Successful Treatment of Acute Radiation Proctitis with Aloe Vera: A Preliminary Randomized Controlled Clinical Trial

Emodin ameliorates acute radiation proctitis in mice by regulating AKT/MAPK/NF-κB/VEGF pathways

BACKGROUND

Emodin, a natural anthraquinone derivative isolated from the roots of Rheum officinale Baill, has many pharmacological effects including anti-inflammatory, antioxidant, antiviral, antibacterial and anti-cancer. However, little is known about the effect of emodin on acute radiation proctitis (ARP). The present study was conducted to determine its effects and elucidate its mechanisms involving AKT/MAPK/NF-κB/VEGF pathways in ARP mice.

METHODS

Total 60 C57BL/6 mice were divided randomly into control group, ARP group, AKT inhibitor MK-2206 group, and different doses of emodin groups. ARP mice were induced by 27 Gy of 6 MV X-ray pelvic local irradiation. MK-2206 was given orally for 2 weeks on alternate days. Emodin was administered daily by oral gavage for 2 weeks. Subsequently, all mice were sacrificed on day 15. The rectal tissues were obtained for further tests. The general signs score and the pathological grade were used to evaluate the severity of ARP. The expression of NF-κB, VEGF and AQP1 were determined by immunohistochemistry and western blot. The expression of p-AKT, p-ERK, p-JNK, p-p38, Bcl-2 and Bax were assessed using western blot.

RESULTS

The worse general signs and damaged tissue structure of ARP mice were profoundly ameliorated by emodin. The expression of p-AKT, p-ERK, NF-κB, VEGF and AQP1 were significantly increased, resulting in the inflammation-induced angiogenesis in ARP mice. However, the expression of p-JNK and p-p38 were decreased, leading to the reduction of apoptosis in ARP mice. Excitedly, emodin reversed these changes, not only inhibited inflammation-induced angiogenesis, but also promoted apoptosis. Notably, the effects of emodin were similar to that of AKT inhibitor MK-2206, suggesting the involvement of AKT signaling in the effect of emodin.

CONCLUSION

These results suggest that emodin attenuates ARP in mice, and the underlying mechanism might involve inhibition of the AKT/ERK/NF-κB/VEGF pathways and the induction of apoptosis mediated by JNK and p38.

Novel mechanisms underlying inhibition of inflammation-induced angiogenesis by dexamethasone and gentamicin via PI3K/AKT/NF-κB/VEGF pathways in acute radiation proctitis

Acute radiation proctitis (ARP) is one of the most common complications of pelvic radiotherapy attributed to radiation exposure. The mechanisms of ARP are related to inflammation, angiogenesis, and so on. In this study we evaluated the effect of dexamethasone (DXM) combined with gentamicin (GM) enema on ARP mice, and explored its possible mechanisms by transcriptome sequencing, western blot and immunohistochemistry. C57BL/6 mice were randomly divided into 3 groups: healthy control group, ARP model group, and DXM + GM enema treatment group. ARP mice were established by using a single 6 MV X-ray dose of 27 Gy pelvic local irradiation. Transcriptome sequencing results showed that 979 genes were co-upregulated and 445 genes were co-downregulated in ARP mice compared to healthy mice. According to gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis, we firstly found that PI3K/AKT/NF-κB/VEGF pathways were mostly correlated with the inflammation-induced angiogenesis in ARP mice. PI3K/AKT pathway leads to the activation of NF-κB, which promotes the transcription of VEGF and Bcl-2. Interestingly, symptoms and pathological changes of ARP mice were ameliorated by DXM + GM enema treatment. DXM + GM enema inhibited inflammation by downregulating NF-κB and upregulating AQP3, as well as inhibited angiogenesis by downregulating VEGF and AQP1 in ARP mice. Moreover, DXM + GM enema induced apoptosis by increasing Bax and suppressing Bcl-2. The novel mechanisms may be related to the downregulation of PI3K/AKT/NF-κB/VEGF pathways.

Aloe vera gel extract: Safety evaluation for acute and chronic oral administration in Sprague-Dawley rats and anticancer activity in breast and lung cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe vera (L.) Burm. f. is a typical traditional Chinese medicine (TCM) collected in the Pharmacopoeia of the People's Republic of China (version 2015). It has been traditionally used for the treatment of constipation, and its potential therapeutic activities have been widely evaluated, including anti-tumor, anti-inflammatory and immune regulatory effects. The wide application of Aloe vera in food and therapy has raised safety issues and there are multiple safety assessments with a diverse toxicity and adverse effects from clinics and animals.

