Formulation and in-vitro and in-vivo evaluation of a mucoadhesive gel containing freeze dried black raspberries: implications for oral cancer chemoprevention

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.

Beyond traditional therapy: Mucoadhesive polymers as a new frontier in oral cancer management

In recent times mucoadhesive drug delivery systems are gaining popularity in oral cancer. It is a malignancy with high global prevalence. Despite significant advances in cancer therapeutics, improving the prognosis of late-stage oral cancer remains challenging. Targeted therapy using mucoadhesive polymers can improve oral cancer patients' overall outcome by offering enhanced oral mucosa bioavailability, better drug distribution and tissue targeting, and minimizing systemic side effects. Mucoadhesive polymers can also be delivered via different formulations such as tablets, films, patches, gels, and nanoparticles. These polymers can deliver an array of medicines, making them an adaptable drug delivery approach. Drug delivery techniques based on these mucoadhesive polymers are gaining traction and have immense potential as a prospective treatment for late-stage oral cancer. This review examines leading research in mucoadhesive polymers and discusses their potential applications in treating oral cancer.

Dried Fruits, Nuts, and Cancer Risk and Survival: A Review of the Evidence and Future Research Directions

Dried fruits and nuts contain high amounts of nutrients and phytochemicals-all of which may have anticarcinogenic, anti-inflammatory, and antioxidant properties. This narrative review summarizes the evidence for dried fruits and nuts and cancer incidence, mortality, and survival and their potential anticancer properties. The evidence for dried fruits in cancer outcomes is limited, but existing studies have suggested an inverse relationship between total dried fruit consumption and cancer risk. A higher consumption of nuts has been associated with a reduced risk of several site-specific cancers in prospective cohort studies, including cancers of the colon, lung, and pancreas, with relative risks per 5 g/day increment equal to 0.75 (95% CI 0.60, 0.94), 0.97 (95% CI 0.95, 0.98), and 0.94 (95% CI 0.89, 0.99), respectively. A daily intake of total nuts of 28 g/day has also been associated with a 21% reduction in the rate of cancer mortality. There is also some evidence that frequent nut consumption is associated with improved survival outcomes among patients with colorectal, breast, and prostate cancer; however, further studies are needed. Future research directions include the investigation of additional cancer types, including rare types of cancer. For cancer prognosis, additional studies with pre- and postdiagnosis dietary assessment are warranted.

Flavonoids as Potential Wound-Healing Molecules: Emphasis on Pathways Perspective

Wounds are considered to be a serious problem that affects the healthcare sector in many countries, primarily due to diabetes and obesity. Wounds become worse because of unhealthy lifestyles and habits. Wound healing is a complicated physiological process that is essential for restoring the epithelial barrier after an injury. Numerous studies have reported that flavonoids possess wound-healing properties due to their well-acclaimed anti-inflammatory, angiogenesis, re-epithelialization, and antioxidant effects. They have been shown to be able to act on the wound-healing process via expression of biomarkers respective to the pathways that mainly include Wnt/β-catenin, Hippo, Transforming Growth Factor-beta (TGF-β), Hedgehog, c-Jun N-Terminal Kinase (JNK), NF-E2-related factor 2/antioxidant responsive element (Nrf2/ARE), Nuclear Factor Kappa B (NF-κB), MAPK/ERK, Ras/Raf/MEK/ERK, phosphatidylinositol 3-kinase (PI3K)/Akt, Nitric oxide (NO) pathways, etc. Hence, we have compiled existing evidence on the manipulation of flavonoids towards achieving skin wound healing, together with current limitations and future perspectives in support of these polyphenolic compounds as safe wound-healing agents, in this review.

Novel Strategies for the Bioavailability Augmentation and Efficacy Improvement of Natural Products in Oral Cancer

Oral cancer is emerging as a major cause of mortality globally. Oral cancer occupies a significant proportion of the head and neck, including the cheeks, tongue, and oral cavity. Conventional methods in the treatment of cancer involve surgery, radiotherapy, and immunotherapy, and these have not proven to completely eradicate cancerous cells, may lead to the reoccurrence of oral cancer, and possess numerous adverse side effects. Advancements in novel drug delivery approaches have gained popularity in cancer management with an increase in the number of cases associated with oral cancer. Natural products are potent sources for drug discovery, especially for anticancer drugs. Natural product delivery has major challenges due to its low solubility, poor absorption, inappropriate size, instability, poor permeation, and first-pass metabolism. Therefore, it is of prime importance to investigate novel treatment approaches for the delivery of bioactive natural products. Nanotechnology is an advanced method of delivering cancer therapy with minimal damage to normal cells while targeting cancer cells. Therefore, the present review elaborates on the advancements in novel strategies for natural product delivery that lead to the significant enhancement of bioavailability, in vivo activity, and fewer adverse events for the prevention and treatment of oral cancer. Various approaches to accomplish the desired results involve size reduction, surface property modification, and polymer attachment, which collectively result in the higher stability of the formulation.

Anti-Inflammatory Mechanisms of Dietary Flavones: Tapping into Nature to Control Chronic Inflammation in Obesity and Cancer

Flavones are natural phytochemicals broadly distributed in our diet. Their anti-inflammatory properties provide unique opportunities to control the innate immune system and inflammation. Here, we review the role of flavones in chronic inflammation with an emphasis on their impact on the molecular mechanisms underlying inflammatory diseases including obesity and cancer. Flavones can influence the innate immune cell repertoire restoring the immune landscape. Flavones impinge on NF-κB, STAT, COX-2, or NLRP3 inflammasome pathways reestablishing immune homeostasis. Devoid of adverse side effects, flavones could present alternative opportunities for the treatment and prevention of chronic inflammation that contributes to obesity and cancer.

