, 5′-TCCCTCAAGATTGTCAGCAA-3′, where GAPDH served as the internal control (18). The reaction mixture, consisting of 2 µl cDNA, 2.5 U REDtaq® ReadymixTM PCR Reaction Mix (Sigma-Aldrich; Merck KGaA) and 0.1 µmol/l primers (Fermentas; Thermo Fisher Scientific, Inc.) was amplified using a Biometra cycler® (Biometra GmbH). Thermocycling started with 4 min of pre-denaturation at 94°C followed by 30 cycles of denaturation at 94°C for 30 sec, annealing at 55°C for 30 sec and extension at 72°C for 1 min. Finally, the mixture was incubated at 72°C for 4 min and cooled to 4°C. Subsequent PCR products were separated on 1.5% (v/v) agarose gels and visualized by ethidium bromide (0.3 µg/ml final concentration) and bands were quantified using the ImageJ software (version 2.0.0; National Institutes of Health).

Evaluation of serum TGF-β and interleukin-6 levels

Commercially available ELISA kits (Cusabio Biotech Co., Ltd.) were used to measure serum levels of TGF-β (cat. no. CSB-E04726m) and IL-6 (cat. no. CSB-E04639m) according to manufacturer's protocol.

Biochemical analysis

Isolated sera were used for the assessment of serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) (cat. no. AT-1034; Bio-diagnostic), albumin (cat. no. AB-1010; Bio-diagnostic), bilirubin (cat. no. BR-1110; Bio-diagnostic), lactate dehydrogenase activity (LDH; cat. no. 278001; Spectrum Diagnostics), total cholesterol (cat. no. CH-1220; Bio-diagnostic) and triglycerides (TG; cat. no. TR-2030; Bio-diagnostic). Liver homogenates were used for estimating levels of lipid peroxides (measured as malondialdehyde, MDA; cat. no. MD-2529; Bio-diagnostic), catalase activity (cat. no. CA-2517, Bio-diagnostic) and total anti-oxidant activity (cat. no. TA-2513, Bio-diagnostic). Commercially available kits were used for measuring the different biochemical parameters according to the manufacturers' protocols.

Histopathology

Freshly isolated liver specimens were first formalin-fixed (10% w/v in PBS, overnight at 4°C) then embedded in paraffin following dehydration in a series of increasing ethanol concentrations. The tissues were then cut into 5 µm-thick sections, de-paraffinized, rehydrated and stained with hematoxylin for 7 min and eosin for 1 min at room temperature (H&E staining) as well as Masson's trichrome (19) or immunostained against COX-2 using a specific COX-2 antibody according to the method described by Wójcik et al (20). An independent pathologist blindly estimated the degree of liver damage using an Optika B-810 microscope (Optika SRL). Knodell index was used for scoring the degree of liver damage as follows: 0, absence of fibrosis; 1, portal fibrosis; 2, fibrous portal expansion; 3, bridging fibrosis (portal-portal or portal-central linkage); and 4, cirrhosis (21).

High-performance liquid chromatography (HPLC) and characterization of BS extract

BS oleo-gum resin used in the present study was previously characterized by HPLC (16,22,23). It was found to be a combination of α- and β-boswellic acids and their derivatives, including 3-O-acetyl-α-boswellic acid, 11-keto-β-boswellic acid (AKB) and 3-O-acetyl-11-keto-β-boswellic acid (AKBA). Based on the data obtained from the provider, the actual concentrations of KBA and AKBA in the extract were 5.48 and 4.66%, respectively.

Statistical analysis

Statistical analysis was performed using GraphPad Prism (version 7; GraphPad Software, Inc.). Data were presented as mean ± standard error of mean (SEM). Comparisons were performed using one-way ANOVA followed by Tukey-Kramer multiple comparisons test. Results of histopathological analyzes were performed using non-parametric Kruskal-Wallis test followed by Bonferroni's correction. P<0.05 was considered to indicate a statistically significant difference.

