Effect of Wheat Bread Incorporated with Chamomile and Wild Thyme on Glycemic and Insulin Responses, Antioxidant Status and Inflammation in Type 2 Diabetic Individuals

doi:10.21203/rs.3.rs-4938027/v1

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Effect of Wheat Bread Incorporated with Chamomile and Wild Thyme on Glycemic and Insulin Responses, Antioxidant Status and Inflammation in Type 2 Diabetic Individuals

https://doi.org/10.21203/rs.3.rs-4938027/v1

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Previous studies suggest that bread incorporated with chamomile and wild thyme powder exhibit lower starch digestibility and higher antioxidant activity in vitro and hence its intake may suppress postprandial blood glucose and enhance antioxidant status in humans. The present study determined the effect of bread incorporating chamomile and wild thyme on blood glucose, insulin, antioxidant status and inflammation in type 2 diabetic individuals. Sixteen male subjects consumed either control bread (CB) or bread incorporated with 3 % chamomile and wild thyme powder in two separate sessions. Blood glucose was measured by finger-prick method at fasting and then postprandially for 2 h. Plasma insulin, antioxidant and inflammatory markers were measured at fasting and 2 h after consumption. A non-significant decrease in blood glucose while a non-significant increase in insulin was observed after the consumption of chamomile and wild thyme-containing bread (CWB) compared to CB. Compared to baseline, the consumption of CWB increased total polyphenols, total antioxidant capacity (TOAC) and superoxide dismutase (SOD) activity by 6%, 20% and 15%, respectively. Similarly, CWB non-significantly decreased thiobarbituric acid reactive substances (TBARS) by 27% and C-reactive protein (CRP) by 12% compared to CB. In conclusion, the consumption of bread incorporated with chamomile and wild thyme resulted in an improvement in blood glucose and plasma insulin levels, a beneficial increase in polyphenols, TOAC, SOD activity and a reduction in TBARS and CRP levels in type 2 diabetic individuals. Further studies are now warranted with large sample sizes and larger doses to achieve significant clinical results.

chamomile

wild thyme

glycemia

plasma insulin

antioxidant activity

oxidative stress

Diabetes mellitus is the fourth most prevalent non-communicable disease, characterized by a deficiency of insulin secretion, action, or both, resulting in hyperglycemia. (Dilworth et al., 2021). Elevated blood glucose levels affect several organs and tissues in the body, increasing human morbidity and mortality (Dhatariya et al, 2020 ). Long-term hyperglycemia enhances free radical generation and oxidative stress, resulting in protein glycation and membrane lipid peroxidation, thereby reducing the body's endogenous antioxidant defense system (Galicia-Garcia et al., 2020). Both pharmacological and non-pharmacological approaches are used to treat hyperglycemia. The most important non-pharmacological therapeutic techniques in diabetes control are medical nutrition therapy and exercise. Pharmacological options include oral antihyperglycemic medications, synthetic drug combinations, insulin therapy, phytoconstituents, and the combination of herbal phytoconstituents with synthetic therapies (Khursheed et al., 2019). Fiber, antioxidants, polyphenols, glucosinolates, inducers of beneficial enzyme activities, polyunsaturated fatty acids, prebiotics, and probiotics are examples of herbal phytoconstituents (Forni et al., 2019).

Chamomile (Matricaria chamomilla L.) is a medicinal herb that contains over 120 bioactive chemicals and was traditionally used to alleviate intermittent fevers for centuries (Singh et al., 2011). In animal studies chamomile extracts ameliorated hyperglycemia and HbA1c level (Emam, 2012; Rajagopalan et al., 2016), enhanced insulin levels and insulin sensitivity (Abdolmaleki & Heidarianpour, 2018) and preserved insulin-producing cells of pancreatic islets (Cemek et al., 2008) in the treatment group compared to placebo. In human studies, chamomile tea showed a marked decrease in HbA1c concentration, serum insulin level, inflamtory markers, oxidative stress markers and an improvement in lipid profile and antioxidant markers (Hajizadeh et al., 2020). Antihyperglycemic mechanisms of chamomile are attributed to modulation of peroxisome proliferator-activated receptors (PPARs), inhibition of intestinal α-glucosidase activities, inhibition of liver glycogen phosphorylase that enhance hepatic glycogen content and inhibition of intestinal glucose transport causing a decrease in carbohydrate absorption (Kato et al., 2008).

