Anti-colonic Inflammation by Black Raspberries through Regulating Toll-like Receptor-4 Signaling in Interlukin-10 Knockout Mice

Rubus Occidentalis and its bioactive compounds against cancer: From molecular mechanisms to translational advances

BACKGROUND

Cancer ranks as the second leading cause of death globally, imposing a significant public health burden. The rise in cancer resistance to current therapeutic agents underscores the potential role of phytotherapy. Black raspberry (BRB, Rubus Occidentalis) is a fruit rich in anthocyanins, ellagic acid, and ellagitannins. Accumulating evidence suggests that BRB exhibits promising anticancer effects, positioning it as a viable candidate for phytotherapy.

PURPOSE

This article aims to review the existing research on BRB regarding its role in cancer prevention and treatment. It further analyzes the effective components of BRB, their metabolic pathways, and the potential mechanisms underlying the fruit's anticancer effects.

METHODS

Ovid MEDLINE, EMBASE, Web of Science, and CENTRAL were searched through the terms of Black Raspberry, Raspberry, and Rubus Occidentali up to January 2023. Two reviewers performed the study selection by screening the title and abstract. Full texts of potentially eligible studies were retrieved to access the details.

RESULTS

Out of the 767 articles assessed, 73 papers met the inclusion criteria. Among them, 63 papers investigated the anticancer mechanisms, while 10 conducted clinical trials focusing on cancer treatment or prevention. BRB was found to influence multiple cancer hallmarks by targeting various pathways. Decomposition of free radicals and regulation of estrogen metabolism, BRB can reduce DNA damage caused by reactive oxygen species. BRB can also enhance the function of nucleotide excision repair to repair DNA lesions. Through regulation of epigenetics, BRB can enhance the expression of tumor suppressor genes, inducing cell cycle arrest, and promoting apoptosis and pyroptosis. BRB can reduce the energy and nutrients supply to the cancer nest by inhibiting glycolysis and reducing angiogenesis. The immune and inflammatory microenvironment surrounding cancer cells can also be ameliorated by BRB, inhibiting cancer initiation and progression. However, the limited bioavailability of BRB diminishes its anticancer efficacy. Notably, topical applications of BRB, such as gels and suppositories, have demonstrated significant clinical benefits.

CONCLUSION

BRB inhibits cancer initiation, progression, and metastasis through diverse anticancer mechanisms while exhibiting minimal side effects. Given its potential, BRB emerges as a promising phototherapeutic agent for cancer treatment.

Berries vs. Disease: Revenge of the Phytochemicals

Secondary metabolites and phytochemicals in plant-based diets are known to possess properties that inhibit the development of several diseases including a variety of cancers of the aerodigestive tract. Berries are currently of high interest to researchers due to their high dietary source of phytochemicals. Black raspberries (BRB), Rubus occidentalis, are of special interest due to their rich and diverse composition of phytochemicals. In this review, we present the most up-to-date preclinical and clinical data involving berries and their phytochemicals in the chemoprevention of a variety of cancers and diseases. BRBs possess a variety of health benefits including anti-proliferative properties, anti-inflammatory activity, activation of pro-cell-death pathways, modulation of the immune response, microbiome modulation, reduction in oxidative stress, and many more. However, little has been done in both preclinical and clinical settings on the effects of BRB administration in combination with other cancer therapies currently available for patients. With the high potential for BRBs as chemopreventive agents, there is a need to investigate their potential in combination with other treatments to improve therapeutic efficacy.

Therapeutic Effects of Oral Application of Menthol and Extracts from Tormentil (Potentilla erecta), Raspberry Leaves (Rubus idaeus), and Loosestrife (Lythrum salicaria) during Acute Murine Campylobacteriosis

Human food-borne infections with the enteropathogen Campylobacter jejuni are becoming increasingly prevalent worldwide. Since antibiotics are usually not indicated in campylobacteriosis, alternative treatment regimens are important. We here investigated potential disease-alleviating effects of menthol and of extracts from tormentil, raspberry leaves, and loosestrife in acute murine campylobacteriosis. Therefore, C. jejuni-infected microbiota-depleted IL-10-/- mice were orally treated with the compounds alone or all in combination from day 2 until day 6 post-infection. Whereas neither treatment regimen affected gastrointestinal pathogen loads, the combination of compounds alleviated C. jejuni-induced diarrheal symptoms in diseased mice on day 6 post-infection. Furthermore, the therapeutic application of tormentil and menthol alone and the combination of the four compounds resulted in lower colonic T cell numbers in infected mice when compared to placebo counterparts. Notably, pro-inflammatory cytokines measured in mesenteric lymph nodes taken from C. jejuni-infected mice following tormentil, menthol, and combination treatment did not differ from basal concentrations. However, neither treatment regimen could dampen extra-intestinal immune responses, including systemic pro-inflammatory cytokine secretion on day 6 post-infection. In conclusion, the combination of menthol and of extracts from tormentil, raspberry leaves, and loosestrife constitutes an antibiotic-independent approach to alleviate campylobacteriosis symptoms.

