Nerolidol, a sesquiterpene, attenuates oxidative stress and inflammation in acetic acid-induced colitis in rats

Chemopreventive and immunomodulatory effects of phenolic-rich extract of Commiphora leptophloeos against inflammatory bowel disease: Preclinical evidence

ETHNOPHARMACOLOGY RELEVANCE

Commiphora leptophloeos (Mart.) J.B. Gillet (Burseraceae) is a medicinal plant native to Brazil, popularly known as "imburana". Homemade leaf decoction and maceration were used to treat general inflammatory problems in the Brazilian Northeast population. Our previous research confirmed the anti-inflammatory activity of the C. leptophloeos hydroalcoholic leaf extract.

AIM OF THE STUDY

Inflammatory bowel disease (IBD) is a chronic and relapsing inflammatory disorder of the gut with no ideal treatment to maintain the remissive status. This work aimed to characterize the phytochemical composition and physicochemical properties of the C. leptophloeos hydroalcoholic leaf extract and its efficacy in chemopreventive and immunomodulatory responses in inflammatory bowel disease in non-clinical models.

MATERIALS AND METHODS

Mass spectrometry and physicochemical tests determined the phytochemical profile and physicochemical characteristics of the Commiphora leptophloeos (CL) extract. The chemopreventive and immunomodulatory effects of CL extract (50 and 125 μg/mL) were evaluated in vitro in the RAW 264.7 lipopolysaccharide (LPS) induced cell assay and in vivo in the model of intestinal inflammation induced by 2,4-Dinitrobenzenesulfonic acid (DNBS) in mice when they were treated with CL extract by intragastric gavage (i.g.) at doses of 300, 400 and 500 mg/kg.

RESULTS

Phytochemical annotation of CL extract showed a complex phenolic composition, characterized as phenolic acids and flavonoids, and satisfactory physicochemical characteristics. In addition, CL extract maintained the viability of RAW macrophages, reduced ROS and NO production, and negatively regulated COX-2, iNOS, TNF-α, IL-1β, IL-6, and IL-17 (p < 0.05). In the intestinal inflammation model, CL extract was able to downregulate NF-κB p65/COX-2, mTOR, iNOS, IL-17, decrease levels of malondialdehyde and myeloperoxidase and cytokines TNF-α, IL-1β and IL-6 (p < 0.05).

CONCLUSION

Based on these findings, CL extract reduced inflammatory responses by down-regulating pro-inflammatory markers in macrophages induced by LPS and DNBS-induced colitis in mice through NF-κB p65/COX-2 signaling. CL leaf extract requires further investigation as a candidate for treating inflammatory bowel disease.

Inhibition of TLR4, NF-κB, and INOS pathways mediates ameliorative effect of syringic acid in experimental ulcerative colitis in rats

OBJECTIVE

Numerous therapeutics and pharmacological properties have been reported in syringic acid (SA). In this study, we aimed to evaluate effect of SA in ulcerative colitis (UC) in rats considering effect on TLR4, NF-κB, and INOS pathways.

MATERIALS AND METHODS

48 Wistar rats were randomly designated into six groups (n = 8). UC was induced via intra-rectal administration of 7% acetic acid (0.8 ml). SA at doses of 10, 25, 50 mg/kg was administrated through gavage, and dexamethasone (2 mg/kg) administrated intra-peritoneally for 5 consecutive days. The macroscopic and histopathological damages as well as expression of inflammatory and apoptotic genes along with superoxide dismutase (SOD) and catalase (CAT) activities, total antioxidant capacity (TAC), nitric oxide (NO), and malondialdehyde (MDA) levels in the colon tissue were assessed.