Chemopreventive Properties of Black Raspberries and Strawberries in Esophageal Cancer Review

Esophageal cancer is one of the most fetal malignancies in the world. Esophageal squamous cell carcinoma (SCC) and esophageal adenocarcinoma (AC) are two main types of esophageal cancer and each with distinct epidemiological, etiological and histopathological characteristics. The continued global prevalence of tobacco use and alcohol consumption, coupled with limited intake of fresh fruits and vegetables, ensures that esophageal cancer will remain one of the major health threats. In addition to promoting quitting smoking and alcohol abuse, one of the strategies of cancer prevention is to identify foods, food components, or dietary patterns that can prevent or delay the onset of esophageal cancer. A food-based approach has the advantage of a complex of mixtures of bioactive components simultaneously targeting multiple processes in carcinogenesis. We have employed a preclinical rodent model of esophageal SCC to assess the effects of black raspberries (BRB) and strawberries. Our investigations demonstrate that BRB and strawberries are potent inhibitors of esophageal cancer. To prepare for this review, a literature search was performed to screen BRB and strawberries against esophageal cancer using electronic databases from PubMed, Science Direct and Google Scholar. Search was conducted covering the period from January 2000 to June 2022. Our present review has provided a systematic review about chemopreventive effects of BRB and strawberries in esophageal cancer by collecting and compiling diverse research findings from the above sources. In this review, we discussed the anti-tumor potentials of BRB and strawberries in esophageal SCC and esophageal AC separately. For each cancer type, we discuss animal models and research findings from both animal bioassays and human clinical studies. We also discuss the potential mechanisms of action of berries and their key bioactive components.

Probiotics-Containing Mucoadhesive Gel for Targeting the Dysbiosis Associated with Periodontal Diseases

Objective

Periodontitis is a common disorder that leads to the loss of both tooth and personal well-being, contributing to worsen the risk for metabolic and cardiovascular diseases. Recently, probiotics, characterized by rapid oral dispersion, have been topically used. Here, we present data of a mucoadhesive gel containing probiotics, capable of ensuring a slow release of bacteria to prevent and treat periodontitis.

Methods

An original mucoadhesive gel (AL0005) that is anhydrous and of food grade, loaded with the blend of lactobacilli and plants' dry extracts, has been assayed.

Results

The release kinetics of the bacterial mixture in different experimental models in vitro, including simulated saliva or physiological solutions, showed a significant and stable release for 5–8 hours. In one in vivo study of a mouse model of periodontitis, a locally applied mucoadhesive gel enriched with probiotic strains improved significantly the tissue pathology when compared with vehicle-exposed mice.

Conclusions

Together, the results suggest that this mucoadhesive gel can be useful in the normalization of the gum bacterial flora and improvement of the tissue pathology of gum disorders.

Black raspberry restores the expression of the tumor suppressor p120ctn in the oral cavity of mice treated with the carcinogen dibenzo[a,l]pyrene diol epoxide

One of the major risk factors for head and neck squamous cell carcinoma (HNSCC) is tobacco smoke exposure, but the mechanisms that can account for disease development remain to be fully defined. Utilizing our HNSCC mouse model, we analyzed oral squamous cell carcinomas (OSCC) induced by the active metabolite of a common smoke constituent, dibenzo[a,l]pyrene diol-epoxide (DBPDE). Analyzing protein expression by either immunofluorescence or immunohistochemistry, we identified biologic processes that are dysregulated in premalignant and invasive cancer lesions induced by DBPDE. Interestingly, p120ctn expression is downregulated in both stages of the disease. In addition to decreased p120ctn expression, there was also increased proliferation (as measured by Ki67), inflammation (as measured by NFkB (p65) expression), neovascularization (as measured by CD31) and recruitment of Ly6G-positive immune cells as well as strong EGFR expression. We also examined the effect of the chemopreventive agent black raspberry (BRB) on p120ctn and EGFR protein expression in DBPDE treated mice. p120ctn, but not EGFR, protein expression increased in mice treated with BRB. Our results suggest that modulation of p120ctn may, in part, account for the mechanism by which BRB inhibits DBPDE induced OSCC in mice.

Chemopreventive Effect of Dietary Anthocyanins against Gastrointestinal Cancers: A Review of Recent Advances and Perspectives

Anthocyanins are a group of dietary polyphenols, abundant mainly in fruits and their products. Dietary interventions of anthocyanins are being studied extensively related to the prevention of gastrointestinal (GI) cancer, among many other chronic disorders. This review summarizes the hereditary and non-hereditary characteristics of GI cancers, chemistry, and bioavailability of anthocyanins, and the most recent findings of anthocyanin in GI cancer prevention through modulating cellular signaling pathways. GI cancer-preventive attributes of anthocyanins are primarily due to their antioxidative, anti-inflammatory, and anti-proliferative properties, and their ability to regulate gene expression and metabolic pathways, as well as induce the apoptosis of cancer cells.

Wine Consumption and Oral Cavity Cancer: Friend or Foe, Two Faces of Janus

The health benefits of moderate wine consumption have been extensively studied during the last few decades. Some studies have demonstrated protective associations between moderate drinking and several diseases including oral cavity cancer (OCC). However, due to the various adverse effects related to ethanol content, the recommendation of moderate wine consumption has been controversial. The polyphenolic components of wine contribute to its beneficial effects with different biological pathways, including antioxidant, lipid regulating and anti-inflammatory effects. On the other hand, in the oral cavity, ethanol is oxidized to form acetaldehyde, a metabolite with genotoxic properties. This review is a critical compilation of both the beneficial and the detrimental effects of wine consumption on OCC.

An Integrated Approach for Preventing Oral Cavity and Oropharyngeal Cancers: Two Etiologies with Distinct and Shared Mechanisms of Carcinogenesis

Head and neck squamous cell carcinoma (HNSCC) was the 7th most common malignancy worldwide in 2018 and despite therapeutic advances, the overall survival rate for oral squamous cell carcinoma (OSCC; ∼50%) has remained unchanged for decades. The most common types are OSCC and oropharyngeal squamous cell carcinoma (OPSCC, survival rate ∼85%). Tobacco smoking is a major risk factor of HNSCC. In the developed world, the incidence of OSCC is declining as a result of tobacco cessation programs. However, OPSCC, which is also linked to human papillomavirus (HPV) infection, is on the rise and now ranks as the most common HPV-related cancer. The current state of knowledge indicates that HPV-associated disease differs substantially from other types of HNSCC and distinct biological differences between HPV-positive and HPV-negative HNSCC have been identified. Although risk factors have been extensively discussed in the literature, there are multiple clinically relevant questions that remain unanswered and even unexplored. Moreover, existing approaches (e.g., tobacco cessation, vaccination, and chemoprevention) to manage and control this disease remain a challenge. Thus, in this review, we discuss potential future basic research that can assist in a better understanding of disease pathogenesis which may lead to novel and more effective preventive strategies for OSCC and OPSCC.

