Bioavailability of Antioxidant Compounds and Effect on Markers of Inflammation by Ingestion of a Hibiscus Sabdariffa Beverage With Glicemic and Insulinemic Response

The following study will be carried out in two stages where an acute single-blind, crossover, randomized, single-blind clinical study will be performed, where 12 volunteers between 18 and 40 years of age, normal weight (BMI 18.5-24.9 kg/m2), without existing pathologies and/or with pharmacological treatment will be required. The characteristics of the study will be explained to the volunteers beforehand, and those who agree with the specifications will sign the informed consent form and become candidates to participate. The study will consist of the administration of a treatment drink based on hibiscus (H. sabdariffa), controlled with a placebo drink, both with a volume of 60 ml.

The first stage will consist of the selection of volunteers who will undergo two interventions. On the day of the 1st intervention, participants will arrive at 7 a.m., central time in Mexico, with an overnight fast of 10-12heures . Prior to the intervention, the clinical history including anthropometric measurements and dietary questionnaire (24eures reminder) will be filled out and participants will be asked to rest for 30 min prior to taking their blood pressure at the time of admission, and they should be seated, upright and with their feet on the floor during the process; the measurement will be performed using a manometer on the left arm, elevated at the level of the heart. Afterwards, samples (urine and blood) were taken. Those corresponding to urine will be taken a basal sample (T=0) in a collection bottle. Once the hibiscus-based drink or placebo is ingested, samples will be collected at the following times: 3h, 6h, 12h and 24h. The samples corresponding to blood will be collected with the help of collecting tubes by venous puncture. Eight samples were taken, the first one at the arrival of the patients being basal time (T=B), then at 30 minutes (T=2), 1heure (T=3), 1:30heures (T=4), 2heures (T=5), 3heures (T=6), 4heures (T=7) and 6heures (T=8) after having ingested the hibiscus-based drink or the placebo. During the intervention the volunteers will receive a Western-type diet after the consumption of the beverage, characterized by excessive consumption of red meat, simple carbohydrates, ultra-processed products, colorants, saturated fats, refined sugars and very little intake of fiber and vitamins. After a washout period of more than 6 days, the participants will undergo a second intervention with a different product than the first time (beverage to be evaluated or placebo as appropriate), and the sampling will be repeated.

The second stage will correspond to the evaluation of the glycemic response (GR) and insulinemic response (IR) of the selected individuals. For this purpose, volunteers should come with homogenized dietary conditions (normocaloric and carbohydrate-controlled diet (300 g/day)), without having performed intense physical activity and with a fasting state of 12 hours; In the place they will consume the treatment drink (BT) and the placebo drink (BP) of 60 mL, accompanied by a portion of white bread, so that the sum of the drink plus the white bread will be 50 g of carbohydrates, the administration of the type of drink will be carried out in different sessions, separated by a washout period of 7 days, so that the participants will consume a different one in each session. The RG and RI will be evaluated at time 0 (preprandial), and at 15, 30, 45, 60, 90, and 120 minutes (postprandial), through capillary blood obtained by fingertip puncture. The evaluation corresponding to the GR will be done by taking the second drop and placing it on highly sensitive test strips of the OneTouch Ultra® System, continuing with the determination of the RI through the collection of blood in BD Microtainer SST tubes, which will be centrifuged for 10 minutes (5000 rpm, 25°C) to obtain the serum, which will be used when employing an ELISA human insulin kit.

The study will be carried out at the Nutricia clinic located in Building M of the Instituto Tecnológico y de Estudios Superiores de Occidente (ITESO) located at Anillo Perif. Sur Manuel Gómez Morín 8585, Santa María Tequepexpan, 45604 Tlaquepaque, Jalisco.