The present invention relates generally to the field of food products. For example, the present invention aims at natural compounds that can help to reduce glucose peaks in the blood of a subject after consumption of food with a high glycemic index. One embodiment of the present invention is a composition comprising an extract of the berries of Morus spp. for use in the treatment or prevention of disorders linked to foods with a high glycemic index.

Background Art

During the past decades, the prevalence of obesity has increased worldwide to epidemic proportion. Approximately 1 billion of people worldwide are overweight or obese, conditions that increase mortality, mobility and economical costs .

Obesity develops when energy intake is greater than energy expenditure, the excess energy being stored mainly as fat in adipose tissue. Obesity is often caused by the consumption of food products with a high caloric density, with most of the calories coming from easily digestible carbohydrates.

Food products with more complex carbohydrates that take longer to digest may be used to increase the duration of satiety and to minimize the risk of developing obesity. Unfortunately, however, food products with easily digestible carbohydrates are generally more liked and hence preferred by the consumer. Obesity represents a serious threat to health because it is associated with an array of chronic diseases, including, e.g., diabetes .

Diabetes mellitus is a metabolic condition characterized primarily by high blood glucose levels that result from the body's inability to make or use insulin. Hyperglycemia can lead to numerous clinical complications including blindness, limb amputations, heart attack or stroke. In 2007, it was estimated that 246 million of adults have diabetes, and if nothing is done to slow down the epidemic, within 25 years the number will reach more than 380 million.

The most common types of diabetes are insulin-dependent diabetes (Type-1 diabetes, T1D) and type-2 diabetes (T2D) , which is by far the most abundant type. The increase in type-2 diabetes is mainly driven by increasing obesity rates. Today, more than 1.1 billion people are estimated to be overweight, of which around 320 million are obese.

The pathophysiology of the development of T2D is complex and multifactorial. Obesity, sedentary life style and/or increased age may lead to insulin resistance and to increased circulating insulin concentrations over time. At some point a loss of control of blood glucose begins to emerge, resulting in impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) and may ultimately result in T2D. Therefore IGT and IFG refer to metabolic states intermediate between normal glucose homeostasis and diabetes.

A further test, the oral glucose tolerance test (OGTT) , may be performed to assess whether the patient is diabetic or has IGT. The OGTT consists of a glucose drink containing 75g of glucose. The patient's blood sugar level is measured at one and two hours following administration of the drink. As glucose is an essential nutrient for the human body, its circulating levels must be carefully maintained constant, in order to supply adequate amounts to peripheral tissues. The liver plays a central role in glucose homeostasis by balancing its uptake and storage via glycogenesis and its release via glycogenolysis and gluconeogenesis . An impairment of glucose homeostasis is a typical feature of T2D. Patients with T2D exhibit increased hepatic glucose production (HGP) , which is identified as the main cause of fasting hyperglycaemia and is associated with a reduced plasma glucose clearance (Gastaldelli A, et al . , Diabetes 2000; 49:1367-1373 ), and a 25-45% reduced synthesis of glycogen compared with non- diabetic subjects (Roden M, et al . , Best Pract Res Clin Endocrinol Metab. 2003;17:365-83). Limiting blood glucose peaks after a meal, in particular in diabetic subjects, constitutes an important target of the overall glycemic control strategy.

Actual treatments for T2D comprise several classes of drugs, which can be used alone or in combination with insulin. Biguanides work by reducing the amount of glucose produced by the liver. Obese patients with T2D are usually started on biguanides. Common side effects include abdominal discomfort, diarrhea, nausea or vomiting, loss of appetite, and metallic taste . Alpha-glucosidase inhibitors slow the digestion of carbohydrates, delay glucose absorption, and reduce the increase in blood glucose after a meal. Common side effects include abdominal pain, diarrhea, and flatulence.

However, it would be desirable to have available a natural compound which is safe to administer without unwanted side effects and that can be used to keep blood glucose levels under control.

Mulberry leaves have been used in Chinese Medicine to cure and prevent 'Xiao-ke' (diabetes) . However, using leaves has the disadvantage that they are subject to environmental circumstances for a very long time and, hence, may contain pesticides or other unwanted compounds.