RESULTS

UC led to an increase in the apoptotic and inflammatory genes, NO and MDA levels as well as decrease in TAC level, and SOD and CAT activities (p < 0.05). UC also caused severe damage, edema, inflammation, and necrosis in the colon. SA significantly reduced gene expressions of INOS, TLR4, IL-6, IL-1β, NF-κB, Caspase-3, Caspase-8, and Bax. SA ameliorated negative macroscopic and histopathologic effects of UC. SA significantly reduced MDA and NO levels, and increased TAC level and CAT activity in the colon tissue in comparison to the UC rats without treatment (p < 0.05).

CONCLUSION

SA via attenuation of the TLR4-NF-κB, NF-κB-INOS-NO pathways, oxidative stress, inflammation, and apoptosis of UC in rats.

Volatile profiling coupled with multivariate analysis, antiproliferative and anti-inflammatory activities of rhizome essential oil of four Hedychium species from India

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Hedychium of family Zingiberaceae comprises several perennial rhizomatous species widely used in perfumery and traditional folk medicine to treat diseases related to asthma, diarrhoea, nausea, stomach disorders, inflammation and tumours. Several species of Hedychium have remained under-explored with respect to their chemical composition and biological activities.

AIM OF THE STUDY

The current research aimed to explore the chemical composition and evaluate the antiproliferative and anti-inflammatory activities of rhizome essential oil from four Hedychium species (H. coccineum, H. gardnerianum, H. greenii and H. griffithianum).

MATERIALS AND METHODS

Compound identification was accomplished using a Clarus 580 gas chromatography system in conjunction with mass spectrometry (GC-MS). The multivariate data statistics using chemometrics (PCA, PLS-DA, sPLS-DA) and cluster analysis (Dendrogram, Heat maps, K-means) were used to compare the similarity and relationship among Hedychium metabolomes. MTT assay was employed to visualize the antiproliferative property against MCF7, HepG2 and PC3 cancerous cell lines. The toxicity of essential oils was determined using 3T3-L1 non-tumorigenic/normal cells. Lipopolysaccharide (LPS)-induced RAW 264.7 cells were used to investigate the anti-inflammatory properties of Hedychium essential oils by measuring the production of nitric oxide (NO) using the Griess reagent method. Furthermore, the levels of prostaglandin (PGE2) and pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) was assessed using the ELISA technique.

RESULTS

In total, 82 compounds were identified in four targeted species of Hedychium from which 1,8-cineole (52.71%), β-pinene (32.83%), α-pinene (19.62%), humulene epoxide II (19.86%) and humulene epoxide I (19.10%) were the major constituents. Monoterpenes (8.5-59.9%) and sesquiterpenes (2.87-54.11%) were the two class of compounds, found as the most prevalent in the extracted essential oils. The multivariate analysis classified the four Hedychium species into three different clusters. Hedychium essential oils exhibited potent antiproliferative activity against MCF7, HepG2 and PC3 cancer cell lines with IC50 values less than 150 μg/mL where H. gardnerianum exhibited the highest selective cytotoxicity against human breast and prostate adenocarcinoma cells with an IC50 value of 44.04 ± 1.07 μg/mL and 56.11 ± 1.44 μg/mL, respectively. The essential oils on normal (3T3-L1) cells displayed no toxicity with higher IC50 values thereby concluding as safe to use for normal human health without causing any side effects. Besides, the essential oils at 100 μg/mL concentration revealed remarkable anti-inflammatory activity in LPS-activated RAW 264.7 murine macrophages by inhibiting the production of inflammatory mediators, with H. greenii exhibiting the maximum anti-inflammation response by significantly suppressing the levels of NO (84%), PGE2 (87%), TNF-α (94.3%), IL-6 (95%) and IL-1β (85%) as compared to LPS treated group.

CONCLUSION

The present findings revealed that the Hedychium species traditionally used in therapeutics could be a potential source of active compounds with antiproliferative and anti-inflammatory properties.