Electrospun nanofibers for the delivery of active drugs through nasal, oral and vaginal mucosa: Current status and future perspectives

Transmucosal surfaces bypass many limitations associated with conventional drug delivery (oral and parenteral routes), such as poor absorption rate, enzymatic activity, acidic environment and first-pass metabolism occurring inside the liver. However, these surfaces have several disadvantages such as poor retention time, narrow absorption window and continuous washout of the drug by the surrounding fluids. Electrospun nanofibers with their unique surface properties and encapsulation efficiency may act as novel drug carriers to overcome the challenges associated with conventional drug delivery routes, so as to achieve desired therapeutic responses. This review article provides detailed information regarding the challenges faced in the mucosal delivery of drugs, and the use of nanofiber systems as an alternative to deliver drugs to the systemic circulation, as well as local drug administration. The physiological and anatomical features of different types of mucosal surfaces and current challenges are systematically discussed. We also address future considerations in the area of transmucosal delivery of some important drugs.

Progress in Drug and Formulation Development for the Chemoprevention of Oral Squamous Cell Carcinoma: A Review

BACKGROUND

Cancer is a life-threatening global problem with high incidence rates. Prioritizing the prevention of cancer, chemopreventive agents have drawn much attention from the researchers.

OBJECTIVE

This review focuses on the discussion of the progress in the development of chemopreventive agents and formulations related to the prevention of oral cancer.

METHODS

In this perspective, an extensive literature survey was carried out to understand the mechanism, control and chemoprevention of oral cancer. Different patented agents and formulations have also exhibited cancer preventive efficacy in experimental studies. This review summarizes the etiology of oral cancer and developments in prevention strategies.

RESULTS

The growth of oral cancer is a multistep activity necessitating the accumulation of genetic as well as epigenetic alterations in key regulatory genes. Many risk factors are associated with oral cancer. Genomic technique for sequencing all tumor specimens has been made available to help detect mutations. The recent development of molecular pathway and genetic tools has made the process of diagnosis easier, better forecast and efficient therapeutic management. Different chemical agents have been studied for their efficacy to prevent oral cancer and some of them have shown promising results.

CONCLUSION

Use of chemopreventive agents, either synthetic or natural origin, to prevent carcinogenesis is a worthy concept in the management of cancers. Preventive measures are helpful in controlling the occurrence or severity of the disease. The demonstrated results of preventive agents have opened an arena for the development of promising chemopreventive agents in the management of oral squamous cell carcinoma.

Expert design and desirability function approach for the development of diazepam thermally sensitive rectal gel

Aim: The aim of the present work was to develop an in situ thermosensitive rectal gel for diazepam by using Expert-design for improving three factors and a three-level process was formed by using a cold method. Methods & materials: Response surface design was utilized to investigate the effect of independent variables like sodium chloride (NaCl, X1), poloxamer 407 (F-127, X2) and diazepam (X3), on different dependent variables such as gelation temperature, mucoadhesive strength, drug content, along with permeation and stability. Results: The obtained results revealed that the addition of diazepam enhanced the gelation temperature of hydrogel while it decreased the gel strength and mucoadhesive force. Conclusion: It is suggested that in situ hydrogels may be suitable candidates for rectal delivery.

Dietary Flavonoids for Immunoregulation and Cancer: Food Design for Targeting Disease

Flavonoids, one of the most abundant phytochemicals in a diet rich in fruits and vegetables, have been recognized as possessing anti-proliferative, antioxidant, anti-inflammatory, and estrogenic activities. Numerous cellular and animal-based studies show that flavonoids can function as antioxidants by preventing DNA damage and scavenging reactive oxygen radicals, inhibiting formation of DNA adducts, enhancing DNA repair, interfering with chemical damage by induction of Phase II enzymes, and modifying signaling pathways. Recent evidence also shows their ability to regulate the immune system. However, findings from clinical trials have been mixed with no clear consensus on dose, frequency, or type of flavonoids best suited to elicit many of the beneficial effects. Delivery of these bioactive compounds to their biological targets through "targeted designed" food processing strategies is critical to reach effective concentration in vivo. Thus, the identification of novel approaches that optimize flavonoid bioavailability is essential for their successful clinical application. In this review, we discuss the relevance of increasing flavonoid bioavailability, by agricultural engineering and "targeted food design" in the context of the immune system and cancer.

Topical oral wound healing potential of anthocyanin complex: animal and clinical studies

Aim: An anthocyanin complex (AC), combined Zea mays and Clitoria ternatea extracts, was evaluated for topical oral wound healing in rats and a clinical trial in orthodontic patients. Methods/results: AC enhanced anthocyanin permeation in vitro. In rats, 10% w/w of AC in a mucoadhesive gel (AG) reduced erythema and sizes of oral wounds after topical applications at higher extent than its placebo gel. Acute orthodontic wounds in 68 volunteers were randomly assigned to topically receive either AG or placebo gel and double-blind assessed. Wound size reduction and wound closure enhancement were obvious in AG-treated group on day 3 (p < 0.05). Conclusion: At 10% w/w, AC promoted wound closure and possessed a potential in healing stimulation of acute oral wounds.

Topical Niosome Gel Containing an Anthocyanin Complex: a Potential Oral Wound Healing in Rats

Anthocyanins from dietary sources showing potential benefits as anti-inflammatory in oral lesions were developed as an anthocyanin complex (AC), comprised of extracts of Zea mays (CC) and Clitoria ternatea (CT), and formulated into a niosome gel to prove its topical oral wound healing in vitro and in vivo investigations. The AC formed nano-sized clusters of crystalline-like aggregates, occurring through both intra- and inter-molecular interactions, resulting in delivery depots of anthocyanins, following encapsulation in niosomes and incorporation into a mucoadhesive gel. In vitro permeation of anthocyanins was improved by complexation and further enhanced by encapsulation in niosomes. Collagen production in human gingival fibroblasts was promoted by AC and AC niosomes, but not CC or CT. The in vivo wound healing properties of AC gel (1 and 10%), AC niosome gel (1 and 10%), fluocinolone acetonide gel, and placebo gel were investigated for incisional wounds in the buccal cavities of Wistar rats. AC gel and AC niosome gel both reduced wound sizes after 3 days. AC niosome gel (10%) gave the highest reduction in wound sizes after day 3 (compared to fluocinolone acetonide gel, p < 0.05), and resulted in 100% wound healing by day 5. Histological observations of cross-sectioned wound tissues revealed the adverse effects of fluocinolone gel and wound healing potential of AC niosome gel. Topical application of AC niosome gel exhibited an anti-inflammatory effect and promoted oral wound closure in rats, possibly due to the improved mucosal permeability and presence of delivery depots of AC in the niosome gel.