Results

Effects of BS on the activities of serum liver enzymes

The levels of ALT, AST and LDH were evaluated in the serum from different test groups as markers of hepatocyte integrity. CCl4 treatment resulted in significant increases in serum ALT and AST activities compared with healthy control animals (P<0.001; Table I). Daily treatment with BS (150 mg/kg) significantly reversed the elevated serum levels of these three biomarkers induced by CCl4 (P<0.001; Table I). The values obtained after BS treatment were comparable to healthy control as well as silymarin treated group (Table I).

Table I.

Levels of liver biomarkers in the different test groups.

Table I.

Levels of liver biomarkers in the different test groups.

ParameterControl (n=8)CCl4 (n=8)CCl4 + Boswellia extract (150 mg/kg) (n=8)CCl4 + Silymarin (100 mg/kg) (n=8)
AST (U/l)91±4.700 240±10.800c 120.0±9.100b 105±11.300b
ALT (U/l)40±2.300 108±9.700c 60±4.800a 45±3.700b
Bilirubin (mg/dl)0.12±0.080 0.46±0.020c 0.15±0.005b 0.13±0.090b
Albumin (mg/dl)5.1±0.410 2.9±0.170c 4.3±0.250a 4.8±0.180b
Triglycerides (mg/dl)73±6.300 130±10.200c 81±4.700b 75±5.400b
Cholesterol (mg/dl)83±3.22 152±5.700c94 ±8.300b 83.00±5.150b

{ label (or @symbol) needed for fn[@id='tfn1-etm-0-0-8353'] } Values represent the mean ± SEM.

a P<0.01

b P<0.001 vs. CCl4

c P<0.001 vs. control. AST, aspartate transaminase; ALT, alanine transaminase; CCl4, carbon tetrachloride.

Effects of BS on serum cholesterol, TG, albumin and bilirubin levels

CCl4 administration resulted in significant increases in the serum levels of cholesterol, TG and bilirubin (P<0.001) along with a significant drop in albumin levels (P<0.001; Table I), effects that were significantly reversed by subsequent BS administration (P<0.001; Table I).

Effects of BS on total antioxidant capacity and catalase activity

The hepatic tissue antioxidant capacity and catalase activity were then measured in the four test groups. A significant reduction in catalase and total antioxidant activities were observed in the CCl4 group compared with normal control (P<0.001, Figs. 1 and 2). Treatment with BS or silymarin resulted in significant increases in catalase and total antioxidant activity compared with the CCl4 group (P<0.001; Figs. 1 and 2).

Effects of BS on lipid peroxidation in hepatic tissues

For the present study, malondialdehyde (MDA) levels in hepatic tissues were used as a marker for lipid peroxidation. CCl4 treatment induced significant increases in tissue MDA levels compared with normal control (P<0.001; Fig. 3). BS treatment resulted in a significant reduction in the elevated MDA levels compared with the CCl4-treated group (P<0.001; Fig. 3), to levels that were comparable to those of healthy control and the silymarin-CCl4-treated group.

Effects of BS on the expression and transcription levels of nuclear NF-κB and TNF-α

Changes in nuclear NF-κB p65 protein expression and TNF-α transcription in liver tissues from the four treatment groups were next measured to assess the anti-inflammatory activity of BS (Fig. 4A and B). CCl4 treatment resulted in an increase in the expression of the pro-inflammatory markers, TNF-α mRNA and NF-κB proteins, compared with healthy controls. BS administration reversed this CCl4-induced effect to levels comparable with control and similar to that induced by silymarin treatment (Fig. 4A-D).

Effects of BS on the expression levels of TGF-β and interleukin-6

To evaluate the effect of different treatments on the expression of inflammatory markers, the levels of the pro-inflammatory markers TGF-β and IL-6 were measured in the serum from the four treatment groups. CCl4 treatment significantly increased the serum levels of both markers as a result of the induced inflammatory response (Fig. 5A and B). Subsequent treatment with BS partially but significantly reversed the increased expression of TGF-β and IL-6 to values comparable to those obtained after silymarin treatment (Fig. 5A and B).

