Smoking Cessation Effect of Tea Filter Through Inhibition of Nicotine Receptor
Condition: Tobacco Cessation
Study type: Observational

Summary: 
      Cigarette smoking is the major risk factor for a series of life threatening diseases
      including cancer and heart attack, which causes millions of deaths each year worldwide. Many
      of the harmful effects of cigarette smoking can be reversed by quitting; however, due to the
      addictive nature of nicotine, quitting smoking is extremely difficult. Despite the efforts,
      currently available methods produce only modest smoking cessation rates with relapse.
      Previously, tea components were shown to protect effect against cigarette smoke-induced
      toxicity. Here the investigator reported an unprecedented smoking cessation effect of tea.
      Green tea was made into cigarette filters and tested for its smoking cessation effect in a
      double-blind clinical study. The tea filter could effectively achieve abstinence relapse
      using smoking process to quite smoking and easy to be used by smoker without any side effects
      and psychological obstacles. This work provides a new idea and innovative method to combat
      tobacco epidemic. Its implementation and popularization may make a great contribution towards
      to reducing the smoking-related diseases, and relieving the public health burden and
      pollution caused by cigarette smoking.
    

Detailed description: 
      Cigarette smoking has been linked to many life threatening diseases including heart diseases,
      cancer and chronic obstructive pulmonary disease. There are about 1.25 billion smokers in the
      world. Five million people die every year because of smoking-related diseases. This rate
      exceeds many other diseases combined. It is estimated that the global cost for
      smoking-related diseases is about $200 billion each year, posing one of the biggest public
      human health problems around the world. Many methods have been developed for smoking
      cessation by scientists and doctors worldwide. However, due to the addictive nature of
      nicotine, quitting smoking is extremely difficult. Despite all the efforts, currently
      available smoking cessation methods produce only modest successful rates with relapse. In
      addition, they are often not convenient and can lead to a wide variety of side effects.
      Therefore, the need of new idea for developing new smoking cessation techniques with better
      efficacy and fewer side effects is urgent.

      Epidemiological evidences have shown that tea is adversely associated with cancer,
      hyperglycemia and other diseases. In addition, we have shown that tea components protect
      cells from cigarette smoke-induced toxicity. Recently, we have developed a new cigarette
      filter containing tea. While testing the filter for detoxification effects, we found that
      several subjects who were smokers decreased their cigarette consumption and subsequently
      abstained from cigarette smoking after using the tea filter for a period of time. Animal
      experiments revealed that a derivative tea component prevented nicotine addiction similar to
      nicotine acetylcholine receptor (nAChR) inhibitor. It significantly inhibited the
      nicotine-induced expression of alpha4,alpha7 and β2 subunits of nAChR and tyrosine
      hydroxylase and release of dopamine. This finding encouraged us to recruit more volunteers to
      test the smoking cessation effect of the tea filter.

      One hundred healthy male cigarette smokers, aged 18 to 30 years, were screened and 30 of them
      were excluded based on the exclusion/inclusion criteria. 70 volunteers were double-blinded,
      placebo-controlled and randomized into 2 groups (smoking with tea filters or regular
      filters). Smoking history, including the nicotine dependence, was assessed at the screening
      visit. Exclusion criteria included treatment with an investigational drug within the previous
      month; major depression within the prior year; panic disorder, psychosis, or bipolar
      disorder; use of nicotine replacement therapy or other drugs within the previous 3 months;
      cardiovascular disease; clinically significant medical disease; drug or alcohol abuse or
      dependence within the past year; and use of tobacco products other than cigarette smoking
      within the previous month. Subjects received brief smoking cessation counseling (up to 10
      minutes) at the baseline visit and at each visit afterwards. Self-reported smoking status
      since the last visit and exhaled carbon monoxide measurement were assessed at each weekly
      visit. Vital signs, weight, and adverse event information were collected at each visit. A
      physical examination was performed prior to randomization and at the final visit. Urine and
      blood were collected at screening, baseline, and at weeks 1, 2, 3, and 4 for biochemical
      analysis.

      The average number of cigarettes consumed daily by one volunteer smoker before the clinic
      trial was calculated as control. The average number of cigarettes consumed daily by one
      volunteer after the clinic trial was calculated and the numbers were then used to calculate
      the averages number of cigarettes consumed daily by one smoker in a week and compared with
      control. Continuous abstinence was defined as self-report of no cigarette use during the
      specified time period confirmed by an exhaled carbon monoxide measurement of 10 ppm or lower.
      To be considered abstinent from smoking during the treatment period, subjects also had to
      report that they did not use any other nicotine-containing products. During the follow-up
      period, use of nicotine replacement therapy did not disqualify subjects from being considered
      abstinent. Subjects who withdrew or were lost to follow-up were assumed to be smokers for the
      remainder of the study. The exhaled carbon monoxide was detected by a carbon monoxidemeter
      (1209-1 CO, DWYER, USA). Nicotine and cotinine in urine was detected using HPLC (HITACH,
      Japan) as reported in the literature.

      30 volunteers in control group and 22 volunteer male cigarette smokers who consumed on
      average approximately cigarettes per day, were randomly divided into 2 groups (double-blind,
      placebo-controlled); smoking with tea filters or with regular filters. After using the tea
      filter for 1 month, the average daily cigarette consumption decreased about 43% in the tea
      filter group. In contrast, no change in average daily cigarette consumption was detected in
      the control group using regular filters. The trial was discontinued for the control group and
      the tea filter group was followed for another month. After using the tea filter for 2 months.

      We then recruited 59 volunteers with longer smoking history and stronger desire for quitting
      smoking for smoking cessation test using the tea filter. The subjects were followed for 5
      month following the same protocol as described earlier.
    

Observational model: Case-Control
Sampling method: Probability Sample
Study population: 
        70 volunteers were double-blinded, placebo-controlled and randomized into 2 groups (smoking
        with tea filters or regular filters).

        The investigators then recruited 59 volunteers with longer smoking history and stronger
        desire for quitting smoking for smoking cessation test using the tea filter.
      
Biospecimen description: 
      CO
    
Keywords: Smoking cessation; tea filter