Polymeric drug delivery systems for intraoral site-specific chemoprevention of oral cancer

Oral cancer is among the most prevalent cancers in the world. Moreover, it is one of the major health problems and causes of death in many regions of the world. The traditional treatment modalities include surgical removal, radiation therapy, systemic chemotherapy, or a combination of these methods. In recent decades, there has been significant interest in intraoral site-specific chemoprevention via local drug delivery using polymeric systems. Because of its easy accessibility and clear visibility, the oral mucosa is amenable for local drug delivery. A variety of polymeric systems-such as gels, tablets, films, patches, injectable systems (e.g., millicylindrical implants, microparticles, and in situ-forming depots), and nanosized carriers (e.g., polymeric nanoparticles, nanofibers, polymer-drug conjugates, polymeric micelles, nanoliposomes, nanoemulsions, and polymersomes)-have been developed and evaluated for the local delivery of natural and synthetic chemopreventive agents. The findings of in vitro, ex vivo, and in vivo studies and the positive outcome of clinical trials demonstrate that intraoral site-specific drug delivery is an attractive, highly effective and patient-friendly strategy for the management of oral cancer. Intraoral site-specific drug delivery provides unique therapeutic advantages when compared to systemic chemotherapy. Moreover, intraoral drug delivery systems are self-administrable and can be removed when needed, increasing patient compliance. This article covers important aspects and advances related to the design, development, and efficacy of polymeric systems for intraoral site-specific drug delivery. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1383-1413, 2018.

Potential Benefits of Edible Berries in the Management of Aerodigestive and Gastrointestinal Tract Cancers: Preclinical and Clinical Evidence

Epidemiological reports as well as experimental studies have demonstrated the significant health benefits provided by regular berry consumption. Berries possess both prophylactic and therapeutic potential against several chronic illnesses, such as cardiovascular, neurodegenerative, and neoplastic diseases. Berries owe their health benefits to phytoconstituents, such as polyphenolic anthocyanins, ellagic acid, and a diverse array of phytochemicals bestowed with potent antioxidant and anti-inflammatory effects as well as the ability to engage a multitude of signaling pathways. This review highlights the principal chemical constituents present in berries and their primary molecular targets. The article presents and critically analyzes the chemopreventive and therapeutic potential of berry extracts, fractions, and bioactive components on various cancers of the gastrointestinal tract (GIT), including esophageal, stomach, intestinal, and colorectal cancers as well as cancers of the upper aerodigestive tract, such as oral cancer. The current status of clinical studies evaluating berry products in several aforementioned cancers is presented. Various emerging issues including dose-ranging and dosage forms, the role of synergy and the usage of combination therapy as well as other relevant areas essential for the development of berry phytoconstituents as mainstream chemopreventive and therapeutic agents against aerodigestive and GIT cancers are critically discussed.

Review of Various Herbal Supplements as Complementary Treatments for Oral Cancer

In the United States, nearly 44,000 people are diagnosed with oral or pharyngeal cancer annually. The life expectancy for those who are diagnosed have a survival rate of 57% after five years. Among them, oral cancer can be classified as benign or malignant tumors and is diagnosed at several stages in the development: premalignant conditions, premalignant lesions, and malignant cancer. The early signs of oral cancer often go unnoticed by the individual and are often discovered during routine dental examinations. Early detection and treatment may help to increase patient survival rates. The most widely used treatments for oral cancer include surgery, radiation, and chemotherapy-alone or in combination. Preclinical and clinical evidence for the use of green tea, raspberry, asparagus, and cannabis extracts is discussed in this review. Diet changes, supplementation with antioxidants, high-dose vitamin C therapy, and cannabinoid use have been suggested to decrease cancer cell replication and increase chance of remission. Early detection and lifestyle changes, including the use of dietary supplements in at-risk populations, are critical steps in preventing and successfully treating oral cancer. The main evidence for supplement use is currently in cancer prevention rather than treatment. Further research, determination, and mechanism of action for bioactive compounds such as epigallocatechin, epicatechin-3-gallate, and Bowman-Birk inhibitor concentrate, through in vitro, in vivo, and clinical trials need to be completed to support the use of natural products and their effectiveness in preventative care and supporting therapeutic approaches.

Suppression of Proinflammatory and Prosurvival Biomarkers in Oral Cancer Patients Consuming a Black Raspberry Phytochemical-Rich Troche

Black raspberries (BRB) demonstrate potent inhibition of aerodigestive tract carcinogenesis in animal models. However, translational clinical trials evaluating the ability of BRB phytochemicals to impact molecular biomarkers in the oral mucosa remain limited. The present phase 0 study addresses a fundamental question for oral cancer food-based prevention: Do BRB phytochemicals successfully reach the targeted oral tissues and reduce proinflammatory and antiapoptotic gene expression profiles? Patients with biopsy-confirmed oral squamous cell carcinomas (OSCC) administered oral troches containing freeze-dried BRB powder from the time of enrollment to the date of curative intent surgery (13.9 ± 1.27 days). Transcriptional biomarkers were evaluated in patient-matched OSCCs and noninvolved high at-risk mucosa (HARM) for BRB-associated changes. Significant expression differences between baseline OSCC and HARM tissues were confirmed using a panel of genes commonly deregulated during oral carcinogenesis. Following BRB troche administration, the expression of prosurvival genes (AURKA, BIRC5, EGFR) and proinflammatory genes (NFKB1, PTGS2) were significantly reduced. There were no BRB-associated grade 3-4 toxicities or adverse events, and 79.2% (N = 30) of patients successfully completed the study with high levels of compliance (97.2%). The BRB phytochemicals cyanidin-3-rutinoside and cyanidin-3-xylosylrutinoside were detected in all OSCC tissues analyzed, demonstrating that bioactive components were successfully reaching targeted OSCC tissues. We confirmed that hallmark antiapoptotic and proinflammatory molecular biomarkers were overexpressed in OSCCs and that their gene expression was significantly reduced following BRB troche administration. As these molecular biomarkers are fundamental to oral carcinogenesis and are modifiable, they may represent emerging biomarkers of molecular efficacy for BRB-mediated oral cancer chemoprevention.

Black raspberries in cancer clinical trials: Past, present and future

BACKGROUND

Black raspberries (BRB) inhibit a broad range of cancers in preclinical models, including in vivo models of oral, esophageal, colon, breast and skin cancer. Promising preclinical results have led to clinical evaluations in cancer patients or patients at increased risk for cancer development.

OBJECTIVE

To summarize clinical investigations targeting cancer or precancerous lesions with BRB and discuss future directions.