Wild thyme (Thymus serpyllum L.), another medicinal herb, is used for various purposes such as expectorant, anthelmintic, antiseptic, carminative, sedative, and tonic (Jaric et al., 2015). In previous animal studies, wild thyme was shown to lower blood glucose level and improve the glucose and insulin tolerance in diabetic animal models (Azhar et al., 2022; Alamgeer et al., 2012). The possible mechanisms underlying the beneficial effects of wild thyme in lowering blood glucose include inhibition of α-amylase activity and improvement in insulin sensitivity (Wahab et al., 2022). These findings supported the use of wild thyme as a beneficial supplement for diabetes. However, despite the beneficial effects of wild thyme in modulating blood glucose in animal models, the potential benefits of wild thyme against type 2 diabetes in humans are not yet investigated.

White bread is a high glycemic staple food, contains high amount of rapidly digested starch, which increases postprandial blood glucose promptly and is therefore, not recommended in individuals with diabetes (Amoah et al., 2022). Therefore, modulating the glycemic features of bread may be a key strategy in managing glucose metabolism in diabetic patients. In the context, different plant-based functional ingredients, such as herbs, underutilized cereal grains, seeds, and other plant parts, have been incorporated into bread due to their health-promoting effects, including but not limited to reducing the glycemic index of bread and enhancing its nutritive value, bioactive properties, and antioxidant activity (Schadow et al., 2023; Amini et al., 2020).

To our knowledge, no study has yet explored the effects of the consumption of bread containing chamomile and wild thyme on the metabolic profile of individuals with type 2 diabetes. Therefore, the present study aimed to investigate the effect of consuming bread incorporated with chamomile and wild thyme on glycemia, plasma insulin, oxidative stress markers and inflammation in individuals with type 2 diabetes. We hypothesized that the consumption of bread incorporated with chamomile and wild thyme powder may provide a complementary effect and could significantly improve the metabolic parameters in individuals with type 2 diabetes.

Procurement of raw materials

All-purpose wheat flour (Waqas general flour mills, Punjab-Pakistan) and other baking materials including salt, sugar, butter and yeast were procured from the local market. Wild thyme was procured from authorized dealers in Skardu, Gilgit-Baltistan while chamomile was purchased from authorized dealers in Karachi (Pakistan’s first Herbal Store, Karachi) in sealed plastic containers. The samples were powdered using a commercial grinder and were stored in plastic jars until use.

Bread preparation

The bread was prepared by the straight dough method. Briefly, a basic dough recipe on a 100 g flour basis for control bread (CB) was followed by mixing the flour with weighted ingredients. The dough was prepared by adding ingredients including 6 g sugar, 1 g salt, 2 g yeast, 5 g oil and 60 ml water to 100 g all-purpose wheat flour. For the preparation of chamomile and wild thyme-containing bread (CWB), the chamomile and wild thyme powders were first mixed at equal proportions. Wheat flour was then replaced with the mixture at 3% incorporation levels. All other ingredients were kept the same for the preparation of the treatment bread. The dough was kneaded with hands for 40 min at room temperature and transferred into baking pans for fermentation for 30 minutes. The bread was baked for 20 min at 220 ^oC in an electric baking oven (Panasonic Digital Oven). Nutrient composition/100 g of control and test breads is shown in Table 1.

Table 1

Nutrients composition/100 g of control and test breads
Ingredients	CB	3% CWB
Bread (g)	103	104
Energy (Kcal)	240.70	248.21
Av. CHO (g)	50	50
Protein (g)	7.88	8.98
Fats (g)	1.02	1.48
Dietary fiber (g)	0.584	2.15
Av. CHO: available carbohydrates; CB: control bread; CWB: chamomile and wild thyme-containing bread.

