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Completed

NCT Number: NCT04372914

Prevention of Oral DNA Damage by Black Raspberries

The purpose of this voluntary research study is to learn about the potential effects that black raspberry (BRB) lozenges may have on reducing the damage caused from cigarette smoke in mouth cells in adult smokers, which may be useful in reducing health risks associated with smoking.

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Key information

Age range

21 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Penn State CTSI Clinical Research Center

Hershey, Pennsylvania, 17033, United States

About this study

This clinical trial will consist of a single arm, where participants, after a 1-week baseline period, will be placed on daily BRB administration for a period of 8 weeks followed by a 4 week washout period. Prior to study enrollment, all participants will have an Oral Cancer screening intraoral exam and persons with oral pathology (e.g. premalignant or oral squamous cell carcinoma) will be referred for appropriate clinical care. Biological samples will be collected at 0, 1, 4, 5, 8, 9, 12 and 13 weeks. An 8-week BRB administration period was selected to allow for ample time for effects to be observed in the major endpoints, based on previous clinical data. Likewise, a 4 week washout period at the end of the trial will allow for effects of BRB withdrawal on major outcomes to be measured.

A total of 58 healthy subjects will be recruited into this intervention study. Eligible subjects, after phone screening, will visit the clinic for an additional in-person screening which includes measurement of expired carbon monoxide and pregnancy test (females). Prior to enrollment, each subject will be offered a free oral cancer screening. After obtaining informed consent, eligible subjects will be administered a questionnaire to obtain information on basic demographics, medical history, lifestyle, tobacco and alcohol consumption, and usual dietary intake and biological samples (exfoliated buccal cells and urine) and anthropometric data (e.g. height and weight) will be collected. Subjects will be asked to return after 1 week (Visit 2, 2nd baseline visit) and biological samples will be collected. Subjects will be provided their first supply of test agent (BRB lozenge) and a usage diary and instructed on the proper method for application and completion of the diary entries. At Visits 3-6 (weeks 4, 5, 8, and 9, respectively) subjects will return any unused product, receive a new batch of lozenges (except for week 9), complete a brief questionnaire on compliance and provide biological samples. At week 9 (Visit 6), subjects will return their study diaries and enter the washout period where no test agent will be provided. At the final visits (Visit 7 and 8, weeks 12 and 13), subjects will provide biological samples.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 21-75
  • Smoke 5 cigarettes per day or more for at least the past 12 months
  • Have an expired air carbon monoxide measurement of greater than 6 parts per million
  • No serious quit attempt in the last one month and not planning to quit in the next 4 months
  • Willing and able to attend all study visits
  • Able to read and write in English
  • Able to understand and provide consent to the study procedures
  • Willingness and ability to attend regular visits over a 14-week period and to respond to research contacts between the 5

Exclusion criteria

  • Unstable or significant medical conditions that affect participant safety or biomarker data in the past 3 months (e.g. recent heart attack, asthma or COPD)
  • Women currently pregnant or nursing
  • Use of any non-cigarette nicotine delivery product in the past 7 days (e.g. e-cigarettes, pipe or cigar)
  • Uncontrolled mental illness or inpatient treatment in the past 6 months; current suicide risk on clinical assessment
  • Any known allergy to raspberries
  • Use of marijuana or other illegal drugs daily or weekly in the past 3 months
  • Use of high dose antioxidant supplements in the past month
  • Use of antibiotics
  • Heavy drinking (>4 drinks/day, 5 days/week)
  • Made no serious cigarette smoking quit attempt or have used any FDA-approved smoking cessation medication in the prior 30 days
  • No plan to quit smoking within the next 4 months

Treatment and study plan

BRB Lozenges

Dietary Supplement

Each lozenge is made from 1 gram of freeze-dried black raspberry powder (equivalent to ~5 black raspberries) in the form of a dissolvable slow-release lozenge.

Primary outcomes

  1. HPB-releasing Adducts (Buccal Cells)

    Time frame: 8 weeks

    The tobacco specific nitrosamine, N'-nitrosonornicotine, is metabolically activated to form DNA adduct that upon hydrolysis releases 4-hydroxy-1-(3-pyridyl)-1-butonone (HPB), which was measured in buccal cells of smokers in picogram per microgram guanine (one of the four bases of DNA).

Secondary outcomes

  1. B[a]P Adducts (Buccal Cells)

    Time frame: 8 weeks

    Benzo[a]pyrene, a tobacco smoke constituent, is metabolized in buccal cells of smoker's into active metabolite namely benzo[a]pyrene-diol epoxide (BPDE). BPDE can react with DNA to form deoxyguanosine adducts (BPDE-N^2-dG) that measured in buccal cells of smokers in picogram per microgram deoxyguanosine.

  2. 8-OXO-dG (Buccal Cells)

    Time frame: 8 weeks

    Cigarette smoke is a rich source of free radicals that can promote oxidative stress and carcinogenesis, including head and neck squamous cell carcinoma. 8-oxo-7,8-dihydro-2'deoxyguanosine (8-oxo-dG) is a valid biomarker of oxidative stress. We measured 8-oxo-dG in buccal cells of smokers and the levels are expressed as picogram per microgram of deoxyguanosine.

  3. Cotinine (Urine)

    Time frame: 8 weeks

    Biomarker of tobacco smoke exposure

  4. Creatinine (Urine)

    Time frame: 8 weeks

    Biomarker of urine dilution

  5. 8-Isoprostane (Urine)

    Time frame: 8 weeks

    Biomarker of systemic oxidative stress

Sponsors and collaborators

Lead sponsor

Milton S. Hershey Medical Center

Other

Collaborators

  • National Cancer Institute (NCI)

Registry information

Official study title

Effect of Oral Black Raspberry Administration on Oral Cell DNA Adducts in Smokers

Important dates

Study start
2021
Primary completion
2024
Study completion
2024
First posted
May 4, 2020
Registry last updated
Feb 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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