Development of Anti-Diabetic Nutraceuticals From Legume Seed Coats

Type 2 diabetes mellitus (T2DM) is one of the leading metabolic disorders worldwide and is associated with increased morbidity and mortality. Elevated postprandial blood glucose levels are recognized as an important risk factor for the development and exacerbation of T2DM and its macro- and micro-vascular complications. The acute glucose fluctuations induce oxidative stress and systemic inflammation and fastens the disease progression. Most oral anti-diabetic medications (metformin, sulfonylureas, thiazolidinediones) lower basal blood glucose levels; nevertheless, for effective long-term glycemic control, postprandial hyperglycemia must also be effectively managed.

Alpha-glucosidase inhibitors (AGIs) are a unique group of oral anti-diabetic medications that help lower post-prandial glucose spikes. They work by blocking the alpha-glucosidase enzyme in the intestine, which normally breaks down complex sugars into glucose for absorption. Currently, a few FDA-approved AGIs-such as acarbose, miglitol, and voglibose-are used to manage type 2 diabetes (T2DM). These drugs have been shown to improve blood sugar control and reduce risks of heart disease. Clinical trials suggest that the efficacy of acarbose to manage blood sugar is comparable to metformin, and the combination of both drugs is even more effective. However, long-term use of acarbose is often limited by digestive side effects. This highlights the need for safer, more selective, and better-tolerated AGIs.

Legume seeds are rich in polyphenols, flavonoids, and dietary fiber, which are known to inhibit alpha-amylase and alpha-glucosidase activity. After screening commonly consumed legumes, our laboratory identified boiled water extracts of certain seed coats with strong alpha-glucosidase inhibition, as well as antioxidant and anti-inflammatory properties. We have developed a palatable soup using these extracts.

This open-label, pre-post clinical trial will test whether daily consumption of the soup improves blood sugar control in individuals at high risk, including those with metabolic syndrome and type 2 diabetes mellitus (T2DM). The study will also include healthy volunteers. Participants will consume the soup daily for one month. Primary outcomes will include changes in fasting blood glucose, HbA1c, and postprandial glucose levels, assessed at predefined time points. Secondary outcomes will examine changes in lipid profile (dyslipidemia), biomarkers of oxidative stress, and markers of systemic inflammation. This study builds on prior laboratory findings and seeks to translate them into a practical, palatable dietary intervention with potential relevance for the prevention and management of hyperglycemia and associated metabolic disorders.

Inclusion criteria

i. Healthy volunteers aged 20 to <60 years. ii. Individuals with one or more of the following risk factors: BMI >25 kg/m², systolic blood pressure (SBP) >130 mmHg, dyslipidemia, or HbA1c between 5.7-6.4% (prediabetes range).

iii. Adults diagnosed with type 2 diabetes mellitus (T2DM).

Exclusion criteria

i. History of gastrointestinal diseases. ii. Use of antibiotics within the past 3 months. iii. Pregnant or lactating women. iv. Individuals diagnosed with cardiovascular disease, chronic kidney disease, cancer, liver disease, or autoimmune disorders.

v. Current use of alpha-glucosidase inhibitor medications.