METHODS

A thorough literature search was conducted through December 1, 2015 to identify all published studies evaluating BRB in cancer focused clinical trials.

RESULTS

Research investigating BRB in clinical settings report positive effects on preneoplastic lesions or cancers of the oral cavity, esophagus and colon. BRB treatment resulted in: histologic regression of oral intraepithelial neoplasia associated with improved histologic grade and significantly reduced loss of heterozygosity at tumor suppressor gene loci, modulated genes linked to RNA processing and growth factor recycling; in the colon, BRB inhibited FAP-associated polyp progression, demethylated tumor suppressor genes and improved plasma cytokine profiles; in Barrett's patients, BRB consumption increased tissue levels of GST-pi and decreased 8-isoprostane, a marker of lipid peroxidation/oxidative stress.

CONCLUSIONS

The precise dose, duration and optimum mode of BRB delivery for cancer inhibition remains to be fully elucidated. Common themes across studies support that BRB are anti-proliferative, anti- inflammatory, reduce oxidative stress and restore tumor suppressive activity. Future directions are included in the conclusions section.

Development and characterization of different black raspberry confection matrices designed for delivery of phytochemicals

Three forms of confections containing black raspberries (BRB) powder were developed to provide controlled release of phytochemicals for oral disease prevention. Our objective was to investigate the impact of varying confection matrices on the release rate of BRB phytochemicals. Confections were developed and prepared. Textural properties of confections were analyzed, compared and correlated with the release rate of phytochemicals from BRB confections with in vitro dissolution test. In the results, BRB content reached 22% in hard candy and pectin-based confections and 40% in starch-based confections, respectively. Pectin- and starch-based confections retained >93% of its original anthocyanins after processing while hard candy had 59%. Starch confections showed higher G' in rheological analysis and higher hardness but lower cohesiveness and springiness in textural profile analysis than pectin confections (P < 0.05). The confection types showed different microstructure with scanning electronic microscopy (SEM). Corresponding to their physicochemical properties, confections showed fast (hard candy), intermediate (pectin confections), and slow (starch confections) release rates with a final releasing time of 90, 150, and 540 min in dissolution studies. Three confections were rated between neither like nor dislike to like slightly (n = 60). Pectin confections had the highest overall acceptance (like slightly) and 62% of subjects rated this type of confection as the most liked ones. These results indicate that delivery matrix could modulate the phytochemical release rate from BRB confection and also influence sensory preference.

Chemoprevention of oral cancer by topical application of black raspberries on high at-risk mucosa

OBJECTIVE

To evaluate the preclinical efficacy of topical administration of freeze-dried black raspberries (BRBs) to inhibit the progression of premalignant oral lesions and modulate biomarkers of cancer development in high at-risk mucosa (HARM).

STUDY DESIGN

Hamster cheek pouches (HCPs) were treated with carcinogen for 6 weeks to initiate a HARM microenvironment. Subsequently, right HCPs were topically administered a BRB suspension in short-term or long-term studies. After 12 weeks, squamous cell carcinoma (SCC) multiplicity, SCC incidence, and cell proliferation rates were evaluated. mRNA expression was measured in short-term treated pouches for selected oral cancer biomarkers.

RESULTS

SCC multiplicity (-41.3%), tumor incidence (-37.1%), and proliferation rate (-6.9%) were reduced in HCPs receiving BRBs. Topical BRBs correlated with an increase in RB1 expression in developing oral lesions.

CONCLUSIONS

Topical BRBs inhibit SCC development when targeted to HARM tissues. These results support the translational role of BRBs to prevent oral cancer development in humans.

Widefield optical imaging of changes in uptake of glucose and tissue extracellular pH in head and neck cancer

The overall objective of this study was to develop an optical imaging approach to simultaneously measure altered cell metabolism and changes in tissue extracellular pH with the progression of cancer using clinically isolated biopsies. In this study, 19 pairs of clinically normal and abnormal biopsies were obtained from consenting patients with head and neck cancer at University of California, Davis Medical Center. Fluorescence intensity of tissue biopsies before and after topical delivery of 2-NBDG (2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose) and Alexa 647-pHLIP [pH (low) insertion peptide] was measured noninvasively by widefield imaging, and correlated with pathologic diagnosis. The results of widefield imaging of clinical biopsies demonstrated that 2-NBDG and pHLIP peptide can accurately distinguish the pathologically normal and abnormal biopsies. The results also demonstrated the potential of this approach to detect subepithelial lesions. Topical application of the contrast agents generated a significant increase in fluorescence contrast (3- to 4-fold) in the cancer biopsies as compared with the normal biopsies, irrespective of the patient and location of the biopsy within a head and neck cavity. This unpaired comparison across all the patients with cancer in this study highlights the specificity of the imaging approach. Furthermore, the results of this study indicated that changes in intracellular glucose metabolism and cancer acidosis are initiated in the early stages of cancer, and these changes are correlated with the progression of the disease. In conclusion, this novel optical molecular imaging approach to measure multiple biomarkers in cancer has a significant potential to be a useful tool for improving early detection and prognostic evaluation of oral neoplasia.

Retention of polyphenolic species in spray-dried blackberry extract using mannitol as a thermoprotectant

The purpose of these studies was to determine if a Büchi Mini Spray Dryer B-290 (Büchi Corporation, New Castle, DE, USA) could be used to prepare blackberry extract powders containing mannitol as a thermoprotectant without extensively degrading anthocyanins and polyphenols in the resulting powders. Three blackberry puree extract samples were each prepared by sonication of puree in 30/70% ethanol/water containing 0.003% HCl. Blackberry puree extract sample 1 (S1) contained no mannitol, while blackberry puree extract sample 2 (S2) contained 3.0:1 (w/w) mannitol:berry extract, and blackberry puree extract sample 3 (S3) contained 6.3:1 (w/w) mannitol:berry extract. The levels of anthocyanins and polyphenols in reconstituted spray-dried powders produced from S1-S3 were compared to solutions of S1-S3 that were held at 4°C as controls. All extract samples could be spray-dried using the Büchi Mini Spray Dryer B-290. S1, with no mannitol, showed a 30.8% decrease in anthocyanins and a 24.1% decrease in polyphenols following spray-drying. However, S2 had a reduction in anthocyanins of only 13.8%, while polyphenols were reduced by only 6.1%. S3, with a ratio of mannitol to berry extract of 6.3:1, exhibited a 12.5% decrease in anthocyanins while the decrease in polyphenols after spray-drying was not statistically significant (P=.16). Collectively, these data indicate that a Büchi Mini Spray Dryer B-290 is a suitable platform for producing stable berry extract powders, and that mannitol is a suitable thermoprotectant that facilitates retention of thermosensitive polyphenolic species in berry extracts during spray-drying.