AIM OF THE STUDY

This study aimed to investigate the safety of Aloe vera barbadensis extract C (AVBEC) in rats and analyze its anticancer activity in cell lines.

MATERIALS AND METHODS

We administrated AVBEC orally in an acute toxicity study and a 6-month chronic toxicity study to observe and confirm its safety in Sprague-Dawley (SD) rats. Additionally, we explored the cytotoxicity of AVBEC in cancer cells and non-cancer cells. We further investigated the anti-tumor activity of AVBEC, and in the meantime, probed the function of component from AVBEC.

RESULTS

No deaths or substance-relative toxicity were observed in the acute toxicity study or the 6-month chronic toxicity study with doses of 44.8 g·kg^-1 and 4.48 g·kg^-1, respectively. In the chronic toxicity study, AVBEC did not cause organ toxicity, including crucial organ structure and chemical function, and peripheral and central immune system damage. Additionally, we found that AVBEC could induce cancer cell apoptosis with a relatively higher apoptotic ratio than in non-cancer cells by decreasing adenosine triphosphate (ATP) concentration and enhancing reactive oxygen species (ROS) production. We also identified components in AVBEC using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) and probed the function of malic acid. This demonstrated that under the same circumstances, malic acid induced cell necrosis in cancer cells and non-cancer cells, while AVBEC did not.

CONCLUSIONS

These results reveal a novel mechanism of aloe gel extract in regulating cancer cell apoptosis via modulating the mitochondrial metabolism and imply a possible application of AVBEC for the treatment of malignant cancer with the safety evaluation from rats and anticancer investigation from cancer cells and non-cancer cells.

Pharmacological Interventions for the Prevention and Treatment of Kidney Injury Induced by Radiotherapy: Molecular Mechanisms and Clinical Perspectives

More than half of cancer patients need radiotherapy during the course of their treatment. Despite the beneficial aspects, the destructive effects of radiation beams on normal tissues lead to oxidative stress, inflammation, and cell injury. Kidneys are affected during radiotherapy of abdominal malignancies. Radiation nephropathy eventually leads to the release of factors triggering systemic inflammation. Currently, there is no proven prophylactic or therapeutic intervention for the management of radiation-induced nephropathy. This article reviews the biomarkers involved in the pathophysiology of radiation-induced nephropathy and its underlying molecular mechanisms. The efficacy of compounds with potential radio-protective properties on amelioration of inflammation and oxidative stress is also discussed. By outlining the approaches for preventing and treating this critical side effect, we evaluate the potential treatment of radiation-induced nephropathy. Available preclinical and clinical studies on these compounds are also scrutinized.

Efficacy of sucralfate ointment in the prevention of acute proctitis in cancer patients: A randomized controlled clinical trial

Background:

Acute radiation proctitis (ARP) is a usual adverse effect in patients undergoing pelvic radiotherapy. The symptoms include diarrhea, rectal blood or mucus discharge, fecal urgency and tenesmus with pain. Sucralfate, an aluminum-based salt of sucrose octasulfate, is a cytoprotective agent that forms a coating barrier at injured sites by adhering to mucoproteins. It has been used in topical management of a wide variety of local lesion. This study was designed to evaluate the preventive effect of rectal sucralfate on acute radiotherapy induced proctitis.

Methods:

Seven percent sucralfate ointment was prepared for topical use. Drug quantification, chemical stability and microbial limit tests were performed carefully. In this randomized double blind placebo controlled trial, fifty-seven patients with pelvic malignancies undergoing radiotherapy were allocated to receive either 1 g of sucralfate or 1 g of placebo, given as a twice daily ointment, one day before and during radiotherapy for six weeks. The eligible patients were evaluated based on RTOG acute toxicity criteria and the following ARP symptoms weekly: rectal hemorrhage, diarrhea, rectal pain, and fecal urgency. The influence of symptoms on lifestyle was also recorded weekly.

Results:

Acute proctitis was significantly less prevalent in patients in the sucralfate group. The incidence of rectal bleeding (P=0.003), diarrhea (P=0.002), rectal pain (P=<0.001) and fecal urgency (P=0.002) was significantly less common in the sucralfate group. No statistical significant difference was observed for radiotherapy induced cystitis in the placebo and sucralfate groups (P=0.27).

Conclusion:

This study suggests that sucralfate7% ointment reduces the incidence of symptoms associated with acute radiation proctitis.