Contents of the Invention

Hence, it was the object of the present invention to provide the art with a natural and water miscible, ideally water soluble, composition that is safe to administer without side effects and without the need for consultation of medical personnel and that can be used to avoid or reduce glucose peaks after consumption of food with a high glycemic index.

The present inventors have addressed this need and were surprised to see that they could achieve this object by the subject matter of the independent claims. The dependant claims further develop the idea of the present invention.

In particular, the present inventors have found that the addition of mulberry fruit concentrate and/or juice to starch, sucrose and/or maltose rich foods and beverages can reduce the speed of glucose generation in the gut, and therefore contribute to a slow release of glucose into the blood, resulting in a low glycemic response and prolonged availability of sugar as energy source.

It was found for example, that the addition of mulberry fruit concentrate and/or juice to food products with a high carbon content allows making available increased glucose levels in the blood later on, in particular 2-4 hours after ingestion, for example 2.5 - 4 hours after ingestion.

Without wishing to be bound by theory, the inventors presently believe that this effect is achieved via the inhibition of alpha-glucosidase by an extract of the berries of Morus spp ..

Hence, the present invention allows using the generally well liked easily digestible carbohydrates in food products while having the advantage that these carbohydrates are in fact slowly digested. Hence, a similar effect is achieved as if one was using more complex carbohydrates, while taste issues are avoided.

Standardized fruit extracts may be used directly, as concentrates or in powdered form for applications in food and beverage products, supplements or pharmaceutical preparations for healthcare and adult nutrition.

These preparations provide naturally produced, cost-effective components that have a demonstrated hypoglycemic and long- lasting energy effect in carbohydrate rich foods (e.g., porridge, pasta, cereal bars, cereal drinks, biscuits) , and sucrose and/or maltose rich beverages and foods (e.g., ice cream) .

Hence, one embodiment of the present invention is a composition comprising an extract of the berries of Morus spp. for use in the treatment or prevention of conditions linked to foods with a high glycemic index.

The composition may be a food composition with a high glycemic index to which an extract of the berries of Morus spp. was added . Consequently, the composition may further comprise a carbohydrate source.

The carbohydrate source may represent at least 50 %, preferably at least 65 %, more preferred at least 80 % of the energy of the composition.

The composition may have an energy density in the range of about 0.2 kcal/g to 5 kcal/g.

A further embodiment of the present invention is a composition comprising an extract of the berries of Morus spp . for reducing glucose peaks and/or insulin peaks after ingestion of a food product, while ensuring a long term provision of energy

The inventors were able to demonstrate in clinical studies that the composition of the present invention also produced a significant reduction in insulin response. The composition of the present invention may be used to increase the energy that can be made available from an ingested product 2-4 hours after ingestion.

This use may be medical or non-medical.

The glycemic index (GI) is a measure of the effects of carbohydrates on blood sugar levels. Carbohydrates that break down quickly during digestion and release glucose rapidly into the bloodstream have a high GI; carbohydrates that break down more slowly, releasing glucose more gradually into the bloodstream, have a low GI . The glycemic index of a food is defined as the area under the two hour blood glucose response curve (AUC) following the ingestion of a fixed portion of carbohydrate (usually 50 g) . The AUC of the test food is divided by the AUC of the standard (glucose) and multiplied by 100. Glucose has hence a GI of 100 per definition.

Food compositions with a GI of > 70 shall be understood as food composition with a high glycemic index.

For example, food compositions with a high glycemic index may have a GI of above 75, above 80, above 85, above 90, or above 95.

The extract of the berries of Morus spp . may be any preparation of berries of Morus spp., e.g., juice or a dried fruit extract.

Berries of Morus spp. have for example the advantage that the plant can be reused annually. Furthermore, berries of Morus spp. are generally well liked and have no negative influence on the taste of a product. Berries of Morus spp. are also well accepted as consumable product. Even further, the berries of Morus spp. naturally contain citric acid which is toxic for unwanted micro-organisms.