Characterization of black raspberry functional food products for cancer prevention human clinical trials

Our team is designing and fully characterizing black raspberry (BRB) food products suitable for long-term cancer prevention studies. The processing, scale-up, and storage effects on the consistency, quality, bioactive stability, and sensory acceptability of two BRB delivery systems of various matrices are presented. BRB dosage, pH, water activity, and texture were consistent in the scale-up production. Confections retained >90% of anthocyanins and ellagitannin after processing. Nectars had >69% of anthocyanins and >66% of ellagitannin retention, which varied with BRB dosage due to the processing difference. Texture remained unchanged during storage. BRB products consumed in a prostate cancer clinical trial were well accepted in sensory tests. Thus, this study demonstrates that two different BRB foods can be formulated to meet quality standards with a consistent bioactive pattern and successfully scaled up for a large human clinical trial focusing on cancer risk and other health outcomes.

Cytomodulin-1, a synthetic peptide abrogates oncogenic signaling pathways to impede invasion and angiogenesis in the hamster cheek pouch carcinogenesis model

Constitutive activation of the various oncogenic signaling pathways plays a pivotal role in promoting malignant transformation. The aim of this study was to investigate the therapeutic potential of a synthetic bioactive heptapeptide cytomodulin-1 (CM-1) against hamster cheek pouch carcinomas based on its influence on the predominant carcinogenic signaling pathways - NF-κB, TGFβ, and Wnt/β-catenin and their downstream target events invasion and angiogenesis. Topical application of CM-1 to DMBA-painted hamsters significantly inhibited activation of the canonical NF-κB pathway by blocking kinase activity of IKKβ and increasing the cytosolic accumulation of the inhibitor IκB-α. In addition, CM-1 inactivated IKKβ by disrupting IKKβ/Nemo interactions. CM-1 also hampered the activation of TGFβ and Wnt/β-catenin signaling by averting the phosphorylation of the key upstream ser/thr kinases TGFβ RI and GSK-3β respectively. Attenuation of these oncogenic signaling pathways by CM-1 also mitigated invasion and angiogenesis by suppressing the expression of pro-invasive matrix metalloproteinases, pro-angiogenic VEGF and HIF-1α and upregulating the anti-angiogenic TIMP-2. Synthetic peptides such as CM-1 that target multiple key molecules in oncogenic signaling pathways and their downstream events are ideal candidate agents for cancer chemotherapy.

The Outline of Prognosis and New Advances in Diagnosis of Oral Squamous Cell Carcinoma (OSCC): Review of the Literature

Objective. Oral squamous cell carcinoma (OSCC) has a remarkable incidence over the world and a fairly strenuous prognosis, encouraging further research on the prognostic factors and new techniques for diagnosis that might modify disease outcome. Data Sources. A web-based search for all types of articles published was initiated using Medline/Pub Med, with the key words such as oral cancer, prognostic factors of oral cancer, diagnostic method of oral cancer, and imaging techniques for diagnosis of oral cancer. The search was restricted to articles published in English, with no publication date restriction (last update April, 2013). Review Methods. In this paper, I approach the factors of prognosis of OSCC and the new advances in diagnostic technologies as well. I also reviewed available studies of the tissue fluorescence spectroscopy and other noninvasive diagnostic aids for OSCC. Results. The outcome is greatly influenced by the stage of the disease (especially TNM). Prognosis also depends or varies with tumour primary site, nodal involvement, tumour thickness, and the status of the surgical margins. Conclusion. Tumour diameter is not the most accurate when compared to tumour thickness or depth of invasion, which can be related directly to prognosis. There is a wide agreement on using ultrasound guided fine needle aspiration biopsies in the evaluation of lymph node metastasis.

Susceptibility of anthocyanins to ex vivo degradation in human saliva

Some fruits and their anthocyanin-rich extracts have been reported to exhibit chemopreventive activity in the oral cavity. Insights regarding oral metabolism of anthocyanins remain limited. Anthocyanin-rich extracts from blueberry, chokeberry, black raspberry, red grape, and strawberry were incubated ex vivo with human saliva from 14 healthy subjects. All anthocyanins were partially degraded in saliva. Degradation of chokeberry anthocyanins in saliva was temperature dependent and decreased by heating saliva to 80 °C and after removal of cells. Glycosides of delphinidin and petunidin were more susceptible to degradation than those of cyanidin, pelargonidin, peonidin and malvidin in both intact and artificial saliva. Stability of di- and tri-saccharide conjugates of anthocyanidins slightly, but significantly, exceeded that of monosaccharide compounds. Ex vivo degradation of anthocyanins in saliva was significantly decreased after oral rinsing with antibacterial chlorhexidine. These results suggest that anthocyanin degradation in the mouth is structure-dependent and largely mediated by oral microbiota.

Mucoadhesive fenretinide patches for site-specific chemoprevention of oral cancer: enhancement of oral mucosal permeation of fenretinide by coincorporation of propylene glycol and menthol

The objective of this study was to enhance oral mucosal permeation of fenretinide by coincorporation of propylene glycol (PG) and menthol in fenretinide/Eudragit RL PO mucoadhesive patches. Fenretinide is an extremely hydrophobic chemopreventive compound with poor tissue permeability. Coincorporation of 5-10 wt % PG (mean J(s) = 16-23 μg cm⁻² h⁻¹; 158-171 μg of fenretinide/g of tissue) or 1-10 wt % PG + 5 wt % menthol (mean J(s) = 18-40 μg cm⁻² h⁻¹; 172-241 μg of fenretinide/g of tissue) in fenretinide/Eudragit RL PO patches led to significant ex vivo fenretinide permeation enhancement (p < 0.001). Addition of PG above 2.5 wt % in the patch resulted in significant cellular swelling in the buccal mucosal tissues. These alterations were ameliorated by combining both enhancers and reducing PG level. After buccal administration of patches in rabbits, in vivo permeation of fenretinide across the oral mucosa was greater (∼43 μg fenretinide/g tissue) from patches that contained optimized permeation enhancer content (2.5 wt % PG + 5 wt % menthol) relative to permeation obtained from enhancer-free patch (∼17 μg fenretinide/g tissue) (p < 0.001). In vitro and in vivo release of fenretinide from patch was not significantly increased by coincorporation of permeation enhancers, indicating that mass transfer across the tissue, and not the patch, largely determined the permeation rate control in vivo. As a result of its improved permeation and its lack of deleterious local effects, the mucoadhesive fenretinide patch coincorporated with 2.5 wt % PG + 5 wt % menthol represents an important step in the further preclinical evaluation of oral site-specific chemoprevention strategies with fenretinide.