Anti-inflammatory natural products modulate interleukins and their related signaling markers in inflammatory bowel disease: A systematic review

This review aims to identify in vivo studies investigating the potential of plant substances and their natural molecules in managing inflammatory bowel disease (IBD). Specifically, the objective is to examine the impact of these substances on interleukins and other key inflammatory signaling markers. Relevant articles published up to December 2022 were identified through a search of the PubMed, Scopus, Web of Science, and Embase databases. The search used keywords including "inflammatory bowel disease", "medicinal plants", "natural molecules", "anti-inflammatory", and "ulcerative colitis", and identified 1,878 potentially relevant articles, of which 89 were included in this review after completion of the selection process. This study provides preclinical data on natural products (NPs) that can potentially treat IBD, including ulcerative colitis. The main actions of these NPs relate to their effects on nuclear factor kappa B (NF-κB), the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway, the regulation of T helper 17/regulatory T cells balance, and oxidative stress. The ability of these NPs to inhibit intestinal inflammation appears to be dependent on lowering levels of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-17, via the Jun N-terminal kinase (JNK)1, NF-κβ-p65, and STAT3 pathways. In addition, NPs were shown to reduce oxidative stress and the severity of ulcerative colitis, as well as increase the activity of antioxidant enzymes. These actions suggest that NPs represent a promising treatment for IBD, and potentially have greater efficacy and safety than current treatments.

Biochemical and histopathological evidence for beneficial effects of Empagliflozin pretreatment on acetic acid-induced colitis in rats

BACKGROUND

Ulcerative Colitis (UC) is a disorder which oxidative stress plays a critical role in its pathogenesis. Empagliflozin (EMPA) is a sodium-glucose cotransporter-2 (SGLT2) inhibitor that has been shown to have anti-inflammatory and antioxidative effects. The aim of this study was to investigate the protective effects of EMPA on acetic acid (AA) induced colitis in rats.

METHODS

A total of twenty-four rats were divided into four groups (six animals in each group) as follows: (1) Control group; (2) acetic acid (AA)-induced colitis group (AA); (3) EMPA treatment group (AA + EMPA); (4) Dexamethasone (Dexa) treatment group (AA + Dexa). Animals in pre-treatment groups received EMPA (10 mg/kg, i.p.) or dexamethasone (4 mg/kg, i.p. as reference drug) for four consecutive days before induction of colitis by intra-rectal acetic acid (4% v/v) administration. Twenty-four hours after AA administration, rats were sacrificed and the colon tissues were removed for histopathological and biochemical evaluations.

RESULTS

Pretreatment with EMPA significantly decreased colon weight/length ratio (81.00 ± 5.28 mg/cm vs. 108.80 ± 5.51 mg/cm) as well as, macroscopic (2.50 ± 0.57 vs. 3.75 ± 0.25) and histological scores (3.3 ± 0.14 vs. 1.98 ± 0.14) compared to the AA-induced colitis group (p < 0.01). Pretreatment with EMPA significantly reduced malondialdehyde (MDA) (324.0 ± 15.93 vs. 476.7 ± 32.26 nmol/mg p < 0.001) and increased glutathione level (117.5 ± 4.48 vs. 94.38 ± 3.950 µmol/mg, p < 0.01) in comparison to the AA-induced colitis group. Furthermore, a significant increase in catalase (44.60 ± 4.02 vs.14.59 ± 2.03 U/mg, P < 0.01), superoxide dismutase (283.9 ± 18.11 vs. 156.4 ± 7.92 U/mg, p < 0.001), and glutathione peroxidase (10.38 ± 1.45 vs. 2.508 ± 0.37, p < 0.01) activities were observed by EMPA pretreatment when compared to the AA-induced colitis group. These results were in line with those of the reference drug.

CONCLUSIONS

It is concluded that EMPA could effectively reduce the severity of tissue injury in experimental colitis. This protective effect may be related to the antioxidative effects of EMPA drug.