Subjects recruitment

Sixteen male diabetic individuals were recruited through personal contacts. The inclusion criteria were: age 30–60 years, BMI ≥ 25.0 kg/m² and fasting blood glucose > 6.1 mmol/L. The study exclusion criteria were: use of insulin, history of gastrointestinal disease, food allergies, smoking, pregnant or lactating women and breakfast skippers. A health screening questionnaire was used for screening. Full details of the study protocol were explained to the participants and their queries were answered before study initiation, and they were allowed to withdraw from the study at any time. This study was performed according to the guidelines laid down in the Declaration of Helsinki. The study was approved by the Human Research Ethics Committee of the Department of Human Nutrition (HN-HREC/2020-008), The University of Agriculture, Peshawar. All the subjects provided written informed consent for participation in the study.

Study design and protocol

Each subject attended two testing sessions. At each session, subjects consumed one of the two test breads in a random order. On arrival to the laboratory after an overnight fast, baseline measurements including height, weight and waist circumference were measured. After 5 min of resting, a peripheral venous catheter was inserted into an antecubital vein. Fasting blood samples were collected in EDTA tubes by venipuncture for the analysis of insulin and other parameters. Blood glucose was measured in capillary blood using finger prick method. Afterward, the test bread was served to the subjects with water (250 ml). Subjects were ensured to finish the test bread within 10 min and advised not to consume anything during the next 2 h. Again venous blood samples were collected from the subjects at 2h after consuming the bread. This time was selected based on the peak absorption time (90–150 min) of polyphenols reported in the literature (Torabian et al., 2009). Plasma was separated from whole blood by centrifugation (3000 rpm for 15 min) at 8 ^oC. The plasma was aliquoted and stored in cryovials at 80^oC until analysis.

Blood glucose analysis

Blood samples from the subjects were collected from warmed fingertip using lancet device, following glycemic index testing protocols (Brouns et al., 2005). Briefly, the subjects get their finger warmed before the prick to increase blood flow. Capillary blood samples were collected without squeezing the finger (to avoid dilution of plasma). A series of blood analyses were taken i.e. at baseline (immediately before bread consumption) and thereafter at 30, 45, 60, 90, and 120 min using Accu Check glucometer. The first drop of the blood was discarded to avoid contamination with alcohol and interstitial fluid and used a second drop on the glucose testing strip. The same glucometer was used throughout the study to minimize “intra-subject variation”. A blood glucose recording sheet was used to record the values.

Plasma insulin analysis

Plasma insulin level in diabetic individuals was measured by electrochemiluminescence immunoassays (ECLIA) for human insulin using Roche Cobas e411 analyzers (Roche Diagnostics GmbH, Mannheim, Germany) at the laboratory of “Institute of Kidney Diseases, Hayatabad, Peshawar”, following the manufacturer protocol.

Measurement of plasma total polyphenols

Total polyphenols were first extracted from the blood plasma as previously described (Khan et al., 2015). The Folin-Ciocalteau method adopted by (Hajira & Khan, 2022) was then used for the determination of plasma total polyphenols. Briefly, 100 µl of the concentrated extract was mixed with 500 µl of 0.2 N Folin-Ciocalteu reagent and 400 µl of Na₂CO₃ (2 M) solution. The mixture was incubated for 90 min at 25°C in the dark. The absorbance was measured using a microplate reader (Multiskan Go, Thermo Fisher Scientific, USA) at 750 nm. Milli-Q water (100 µl) was used as a blank. A calibration curve was constructed from gallic acid concentration in the range of 0–500 mg/l and results were presented as mg of gallic acid equivalents (GAE) per liter of blood.