Histopathological analysis

Liver sections from the four treatment groups were subsequently stained against COX-2 to investigate the extent of inflammation. Upon CCl4 treatment, strong COX-2 expression was detected in infiltrated mononuclear phagocytes compared with control sections (Fig. 6A and B). This expression was ameliorated following BS or silymarin treatment (Fig. 6C and D), suggestive of their curative effects.

Examination of liver sections stained using H&E reflected normal morphology and architecture in the control group (Fig. 7A). In contrast, extensive hepatocellular damage including portal inflammation, venous congestion, and fatty changes in the form of hepatocyte vacuolization and fatty droplets were observed in liver tissue sections from animals treated with CCl4 (Fig. 7B). BS treatment ameliorated CCl4-induced liver damage, an effect that was similar to that achieved by silymarin treatment (Fig. 7C and D). BS and silymarin treatment significantly reversed CCl4-induced histopathological damage in terms of fibrosis and inflammation scores (P<0.05; Fig. 7E and F).

Masson's trichrome staining was performed to evaluate the extent of liver fibrosis. Liver sections prepared from normal control rats exhibited normal architecture with minimal accumulation of collagen fibers (Fig. 8A). Tissues from rats following the administration of CCl4 showed disrupted tissue architecture, extended collagen fibers, formation of large fibrous septa, separation of the pseudolobe and accumulation of collagen as observed by intense signals of collagen staining (Fig. 8B). BS and silymarin treatment reversed these pathological changes and decreased collagen deposition (Fig. 8C and D).

Discussion

In the present study, CCl4-treated rats exhibited severe inflammatory reactions in the form of increased levels of NF-κB, TNF-α, TGF-β, IL-6, and COX-2 expression. In addition, lipid peroxidation was increased following CCl4 treatment, which was accompanied with depleted endogenous antioxidant capacity. As a consequence of CCl4-induced liver damage, hepatocytes lost their membrane integrity and the ability to conjugate or excrete bilirubin, as reflected by the observed elevations in serum bilirubin and liver enzymes levels and activities (ALT, AST and LDH) and disrupted lipid profiles, concordant with a previous report (24).

BS treatment effectively alleviated CCl4-induced liver injury as it normalized the expression levels of TNF-α and NF-κB. It also reversed signs of the inflammation as reported by the observed normalization of tissue COX-2 expression and serum levels of TGF-β and IL-6. BS treatment reduced lipid peroxidation, recovered antioxidant capacity and increased catalase activity following preceding CCl4 treatment. BS also normalized lipid profiles, levels and activities of hepatic enzymes and serum bilirubin levels in addition to improving cell integrity.

These effects of BS were comparable to those observed following silymarin treatment, a well-documented hepatoprotective agent. Silymarin consists of a complex of flavonolignans derived from the milk thistle and is famous for its antioxidant, anti-inflammatory, antifibrotic and properties in the liver (25).

Metabolism of xenobiotics such as CCl4, among other molecules, usually result in the generation of free reactive radicals, a main inducer of hepatocellular injury (26). The hepatotoxic effects of CCl4 is caused by the intensive oxidative stress generated from its metabolism into highly reactive free radicals (27,28). These free radicals attack several molecules causing lipid peroxidation, loss of membrane integrity, leakage of intracellular enzymes, inflammation and liver injury (17). Prolonged liver injury leads to the development of fibrosis, cirrhosis and finally hepatocellular carcinoma. However, fibrosis can be reversed by removing the causative agents, including relieving oxidative stress, modifying the inflammatory response, preventing activation of hepatic stellate cells (HSCs) or reducing the production of extracellular matrix (ECM) components, to permit hepatocyte regeneration (29).

However, chronic hepatic injury impairs the regenerative capacity of hepatocytes by activating apoptosis. In response to injury, Kupffer cells (KCs) release cytokines and inflammatory factors, including interleukins, COX-2, TNF-α and TGF-β as reported in the present and a previous study (28). This activates and transforms HSCs into hepatic myofibroblasts, which in turn deposit components of the ECM to initiate fibrosis (30).