Aloe vera for Prevention of Acute Radiation Proctitis in Colorectal Cancer a Preliminary Randomized, Placebo-Controlled Clinical Trial

OBJECTIVE

To examine the preventive effects of Aloe vera in colorectal cancer patients undergoing radiotherapy.

MATERIAL AND METHOD

Twenty colorectal cancer patients, who received radiation, were randomized to receive Aloe vera 3% or placebo ointment, 1 g twice daily for 6 weeks. At weekly visits, acute radiation proctitis (ARP) was evaluated by Radiation Therapy Oncology Group and clinical presentation criteria as the primary endpoint. We also evaluated secondary endpoints of quality of life, psychosocial status, by applying Hospital Anxiety-Depression (HAD) Scale and laboratory measures of quantitative measurement of C-reactive protein (CRP) as a marker for systemic inflammation.

RESULTS

There was a significant improvement in the symptom index (before treatment vs. after treatment with Aloe vera) for diarrhea (p = 0.029, median score: 0.5 vs. 0.001). The overall primary and secondary outcomes favored Aloe group, while the measures of toxicity did not achieve a statistical significant difference. The lifestyle score improved significantly with A. vera (p = 004), and they also had a lower depression score in HAD scale (p = 0.008). Furthermore, quantitative CRP decreased significantly during the course of treatment with Aloe vera.

CONCLUSION

The use of topical formulation of Aloe vera 3% diminishes the severity of ARP in colorectal cancer patients.

Quality Evaluation of the Clinical Trials for Natural Products Used in Cancer: An Evidence-Based Literature Review

The amount of data regarding the use of herbs/herbal products in cancer clinical trials at times creates a great challenge for oncologists to prescribe or counsel patients. It urges critical evaluation of the quality of clinical trials. Herein, for the first time, the clinical trials for herbs used in cancer were critically evaluated on the basis of three widely used scales, i.e., Jadad, Delphi, and Cochrane scales. The literature was collected with the help of online databases, journals, libraries, and books using a number of specific keywords as mentioned in detail in forthcoming sections. A total of 73 clinical trials were extracted, evaluated, and scored for 14 herbs, according to the predefined criteria mentioned below. A major deficiency of “non-blinding of clinical trials” was observed. The principal component analysis revealed four components (PC1–PC4) with a total variability of 68.21%, wherein the highest percentage variability was observed for PC1 loaded with “non-blinding of the clinical trials, no concealment of the treatment allocation, non-blindness of the patient and care provider”, which accounted for 30.81% of the total variability. The next major variability of 14.70% was observed for PC2 loaded with “non-randomization of the studies, non-blinding of the outcome assessors, no proper drop-out procedures, and lack of information regarding baseline characteristics for the groups”. Pearson’s correlation further confirmed a similar correlation pattern for the mentioned deficiencies (p = 0.05). An in-house grading scale was developed, showing a very small portion (16.44%), i.e., 12/73 studies with a good quality, whereas the majority (57.54%) of the studies, i.e., 42/73, were found to be of poor quality. The rules and regulations governing the quality of clinical trials needs to be more stringent and updated for the natural products/herbs used in cancer clinical trials.

Plant Extracts as Possible Agents for Sequela of Cancer Therapies and Cachexia

Cancer is a leading cause of the death worldwide. Since the National Cancer Act in 1971, various cancer treatments were developed including chemotherapy, surgery, radiation therapy and so forth. However, sequela of such cancer therapies and cachexia are problem to the patients. The primary mechanism of cancer sequela and cachexia is closely related to reactive oxygen species (ROS) and inflammation. As antioxidant properties of numerous plant extracts have been widely reported, plant-derived drugs may have efficacy on managing the sequela and cachexia. In this study, recent seventy-four studies regarding plant extracts showing ability to manage the sequela and cachexia were reviewed. Some plant-derived antioxidants inhibited cancer proliferation and inflammation after surgery and others prevented chemotherapy-induced normal cell apoptosis. Also, there are plant extracts that suppressed radiation-induced oxidative stress and cell damage by elevation of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and regulation of B-cell lymphoma 2 (BcL-2) and Bcl-2-associated X protein (Bax). Cachexia was also alleviated by inhibition of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) by plant extracts. This review focuses on the potential of plant extracts as great therapeutic agents by controlling oxidative stress and inflammation.