Terpenes: Modulating anti-inflammatory signaling in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) are autoimmune diseases characterized by chronic intestinal inflammation. Considered a western disease, IBD incidence in newly developed countries is skyrocketing. Accordingly, global prevalence is steadily increasing. There are two major IBD phenotypes, ulcerative colitis (UC) and Crohn's disease (CD). UC manifests as uninterrupted inflammation localized in the colon and rectum. Meanwhile, CD presents as interrupted inflammation that can occur throughout the digestive tract. As a result, therapeutics have focused on anti-inflammatory approaches for its treatment. Unfortunately, only 50% of patients benefit from current Food and Drug Administration approved treatments, and all are associated with serious adverse effects. Thus, there is a need for safer and novel therapeutics to increase the efficacy in this population. One aspect that is critical in understanding IBD is how food and phytochemicals therein may be associated with modifying the pathogenesis of IBD. A variety of retrospective and prospective studies, and clinical trials have shown benefits of plant-rich diets on the prevention and symptomatic improvement of IBD. The Mediterranean diet is rich in vegetables, fruits, legumes, and herbs; and characterized by the abundance of anti-inflammatory phytochemicals. An understudied phytochemical class enriched in this diet is terpenes; isoprene-based molecules are widely available in Mediterranean herbs and citrus fruits. Various terpenes have been evaluated in different IBD models. However, some present contradictory or inconclusive results. Therefore, in this review we evaluated preclinical studies of terpenes modulating basic inflammatory signaling related to IBD.

Quinic acid ameliorates ulcerative colitis in rats, through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways

OBJECTIVE

In this study, the therapeutic effect of quinic acid (QA), which has anti-inflammatory activity, was investigated on acetic acid-induced colitis in male Wistar rats.

METHODS

Ulcerative colitis (UC) was induced in rats by acetic acid intrarectally, and the protective effects of QA in 10, 30, 60, and 100 mg/kg doses were investigated. Rats were treated for 5 days and their colon tissues were dissected out at the end. Macroscopic and histopathological examinations were performed in colon tissues. Also, the expression of inflammatory and apoptotic genes, including TLR4, IL-1β, INOS, IL-6, TNF-α, NF-κB, Caspase-3, Caspase-8, Bax, and Bcl-2, was measured. Biochemistry indices, such as malondialdehyde (MDA) and nitrite oxide (NO) content, in addition to, total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), and enzymes activities were also assessed.

RESULTS

Colitis increased the levels of MDA and NO, and enhanced the inflammatory and apoptotic gene expressions, while reducing the SOD and CAT enzymes activity, and TAC levels in the colitis rats. Also, results showed that colitis was associated with the infiltration of inflammatory cells, epithelium damage, and edema in colon tissue. QA significantly ameliorated histopathological indices, oxidative stress, inflammation, and apoptosis in colitis rats.

CONCLUSION

QA ameliorated UC through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways, which results in the reduction of colitis complications, including oxidative stress, inflammation, apoptosis and histopathological injuries in rats. Therefore it can be concluded, that QA exerts its therapeutic effects through antiapoptotic, antioxidant, and anti-inflammatory properties.

Coumaric acid ameliorates experimental colitis in rats through attenuation of oxidative stress, inflammatory response and apoptosis

OBJECTIVE

Due to the high side effects of commonly used drugs and according to the pharmacological properties reported for coumaric acid (CA), this study was designed to determine the impact of CA on acetic acid-induced colitis in rats, considering its possible anti-inflammatory, antioxidant, and anti-apoptotic properties.

MATERIALS AND METHODS

Forty-eight male Wistar rats were divided into 6 equal groups (n = 8). Colitis was induced by acetic acid intrarectally. CA in three different doses (50, 100, and 150 mg/kg) was administrated for 5 days. Finally, the macroscopic and histopathological changes in the colon tissue were examined. The expression of inflammatory and apoptotic genes, including NF-κB, TNF-α, INOS, IL-1β, IL-6, TLR4, Caspase-3, Caspase-8, Bax, Bcl-2 was assessed. In addition, changes in the levels of catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), nitrite, and total antioxidant capacity (TAC) were measured in the colon tissue.