TNF-α along with interleukins serve a role in the overexpression of cyclooxygenase-2 and activating the transcriptional factor NF-κB (31). Activated NF-κB amplifies the inflammatory response by activating the transcription of genes involved in the inflammatory response and induces fibrosis by stimulating TGF-β signaling and HSCs activation (32). Cyclooxygnase-2 catalyzes the synthesis of prostanoids that are involved in inflammation, fibrosis and oncogenesis (33).

Membrane integrity of intact liver cells prevents excessive leakage of liver enzymes, including ALT, AST and LDH from the cytosol into the circulation. As membrane integrity becomes lost in response to CCl4-induced hepatotoxicity, liver enzymes escape into the circulation reflecting the severity of the damage (34), and the hepatocytes lose their ability to conjugate or excrete bilirubin, resulting in elevated serum bilirubin levels (24).

Based on the observed antioxidant effects of BS, its administration alleviated oxidative stress leading to diminished cellular damage and improved hepatocyte integrity and functionality. This was evident by the reductions in serum bilirubin and liver enzymes levels, in addition to the downregulation of cytokines and profibrogenic factors, including TNF-α, NF-κB, IL-6, TGF-β and COX-2. This was confirmed by the positive effects of BS on regenerating liver cells by histological analysis of liver tissue sections.

The antioxidant capacity of natural products is generally associated with the content of polyphenolic compounds in their composition (35). Among other constituents, BS oleo-gum resin is rich in pentacyclic terpenoids that exhibited anti-inflammatory effects by targeting multiple pathways in a range of disorders, including rheumatoid arthritis, ulcerative colitis, bronchial asthma, osteoarthritis and cancer (12). AKBA and boswellic acids have been previously reported to inhibit the activation of NF-κB and production of TNF-α, IL-1, −2, −4 and −6 (7).

Histopathological evaluation of H&E and Masson's trichrome staining showed that CCl4-treatment induced histopathological damage and increased collagen deposition. Treatment with BS resulted in the reduction in fibrosis scoring and achieved marked improvements in reversing these pathological changes. This could be due to the observed ability of BS to recover endogenous antioxidant mechanisms, resulting in the free radicals being scavenged to allow hepatocyte regeneration. This antioxidant effect breaks the vicious cycle of continuous inflammation-fibrosis resulting from the continuous activation of KCs, causing a release of proinflammatory factors, activation of HSCs and the deposition of ECM, aiding fibrosis.

In addition to the low costs on the long-term use, no adverse effects were reported following the use of BS in treating whole rats (36) or colon cancer cell lines (37).

Collectively, these findings lead to the conclusion that BS oleo-gum resin is effective in alleviating CCl4-induced inflammation and fibrosis in the rat liver. This effect may be due to its antioxidant properties and its ability to recover endogenous antioxidant capacity whilst downregulating the inflammatory response. These effects reported in the present study in addition to the lack of reported adverse effects, suggest BS to be a potential therapeutic hepatoprotective agent.

Acknowledgements

The authors would like to thank Professor Kawkab A. Ahmed, Professor of Pathology, Faculty of Veterinary Medicine, Cairo University (Cairo, Egypt), for her assistance in the analysis of histopathological data.

Funding

No funding was received.

Availability of data and materials

All data generated or analyzed during this study are included in this published article.

Authors' contributions

HME performed the western blot analysis and histochemistry, edited and revised the manuscript; MAF performed the biochemical analysis and took part in writing the manuscript; EMM performed animal maintenance, drug administration, interpreted the data and took part in writing the manuscript; MAA took part in writing and revising the manuscript and the statistical analysis of data; AMS provided Boswellia and took part in data analysis and verification; MMA designed the study, and revised and edited the manuscript.

Ethics approval and consent to participate

Experiments on animals were performed in accordance with the international ethical guidelines for animal care of the United States Naval Medical Research Centre, Unit No. 3, Abbaseya, Cairo, Egypt, accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International. The present study was approved by The Research Ethics Committee of the Faculty of Pharmacy, Minya University (Minya, Egypt).