RENISUS Plants and Their Potential Antitumor Effects in Clinical Trials and Registered Patents

Cancer is a significant cause of morbidity and mortality. Scientific advances, coupled with potential flaws in current treatments, are driving research into the discovery of new bioactive molecules. This systematic review focused on scientific studies with clinical trials and patents registered on the National Relation of Medicinal Plants of Interest to the Unified Health System (RENISUS) plants (or derivative compounds) with antitumor potential. Studies with 19 different forms of cancer were found, the prostate being the organ with the highest research incidence and the species Glycine max, Curcuma longa, and Zingiber officinale, beside the phytochemicals curcumin and soy isoflavone were the most tested in clinical trials/patents.

Changrui enema inhibits inflammation-induced angiogenesis in acute radiation proctitis by regulating NF-κB and VEGF

Purpose

Changrui enema, a traditional Chinese medicine prescription, is used as a supplementary treatment for acute radiation proctitis (ARP). Herein we explored the inhibition effects of Changrui enema on NF-κB and VEGF in ARP mice.

Methods

A total of 120 C57BL/6 mice were divided randomly into normal mice group, ARP mice group, western medicine enema group (dexamethasone combined with gentamicin), and Changrui enema group. ARP mice were established by pelvic local irradiation. The expression of IL-1β, NF-κB, VEGF, AQP1, AQP3, p-ERK1/2 and p-JNK was determined by immunohistochemistry or western blot.

Results

The study firstly found that Changrui enema alleviated ARP mice. The expression of IL-1β, NF-κB, VEGF, AQP1 and p-ERK1/2 was increased in ARP mice, and was reserved by Changrui enema. However, the expression of AQP3 and p-JNK was decreased in ARP mice, and was up-regulated by Changrui enema.

Conclusions

Changrui enema is an effective treatment with fewer side effects for ARP. The mechanism of Changrui enema may be related to the inhibition of inflammation-induced angiogenesis. Changrui enema inhibits IL-1β and NF-κB expression as well as VEGF expression. Interestingly, AQP1 promotes angiogenesis, while AQP3 inhibits inflammation. Changrui enema probably inhibits AQP1 expression by down-regulating p-ERK1/2, and improves AQP3 expression by up-regulating p-JNK.

Prevention of acute radiation-induced Proctitis by Aloe vera: a prospective randomized, double-blind, placebo controlled clinical trial in Pelvic Cancer patients

Background

Acute radiation-induced proctitis (ARP) is the most common side effect following radiotherapy for malignant pelvic disease. This study evaluated the efficacy of Aloe vera ointment in prevention of ARP.

Methods

Forty-two patients receiving external-beam radiotherapy (RT) for pelvic malignancies were randomized to receive either Aloe vera 3% or placebo topical ointment during radiotherapy for 6 weeks. These patients were evaluated based on the severity (grade 0–4) of the following symptoms weekly: rectal bleeding, abdominal/rectal pain, diarrhea, or fecal urgency. RTOG acute toxicity criteria and psychosocial status of the patients were also recorded weekly. Lifestyle impact of the symptoms, and quantitative measurement of C-reactive protein (CRP), an indicator of systemic inflammation, were also measured.

Results

The results of present study demonstrated a significant preventive effect for Aloe vera in occurrence of symptom index for diarrhea (p < 0.001), rectal bleeding (p < 0.001), and fecal urgency (p = 0.001). The median lifestyle score improved significantly with Aloe vera during RT (p < 0.001). Intervention patients had a significant lower burden of systemic inflammation as the values for quantitative CRP decreased significantly over 6 weeks of follow-up (p = 0.009).

Conclusion

This study showed that Aloe vera topical ointment was effective in prevention of symptoms of ARP in patients undergoing RT for pelvic cancers.

Trial registration

IRCT201606042027N6. Registration date: 2016-09-04.

Pharmacological Update Properties of Aloe Vera and its Major Active Constituents

Aloe vera has been traditionally used to treat skin injuries (burns, cuts, insect bites, and eczemas) and digestive problems because its anti-inflammatory, antimicrobial, and wound healing properties. Research on this medicinal plant has been aimed at validating traditional uses and deepening the mechanism of action, identifying the compounds responsible for these activities. The most investigated active compounds are aloe-emodin, aloin, aloesin, emodin, and acemannan. Likewise, new actions have been investigated for Aloe vera and its active compounds. This review provides an overview of current pharmacological studies (in vitro, in vivo, and clinical trials), written in English during the last six years (2014–2019). In particular, new pharmacological data research has shown that most studies refer to anti-cancer action, skin and digestive protective activity, and antimicrobial properties. Most recent works are in vitro and in vivo. Clinical trials have been conducted just with Aloe vera, but not with isolated compounds; therefore, it would be interesting to study the clinical effect of relevant metabolites in different human conditions and pathologies. The promising results of these studies in basic research encourage a greater number of clinical trials to test the clinical application of Aloe vera and its main compounds, particularly on bone protection, cancer, and diabetes.

