Protective effect of Callistemon citrinus on oxidative stress in rats with 1,2-dimethylhydrazine-induced colon cancer

Use of Callistemon citrinus as a gastroprotective and anti-inflammatory agent on indomethacin-induced gastric ulcers in obese rats

Background

Obesity leads to an elevated risk of developing gastrointestinal disease such as gastric ulcers. Callistemon citrinus leaf extract has shown antioxidant, antimicrobial, hepatoprotective, and chemoprotective effects against colon cancer. The aim of this study is to evaluate the gastroprotective effect of C. citrinus leaf extract on indomethacin-induced gastric ulcers in obese rats.

Methods

Gastric ulcers were induced in female obese Wistar rats using a single oral dose of indomethacin (IND). In the first stage, the rats were fed with a high fat sugar diet (HFSD) for 15 weeks to induce obesity and, at the same time, the diet of the other group of animals included daily administration of ethanolic C. citrinus leaf extract (250 mg/kg) in addition to HFSD. In the second stage, gastric ulcers were induced with IND (30 mg/kg). The gastroprotective activity of C. citrinus, the inflammatory enzyme activities, and cytokines in the stomach were determined.

Results

C. citrinus produced a reduction of gastric lesions caused by IND. Myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) activities also decreased. Although inflammatory biomarkers such as TNFα, IL-6, AOPP, and leptin were significantly decreased by C. citrinus, adiponectin levels increased. Moreover, C. citrinus decreased weight gain and morphological and biochemical parameters.

Conclusion

The use of indomethacin in rats fed with a high fat-sugar diet increased gastric ulcers. Gastroprotective effect of C. citrinus in obese rats is attributed to the reduction of pro-inflammatory cytokines and the inflammatory enzymes.

Development and Evaluation of Phytosomes Containing Callistemon citrinus Leaf Extract: A Preclinical Approach for the Treatment of Obesity in a Rodent Model

Callistemon citrinus has several biological effects; it is anti-inflammatory, anti-obesogenic, antioxidant, hepatoprotection, and chemoprotective. Its bioactive compounds include terpenoids, phenolic acids, and flavonoids which have low oral bioavailability and absorption. This study aimed at developing phytosomes of C. citrinus to improve oral bioavailability and absorption. Phytosomes were formulated with soybean phosphatidylcholine and C. citrinus leaf extract using the thin layer sonication method. Phytosomes were evaluated by scanning electron microscopy (SEM), entrapment efficiency, solubility, and particle size determination. Antioxidant capacity and total phenolic, flavonoid, and terpenoid contents were also measured. The in vivo anti-obesogenic activity was evaluated. Phytosomes loaded with C. citrinus (P C.c) extract had small spherical shapes. The average particle size was 129.98 ± 18.30 nm, encapsulation efficiency 80.49 ± 0.07%, and solubility 90.00%; the stability study presented no significant changes in the average particle size at 20 °C. P C.c presented high antioxidant capacity. For the first time, ellagic acid is reported in this plant. The in vivo obesity study showed a strong anti-obesogenic activity of phytosomes with C. citrinus to reduce 40% body weight as well as morphometric and biochemical parameters.

Evaluation of the toxicology, anti-lipase, and antioxidant effects of Callistemon citrinus in rats fed with a high fat-fructose diet

CONTEXT

Callistemon citrinus Skeels (Myrtaceae) exhibits many biological activities.

OBJECTIVE

This study analyzes for the first time, the toxicity, obesogenic, and antioxidant effects of C. citrinus in rats fed with a high fat-fructose diet (HFFD).

MATERIALS AND METHODS

Four studies using male Wistar rats were conducted: (a) 7 groups (n = 3): control (corn oil) and ethanol extract of C. citrinus leaf (single oral dose at 100-4000 mg/kg) for acute toxicity; (b) 2 groups (n = 8): control (corn oil) and C. citrinus (1000 mg/kg/day) for 28 days for subacute toxicity; (c) 3 groups (n = 4) with single oral dose of lipid emulsion: control (lipid emulsion), C. citrinus and orlistat (250 and 50 mg/kg, respectively) for lipid absorption; (d) 4 groups (n = 6): control (normal diet) and 3 groups fed with HFFD: HFFD only, C. citrinus and simvastatin (oral dose 250 and 3 mg/kg, respectively) for 13 weeks. Antioxidant enzymes and biomarkers were evaluated and inhibition of pancreatic lipase was determined in vitro.

RESULTS

Toxicological studies of C. citrinus showed no differences in biochemical parameters and lethal dose (LD₅₀) was higher than 4000 mg/kg. C. citrinus inhibited pancreatic lipase activity, with IC₅₀ of 392.00 µg/mL, and decreased lipid absorption by 70%. Additionally, it reduced the body weight 22%, restored the activities of antioxidant enzymes, and reduced the biomarkers of oxidative stress.

CONCLUSIONS

Callistemon citrinus showed an effect against oxidative stress by reducing biomarkers and induced antioxidant system, without toxic effects.

