3.1. Plant Materials
Dried anise, black caraway, ajwain, and fennel seeds were purchased from a traditional herbal shop in Tehran, Iran, and identified in the Herbarium Center of School of Pharmacy, Tehran University of Medical Sciences, under PMP-1615, PMP-1616, PMP-1617, and PMP‑1618 voucher numbers, respectively.
3.2. Drug Preparation
The formula and placebo capsules were prepared by Tooba Green Gold Company (Tehran, Iran). For this study, 50% hydroethanolic extracts were prepared by repeated maceration method and then freeze-dried. The volume of the resultant lyophilized powder was adjusted with pharmaceutical-grade starch (as a filler); accordingly, each 500 mg capsule contained extracts of 3 gr of fennel, 3 gr of anise, 2 gr of black caraway, and 2 gr of ajwain. The dose used in this study was consistent with the dose suggested in a valid PM textbook, Qarabadin Salehi. The formula mentioned in Qarabadin Salehi includes some components, namely Carum carvi (caraway), Pimpinella anisum (anise), Foeniculum vulgare (fennel), and Trachyspermum ammi (ajwain).
The recommended species in this formula is
Carum carvi (caraway). Because this species grows very limitedly in Iran and is not available in the market of Iran, seeds are used in most pharmaceutical products, including the product used in this study,
Bunium persicum (black caraway). It should be noted that in reliable PM sources, including the book
Makhzan Al-Advieh,
Bunium persicum (black caraway) has been introduced as an alternative to caraway due to their similar properties (
11,
16).
Placebo capsules were filled with Avicel. Trace amounts of the extracts and permitted food coloring were used to match the odor and color of the formula and placebo. The capsules were placed in completely similar opaque cans. They were encoded by a coinvestigator who was not involved in the study based on the randomized allocation list.
3.3. Drug Standardization Based on Total Phenolic and Flavonoid Contents
Spectrophotometry was used to calculate total phenolic content. Initially, an ethanol solution of the extract (1 mg/mL) was prepared, and the reaction mixture was made by mixing ethanol solution (0.5 mL), 10% Folin-Ciocâlteu reagent (2.5 mL), and 7.5% NaHCO
3 (2.5 mL). Subsequently, the samples were incubated at 45°C for 45 minutes. A spectrophotometer was used to determine the absorbance at 765 nm versus a blank. Gallic acid was used as a standard to construct the standard curve. Total phenolic content was expressed as mg gallic acid per milliliter of preparation (
17).
Colorimetric analysis was used to calculate the total flavonoid content. The samples consisting of 1 mL ethanol solution of the extract (1 mg/mL) and 1 mL aluminum chloride 2% solution dissolved in methanol were prepared. Subsequently, the samples were incubated for 1 hour at room temperature. Absorbance was determined at 415 nm versus a blank. Standard quercetin was used to plot the calibration curve. Total flavonoid content was expressed as mg quercetin equivalent per milliliter of preparation (
18).
3.4. Ethical Considerations
This study was approved by the Ethics Committee of Tehran University of Medical Sciences (
IR.TUMS.MEDICINE.REC.1400.145) and conducted in accordance with the principles of the Declaration of Helsinki. The clinical trial protocol was registered in the Iranian Registry of Clinical Trials system (
IRCT20210510051241N1).
3.5. Participants
This study was a triple-blinded, randomized, controlled clinical trial. Given the higher prevalence of obesity in women and their higher likelihood of using weight loss medications, this study was performed only on women (
19). Recruitment posters were put up in the clinics of Tehran University of Medical Sciences and on social networks. Volunteers (n = 94) were invited to Ahmadiye Clinic (i.e., a specialized traditional medicine treatment center) for interviews from July to September 2021. A sample size of 26 per group was calculated based on a previous study due to weight changes (
20), taking into account a 95% confidence interval and 95% test power. Considering a 20% probable drop-out rate, 35 participants were enrolled in each group (n = 70).
3.6. Random Allocation and Concealment
The participants were divided into two groups using a random allocation list generated by R4.0.2 software. To achieve concealment, the bottled KF and placebo samples were coded by a person who was not involved in the trial. The researchers, participants, and a statistician were completely blind to group allocations.
3.7. Inclusion and Exclusion Criteria
The inclusion criteria were women aged 20 - 40 or 40 - 50 years with normal mammography and a body mass index (BMI) of 25 - 34.9 kg/m2. The exclusion criteria comprised a history of cardiovascular, hepatic, renal, thyroid or pancreatic diseases, diabetes mellitus, hypertension, excessive menstrual bleeding, any type of malignancy, allergies, hormonal disorder, recent or active infectious diseases, pregnancy, lactation, or postmenopause, excessive use of decoctions and herbal medicines, smoking or alcohol consumption, a family history of breast or endometrial cancer in first-degree relatives, continuous use of acetaminophen (paracetamol), anticoagulants, or antiplatelet drugs, such as aspirin, warfarin, and heparin, and following a weight loss diet or having consumed weight loss medications in the past 6 months.
