Herbal Theraphies in the Treatment of Diabetes: A Review

Type II diabetes is an endocrine problem characterized by a permanent increase in blood glucose levels, causing various metabolic disorders [1,2]. Diabetes Mellitus (DM) is a chronic metabolic health problem that occurs as a result of insulin hormone deficiency or insulin resistance in cells, affects many organs and is characterized by high blood sugar [1]. Type 2 diabetes, which constitutes 90% of DM types, occurs as a result of dysfunctional pancreatic beta cells or impaired insulin response of body cells [2]. If left untreated succesfully or managed badly, it can lead to a number of serious complications affecting more than one organ system. It causes problems in various organs, heart, eyes, kidneys, neurons, vessels and can even lead to death. The most common complications include coronary heart disease, heart failure and cardiovascular diseases and these complications are continuously more common in diabetes with hyperglycemia, dyslipidemia and hypertension [3-5]. In addition, in individuals with diabetes, both of them have a higher risk of developing diabetic foot ulcers, which can lead to cognitive regression and demans as well as infections associated with long-term hyperglycemia and vascular lesions. Early detection and careful management of blood sugar, blood pressure and lipids are very important to prevent or delay these complications[4,5].

There is no definitive treatment for this disease, which can lead to various life-threatening complications and even death. Applications made as treatment are aimed at keeping blood glucose levels under control. However, the drugs applied may have different side effects. Along with this situation, medicinal plants with antihypoglycemic and antidiabetic potential have begun to be used as supportive in diabetes [6,7]. In addition to traditional medical treatments in the management of diabetes, complementary medical practices see interest. These methods allow individuals to adopt a more more approach to disease management and aim to improve the quality of life of the patients. It is important to be meticulous about the effectiveness and safety of this tour treatment methods. In this context, herbal treatments have become one of the most commonly preferred among the methods of satisfaction [8]. Approximately 60- 80% of the world’s population uses traditional medicines obtained from medicinal plants for various diseases, especially DM. There are many plants with anti-diabetic properties Currently, there are plants that are used effectively for chronic diseases such as diabetes, for which there is no definitive cure [9]. The aim of herbal supportive therapy in diabetes is to enhance the effectiveness of medical treatment, reduce the effects of complications caused by the disease, and improve patients’ living standards. The purpose of this review is to reveal the effects of various medicinal plants on diabetes and facilitate blood sugar regulation. The purpose of this review is to highlight the effects of various medicinal plants on diabetes and facilitate blood sugar regulation. Balancing blood sugar levels in diabetic patients can prevent the development of acute and chronic complications related to diabetes and reduce hospitalizations.

Cinnamon

It is obtained from the bark of trees belonging to the Cinnamomum genus of the Lauraceae family [10]. Although there are four main species used as spices, Cinnamomum zeylanicum and Cinnamomum aromaticum are the most commonly used species Invivo studies have shown that cinnamaldehyde and cinnamon can help glycemic control depending on the dose [11-13]. Among the proposed mechanisms of action are increased insulin-mediated glucose utilization by increasing the efficiency of the insulin signaling pathway and having an insulin-like effect [14]. In a 2012 Cochrane review, a total of 10 clinical studies investigating the effects of cinnamon on type 1 and type 2 diabetes were examined. In the studies, it was determined that Chinese cinnamon was mostly given at an average dose of 2 gram/day for 4-16 weeks. As a result of the meta-analysis, it was reported that the evidence for the change in fasting blood glucose was insufficient. It was determined that there was no statistically significant change in Hemoglobin A1c (HbA1c), serum insulin or postprandial glucose levels in those consuming cinnamon compared to those taking placebo [15].

Black cumin

It is known that black cumin seeds contain more than 100 chemical compounds, but thymoquinone, thymohydroquinone, dithymoquinone and thymol are the most important active components [16]. Black cumin increases insulin sensitivity in the liver, suppresses gluconeogenesis, increases glucose utilization in the muscles, increases insulin secretion and β cell proliferation in the pancreas and reduces glucose absorption from the gastrointestinal system [17]. Although in-vitro and in-vivo studies are promising, the transfer of studies to the clinic is still very new. In a study conducted by Kaatabi et al. [18] 2 grams of black cumin seeds or placebo were given to type 2 diabetic patients for one year in addition to standard oral antidiabetic treatment [18]. At the end of the study, it was determined that there were statistically significant decreases in fasting blood glucose and HbA1c levels in the black cumin group compared to the control group. In addition, it was determined that insulin resistance was lower and β-cell activity was higher in the group receiving black cumin compared to the beginning. Bamosa et al. [19] examined the effect of different doses of black cumin seeds on glycemic control. In the study conducted by giving 1, 2 and 3g/ day of black cumin for a total of 12 weeks, it was determined that the optimum dose was 2g/day. It was shown that with a daily dose of 2g, an average of 56mg/dL was achieved in fasting blood glucose levels and an average of 1.52% decrease was achieved in HbA1c levels at the end of 12 weeks [19].