The extract of the berries of Morus spp. shows in particular beneficial effects if it is directly co-administered with the food product with the high glycemic index.

The composition of the present invention serves to treat or prevent conditions and/or disorders, for example chronic diseases, linked to foods with a high glycemic index. It avoids the generation of glucose peaks in the bloodstream. As such, the composition of the present invention may be used to at least partially avoid the generation of glucose peaks in the blood of a consumer after consumption of a meal or beverage rich in digestible carbohydrates.

The meal may be a food rich in digestible carbohydrates, and the beverage may be rich in sucrose and/or maltose. It allows increasing the time span during which a body can use ingested food as energy source. Hence, the composition of the present invention may be used to increase the time span during which energy can be extracted from ingested food.

It also allows prolonging the feeling of satiety after consumption of the composition.

The disorders linked to foods with a high glycemic index that may be treated or prevented by the composition of the present invention may be selected from the group consisting of glucose intolerance abnormalities, impaired glucose tolerance (IGT), impaired fasting glucose (IFG), diabetes, overweightness , obesity, high blood pressure, high blood cholesterol, and heart disease.

"Overweight" is defined for an adult human as having a BMI between 24 and 28 in China or 25 and 30 in western countries.

"Body mass index" or "BMI" means the ratio of weight in kg divided by the height in metres, squared.

"Obesity" is a condition in which the natural energy reserve, stored in the fatty tissue of animals, in particular humans and other mammals, is increased to a point where it is associated with certain health conditions or increased mortality. "Obese" is defined for an adult human as having a BMI greater than 28 in China and 30 in western countries. The composition may also be used to support weight management.

The composition of the present invention may also consist of an extract of the berries of Morus spp .

The composition of the present invention may be any kind of consumable composition, for example selected from the group consisting of food products, animal food products or pharmaceutical compositions. For example, the composition may be a nutritional composition, a nutraceutical , a drink, a food additive or a medicament.

As such, the composition of the present invention may be intended to be consumed immediately before, during and/or immediately after a meal or beverage.

Immediately before or after a meal shall be understood as the time frame ranging form about 30 minutes before a meal to about 30 minutes after a meal, preferably about 15 minutes before a meal to about 15 minutes after a meal.

If the composition is to be consumed during a meal, it may be intended to be mixed with the meal or it may be consumed as accompanying drink, for example.

Any kind of berries from the Morus spp. may be used for the purposes of the present invention. For example, the Morus spp. may be selected from the group consisting of White Mulberry (Morus alba L.) , Black Mulberry (Morus nigra L.), American Mulberry, Red Mulberry (Morus rubra L.) , hybrid forms between Morus alba and Morus rubra, Korean Mulberry (Morus australis) , Himalayan Mulberry (Morus laevigata) , and combinations thereof

The composition of the present invention may contain any amount of an extract of the berries of Morus spp.. The effectiveness of the composition follows a dose-response curve which eventually reach a plateau phase at very high concentrations of an extract of the berries of Morus spp ..

For example, the composition of the present invention may comprise at least 10 weight-%, at least 20 weight-%, at least 30 weight-%, at least 40 weight-%, at least 50 weight-%, at least 60 weight-%, at least 70 weight-%, at least 80 weight-%, or at least 90 weight-% of an extract of the berries of Morus spp . The berries of Morus spp. contain for example 1- deoxyno j irimycin (DNJ) in very large quantities compared to other plants and other parts of the Morus plant.

1-deoxyno jirimycin (DNJ) is thought to inhibit intestinal and pancreatic a-glucosidase. In one embodiment of the present invention the composition comprises at least 0.1 mg 1-deoxyno jirimycin (DNJ) per g dry weight, preferably at least 1 mg DNJ per g dry weight.

The berries of Morus ssp. contain also anthocyanins and flavonoids, which both have beneficial effects for the health of the consumer.

Hence, the composition of the present invention may comprise DNJ, anthocyanins and flavonoids in a weight ratio in the range of about 1:0.07:0.05 to 1:45:1.5.

DNJ may act in concert and/or synergistically with other analogues of DNJ present in mulberry.