Patient consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

References

1 

Jia C: Advances in the regulation of liver regeneration. Expert Rev Gastroenterol Hepatol. 5:105–121. 2011. View Article : Google Scholar : PubMed/NCBI

2 

Biswas SK: Does the Interdependence between oxidative stress and inflammation explain the antioxidant paradox? Oxid Med Cell Longev. 2016:56989312016. View Article : Google Scholar : PubMed/NCBI

3 

Rates SM: Plants as source of drugs. Toxicon. 39:603–613. 2001. View Article : Google Scholar : PubMed/NCBI

4 

Liu J, Wang X, Liu R, Liu Y, Zhang T, Fu H and Hai C: Oleanolic acid co-administration alleviates ethanol-induced hepatic injury via Nrf-2 and ethanol-metabolizing modulating in rats. Chem Biol Interact. 221:88–98. 2014. View Article : Google Scholar : PubMed/NCBI

5 

Cui Y, Yang X, Lu X, Chen J and Zhao Y: Protective effects of polyphenols-enriched extract from Huangshan Maofeng green tea against CCl4-induced liver injury in mice. Chem Biol Interact. 220:75–83. 2014. View Article : Google Scholar : PubMed/NCBI

6 

Kimmatkar N, Thawani V, Hingorani L and Khiyani R: Efficacy and tolerability of Boswellia serrata extract in treatment of osteoarthritis of knee-a randomized double blind placebo controlled trial. Phytomedicine. 10:3–7. 2003. View Article : Google Scholar : PubMed/NCBI

7 

Ammon HP: Modulation of the immune system by Boswellia serrata extracts and boswellic acids. Phytomedicine. 17:862–867. 2010. View Article : Google Scholar : PubMed/NCBI

8 

Zhang Y, Ning Z, Lu C, Zhao S, Wang J, Liu B, Xu X and Liu Y: Triterpenoid resinous metabolites from the genus Boswellia: Pharmacological activities and potential species-identifying properties. Chem Cent J. 7:1532013. View Article : Google Scholar : PubMed/NCBI

9 

Cuaz-Pérolin C, Billiet L, Baugé E, Copin C, Scott-Algara D, Genze F, Büchele B, Syrovets T, Simmet T and Rouis M: Antiinflammatory and antiatherogenic effects of the NF-kappaB inhibitor acetyl-11-keto-beta-boswellic acid in LPS-challenged ApoE-/- mice. Arterioscler Thromb Vasc Biol. 28:272–277. 2008. View Article : Google Scholar : PubMed/NCBI

10 

Buchele B, Zugmaier W and Simmet T: Analysis of pentacyclic triterpenic acids from frankincense gum resins and related phytopharmaceuticals by high-performance liquid chromatography. Identification of lupeolic acid, a novel pentacyclic triterpene. J Chromatogr B Analyt Technol Biomed Life Sci. 791:21–30. 2003. View Article : Google Scholar : PubMed/NCBI

11 

Umar S, Umar K, Sarwar AH, Khan A, Ahmad N, Ahmad S, Katiyar CK, Husain SA and Khan HA: Boswellia serrata extract attenuates inflammatory mediators and oxidative stress in collagen induced arthritis. Phytomedicine. 21:847–856. 2014. View Article : Google Scholar : PubMed/NCBI

12 

Liu JJ, Toy WC, Liu S, Cheng A, Lim BK, Subramaniam T, Sum CF and Lim SC: Acetyl-keto-β-boswellic acid induces lipolysis in mature adipocytes. Biochem Biophys Res Commun. 431:192–196. 2013. View Article : Google Scholar : PubMed/NCBI

13 

Altmann A, Poeckel D, Fischer L, Schubert-Zsilavecz M, Steinhilber D and Werz O: Coupling of boswellic acid-induced Ca2+ mobilisation and MAPK activation to lipid metabolism and peroxide formation in human leucocytes. Br J Pharmacol. 141:223–232. 2004. View Article : Google Scholar : PubMed/NCBI

14 

Vargas-Mendoza N, Madrigal-Santillán E, Morales-González A, Esquivel-Soto J, Esquivel-Chirino C, García-Luna Y, González-Rubio M, Gayosso-de-Lucio JA and Morales-González JA: Hepatoprotective effect of silymarin. World J Hepatol. 6:144–149. 2014. View Article : Google Scholar : PubMed/NCBI

