Safety and Efficacy of Medicinal Plant Extract in Overweight and Obese Participants.

Medicinal plants are widely used for their accessibility, safety and effectiveness and may be an excellent alternative strategy for developing future drugs with minor adverse effects. Several studies concerning the potential of bioactive components in plants and food products and their link to many diseases including, diabetes, cardiovascular disease and obesity.

Nitraria retusa is a salt-tolerant plant that belongs to the Nitrariaceae family. It is particularly distributed in Asia, China, North Africa, Russia and Europe.It grows in the southern part of Tunisia and it is locally known as Ghardaq. The leaves serve as supplement for the tea and are used as poultice. Fresh leaves of Nitraria retusa have been used in traditional medicine in case of poisoning, upset stomach, ulcers, gastritis, enteritis, heartburn, colitis, and colonic abdominal pain.

Moreover, anticancer, antioxidant, antiviral and antimicrobial activities of N. retusa have been reported .Several reports evinced that the leaf of Nitraria retusa contains high amounts of tannins, alkaloids, steroids and flavonoids, which could be responsible for its beneficial effects . Previous studies have demonstrated the effect of Nitraria retusa extract in obese mice against high fat diet through lowering glucose and triglycerides and the enhancement of the lipid metabolism in liver.

The purpose of this study was to evaluate the efficacy and safety of short daily administration of Nitraria retusa extract in lipid profile in overweight and obese patients, during 10 days.

This study will be carried out in 2 departments: the laboratory of biophysics of the Faculty of Medicine of Sousse and Endocrinology and diabetology of CHU Farhat Hached Sousse ,Tunisia. At day 0 and day 10 all the population will benifit of biological assessment which include:

• Biochimical parameters

• Complete lipid profile (Total Cholesterol (T-C), High-density Lipoprotein (HDL) Low-density Lipoprotein (LDL) and Triglycerides( TG) .
• Blood sugar
• Liver Function Test : Alkaline phosphatase (ALP), gamma-glutamyltransferase (G-GT), albumin, Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), total ( TB) and direct bilirubin (DB).
• Renal Function Test : Serum Creatinine, urea
• Inflammatory assessment: Reactive protein C
• Hematological parameters : (Red blood cells (RBC), White blood cell (WBC), Platelet, Hemoglobin and Hematocrit).

All Population will be randomized :Participant will be assigned to one of two treatments (low dose flavonoids or high dose flavonoids ). The diatry supplement :Nitraria retusa infusion will be prescribed at a quantity of powder which contained 5 mg of flavonoids or which contained 20 mg of flavonoids , added to 100 ml of boiling water and will be taken once a day at a bed time for 10 consecutive days.

Statistical analysis Data entry and analysis will be performed using SPSS 22.0 for Windows(IBM Corp., NY, USA ). Results will be considered significant at p < 0.05 Normal distributions of the data will be assessed by Shapiro-Wilk test. Within-group differences in the biological parameters before and after the intervention will be compared using paired t-test when data are normally distributed and Wilcoxon Signed Rank Test when data are not normaly distrubuted. Between-group differences (low dose vs high dose) in the parameters will be assessed by independent samples t-test (parametric and equal variances), Welch's t-test (unequal variances) and Mann-Whitney U test (nonparametric)

Inclusion criteria

• Males and females
• age range of 18 and 75 years
• BMI >25 kg/ m^2

Exclusion criteria

• Hypertension
• Diabetes
• Asthma
• Smoking
• Professional athletic
• Pregnancy and breast feeding
• Participant with medical or psychiatric disorder or chronic pathology,
• Participant with eating disorder, food allergies.
• Participant with a history of cardiovascular disease,
• Participant with medication known to affect lipid metabolism,
• Participant with major gastrointestinal problems.