Antioxidant and Anticancer Potentials of the Olive and Sesame Mixture against Dimethylhydrazine-Induced Colorectal Cancer in Wistar Rats

Cancer is one of the leading causes of death worldwide, and natural agents have shown some promise in fighting it. Thus, the present study tried to evaluate the healing potential of an equal combination of olive and sesame extract (MOS) against the colorectal cancerous lesions that were induced by dimethylhydrazine (DMH) in male rats and also compare the anticarcinogenic potential of the MOS and vitamin E with each other. Therefore, the mixture of equal olive and sesame extract (MOS) was used as the main treatment, alongside vitamin E as a parallel treatment. This study examined the red blood cell (RBC) and white blood cell (WBC) levels, biochemical indices, lactate dehydrogenase (LDH), C-reactive protein (CRP), total protein (TP), creatine kinase (CPK), albumin, and the colon tissue pathology, as well as the level of protein expression of the adenomatous polyposis coli (APC), proliferating cell nuclear antigen (PCNA), carcinoembryonic antigen (CEA), and platelet-derived growth factor (PDGF). Also, the tissue stress markers including total antioxidant capacity (TAC), malondialdehyde (MDA), and superoxide dismutase (SOD) were analyzed. Overall, the results represented a significant reduction in the congestion, mitotic index, inflammation, and cell destruction in the MOS group compared to the DMH group. In terms of the oxidative stress level, a significant increase was observed in the DMH group in comparison with the DMH-MOS group (P < 0.05), and the MOS significantly increased TAC level (P < 0.05). Furthermore, the DMH+MOS-exposed group exhibited a significantly lower expression of the PCNA, CEA, and PDGF proteins than those of the DMH group. Overall, the MOS showed that it can effectively prevent DMH-induced colon lesions. This mixture, as a strong antioxidant agent, can be clinically applied for preventing and treating colorectal cancer, the effectiveness of which is higher than that of vitamin E.

In Vitro and In Vivo Antioxidant and Anticancer Potentials of Royal Jelly for Dimethylhydrazine-Induced Colorectal Cancer in Wistar Rats

Methods

This study was conducted among 60 rats, and groups consist of control, three separate groups for RJ, dimethylhydrazine (DMH), and vitamin E, and two separate treated groups with DMH + RJ and DMH + vitamin E. Additionally, the cytotoxicity of royal jelly was examined on HT-29 cell line. Findings. Based on the in vitro assessment using MTT assay, the LC50 of royal jelly was 1.781 mg/ml, and the highest cytotoxicity was observed at 25 mg/ml concentration after 48 hours. Meanwhile, in the in vivo study, after the 13th week, compared to the DMH group, the rats exposed to DMH + royal jelly experienced a significant less oxidative stress (P < 0.05) and a significantly greater total antioxidant capacity (TAC) level (P < 0.05). The expression of proliferating cell nuclear antigen (PCNA), platelet-derived growth factor (PDGF), and carcinoembryonic antigen (CEA) proteins significantly decreased among the animals receiving DMH + royal jelly compared to the DMH group. The pathological examinations revealed less congestion, necrosis, inflammation, and cell proliferation in the colon tissue of the RJ-treated group than that of the DMH group. Overall, the biochemical indices were better in the treatment groups in comparison with the DMH group.

Conclusion

The results represented the clinical usability of royal jelly, as a substance with anticancer properties, to prevent and treat colorectal cancer. This issue is related to its effective antioxidant potential, which even exhibits more effectiveness than the vitamin E, which is known as a strong antioxidant.

Anti-inflammatory and Antioxidant Effect of Lycoperoside H against the 1,2-Dimethyl Hydrazine (DMH) Induced Colorectal Cancer in Rats

In many developed countries, colorectal cancer is a leading cause of morbidity and mortality and its etiology is familiar to be a grouping of nutritional and environmental factors, less physical activity and hereditary factors. Lycoperoside H (LH) is a steroidal alkaloid saponin commonly found in the tomato and exhibited the various pharmacological effects. The aim of the current study was to scrutinized the anticancer effect of LH against 1,2‑Dimethyl Hydrazine (DMH) induced colorectal cancer (CRC) in rats. Subcutaneous injection of DMH (20 mg/kg) was used for induction the CRC and rats were received the oral administration of LH (10, 20 and 40 mg/kg) for 16 weeks. At the end of the investigation, the tumor incidence, weight, and body weight were calculated. Antioxidant enzymes (phase I and II), inflammatory cytokines, lipids and inflammatory markers were all examined. DMH induced rats exhibited the increased tumor incidence, reduced body weight and LH treatment significantly (p < 0.001) suppressed the tumor incidence, and enhanced the body weight. LH treatment significantly (p < 0.001) boosted the level of SOD, GPx, GSH, CAT and suppressed the MDA level. LH treatment suppressed the level cytochrome b5 (Cyto b5), cytochrome P450 (Cyto P450) and boosted the level of glutathione S‑transferase (GST), uridine diphosphoglucuronyltransferase (UDP‑GT) in the liver and colon tissue. LH also decreased the level of cytokines includes interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α); inflammatory mediators like Inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin (PGE2) and nuclear factor kappa B (NF-κB) in the hepatic and colon tissue. We can conclude that LH revealed the anticancer effect against the DMH induced CRC via suppression of inflammation and oxidative stress.