15 

Wang G, Li Z, Li H, Li J and Yu C: Metabolic profile changes of CCl4-liver fibrosis and inhibitory effects of jiaqi ganxian granule. Molecules. 21:6982016. View Article : Google Scholar

16 

Shehata AM, Quintanilla-Fend L, Bettio S, Singh CB and Ammon HP: Prevention of multiple low-dose streptozotocin (MLD-STZ) diabetes in mice by an extract from gum resin of Boswellia serrata (BE). Phytomedicine. 18:1037–1044. 2011. View Article : Google Scholar : PubMed/NCBI

17 

Abouzied MM, Eltahir HM, Abdel Aziz MA, Ahmed NS, Abd El-Ghany AA, Abd El-Aziz EA and Abd El-Aziz HO: Curcumin ameliorate DENA-induced HCC via modulating TGF-β, AKT and caspase-3 expression in experimental rat model. Tumour Biol. 36:1763–1771. 2015. View Article : Google Scholar : PubMed/NCBI

18 

Zhao J, Zheng H, Liu Y, Lin J, Zhong X, Xu W, Hong Z and Peng J: Anti-inflammatory effects of total alkaloids from Rubus alceifolius Poir [corrected]. on non-alcoholic fatty liver disease through regulation of the NF-κB pathway. Int J Mol Med. 31:931–937. 2013. View Article : Google Scholar : PubMed/NCBI

19 

Suvik A and Effendy AWM: The use of modified Masson's trichrome staining in collagen enaluation in wound healing study. Malays J Vet Res. 3:39–47. 2012.

20 

Wójcik M, Ramadori P, Blaschke M, Sultan S, Khan S, Malik IA, Naz N, Martius G, Ramadori G and Schultze FC: Immunodetection of cyclooxygenase-2 (COX-2) is restricted to tissue macrophages in normal rat liver and to recruited mononuclear phagocytes in liver injury and cholangiocarcinoma. Histochem Cell Biol. 137:217–233. 2012. View Article : Google Scholar : PubMed/NCBI

21 

Brunt EM: Grading and staging the histopathological lesions of chronic hepatitis: The Knodell histology activity index and beyond. Hepatology. 31:241–246. 2000. View Article : Google Scholar : PubMed/NCBI

22 

Ammon HP: Boswellic acids in chronic inflammatory diseases. Planta Med. 72:1100–1116. 2006. View Article : Google Scholar : PubMed/NCBI

23 

Tawab MA, Kaunzinger A, Bahr U, Karas M, Wurglics M and Schubert-Zsilavecz M: Development of a high-performance liquid chromatographic method for the determination of 11-keto-beta-boswellic acid in human plasma. J Chromatogr B Biomed Sci Appl. 761:221–227. 2001. View Article : Google Scholar : PubMed/NCBI

24 

Tabor E: Hepatocellular carcinoma: Global epidemiology. Dig Liver Dis. 33:115–117. 2001. View Article : Google Scholar : PubMed/NCBI

25 

Rasool M, Iqbal J, Malik A, Ramzan HS, Qureshi MS, Asif M, Qazi MH, Kamal MA, Chaudhary AG, Al-Qahtani MH, et al: Hepatoprotective effects of Silybum marianum (Silymarin) and Glycyrrhiza glabra (Glycyrrhizin) in combination: A possible synergy. Evid Based Complement Alternat Med. 2014:6415972014. View Article : Google Scholar : PubMed/NCBI

26 

Jaeschke H, Gores GJ, Cederbaum AI, Hinson JA, Pessayre D and Lemasters JJ: Mechanisms of hepatotoxicity. Toxicol Sci. 65:166–176. 2002. View Article : Google Scholar : PubMed/NCBI

27 

Recknagel RO, Glende EA Jr, Dolak JA and Waller RL: Mechanisms of carbon tetrachloride toxicity. Pharmacol Ther. 43:139–154. 1989. View Article : Google Scholar : PubMed/NCBI