The present invention also extends to a method to reduce the glycemic index of a food product, e.g. a food product with a high glycemic index, comprising the step of adding an extract of the berries of Morus spp . to the food product.

Those skilled in the art will understand that they can freely combine all features of the present invention described herein, without departing from the scope of the invention as disclosed. In particular, features described for the composition of the present invention may be applied to the method of the present invention and vice versa.

Further advantages and features of the present invention are apparent from the following Examples and Figures.

Description of Figures

Figure 1 shows the blood glucose response of maltose in mice as affected by mulberry fruit juice (MB) at different dose levels or the positive control acarbose. Data are average of results from 10 mice. Detailed description can be found in Example 1 below.

Figure 2 shows postprandial blood glucose response of white bread as affected by MB in healthy subjects. Detailed description can be found in the Example 2 below. Figure 3 shows the effect of mulberry juice on blood glucose level in Chinese adults.

Mode of Carrying Out the Invention

Example 1 :

The effect of mulberry juice on blood glucose level in animals was assessed as follows: Experimental D

Male ICR mice age around 5 weeks old and body weight around 24-28 g were purchased from Shanghai Slac Laboratory Animal Co Ltd. They were hosted in a SPF grade animal facility and maintained under 12:12 light-dark cycle with free access to water and food. The regular diet contained 24% protein, 5.4% fat and 59% carbohydrate by weight. Mulberry fruit juice (MB) to be tested was in a concentrated form ( 60 ⁰ Brix) and obtained from the Bosun Healthy Food R&D Center Guangdong, China. It was dissolved in distilled water to the final concentration of 0.1, 0.2 and 0.4 g/ml. Maltose was dissolved in distilled water to a final concentration of 0.25 g/ml. Acarbose was dissolved in distilled water to a final concentration of 2 mg/ml.

The mice were randomized based on the rank of body weight of the experiment day into 5 groups (n=10 in each group) . Three levels of MB (1, 2 and 4 g/kg BW) , plus the negative control (water) and the positive control (acarbose) , were evaluated for their effect on maltose digestion by co-ingestion with maltose solution. The dietary treatment of five groups were as following:

Group 1: Maltose 2.5g/kg + MB lg/kg

Group 2: Maltose 2.5g/kg + MB 2g/kg

Group 3: Maltose 2.5g/kg + MB 4g/kg

Group 4: Maltose 2.5g/kg + Acarbose 20mg/kg

Group 5: Maltose 2.5g/kg + Vehicle (distilled water)

Specifically, after 6 hours fasting, the mice in group 1 to 3 were given 10 ml/kg of maltose (0.25 g/ml) together with 10 ml/kg of different doses of MB (0.1, 0.2 and 0.4 g/ml) by gavage . The mice in group 4 were given 10 ml/kg of maltose (0.25g/ml) together with 10 ml/kg of acarbose (2mg/ml) by gavage . The mice in group 5 were given 10 ml/kg of maltose

(0.25g/ml) together with 10 ml/kg of vehicle (distilled water) by gavage. Blood glucose values were measured at 0, 30, 60 and 120 min after maltose loading by clipping the tail of the mice using a ACCU-CHEK Glucose Monitor (Roche Diagnostics GmbH, Mannheim, Germany) .

Results :

The results of oral maltose test are shown in Figure 1. High dose of MB (4 g/kg) significantly reduced the postprandial increase of glucose level at 30 minutes after maltose loading, and tendency of decrease was also observed in the medium dose group (3 g/kg (p=0.10) . These data provides strong evidence on alpha-glucosidase inhibitory activity of the mulberry fruit juice and the effective dose is around 4/kg BW in mice.

Example 2 : A crossover clinical study was designed to study the postprandial glycemia after ingestion of mulberry fruit juice (MB) with a high carbohydrate diet (white bread) .

Dietary Treatments:

Control Product: White bread plus 10 g of a sugar solution containing same amount of mono- and di-sugars as in 10 g of MB. And the total digestible carbohydrates are 75 grams.