3.8. Study Design
All the participants read and signed a written informed consent form. At the beginning of the interview, a questionnaire for general information, including name, age, education, occupation, family history of obesity, history of previous diseases, and used medications, was completed by the researcher. Observing the principles of medical ethics and the fact that patients were not to be deprived of conventional treatments, an individualized weight loss diet was designed for all the volunteers by a nutritionist.
3.9. Diet Design
The amounts of dietary calories were calculated using the Mifflin equation for all the participants (
21). Based on the personal characteristics and dietary habits of each participant, an individualized diet was designed. Total energy expenditure was estimated by considering the coefficient of physical activity and a 10% thermic effect of food. Since all the participants were overweight or obese, 500 kcal was deducted from the total calculated calories. The diet comprised 50%, 20%, and 30% carbohydrate, protein, and fat, respectively.
The duration of the study was 8 weeks based on similar previous studies (
22,
23). Three face-to-face visits (i.e., the first visit, the end of the fourth week, and the end of the eighth week) were scheduled for the participants. At each visit, the researcher assessed anthropometric indices and food intake using a 24-hour food recall questionnaire (2 working days and 1 weekend day). Biochemical indicators and physical activity levels were also examined at the beginning of the study and the end of the trial using blood tests (after 12 hours of fasting) and the short form of the International Physical Activity Questionnaire (IPAQ), respectively.
Each participant in the intervention group received 2000 mg of KF daily (one capsule (500 mg) 30 minutes before breakfast, two capsules (1000 mg) 30 minutes before lunch, and one capsule (500 mg) 30 minutes before dinner for 8 weeks. The placebo group received the same amount of oral Avicel. The participants were instructed not to change their routine physical activity during the study and to inform the researcher of any new medications. Half of the medicines (two 60-capsule containers) were given to the participants at the beginning of the study, and the other half was delivered on the second visit. Phone calls were made once a week to reduce the risk of drop-outs, ensure the correct use of drugs, and obtain information about drug side effects. For compliance assessment, the participants were asked to deliver their capsule containers (full or empty) to the researcher on the second and third visits. The participants were excluded from the study if less than 95% of the drug was consumed.
3.10. Measured Variables
Anthropometric Measurements: Height and waist circumference were measured by the researcher on the first visit, and other anthropometric indices were measured on all three visits. Height was measured without shoes by a Seca stadiometer (Seca, Hamburg, Germany) with an accuracy of 0.5 cm. Weight measurement was performed by Seca scales (Seca, Hamburg, Germany) on all three visits, with an accuracy of 0.1 kg. The participants were fasting, had no shoes on, had minimum clothing, and were asked to wear the same garment in all visits.
• The BMI was calculated by dividing weight in kilograms by height in square meters.
• Waist circumference (WC) was measured with an inelastic plastic meter in the smallest circumference of the distance between the last rib and the iliac bone with an accuracy of 0.5 cm.
• Hip circumference (HC) was measured with an inelastic plastic meter in the largest HC with an accuracy of 0.5 cm.
• Wrist circumference was measured with an inelastic plastic meter exclusively from the right side at the junction of the wrist to the forearm on the styloid appendage of the ulnar bone with an accuracy of 0.5 cm.
• The waist-to-hip ratio (WHR) was obtained by dividing WC by HC.
Biochemical Evaluation: At the beginning and end of the intervention, 8 cc of blood was taken from a vein in the left arm after 12 hours of fasting and while in a sitting position. Serum was separated by centrifugation, and the mentioned factors were measured by an enzymatic method immediately after blood sampling. All the tests at the beginning and end of the study were performed using kits with the same LAT number and in the same laboratory.
Questionnaires: For physical activity measurement, the IPAQ (
24) was completed by the researcher at the beginning and end of the study. The participants were accordingly divided into three groups, namely sedentary, moderately active, and highly active.
The amount of food intake was recorded during all visits by the researcher using a 24-hour food recall questionnaire (2 working days and 1 weekend day). Nutritionist IV software (version 3.5.2; First Databank Inc., Hearst Corp., San Bruno, CA, USA), modified to suit Iranian food, was used to measure the amounts of consumed macronutrients and dietary fiber.
3.11. Statistical Analysis
Data distribution was checked for normality using the Kolmogorov-Smirnov test. Quantitative data were expressed as mean and standard deviation. Qualitative data were presented as percentages. Intra-group comparison for the data with normal distribution was performed using the paired t-test. A t-test was used for intergroup comparison. Analysis of covariance was used to modify confounders. All the analyses were performed by SPSS software (version 26). A p-value of less than 0.05 was considered statistically significant.