Antioxidant and Anticarcinogenic Potentials of Propolis for Dimethylhydrazine-Induced Colorectal Cancer in Wistar Rats

Propolis is a natural compound with anticarcinogenic properties. The present study aimed to compare the inhibitory effect of ethanolic extract of propolis (EEP) and vitamin E on dimethylhydrazine-induced colon lesions in rats. In this study, 60 rats were randomly categorized into six 10-member groups. After 13 weeks, blood and colon tissue were sampled to examine some factors. The parameters included red (RBC) and white (WBC) blood cell profile, lactate dehydrogenase (LDH), C-reactive protein (CRP), total protein (TP), creatine kinase (CPK), and albumin, as well as the extent of colon histological lesions, protein expression (adenomatous polyposis coli (APC), proliferating cell nuclear antigen (PCNA), carcinoembryonic antigen (CEA), and platelet-derived growth factor (PDGF)), and oxidative stress markers (total antioxidant capacity (TAC), malondialdehyde (MDA), and superoxide dismutase (SOD)) in colon tissue. A significant decrease was observed in congestion, mitotic index, inflammation, and cell destruction in colon tissue in dimethylhydrazine group in comparison with the control group (P < 0.05). The EEP exposed rats exhibited a significant lower oxidative stress than the DMH group (P < 0.05). Furthermore, the extract significantly affected TAC level (P < 0.05). While the expression level of APC rose substantially in the EEP-treated group compared to the DMH group, the level of PCNA, CEA, and PDGF proteins significantly reduced. It seems that the EEP can efficiently prevent DMH-induced colonic lesions. Furthermore, its effectiveness is more than the vitamin E, which is a strong antioxidant.

Pharmacological action and underlying molecular mechanism of Callistemon: A genus of promising medicinal herbs

INTRODUCTION

The genus Callistemon belongs to a group of medically significant plants which have found tremendous use in traditional medicine across the globe. They are reported for anti-cancer, neuroprotective, anti-inflammatory, antioxidant, anti-microbial, and many other significant medicinal attributes. However, the current use of this genus is limited mainly to ornamental and recreational purposes. Recent studies have reported several novel compounds like phloroglucinol derivatives, terpenes, phenolics, etc., from Callistemon spp., which have great medical significance. Further, there is a surge of recent studies reporting novel pharmacological properties of Callistemon. The number of review studies discussing the underlying molecular mechanism behind the pharmacological action of Callistemon is quite limited.

METHODS

The literature search for studies published from 1991 to 2021 using Google scholar and PubMed were selected. The review documented relevant literature focused on Callistemon spp exhibiting significant pharmacological effects.

RESULTS

This review deals with the pharmacological properties of Callistemon and the underlying molecular mechanism responsible for protective effect in several pathophysiological conditions. This study updated the current information regarding the medicinal importance of Callistemon spp. for research and the public community.

DISCUSSION AND CONCLUSIONS

The preliminary studies, interrogating pharmacological properties of Callistemon spp., hold great promise and demand further research to decipher the mode of action. More and more research are needed in this direction to explore the full potential of the genus Callistemon as a medicinal herb.

The phloroglucinol calcitrinone A, a novel mitochondria-targeting agent, induces cell death in breast cancer cells

Breast cancer is the most common cancer and the leading cause of cancer-related mortality among females worldwide. From the leaves of Callistemon citrinus, we have isolated a novel phloroglucinol dimer, calcitrinone A, and analyzed its potential anticancer activity using the triple-negative breast cancer cell line MDA-MB-231. Calcitrinone A decreased the total intracellular ATP levels, inhibited proliferation, and induced apoptosis in MDA-MB-231 cells, but was less toxic to peripheral blood mononuclear cells. The antiproliferative and apoptosis-inducing effects of calcitrinone A were confirmed in vivo using breast cancer xenografts grown on chick chorioallantoic membranes. Mechanistic analysis showed mitochondrial membrane-potential dissipation and interference with energy-yielding processes resulting in cell accumulation in the S phase of the cell cycle. Seahorse assay analysis revealed an early inhibition of mitochondrial oxidative phosphorylation (OXPHOS). At the molecular level, calcitrinone A inhibited activity of the succinate-coenzyme Q reductase (SQR) (mitochondrial complex II). In silico docking identified the coenzyme Q binding pocket as a possible high affinity binding site for calcitrinone A in SQR. Inhibition of complex II was accompanied by strong elevation of mitochondrial superoxide and cytoplasmic ROS. Calcitrinone A might be a promising anticancer lead compound acting through the interference with the mitochondrial complex II activity.