Optimizing therapeutic efficacy of chemopreventive agents: A critical review of delivery strategies in oral cancer chemoprevention clinical trials

Due to its characterized progression from recognized premalignant oral epithelial changes (i.e., oral epithelial dysplasia) to invasive cancer, oral squamous cell carcinoma represents an optimal disease for chemopreventive intervention prior to malignant transformation. The primary goal of oral cancer chemoprevention is to reverse, suppress, or inhibit the progression of premalignant lesions to cancer. Over the last several decades, numerous oral cancer chemoprevention clinical trials have assessed the therapeutic efficacy of diverse chemopreventive agents. The standard of care for more advanced oral dysplastic lesions entails surgical excision and close clinical follow-up due to the potential (~33%) for local recurrence at a similar or more advanced histological stage. The purpose of this review was to identify prominent oral cancer chemoprevention clinical trials, assess their overall therapeutic efficacy, and delineate effects of local versus systemic drug administration. In addition, these compiled clinical trial data present concepts for consideration in the design and conduction of future clinical trials.

Plant phenolics: extraction, analysis and their antioxidant and anticancer properties

Phenolics are broadly distributed in the plant kingdom and are the most abundant secondary metabolites of plants. Plant polyphenols have drawn increasing attention due to their potent antioxidant properties and their marked effects in the prevention of various oxidative stress associated diseases such as cancer. In the last few years, the identification and development of phenolic compounds or extracts from different plants has become a major area of health- and medical-related research. This review provides an updated and comprehensive overview on phenolic extraction, purification, analysis and quantification as well as their antioxidant properties. Furthermore, the anticancer effects of phenolics in-vitro and in-vivo animal models are viewed, including recent human intervention studies. Finally, possible mechanisms of action involving antioxidant and pro-oxidant activity as well as interference with cellular functions are discussed.

Formulation and in vitro-in vivo evaluation of black raspberry extract-loaded PLGA/PLA injectable millicylindrical implants for sustained delivery of chemopreventive anthocyanins

PURPOSE

The objective of this study was to formulate and evaluate freeze-dried black raspberry (FBR) ethanol extract (RE) loaded poly(DL-lactic-co-glycolic acid) (PLGA) and poly(DL-lactic acid) (PLA) injectable millicylindrical implants for sustained delivery of chemopreventive FBR anthocyanins (cyanidin-3-sambubioside (CS), cyanidin-3-glucoside (CG) and cyanidin-3-rutinoside (CR)).

METHODS

Identification and quantitation of CS, CG, and CR in RE was performed by mass spectroscopy and HPLC. RE:triacetyl-beta-cyclodextrin (TA-beta-CD) inclusion complex (IC) was prepared by a kneading method and characterized by X-ray diffraction (XRD), nuclear magnetic resonance spectroscopy (NMR) and UV-visible spectroscopy. RE or RE:TA-beta-CD IC-loaded PLGA or PLA implants were prepared by a solvent extrusion method. In vitro and in vivo controlled release studies were conducted in phosphate-buffered saline Tween-80 (pH 7.4, 37 degrees C) and after subcutaneous administration in male Sprague-Dawley rats, respectively. Anthocyanins were quantified by HPLC at 520 nm.

RESULTS

The content of CS, CG, and CR in RE was 0.2, 1.5, and 3.5 wt%, respectively. The chemical stability of anthocyanins in solution was determined to be pH-dependent, and their degradation rate increased with an increase in pH from 2.4 to 7.4. PLGA/PLA millicylindrical implants loaded with 5 or 10 wt% RE exhibited a high initial burst and short release duration of anthocyanins (35-52 and 80-100% CG + CR release after 1 and 14 days, respectively). The cause for rapid anthocyanins release was linked to higher polymer water uptake and porosity associated with the high osmolytic components of large non-anthocyanin fraction of RE. XRD, (1)H NMR and UV-visible spectroscopy indicated that the non-anthocyanin fraction molecules of RE formed an IC with TA-beta-CD, decreasing the hydrophilicity of RE. Formation of an IC with hydrophobic carrier, TA-beta-CD, provided better in vitro/in vivo sustained release of FBR anthocyanins (16-24 and 97-99% CG + CR release, respectively, after 1 and 28 days from 20 wt% RE:TA-beta-CD IC/PLA implants) over 1 month, owing to reduced polymer water uptake and porosity.

CONCLUSION

PLA injectable millicylindrical implants loaded with RE:TA-beta-CD IC are optimal dosage forms for 1-month slow and continuous delivery of chemopreventive FBR anthocyanins.

A rapid and sensitive LC-MS/MS method for quantification of four anthocyanins and its application in a clinical pharmacology study of a bioadhesive black raspberry gel

Cyanidin 3-glucoside (C3GLU), cyanidin 3-rutinoside (C3RUT), cyanidin 3-sambubioside (C3SAM) and cyanidin 3-(2(G)-xylosyl) rutinoside (C3XRUT) are the four constituent black raspberry anthocyanins that contribute significantly to the chemopreventive effects of freeze-dried black raspberries (FBR). A highly sensitive and specific LC-MS/MS assay was developed and validated to simultaneously quantify these four FBR anthocyanins in human saliva, plasma and oral tissue homogenates. In saliva, the lower limit of quantification (LLOQ) for these anthocyanins was 1.0 ng/mL. The within-run and between-run coefficients of variations (CVs) at the quality control concentrations (1.0, 5.0, 50 and 500 ng/mL) were all <12%, except for C3SAM and C3RUT at the LLOQ, which showed a within-run CV of 18.3% and between-run CV of 16.0%, respectively. The accuracy values ranged from 87.5 to 110%. In plasma, the LLOQ for C3GLU and C3RUT was 1.0 ng/mL and for C3SAM 5.0 ng/mL. The CVs at the above concentrations were <15%, except for C3GLU at the LLOQ, which showed the between-run CV of 16.9%. The accuracy values ranged from 90.7% to 112.7% except for C3GLU at the LLOQ, which showed 119.3%. In tissue homogenates, the LLOQ for C3GLU and C3RUT was 2.0 ng/mL, and C3SAM 5.0 ng/mL. The CVs and accuracy values at concentrations (2.0, 5.0, 50 and 500 ng/mL) were similar to those in human plasma. This assay was subsequently used in a pilot pharmacology study to evaluate the effects of topical application of a 10% (w/w) FBR bioadhesive gel to selected mucosal sites in the posterior mandibular gingiva. Measurable saliva and tissue levels of the FBR anthocyanins confirmed that gel-delivered anthocyanins are readily distributed to saliva and easily penetrate human oral mucosa.