Total antioxidant capacity (TAOC)

TAOC was measured by enzyme-linked lmmunosorbent assay (ELISA) kit: Cat. No E2199Hu (Bioassay Technology Laboratory, China). This sandwich kit is used for the accurate quantitative detection of human total antioxidant capacity (TAOC) in serum, plasma, cell culture supernates, cell lysates and tissue homogenates. Its calibration curve was ranging from 0.3U/ml-90U/ml with a sensitivity of 0.14 U/ml. All reagents, standard solutions and samples were prepared as per the instruction of the manufacturer. The assay was performed at room temperature. Briefly, 50µl standard was added to the standard well and 40µl sample to sample wells. Antibody was not added to a standard well because the standard solution contained a biotinylated antibody. Then added 10µl anti-TAOC antibody to sample wells and 50µl streptavidin-HRP to sample and standard wells (Not blank control well). Mixed thoroughly covered with a sealer and incubated for 60 minutes at 37°C. Removed sealer and washed the plate 5 times for 30 seconds to 1 minute with wash buffer (0.35 ml). After blotting onto paper towels or other absorbent materials, 50µl substrate solution A and 50µl substrate solution B was added to each well. Incubation of plate covered with a new sealer for 10 minutes at 37°C in the dark was performed. Stop solution (50µl) was added to each well, the blue color changed immediately into yellow color. The optical density (OD value) of each well was determined immediately using a microplate reader (Multiskan Go, Thermo Fisher Scientific, USA) set to 450 nm within 10 minutes after adding the stop solution. A standard curve was constructed to measure the TOAC.

Superoxide dismutase (SOD) activity

SOD activity was determined by ELISA. SOD-1 assay kit of Cat. No E0700 Hu was purchased from Bioassay Technology Laboratory, China. The plate had been pre-coated with a human SOD-1 antibody. Samples (containing SOD), were added to the wells and bound to coated antibodies. Then biotinylated human SOD-1 antibodies were added that were conjugated with SOD-1 in the sample. Afterward, Streptavidin-HRP was added and combined with the Biotinylated SOD-1 antibody. After incubation unbound Streptavidin-HRP was washed away during a washing step. Later on, the substrate solution was added and color developed in proportion to the amount of human SOD-1. The reaction was terminated by the addition of acidic stop solution and absorbance was measured at 450 nm with the help of a Multiskan GO microplate reader (Thermo Fisher Scientific, USA). The concentration was determined using the calibration curve.

Thiobarbituric acid reactive substance (TBARS)

TBARS ELISA kit: Cat.NoE3642 Hu was used supplied and manufactured by Bioassay Technology Laboratory, China. This kit had a standard curve cange: 0.05 nmol/ml – 30 nmol/ml with a sensitivity of 0.022 nmol/ml. 50µl standard containing biotinylated antibody was added to a standard well. Next, added a 40 µl sample to the sample wells and 10µl anti-TBARS antibody to the sample wells, then added 50 µl streptavidin-HRP to the sample wells and standard wells (Not blank control well). Covered the plate with a sealer and ncubated for 60 minutes at 37°C. Removed the sealer and washed the plate 5 times with wash buffer. Soaked wells with at least 0.35 ml wash buffer for 30 seconds to 1 min for each wash. For automated washing, aspirated all wells and washed 5 times with wash buffer, overfilling wells with wash buffer. Blotted the plate onto paper towels or other absorbent material. Added 50µl substrate solution A to each well and then added 50µl substrate solution B to each well. The incubated plate was covered with a new sealer for 10 minutes at 37°C in the dark. Added 50µl stop solution to each well, the blue color changed into yellow immediately. Determined the optical density (OD value) of each well immediately using “Multiskan GO microplate reader” (Thermo Fisher Scientific, USA), within 10 minutes after adding the stop solution. The wavelength was set to 450 nm. A calibration curve was constructed for measuring the concentration.