Test Product: White bread plus 10 g of MB with total of 75 grams of digestible carbohydrates.

White Bread was purchased from Walmart (Zhichun Road Store) in Beijing. Mulberry fruit juice concentrate was 60 ⁰ Brix, obtained from Bosun Healthy Food R&D Center Guangdong, China. Sugar solution was prepared by Nestle R&D Shanghai based on the results of component analysis of mulberry juice.

Subjects : Twenty-three healthy subjects participated in this study. The age of subjects ranged from 20 to 50 year old, 16 females and 7 males. The average Body Mass Index (BMI) was 21.54 kg/m ² , ranging from 18.08 - 24.44.

Experimental Design: In a crossover design, subjects were randomly given either control product or test product after overnight fasting. The washout period was one week. All dietary products were taken orally. All foods were consumed within 12 minutes, 250 ml of water was given with each product. A stopwatch was started for each subject as soon as the subject started eating. Blood samples were collected at time 0, 15, 30, 45, 60, 90, and 120 minutes for postprandial glucose monitoring.

Results :

The mean blood glucose response to the test products is shown in Figure 2. Fasting glucose levels did not differ before the treatments. The maximum peak concentration of glucose was statistically lower in the MB group compared to the Sugar group (p=0.0032) .

The incremental blood glucose AUC was determined by a mixed log-linear trapezoidal model, excluding area that fell below 0 min values. The mixed log-linear trapezoidal model performed the AUC calculation in the following way: the linear rule (trapezoidal) is applied to the range where concentration is ascending and the log linear rule is applied to the range where concentration is descending. Combination of the two trapezoidal methods enhance the estimation of the AUC in reducing errors inherent to both methods by applying them under condition of best estimate.

The glycemic index was calculated by dividing the area under the curve (AUC) for the Test Product by the AUC for the Control Product. MB was associated with reduction of blood glucose AUC over 120 minutes compared to ingestion of the Control Product. The Mean Glycemic Index of MB versus the control (AUC _MB /AUC _C ) was 80%, which was borderline significant at p=0.0677.

These results provide evidence on the hypoglycemic activity of Mulberry fruit juice concentrate in healthy volunteers when consumed together with a carbohydrate-rich diet. MB is effective in lowering postprandial glycemia. The glycemic index of white bread was reduced by 20% when ingested together with MB.

Example 3 : The effect of mulberry juice on blood glucose level in Chinese adults was assessed.

This clinical trial demonstrates the effect of mulberry juice concentrate on long-lasting energy, especially the Tmax and Cmax of 4-hour postprandial blood glucose after taking the mulberry juice together with a cereal. The primary parameters were the changes in blood glucose level after co-ingesting mulberry juice with a rice-based cereal with a high carbohydrate content as comparing to the cereal alone. The clinical trial also allows showing the effect of mulberry juice on the time it takes the blood glucose level to return to baseline level.

Further, the effect of mulberry juice concentrate on AUC of postprandial glycemia during 4 hours after taking the mulberry juice together with a cereal is demonstrated.

The effect of mulberry juice concentrate on insulinemia (Cmax, Tmax, AUC) during 4 hours after taking the mulberry juice together with a cereal is shown The effect of mulberry juice concentrate on satiety over 4 hours after food intake is shown including Tmax and Cmax.

110 healthy voluntary Chinese people (50% males and 50% females), age 18-50, were recruited for a trial.

The subjects were tested on two dietary treatments in a random order, while the washout period was 1 week.

Treatment 1: Rice-based cereal flakes plus sugar solution containing same amount of mono- and di-sugars as in mulberry fruit juice concentrate.

Treatment 2 : Rice-based cereal flakes plus mulberry fruit juice concentrate.

Mulberry fruit juice concentrate, Brix 60 (approx. 60% sugar), was obtained from Bosun Healthy Food R&D Center of Guangdong, China . lOg of Mulberry fruit juice concentrate or lOg of sugar solution were consumed together with the cereal. Total food portion (cereal with sugar solution or cereal with mulberry fruit juice) contained 75 g digestible carbohydrates.

