More than just lowering blood sugar, this medicine-food combination has a new discovery!

Recently, a new study published in Nutrients found that white mulberry leaf (Morus alba L.) extract has antihypertensive effects, improves vascular reactivity, and reduces platelet aggregation in an arterial hypertension model. These effects are mainly related to increased nitric oxide activity [1].

1.Mulberry leaf extract can improve cardiovascular health

This study divided male Sprague-Dawley hypertensive rats into four groups: 1) control group; 2) L-NAME group, rats were treated with L-NAME (Nω-nitro L-arginine methyl ester, a NO synthase inhibitor) for 6 weeks; 3) white mulberry leaf extract (MAE) group, rats were treated with L-NAME and MAE extract (100 mg/kg/day, administered by gavage); 4) captopril group, rats were treated with L-NAME and captopril (angiotensin converting enzyme inhibitor) at the same time, at a dose of 100 mg/kg/day. After 6 weeks of treatment, blood pressure, aortic endothelial vascular function, and platelet aggregation function were measured in mice.

The results showed that white mulberry leaf extract (MAE) showed antihypertensive effects in an experimental model of arterial hypertension caused by nitric oxide deficiency and improved vascular reactivity and platelet aggregation. These beneficial effects seemed to be closely related to enhanced nitric oxide activity.

1) Antihypertensive

The results showed that long-term administration of L-NAME significantly increased mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) parameters in rats. However, administration of MAE or captopril significantly reduced the above three parameters, indicating that MAE largely prevented the hypertensive effect caused by L-NAME.

2）Improved vascular response

Figure 2 depicts the vasoconstrictor response of aortic rings to phenylephrine. Compared with the control group, the L-NAME group showed an enhanced response. The MAE group reduced this response.

Figure 3 illustrates the vasodilator response of aortic rings to acetylcholine. The control and captopril groups showed the highest vasodilatory response (about 90%), while the L-NAME group showed only a 10% response. MAE treatment of L-NAME treated animals significantly improved the vasodilatory response to nearly 60%.

In the vascular reactivity test in aortic rings, the vasoconstrictor response of the L-NAME animal group was significantly higher than that of the control group. This enhanced response was due to the reduction of nitric oxide production, but the use of MAE reduced this enhanced vasoconstrictor response, indicating that MAE may increase nitric oxide levels in aortic rings and normalize vasoconstrictor responses. In addition, when L-NAME was acutely added to aortic rings, nitric oxide was eliminated, which confirmed that MAE can promote nitric oxide production in blood vessels.

3）Improved platelet aggregation

Figure 4 depicts the percentage of platelet aggregation in different rat groups to adenosine diphosphate (ADP) and collagen. Rats that received L-NAME for a long time had increased platelet aggregation responses. Compared with the control group, rats in the MAE group significantly improved these responses, but did not completely normalize them.

2. Mulberry leaves: a food and medicine with many benefits

Mulberry (Morus, Moraceae) is an economical and widely distributed woody plant that is widely cultivated in Asian countries. There are many varieties of mulberry trees. The three most popular varieties in the world are white mulberry (Morus alba), black mulberry (Morus nigra) and red mulberry (Morus rubra). Since mulberry trees are food for silkworms, mulberry leaves have important economic value to the silk industry [2].

In 2002, the "Notice of the Ministry of Health on Further Standardizing the Management of Health Food Ingredients" (Weifajianfa [2002] No. 51) officially listed mulberry leaves as the first batch of food and medicine substances. All parts of the mulberry tree, from root bark to leaves, have been widely studied for their health benefits. Among them, mulberry leaves are rich in nutrients. Their active substances mainly include alkaloids, flavonoids, mulberry leaf polysaccharides, etc., which give mulberry leaves excellent blood sugar and cholesterol lowering, anti-inflammatory, anti-hypertensive, and antibacterial properties.

Hypoglycemic: Mulberry leaf extract has long been used in traditional diabetes treatment, thanks to its active ingredient 1-deoxynojirimycin. 1-Deoxynojirimycin is a potent α-glucosidase inhibitor. It blocks the absorption of carbohydrates from the gastrointestinal tract by inhibiting the enzymatic activity that degrades disaccharides into monosaccharides, thereby inhibiting blood sugar elevation.

In addition, some components found in mulberry leaves, such as triflavonoids, gallic acid, and chlorogenic acid, have the ability to regulate insulin receptor substrate 1, glycogen synthase kinase 3β, interleukin 6, and other proteins responsible for insulin signaling pathways, glucose metabolism, nephrotic diabetes, obesity, and other diabetes-dependent factors.

Anti-hyperlipidemia: Studies have shown that mulberry leaves can significantly reduce the levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) in animal blood circulation, and mulberry leaves can also reduce liver lipid accumulation. 1-Deoxynojirimycin, quercetin, and kaempferol in mulberry leaf extract can activate the expression of AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR)-α, leading to increased β-oxidation of free fatty acids and lipolysis. At the same time, caffeic acid, quercetin, and hydroxyflavin in mulberry leaf extract reduce lipogenesis by regulating the activities of fatty acid synthase (FAS), glycerol-3-phosphate acyltransferase (GPAT), sterol regulatory element binding protein (SREBP)-1c, and liver X receptor (LXR) [3].

Anti-inflammatory: Resveratrol in mulberry leaves has anti-inflammatory effects, which can reduce the production of cytokines, reduce the expression of proinflammatory mediators, the expression of alternating adhesion molecules, and inhibit neutrophil activity. Resveratrol can inhibit the inflammatory response stimulated by lipopolysaccharide (LPS) in RAW 264.7 macrophages. These compounds further inhibited the production of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), and suppressed the mRNA and protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) in LPS-stimulated RAW 264.7 macrophages.

3.Market analysis of mulberry leaves

Market research future data shows that the mulberry leaf extract market size is about US$2 billion in 2023 and is expected to grow to US$3.8 billion in 2032. During the forecast period (2024-2032), the compound annual growth rate (CAGR) of the mulberry leaf extract market is about 7.41%[4]. As a natural active ingredient that can effectively reduce the risk of chronic diseases, the demand for mulberry leaf extract is expected to increase in the future.

Mulberry leaf powder launched by WAY 4 ORGANIC W4O can be consumed with smoothies, beverages, cakes and other foods. Many people use this mulberry leaf powder as a sugar substitute.

Swanson has launched a capsule containing mulberry leaves, which helps maintain healthy blood sugar levels and also promotes cardiovascular health.