High sensitivity C-reactive protein (hs-CRP)

Particle enhanced immunoturbidimetric assay was used for determination of plasma hs-CRP on Roche/Hitachi automated analyzer (Cobas C311, Roche diagnostics GmbH, Mannheim, Germany). Roche diagnostic kit, Ireland; was purchased and the manufacturer’s quality controls and calibration materials were used. Two working solutions reagent 1 (R1) and reagent 2 (R2) were provided in the kit. R1 (TRIS) is a buffer solution with bovine serum albumin and immunoglobulin from the mouse. While anti-CRP antibodies collected from mice were supplied as R2 (latex particles). Plasma CRP adhered to latex particles (R2) and produced insoluble immune complexes, causing turbidity in proportion to the concentration of CRP in the testing material. All processes including dispensing of samples were carried out automatically and the concentration of samples was obtained at 546 nm. Results were obtained automatically using 6 levels of a calibration curve. The coefficient of variation (CVs) was < 6%.

Statistical analysis

SPSS (version 21, SPSS Inc. Chicago, lL, USA) was used for statistical analysis. Normality of the data and homogeneity of variance were checked using Kolmogorov–Smirnov and Levene’s tests, respectively.Values are presented as means ± SEMs. Two ways repeated-measures ANOVA with post-hoc Bonferroni adjustment was used to investigate the effect of time, treatment and their interaction on blood glucose. The effect of treatment on blood glucose iAUCs was determined using paired t-test. The effect of treatment, time and their interaction on insulin level was determined by two-way ANCOVA taking the baseline values as a covariate. The effect of treatment on insulin AUC was determined using paired t-test. For intragroup comparison (baseline vs. 2-hour values) of plasma polyphenols, antioxidant markers (TAOC, SOD activity and TBARS) and hs-CRP, paired sample t-test was used. A (p < 0.05) was used for statistical significance.

Baseline characteristics

Baseline data of the recruited diabetic subjects are presented in Table 2. Mean age (years), body mass index (BMI = kg/m²), fasting blood glucose (mg/dl) and waist circumference (WC) of diabetic subjects were 49.10, 27.06, 205.75 and 99.2 cm respectively. Fasting blood glucose (FBG) levels were in the range of 193 to 219 with a mean value of 205.75 ± 13.31.

Table 2

Baseline characteristics of the Diabetic participants.
Variable	Ratio/ Mean ± SEM
M/F	16/0
Age(y)	49.10 ± 1.62
Weight (kg)	78.44 ± 2.99
Height (m)	170.20 ± 1.89
BMI (kg/m²)	27.06 ± 1.04
Waist circumference (cm)	99.20 ± 2.30
Fasting plasma glucose (mg/dl)**	205.75 ± 13.31
Systolic blood pressure (mm Hg)	132.60 ± 5.03
Diastolic blood pressure (mm Hg)	95.50 ± 2.84
∗∗Mean value of 3 measurements performed during the OGTT.

Blood glucose response in diabetic subjects

Mean change in blood glucose from baseline and incremental areas under the curves (iAUC) in diabetic subjects (n = 16) after consumption of 3% CWB or CB is presented in Fig. 1. There was a significant effect of time (p < 0.001) but a non-significant effect of treatment (P = 0.411) and time x treatment (p < 0.813) on postprandial blood glucose levels in diabetic subjects. The consumption CWB resulted in lower blood glucose concentration compared to CB however, this difference was not significant. The highest mean difference in peak blood glucose concentration between CWB and CB of 8.30 mg/dl was observed at 60 min. There was no significant difference (p = 0.367) in iAUC between CWB and CB.

Plasma insulin response

Plasma insulin level is presented in Fig. 2. Plasma insulin levels of CB and CWB at the baseline were 17.18 pmol/l and 18.59 pmol/l, respectively. This level increased to 26.80 pmol/l at 1 h and 27.76 pmol/l at 2 h after CB consumption. However, a 2-fold increase in insulin levels occurred after CWB consumption at 1 h and 2 h compared to baseline values. On the other hand, comparing these values between the groups, 46.6 and 34% increase occurred at 1 h and 2 h, respectively after consumption of CWB compared to CB. However, treatment and treatment x time interaction effects were not significant (p > 0.05). The insulin iAUC value for CWB was non-significantly high than the insulin iAUC for CB.