Therapeutic potential of medicinal plants indicated by the Brazilian public health system in treating the collateral effects induced by chemotherapy, radiotherapy, and chemoradiotherapy: A systematic review

OBJECTIVE

This study, through a systematic review, evaluated the therapeutic effect of medicinal plants that were of interest to the Unified Health System (SUS) in treating the side effects induced by chemotherapy, radiotherapy and chemoradiotherapy in cancer patients.

METHODOLOGY

According to the PRISMA guidelines, a systematic search was conducted in the PubMed, Lilacs and Scopus databases from January 2009 to December 2018, using the groups of descriptors (Cancer OR Neoplasia OR Tumor) and (controlled clinical trial OR randomized clinical trial) associated with the scientific names of the 71 medicinal plants described in RENISUS. The study is registered in PROSPERO CRD42019129927.

RESULTS

Of the 29 articles selected, only 17 demonstrated the therapeutic potential of plants included in RENISUS to prevent or treat the side effects induced by chemotherapy, radiotherapy or chemoradiotherapy, either solely or through an adjuvant effect from drugs already used in the medical clinic. The two plant-based therapies that had the most studies exploring their therapeutic potential on side effects were Zingiber officinale and Aloe vera.

CONCLUSION

This study showed that some plants listed in RENISUS have shown preventive and curative potential on side effects induced by conventional treatments in patients with different types of cancer. Therefore, the use of scientifically proven herbal products, in conjunction with conventional therapies, can contribute to a better quality of life in cancer patients undergoing conventional treatments.

Therapeutic potential of natural plant products and their metabolites in preventing radiation enteropathy resulting from abdominal or pelvic irradiation

Radiation-induced gastrointestinal injury or radiation enteropathy is an imminent risk during radiation therapy of abdominal or pelvic tumors. Despite remarkable technological advancements in image-guided radiation delivery techniques, the risk of intestinal injury after radiotherapy for abdominal or pelvic cancers has not been completely eliminated. The irradiated intestine undergoes varying degrees of adverse structural and functional changes, which can result in transient or long-term complications. The risk of development of enteropathy depends on dose, fractionation, and quality of radiation. Moreover, the patients' medical condition, age, inter-individual sensitivity to radiation and size of the treatment area are also risk factors of radiation enteropathy. Therefore, strategies are needed to prevent radiotherapy-induced undesirable alteration in the gastrointestinal tract. Many natural plant products, by virtue of their plethora of biological activities, alleviate the adverse effects of radiation-induced injury. The current review discusses potential roles and possible mechanisms of natural plant products in suppressing radiation enteropathy. Natural plant products have the potential to suppress intestinal radiation toxicity.

Natural Product Interventions for Chemotherapy and Radiotherapy-Induced Side Effects

Cancer is the second leading cause of death in the world. Chemotherapy and radiotherapy are the common cancer treatments. However, the development of adverse effects resulting from chemotherapy and radiotherapy hinders the clinical use, and negatively reduces the quality of life in cancer patients. Natural products including crude extracts, bioactive components-enriched fractions and pure compounds prepared from herbs as well as herbal formulas have been proved to prevent and treat cancer. Of significant interest, some natural products can reduce chemotherapy and radiotherapy-induced oral mucositis, gastrointestinal toxicity, hepatotoxicity, nephrotoxicity, hematopoietic system injury, cardiotoxicity, and neurotoxicity. This review focuses in detail on the effectiveness of these natural products, and describes the possible mechanisms of the actions in reducing chemotherapy and radiotherapy-induced side effects. Recent advances in the efficacy of natural dietary supplements to counteract these side effects are highlighted. In addition, we draw particular attention to gut microbiotan in the context of prebiotic potential of natural products for the protection against cancer therapy-induced toxicities. We conclude that some natural products are potential therapeutic perspective for the prevention and treatment of chemotherapy and radiotherapy-induced side effects. Further studies are required to validate the efficacy of natural products in cancer patients, and elucidate potential underlying mechanisms.