Berry Extracts and Their Bioactive Compounds Mitigate LPS and DNFB-Mediated Dendritic Cell Activation and Induction of Antigen Specific T-Cell Effector Responses

Berries have gained widespread recognition for their abundant natural antioxidant, anti-inflammatory, and immunomodulatory properties. However, there has been limited research conducted thus far to investigate the role of the active constituents of berries in alleviating contact hypersensitivity (CHS), the most prevalent occupational dermatological disease. Our study involved an ex vivo investigation aimed at evaluating the impact of black raspberry extract (BRB-E) and various natural compounds found in berries, such as protocatechuic acid (PCA), proanthocyanidins (PANT), ellagic acid (EA), and kaempferol (KMP), on mitigating the pathogenicity of CHS. We examined the efficacy of these natural compounds on the activation of dendritic cells (DCs) triggered by 2,4-dinitrofluorobenzene (DNFB) and lipopolysaccharide (LPS). Specifically, we measured the expression of activation markers CD40, CD80, CD83, and CD86 and the production of proinflammatory cytokines, including Interleukin (IL)-12, IL-6, TNF-α, and IL-10, to gain further insights. Potential mechanisms through which these phytochemicals could alleviate CHS were also investigated by investigating the role of phospho-ERK. Subsequently, DCs were co-cultured with T-cells specific to the OVA323-339 peptide to examine the specific T-cell effector responses resulting from these interactions. Our findings demonstrated that BRB-E, PCA, PANT, and EA, but not KMP, inhibited phosphorylation of ERK in LPS-activated DCs. At higher doses, EA significantly reduced expression of all the activation markers studied in DNFB- and LPS-stimulated DCs. All compounds tested reduced the level of IL-6 in DNFB-stimulated DCs in Flt3L as well as in GM-CSF-derived DCs. However, levels of IL-12 were reduced by all the tested compounds in LPS-stimulated Flt3L-derived BMDCs. PCA, PANT, EA, and KMP inhibited the activated DC-mediated Interferon (IFN)-γ and IL-17 production by T-cells. Interestingly, PANT, EA, and KMP significantly reduced T-cell proliferation and the associated IL-2 production. Our study provides evidence for differential effects of berry extracts and natural compounds on DNFB and LPS-activated DCs revealing potential novel approaches for mitigating CHS.

Metabolomics Study of Shaoyao Plants Decoction on the Proximal and Distal Colon in Mice with Dextran Sulfate Sodium-Induced Colitis by UPLC-Q-TOF-MS

Purpose

Shaoyao decoction (SYD) is a traditional Chinese medicine used to treat ulcerative colitis (UC). The exact mechanism of action of SYD in UC treatment is still unclear. Here, we examined the therapeutic effects of SYD in mice with dextran sulfate sodium (DSS)-induced colitis and explored the underlying mechanism.

Methods

The experimental group was divided into normal control, UC, and SYD treatment groups. The UC model of C57BL/6 mice was induced using 3% (w/v) DSS for 7 days. SYD was orally administered for 7 days. The proximal and distal colonic metabolic profiles were detected using quadrupole-time-of-flight mass spectrometry-based untargeted metabolomics.

Results

SYD significantly increased weight, reduced disease activity index scores, and ameliorated colon length shortening and pathological damage in mice. In the distal colon, SYD increased the abundance of phosphatidic acid and lysophosphatidylethanolamine and decreased the abundance of lactosylceramide, erythrodiol 3-palmitate, and lysophosphatidylcholine. In the proximal colon, SYD increased the abundance of palmitic acid, cyclonormammein, monoacylglyceride, 13S-hydroxyoctadecadienoic acid, and ceanothine C and decreased the abundance of tetracosahexaenoic acid, phosphatidylserine, and diglyceride.

Conclusion

Our findings revealed that SYD could alleviate UC by regulating metabolic dysfunction, which provides a reference for further studies on SYD.

Dietary Supplementation with Black Raspberries Altered the Gut Microbiome Composition in a Mouse Model of Colitis-Associated Colorectal Cancer, although with Differing Effects for a Healthy versus a Western Basal Diet

Black raspberries (BRB) are rich in anthocyanins with purported anti-inflammatory properties. However, it is not known whether dietary supplementation would ameliorate Western-diet enhanced gut inflammation and colon tumorigenesis. We employed a mouse model of colitis-associated colorectal cancer (CAC) to determine the effects of dietary supplementation with 5 to 10% (w/w) whole, freeze-dried BRB in male C57BL/6J mice fed either a standard healthy diet (AIN93G) or the total Western diet (TWD). In a pilot study, BRB suppressed colitis and colon tumorigenesis while also shifting the composition of the fecal microbiome in favor of taxa with purported health benefits, including Bifidobacterium pseudolongum. In a follow-up experiment using a 2 × 2 factorial design with AIN and TWD basal diets with and without 10% (w/w) BRB, supplementation with BRB reduced tumor multiplicity and increased colon length, irrespective of the basal diet, but it did not apparently affect colitis symptoms, colon inflammation or mucosal injury based on histopathological findings. However, BRB intake increased alpha diversity, altered beta diversity and changed the relative abundance of Erysipelotrichaceae, Bifidobacteriaceae, Streptococcaceae, Rikenellaceae, Ruminococcaceae and Akkermansiaceae, among others, of the fecal microbiome. Notably, changes in microbiome profiles were inconsistent with respect to the basal diet consumed. Overall, these studies provide equivocal evidence for in vivo anti-inflammatory effects of BRB on colitis and colon tumorigenesis; yet, BRB supplementation led to dynamic changes in the fecal microbiome composition over the course of disease development.