28 

Dinarello CA: Proinflammatory cytokines. Chest. 118:503–508. 2000. View Article : Google Scholar : PubMed/NCBI

29 

Cohen-Naftaly M and Friedman SL: Current status of novel antifibrotic therapies in patients with chronic liver disease. Therap Adv Gastroenterol. 4:391–417. 2011. View Article : Google Scholar : PubMed/NCBI

30 

Meyer DH, Bachem MG and Gressner AM: Modulation of hepatic lipocyte proteoglycan synthesis and proliferation by Kupffer cell-derived transforming growth factors type beta 1 and type alpha. Biochem Biophys Res Commun. 171:1122–1129. 1990. View Article : Google Scholar : PubMed/NCBI

31 

Gambhir S, Vyas D, Hollis M, Aekka A and Vyas A: Nuclear factor kappa B role in inflammation associated gastrointestinal malignancies. World J Gastroenterol. 21:3174–3183. 2015. View Article : Google Scholar : PubMed/NCBI

32 

Seki E, De Minicis S, Osterreicher CH, Kluwe J, Osawa Y, Brenner DA and Schwabe RF: TLR4 enhances TGF-beta signaling and hepatic fibrosis. Nat Med. 13:1324–1332. 2007. View Article : Google Scholar : PubMed/NCBI

33 

Cheng J and Hada T: The significance of COX-2 and COX-2 inhibitors in liver fibrosis and liver cancer. Cur Med Che Anti Infl Anti Allergy Agents. 4:199–206. 2005. View Article : Google Scholar

34 

Brattin WJ, Glende EA Jr and Recknagel RO: Pathological mechanisms in carbon tetrachloride hepatotoxicity. J Free Radic Biol Med. 1:27–38. 1985. View Article : Google Scholar : PubMed/NCBI

35 

Younis T, Khan MR and Sajid M: Protective effects of Fraxinus xanthoxyloides (Wall.) leaves against CCl4 induced hepatic toxicity in rat. BMC Complement Altern Med. 16:4072016. View Article : Google Scholar : PubMed/NCBI

36 

Singh P, Chacko KM, Aggarwal ML, Bhat B, Khandal RK, Sultana S and Kuruvilla BT: A-90 day gavage safety assessment of Boswellia serrata in rats. Toxicol Int. 19:273–278. 2012. View Article : Google Scholar : PubMed/NCBI

37 

Takahashi M, Sung B, Shen Y, Hur K, Link A, Boland CR, Aggarwal BB and Goel A: Boswellic acid exerts antitumor effects in colorectal cancer cells by modulating expression of the let-7 and miR-200 microRNA family. Carcinogenesis. 33:2441–2449. 2012. View Article : Google Scholar : PubMed/NCBI

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January 2020
Volume 19 Issue 2

Print ISSN: 1792-0981
Online ISSN:1792-1015

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APA
Eltahir, H.M., Fawzy, M.A., Mohamed, E.M., Alrehany, M.A., Shehata, A.M., & Abouzied, M.M. (2020). Antioxidant, anti‑inflammatory and anti‑fibrotic effects of Boswellia serrate gum resin in CCl4‑induced hepatotoxicity. Experimental and Therapeutic Medicine, 19, 1313-1321. https://doi.org/10.3892/etm.2019.8353
MLA
Eltahir, H. M., Fawzy, M. A., Mohamed, E. M., Alrehany, M. A., Shehata, A. M., Abouzied, M. M."Antioxidant, anti‑inflammatory and anti‑fibrotic effects of Boswellia serrate gum resin in CCl4‑induced hepatotoxicity". Experimental and Therapeutic Medicine 19.2 (2020): 1313-1321.
Chicago
Eltahir, H. M., Fawzy, M. A., Mohamed, E. M., Alrehany, M. A., Shehata, A. M., Abouzied, M. M."Antioxidant, anti‑inflammatory and anti‑fibrotic effects of Boswellia serrate gum resin in CCl4‑induced hepatotoxicity". Experimental and Therapeutic Medicine 19, no. 2 (2020): 1313-1321. https://doi.org/10.3892/etm.2019.8353