Plasma total polyphenols

Total polyphenols level of the subjects at baseline and after 2 h consumption of treatment breads are shown in Fig. 3. Total phenolic content in plasma slightly reduced at 120 min compared to baseline values (0 min) after consumption of CB. The polyphenolic content of plasma slightly increased after consumption of CWB at 120 min compared to baseline values. However, the increase was not significant (p > 0.05).

Plasma total antioxidant capacity

The plasma total antioxidant capacity (TOAC) of both CWB and CB is shown in Fig. 4. TOAC improved and an increase was seen after the consumption of CWB at 120 min compared to baseline values (0 min). Howvere this increase wa not significant statistically ( p > 0.05).

Plasma superoxide dismutase (SOD) activity

The level of plasma SOD activity is presented in Fig. 5. No significant changes were observed in SOD activity after the consumption of either CB or CWB at 120 min compared to baseline values (0 min). CWB resulted in an increase in SOD activity at 120 min compared to baseline values (0 min) however, this increase was not significant (p > 0.05).

Plasma thiobarbituric acid reactive substances

The concentration of TBARS is presented in Fig. 6. At baseline, TBARS levels in both groups were almost the same. Plasma TBARS level did not differ significantly (P > 0.05) 2 h after consumption of any of the two test bread compared to their corresponding baseline level (0 min). A decrease was seen in TABRS at 120 min compared to baseline values (0 min) after consumption of CWB however, this decrease was not significant (P > 0.05).

High-sensitivity C-reactive protein

Serum hs-CRP is presented in Fig. 7. The mean hs-CRP concentration of CB at fating was 1.6 ± 2.25 mg/l. This level remained almost stable (1.85 mg/l) at 120 min after the consumption of CB. The hs-CRP level decrease by 12% after consumption of CWB at 120 min compared to baseline values (0 min) however, these changes were not statistically significant (p > 0.05).

The current study, for the first time, investigated the effect of CWB on glycemic profile, insulin and some biochemical indicators of oxidative stress in a cohort of diabetic participants. Consumption of CWB resulted in an improvement in glycemic response and plasma insulin level. It also enhanced plasma polyphenol, antioxidant capacity and SOD and beneficially improved markers of oxidative stress (TBARS) and inflammation (hs-CRP).

The results of of the current clinical trial, regarding the antihyperglycemic potential of chamomile were consistent with previous studies. Cemek et al., (2008) and Emam (2012) proved that chamomile extracts significantly diminished blood glucose and developed insulin sensitivity in streptozotocin (STZ)-induced diabetic rats. Polyphenols found in chamomile have been shwon to decrease circulating blood glucose levels dramatically in diabetic rats by inhibiting intestinal alpha-glucosidase activities (Alam et al., 2022), reducing oxidative stress (Cemek et al., 2008), upregulating peroxisome proliferator-activated receptors (PPAR) (Weidner et al., 2013), modulating glucose transporter (GLUT)-4 receptors and triggering the 5-adenosine monophosphate protein kinase (AMPK) pathway by enhancing the expression of the adiponectin gene (Ding et al., 2010).

The current study's findings on the antihyperglycemic properties of wild thyme (WT) were similarly consistent with earlier investigations. In their review Jalil et al., (2024) pointed out that the alkaloids, glycosides, thymol or carvacrole, flavonoids and terpenoids present in wild thyme reduced blood glucose levels, imitated insulin, decreased glucagon secretion, restored the impaired β-cells, promoted glycolysis and decreased glucose absorption from the alimentary canal by inhibitory action on releasing α-glucosidase.

