Diabetes Management: The Use of Anti-Diabetic Black Tea Fortified with Guava Leaves Extract

 

INTRODUCTION

Diabetes is a common metabolic disease associated with an unusual postprandial surge of the glucose in the blood resulting from insulin insufficiency or dysfunction. Moreover, the disorder occurs in three forms which include: gestational, type 1, and 2 diabetes. The most affected individuals are the obese due to their poor eating habits and the older who tend to be less active. An alpha-glucosidase enzyme secreted from intestinal chorionic epithelium hydrolyzes complex carbohydrates to simple sugars which are easily absorbed into the bloodstream. Nevertheless, inhibition of this enzyme tends to decelerates the process of absorption and digestion of carbohydrates. The overall peak concentration of postprandial blood glucose is reduced, and the blood sugar level comes under control. However, the inhibitor does not cause the pancreas to produce more insulin but blocks the pancreatic amylase which hydrolyzes complex oligosaccharides in the small intestine lumen. This gives pancreas more time to secrete insulin to cover the meal. For instances, catechins, flavonoids, tannins, alkaloids, anthocyanidins, betulinic acid, lupeol and phenol compounds are observed to play a major role in the control of type 2 diabetes. The antioxidants act as alpha-glucosidase inhibitors. In some countries, Psidium guajava leaf tea is used for the control and management of health complications due to the presence of alkaloid, quinones, saponins, flavonoids, as well as steroids/triterpenoids. Alkaloids, flavonoids, saponins, tannins, steroids/triterpenoids occur as bioactive antidiabetic principles which act as alpha-glucosidase inhibitors. This review mainly concentrates on the control of diabetes by inhibition of carbohydrate hydrolyzing enzyme by use of black tea fortified with guava leaves extract

Antidiabetic Properties of Guava leaves Extract

Drying of the guava leaves was carried out to reduce the moisture content as well as remove the wax on the surface of the leaves. Rupturing of the cell walls helped to increase the extraction efficiency of phenolic compounds. The organoleptic characteristics including color, odor and flavor of guava leaves extract didn’t change with drying. Guava leaves were observed to have higher concentration of phenolic compound since the total phenols in tea are reduced during processing. Fermentation and roasting of the tea leaves resulted in the reduction of total phenolic content. During fermentation catechins were oxidized to orthoquinone which underwent dimerization to form bisflavonols. Fortified black tea had a desirable flavor due to the presence of anthocyanins in the guava leaves. The presence of flavonoids and the reduction of the moisture content of the guava leaves increased the shelf stability of the tea. The presence of bioactive compounds in the guava leaves increased the nutritive value of the tea.

MECHANISM

Diabetes is a well-known metabolic disorder characterized by an abnormal postprandial increase of blood glucose level resulting from insulin insufficiency or dysfunction. Diabetes Mellitus is a non-communicable disease that is considered as one of the five leading causes of death in the world. There are three types of diabetes: type 1, type 2, and gestational diabetes. There is no known effective cure for the disease. Only lifelong treatment and management of diabetes is acknowledged. The diabetic patients have to put up with the available drugs and insulin that are currently in use and which are associated with several undesirable side effects. These undesirable side effects and the high cost of anti-diabetic drugs have steered the search for plants with hypoglycemic properties and their use in the management of diabetes. An alpha-glucosidase enzyme secreted from intestinal chorionic epithelium hydrolyzes complex carbohydrates to simple sugars which are easily absorbed into the bloodstream. Inhibition of this enzyme by guava leaves extract slows down the process of digestion and absorption of carbohydrates. The peak concentration of postprandial blood glucose is reduced, and the blood sugar level comes under control. The inhibitor does not cause the pancreas to produce more insulin but blocks the pancreatic amylase which hydrolyzes complex oligosaccharides in the small intestine lumen. This gives pancreas more time to secrete insulin to cover the meal. The mechanism of antidiabetic activities of Psidium guajava leaves is associated with the activity of the intestinal glycosidase that is related to postprandial hyperglycemia. These inhibitors are later on broken down by the bacteria, and absorbed, and eliminated by the kidney hence has no side effects on the body.