Distribution of anthocyanins delivered from a bioadhesive black raspberry gel following topical intraoral application in normal healthy volunteers

PURPOSE

Results from our oral cavity chemoprevention trial demonstrated appreciable interpatient variations regarding chemopreventive efficacy of a freeze dried black raspberry (FBR) gel. We speculated these data reflected individual patient-related differences in absorption, target tissue uptake and local compound metabolism of key FBR compounds (anthocyanins). Accordingly, this study assessed the distribution of anthocyanins from the 10% (w/w) FBR gel in saliva, oral tissues and plasma.

METHODS

Human subject participation entailed collection of: (1) saliva, tissue and plasma (5 min following gel application, keratinized tissues), (2) saliva and plasma (5 min after sublingual gel application), (3) saliva and plasma at 1, 2, and 4 h post gel application (keratinized tissues), and (4) saliva (cyanidin 3-rutinoside incubations). Levels of FBR anthocyanins in the respective samples were analyzed by LC/MS/MS.

RESULTS

Our data show: significantly higher anthocyanin levels in saliva and oral tissues relative to matched plasma samples, marked donor-specific variations in anthocyanin uptake, sustainability of anthocyanins at the target site, pH affects anthocyanin penetration and intraoral anthocyanin decomposition and/or metabolism.

CONCLUSIONS

No previous oral cavity chemoprevention trials evaluated compound distribution at the treatment site. Our data, which demonstrate a local delivery-derived pharmacologic advantage, provide insights which could advance oral cavity chemoprevention strategies.

Topical application of a bioadhesive black raspberry gel modulates gene expression and reduces cyclooxygenase 2 protein in human premalignant oral lesions

Reduced expression of proapoptotic and terminal differentiation genes in conjunction with increased levels of the proinflammatory and angiogenesis-inducing enzymes, cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS), correlate with malignant transformation of oral intraepithelial neoplasia (IEN). Accordingly, this study investigated the effects of a 10% (w/w) freeze-dried black raspberry gel on oral IEN histopathology, gene expression profiles, intraepithelial COX-2 and iNOS proteins, and microvascular densities. Our laboratories have shown that freeze-dried black raspberries possess antioxidant properties and also induce keratinocyte apoptosis and terminal differentiation. Oral IEN tissues were hemisected to provide samples for pretreatment diagnoses and establish baseline biochemical and molecular variables. Treatment of the remaining lesional tissue (0.5 g gel applied four times daily for 6 weeks) began 1 week after the initial biopsy. RNA was isolated from snap-frozen IEN lesions for microarray analyses, followed by quantitative reverse transcription-PCR validation. Additional epithelial gene-specific quantitative reverse transcription-PCR analyses facilitated the assessment of target tissue treatment effects. Surface epithelial COX-2 and iNOS protein levels and microvascular densities were determined by image analysis quantified immunohistochemistry. Topical berry gel application uniformly suppressed genes associated with RNA processing, growth factor recycling, and inhibition of apoptosis. Although the majority of participants showed posttreatment decreases in epithelial iNOS and COX-2 proteins, only COX-2 reductions were statistically significant. These data show that berry gel application modulated oral IEN gene expression profiles, ultimately reducing epithelial COX-2 protein. In a patient subset, berry gel application also reduced vascular densities in the superficial connective tissues and induced genes associated with keratinocyte terminal differentiation.

Laboratory and clinical studies of cancer chemoprevention by antioxidants in berries

Reactive oxygen species (ROS) are a major cause of cellular injury in an increasing number of diseases, including cancer. Most ROS are created in the cell through normal cellular metabolism. They can be produced by environmental insults such as ultraviolet light and toxic chemicals, as well as by the inflammatory process. Interception of ROS or limiting their cellular effects is a major role of antioxidants. Due to their content of phenolic and flavonoid compounds, berries exhibit high antioxidant potential, exceeding that of many other foodstuffs. Through their ability to scavenge ROS and reduce oxidative DNA damage, stimulate antioxidant enzymes, inhibit carcinogen-induced DNA adduct formation and enhance DNA repair, berry compounds have been shown to inhibit mutagenesis and cancer initiation. Berry constituents also influence cellular processes associated with cancer progression including signaling pathways associated with cell proliferation, differentiation, apoptosis and angiogenesis. This review article summarizes laboratory and human studies, demonstrating the protective effects of berries and berry constituents on oxidative and other cellular processes leading to cancer development.

Effects of a topically applied bioadhesive berry gel on loss of heterozygosity indices in premalignant oral lesions

PURPOSE

The aim of this study was to assess the effects of topical application of a 10% (w/w) freeze-dried black raspberry (FBR) gel on oral intraepithelial neoplasia (IEN) variables that included histologic diagnoses and loss of heterozygosity (LOH) indices. Microsatellite instability and/or LOH at tumor suppressor gene-associated chromosomal loci have been associated with a higher risk for oral IEN progression to oral squamous cell carcinoma. Previously, our laboratories have shown that FBRs are well tolerated and possess potent antioxidant, apoptotic, and differentiation-inducing properties.

EXPERIMENTAL DESIGN

Each participant with IEN served as their own internal control. Before treatment, all lesions were photographed, and lesional tissue was hemisected to obtain a pretreatment diagnosis and baseline biochemical and molecular variables. Gel dosing (0.5 g applied four times daily for 6 weeks) was initiated 1 week after the initial biopsy. Genomic DNA was isolated from laser-captured basilar and suprabasilar surface epithelial cells followed by PCR amplification using primer sets that targeted known and presumed tumor suppressor gene loci associated with INK4a/ARF, p53, and FHIT. Allelic imbalance was determined by sequence analysis using normal participant tissues to establish microsatellite marker peak patterns and allele sizes.

RESULTS

Confirming earlier phase I data, none of the 27 participants developed FBR gel-associated toxicities. Furthermore, our results show histologic regression in a subset of patients as well as statistically significant reduction in LOH at tumor suppressor gene-associated loci.

CONCLUSIONS

These preliminary data suggest that further evaluation of berry gels for oral IEN chemoprevention is warranted.