The new study's findings on plasma polyphenol contents and antioxidant capacity were like those of previous research. Dietary and plasma polyphenol contents were investigated by several investigators using different foods separately or by incorporation of one or more food ingredients. Fuhrman et al. (2005) used fruits; while, tea, olive oil, chocolate and red sorghum were used by Henning et al. (2004), Covas et al. (2003), Serafini et al. (2003) and Khan et al. (2015) respectively in separate studies. They reported a direct relation between polyphenols and total antioxidant capacity and suggested that simple incorporation of rich polyphenolic diet (1–2 servings/day) into the diet to increase both dietary/plasma polyphenol and plasma antioxidant capacity for favorable health benefits through antioxidant protection. Although, they could not explain the exact mechanisms and absorption sites of polyphenols in humans and speculated that the absorption of polyphenols might have mostly taken place within 90 min in the upper tract of the gastrointestinal tract. However, they hypothesized that polyphenols present in the diet reduced the production of superoxide anions through antioxidant properties, lipid peroxyl radicals and hydroxyl radicals improving cardiometabolic health. These authors suggested further studies to absolutely recognize the kinetics of polyphenols in humans while measuring some of the urinary metabolites.

Oxidative stress is a toxic process that injures cells of the body. Premature aging, arthritis, cardiovascular diseases, diabetes, cancer, autoimmune, and neurological disorders are all related to increased oxidative stress (Gupta et al., 2014). The current study's findings were likewise equivalent to those of Ramadan and Emam (2012). They treated diabetic animals with an aqueous extract of chamomile (100 mg/kg/day) and observed that the levels of endogenous antioxidant enzymes increased significantly bringing oxidative stress closer to normal level. In comparison to untreated diabetic animals, this intervention considerably reduced malondialdehyde (MDA) production. Same results were confirmed by Alouie et al. (2017) and Al-Musa & Al-Hashem (2014) in other animal studies. Similarly, in a human study, taking three daily cups of chamomile tea (3 g/150 ml hot water) for eight weeks, Zemestani et al. (2016) discovered a significant increase in SOD, catalase, and glutathione peroxidase activities, as well as a significant reduction in MDA levels in type 2 diabetic individuals.

The consumption of CWB decrease hs-CRP by 12% compared to baseline values in the present study. Several researchers have investigated the effects of chamomile extract and essential oil on inflammation (Wu et al., 2012; Fabian et al., 2011). They concluded that chamomile extract affected the vascular system by lowering inflammation and edema caused by croton oil, which was similar to benzydamine, in the ears and paws of rats. Zemestani et al. (2018) determined the anti-inflammatory impact of 3 g/day chamomile tea intake in the type 2 diabetic individuals and observed a dropping effect of chamomile tea on tumor necrosis factor-α (TNFα) and high sensitive-C reactive protein (hs-CRP). Although the present study showed a decrease in oxidative stress and inflamttory markers, these effects were not significant. The possible reason for not showin significant effects on these biomarkers could be attributed to the low dose and acute nature of the current study.

In conclusion, 3% CWB non-significantly improved postprandial glucose, insulin level, plasma polyphenols, antioxidant status and SOD activity in type 2 diabetic individuals. Similarly, a non-significant reduction in the biomarker of inflammation (CRP) and lipid peroxidation (TBARS) was observed. In future studies, the duration and dose of chamomile and/or wild thyme should be considered for inhibitory influence on carbohydrate and lipid absorption.

Funding

This study received no financial support.

Conflict of Interest

The authors declare that there are no conflicts of interest.

Acknowledgements

The authors extend their appreciation to the Researchers Supporting Project number (RSP2024R502), King Saud University, Riyadh, Saudi Arabia.

Authors’ Contributions

IK and IA designed the study. IK and IA conducted the study and analyzed the data. IK, IA and JA drafted the manuscript. IK, SKJ, JA and AMA critically revised the manuscript. All authors read and approved the final version of the manuscript.

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No competing interests reported.

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Effect of Wheat Bread Incorporated with Chamomile and Wild Thyme on Glycemic and Insulin Responses, Antioxidant Status and Inflammation in Type 2 Diabetic Individuals

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