RESULTS

Colitis led to a decrease in TAC and the activity levels of CAT and SOD and an increase in the expression of inflammatory and apoptotic genes, MDA, and nitrite levels in the colon. Colitis was also associated with edema and severe damage to the epithelium, infiltration of inflammatory cells, and the presence of ulcers and necrosis in the colon tissue. CA significantly improved the inflammation, oxidative stress, apoptosis, and histopathological indices caused by acetic acid-induced colitis on the colon.

CONCLUSION

It is concluded that CA probably exerts its positive effects in the management of colitis, through its anti-inflammatory, antioxidant, and anti-apoptotic properties.

Modulating effect of Xuanfei Baidu granule on host metabolism and gut microbiome in rats

Xuanfei Baidu granule (XFBD) is a recommended patented drug for the prevention and treatment of Corona Virus Disease 2019 (COVID-19), which is approved by the National Medical Products Administration. XFBD suppresses the over-activated immune response caused by inflammatory factor storms in COVID-19 infection. The intestine plays a crucial role in the immune system. The mass spectrometry based fecal metabolomics with 16S rDNA sequencing were combined to evaluate the effects of XFBD on host metabolism and gut microbiome. Short-chain fatty acids (SCFAs) contents in fecal matter were quantified by gas chromatography-mass spectrometry (GC-MS). Plasma samples were used to detect immune and inflammatory levels. The results were verified with a rat model of intestinal disorder. Results indicated that XFBD could increase the immune level of Immunoglobulin A (IgA), Immunoglobulin G (IgG) and Immunoglobulin M (IgM) (p &lt; 0.05). The OPLS-DA analysis results showed that a total of 271 differential metabolites (178 up-regulated and 93 down-regulated) were identified based on the VIP ≥1, p &lt; 0.05, FC ≥ 2 and FC ≤ 0.5. The metabolic pathways mainly involved D-Glutamine and D-glutamate metabolism, Arginine biosynthesis, Biotin metabolism, et al. XFBD modified the gut bacteria structure according to the principal component analysis (PCA), that is, 2 phyla, 3 classes, 5 orders, 11 families and 14 genera were significantly different based on taxonomic assignment. In addition, it could partially callback the relative abundance of intestinal microflora in bacterial disorder rats caused by antibiotics. It is suggested that the intervention mechanism of XFBD might be related to the regulation of intestinal flora composition. The evidence obtained in the study provides a useful reference for understanding the mechanism of XFBD.

The emerging coloprotective effect of sildenafil against ulcerative colitis in rats via exerting counterbalance between NF-κB signaling and Nrf-2/HO-1 pathway

The current work explored the influences of time dependent Sildenafil (SILD) administration, and the possible outcomes from its concomitant administration with dexamethasone against acetic acid-induced ulcerative colitis in rats. Rats were assigned into six random groups: diseased group (AA), injected once with 2 ml acetic acid (3%) intrarectally, 2 days before sacrification. SILD + AA, received sildenafil (25 mg/kg, orally) for 6 days starting 3 days pre-injection of AA; SILD-t + AA, received sildenafil (25 mg/kg, orally), starting at time of AA injection and continued for 3 days; DEXA + AA, received dexamethasone (2 mg/kg, i.p.) for 3 days, starting at time of AA injection; SILD-t + DEXA + AA, received sildenafil (25 mg/kg, orally) and dexamethasone (2 mg/kg, i.p.), as mentioned. Sildenafil markedly ameliorated disease activity index (DAI), ulcer scores, colon length shortening and colonic histopathological changes. Mechanistically, Sildenafil markedly attenuated immunoexpression of NF-κB p65/ TNF-α and COX-2, diminished oxidative stress (↓ MDA/NO levels and ↑ GSH level and SOD activity), increased levels of Nrf-2/HO-1, compared to untreated group. Taken together, Sildenafil treatment suppressed acetic acid-induced ulcerative colitis, probably via inhibiting NF-κB/TNF-α signaling dependent of Nrf-2/HO-1 pathway, reducing oxidative stress and attenuating inflammation. Surprisingly, effects of sildenafil were unpromoted in a time dependant manner. Short term treatment with sildenafil was sufficient to exert its coloprotective effect, while longer term pretreatment was only superior among other treatments in the macroscopical changes. Moreover, concurrent administration of sildenafil and dexamethasone had the preference in boosting the antioxidant defense and anti-inflammatory mechanisms, visualized by histopathological/immunohistochemical changes.