Pomegranate of power

The fruits of bitter melon a plant from the Cucurbitaceae family, are used as vegetables in various parts of the world and consumed as a dish [19,20]. It is known that the fruit and seeds of bitter melon are popular among the plants used against diabetes in Southeast Asia [20]. Studies have determined that bitter melon has an antioxidant effect and is effective in the regulation of glucose and lipid metabolism [20-23]. Studies conducted with different extracts have determined that it has a hypoglycemic effect in rats with high blood glucose levels [18-20]. In a 2012 Cochrane review examining four randomized controlled studies (n=479), it was concluded that bitter melon had no significant effect compared to placebo in controlling type 2 diabetes [24]. It has been reported that bitter melon may cause miscarriage because it increases uterine contractions and therefore should not be used by pregnant women. It should also not be used by children, breastfeeding mothers, individuals undergoing infertility treatment and those allergic to plants/foods in the Cucurbitaceae family. Since the plant has a bitter taste, it can be preferred to use it in capsule form in freeze-dried powder form. Care should be taken to ensure that this does not cause high-dose consumption and toxicity [25].

Ginger

Ginger rhizomes, which grow naturally in Southeast Asia, are a popular plant with their unique odor and their effect against nausea and vomiting due to motion sickness. The group of compounds responsible for the sharp taste of fresh ginger is gingerols. In addition to gingerols, bioactive components in its composition include zingiberene and shogaols [26]. In preclinical studies, ginger has been reported to be effective in inhibiting α-amylase, α-glucosidase enzymes, increasing Glucose Transporter Protein-4 (GLUT-4) translocation and insulin sensitivity [27]. Although current clinical studies are limited, they seem to support the preclinical findings. In a randomized, double-blind, placebo-controlled study conducted with 64 type 2 diabetic patients, it was found that 2g/day ginger consumption for two months was associated with increased insulin sensitivity compared to placebo. No effect was observed on fasting blood glucose and HbA1c levels [28]. Arablou et al. [29] found that daily use of 1600mg of ginger in diabetic individuals had a positive effect on glycemic parameters after 12 weeks [29].

Nettle

Nettle, which grows widely all over Turkey, is a plant commonly used among the public against various diseases [16]. In recent years, it has been determined that both the aboveground and underground parts of the plant, which has become popular among cancer patients due to the influence of the media [30], are also frequently used against diabetes in ethnobotanical studies [31]. Despite this widespread use among the public, clinical studies investigating the antidiabetic activity of nettle are very limited [28,29]. In a single-blind, placebo-controlled study conducted by Kianbakht et al. [31] individuals with type 2 diabetes were given 500mg of ethanolic extract of nettle leaves (n=46) or placebo (n=46) three times a day in addition to standard treatment. At the end of the study, which lasted a total of 12 weeks, it was determined that there were statistically significant decreases in fasting blood glucose, postprandial glucose and HbA1c levels compared to the placebo group [31].

Vernonia amygdalina

Fresh extracts of V. amygdalina has been noticed to contain alkaloids, saponins, tannins, flavonoids and proteins [32,33]. The leaf decoction of the plant is popular in traditional medicine as an antidiabetic drug; its potency and safety are documented [34]. The hypoglycemic potential of V. amygdalina has been documented [35]. Although several biologically active components have been reported to be present in the extracts [34,35]. It has not been shown which phytochemical groups are responsible for its antidiabetic effects and mechanism of action [36-40]. The sudden and significant decrease in blood glucose in both fasting normal and alloxan diabetic rats suggests a mechanism of action that is different from the mechanism of action of sulfonylureas and unrelated to insulin secretion from pancreatic β-cells [34].

Plants certainly have an important role and effect in the treatment of diabetes, as in many diseases. The origins of antidiabetics, which are used frequently today, are also based on plants [41-47]. Plants can be useful in the treatment of diabetes, but they also have the potential to be harmful to other organs or systems. If we start from the idea that the dose is what distinguishes a drug from a poison; the dosage of plants can be used as a supplement in the treatment of chronic diseases, provided that attention is paid to their interactions with other drugs and nutrients. The current data is not sufficient to directly recommend any of these plants. The number of clinical studies on the plants examined is quite low. In the future, when well-planned randomized controlled clinical studies are available, as well as data on efficacy, dosage, method of use, side effects and long-term use, their roles in the treatment of diabetes will be clarified.

Actually, there is no one to thank me for this article. I use plants fondly for myself in many areas, I am glad that they exist, plants are the ornament of nature.

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