The study was carried out at the Shanghai Sixth People's Hospital, Shanghai Jiaotong University. This hospital is specialized in treating diabetic patients.

For subjects participating the trial, the experimental period was 8±1 days. On Day 1, each subject received one of the two treatments in a random manner after an overnight fast, and consumed the treatment within 12 minutes. Venous blood samples were drawn immediately before eating and at 15, 30, 45, 60, 90, 120, 150, 180, 210, and 240 min after eating has commenced. On Day 8±1, each subject received another one of the two treatments in an identical fashion, venous blood samples were drawn in an identical fashion. The total duration for each subject was around two weeks.

The results of this study are shown in the following tables 1- 5 and in figure 3.

Table 1 Postprandial satiety score ( ^{x ± s} )

Time ( min) CONTRL MULBERRY P VALUE ( aired t-test)

( n=107) ( n=107)

0 29.37*14.01 30.25i13.96 0.563

15 52.93i24.48 53.89i17.71 0.609

30 52.61i18.02 53.76i18.87 0.403

60 51.07i18.06 52.35i16.73 0.288

120 46.05i17.34 44.74*16.70 0.392

180 36.96±15.14 37.28i15.20 0.822

240 24.15*14.92 24.44i14.92 0.832 Table 2 AUC of blood glucose postprandial (mmol/L ^* mins) (

CONTRL MULBERRY P Value

( n=107) (n=107) (paired t-test)

2riAUC 698.72*120.79 711.05*118 31 0.211

4 AUC 1246.78*176.24 1243.58*172.02 0.845

2-4 difference of AUC 533.29*76.69 542.98*91.58 0.346

AUC of blood insulin postprandial (mmol L *mins) { ^x - ^s )

CONTRL MULBERRY P Value

(n=104) ( n=104) (paired t-test)

2hAUC 4994.90*2306.67 4551.14*1950.62 0.030

4ft AUC 7241 11*3466.41 6487.41*2851.94 0.018

2-4h difference of AUC 2272.60*1583.50 1917.83*1200.33 0.031

Table 4 Postprandial blood glucose Tmax, Insulin Tmax and the peak value ( ^{x ± s} )

CONTRL MULBERRY P Value

( n=107) ( n=107) (paired t-test)

Blood glucose Tmax 38.41*10.34 41.36*23.02 0.231

(mins)

Peak blood glucose 7.58*1.27 7.34*1.20 0.019

(mmol L)

Insulin Tmax 76.73*37.62 63.82*25.53 0

(mins)

Peak insulin 49.90*23.87 55.24*32.60 0.186

(mmol/L)

Table 5 Blood glucose levels (mmol/L) ( ^{x ± s} ) mean±SD d-value meaniSD

CONTRL MULBERRY CONTRL MULBERRY

0 4.73*0.40 4.76*0.46 15 5.41 ±0.75 5.40±0.58 0.69±0.68 0.64±0.53

30 7.15±1.01 6.91 ±1 .11 2.43±0.92 ^* 2.15±1.01

45 7.10±1.49 6.81 ±1 .49 2.38±1.38 2.04±1.41

60 6.28±1.57 6.14±1 .66 1.56±1.49 1.38±1.59

90 5.45±1.28 5.40±1 .33 0.73±1.25 0.64±1.26

120 5.06±1.08 5.08±1 .05 0.33±1.05 0.32±1.05

150 4.86±0.91 4.89±0.90 0.14±0.94 0.13±0.91

180 4.22±0.79 ^* 4.50±0.98 -0.50±0.82 ^Δ -0.26±0.98

210 4.05±0.72 ^* 4.24±0.69 -0.68±0.73 -0.52±0.75

240 4.18±0.59 4.22±0.44 -0.55±0.57 -0.54±0.54

^* P<0.05, comparing with control group

ΔΡ=0.05, comparing with control group

These results confirm the hypoglycemic activity of Mulberry fruit juice concentrate in healthy volunteers when consumed together with a carbohydrate-rich diet. Evidence is provided that a glucose peak is reduced, while glucose is available in the blood for extended times, in particular 2 - 4 hours after ingestion .