Anethole Ameliorates Acetic Acid-Induced Colitis in Mice: Anti-Inflammatory and Antioxidant Effects

Anethole has possessed anti-inflammatory and antioxidant responses in numerous studies. Oxidative stress has a pivotal role in the pathophysiology of colitis. The current study is designed to determine the effect of anethole on acetic acid-induced colitis in mice in view of its possible anti-inflammatory and antioxidant properties. In this study, 48 mice were grouped into 6 groups (n = 8), and colitis was induced with 0.2 ml of 7% acetic acid. Mice received intraperitoneally (i.p.) for 7 constant days normal saline and/or anethole at doses of 31.25, 62.5, 125, and 250 mg/kg, respectively. After treatments, the colon was dissected out, and histopathological changes, expression of inflammatory genes (IL-1β, TNF-α, and TLR4), and evaluation of malondialdehyde (MDA) levels and total antioxidant capacity (TAC) were assessed. The results showed that colitis is associated with edema and inflammatory responses in all layers and severe damage to the epithelium of the colon. Colitis causes a decrease in TAC, an increase in MDA levels, and an increase in inflammatory genes in the colon. Findings determined that anethole ameliorated the adverse effects of acetic acid-induced colitis in the colon. It is concluded that anethole, partially at least, possessed protective effects in acetic acid-induced colitis in mice through attenuation of oxidative stress and inflammatory response.

Isosteviol Sodium Ameliorates Dextran Sodium Sulfate-Induced Chronic Colitis through the Regulation of Metabolic Profiling, Macrophage Polarization, and NF-κB Pathway

Inflammatory bowel diseases (IBDs) constitute a group of chronic intestinal conditions prominently featuring deranged metabolism. Effective pharmacological treatments for IBDs are lacking. Isosteviol sodium (STV-Na) exhibits anti-inflammatory activity and may offer therapeutic benefits in chronic colitis. However, the associated mechanism remains unclear. This study is aimed at exploring the therapeutic effects of STV-Na against chronic colitis in terms of metabolic reprogramming and macrophage polarization. Results show that STV-Na attenuated weight loss and colonic pathological damage and restored the hematological and biochemical parameters in chronic colitis mice models. STV-Na also restored intestinal permeability by increasing the goblet cell numbers, which was accompanied by lowered plasma lipopolysaccharide and diamine oxidase levels. Metabolomic analysis highlighted 102 candidate biomarkers and 5 vital pathways that may be crucial in the potential pharmacological mechanism of STV-Na in regulating intestinal inflammation and oxidative stress. These pathways were glycerophospholipid metabolism, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, the pentose phosphate pathway, and phosphonate and phosphinate metabolism. Furthermore, STV-Na significantly decreased M1 macrophage polarization in the spleen and colon. The mRNA and protein levels of IL-1β, TNF-α, and NF-κB/p65 in colonic tissue from the colitis mice were decreased after the STV-Na treatment. Overall, STV-Na could alleviate chronic colitis by suppressing oxidative stress and inflammation levels, reprogramming the metabolic profile, inhibiting macrophage polarization, and suppressing the NF-κB/p65 signaling pathway. STV-Na remains a promising candidate drug for treating IBDs.