Mulberry leaf reduces inflammation and insulin resistance in type 2 diabetic mice by TLRs and insulin Signalling pathway

Abstract

BackgroundIt has been testified that Diabetes mellitus (DM) has a close association with chronic inflammation and Toll-like Receptors (TLRs), and DM could be prevented by mulberry leaf. Therefore, a hypothesis came into being that mulberry leaf could ameliorate proinflammation and insulin resistance (IR) through TLRs and insulin signalling pathways.MethodsWater extracts of mulberry leaf (WEM) was given to diabetic mice by gavage for 10 weeks, and the diabetic mice was injected with low-dose streptozocin, fed with high-fat and high-sugar diet. Oral glucose tolerance tests (OGTTs) were conducted. At the same time, homeostasis model assessment of insulin (HOMA-IR) and the level of the inflammatory factor, tumour necrosis factor-α (TNF-α) was measured. The expressions of critical nodes of TLRs and insulin signalling pathway were also examined.ResultsWEM contributed to a significant decrease in fasting blood glucose, AUC from the investigation of OGTTs and HOMA-IR. The levels of the inflammatory factor, tumour necrosis factor-α (TNF-α) also declined. Moreover, WEM suppressed the expression of TLR2, myeloid differentiation primary-response protein 88 (MyD88), tumour-necrosis-factor receptor-associated factor 6 (TRAF6), nuclear factor kappa B (NF-κB) in the skeletal muscle. WEM could up-regulate the expression of insulin receptor (InsR) and insulin receptor substrate 1 (IRS1), and down-regulate the phosphorylation of IRS1 in adipose tissue.ConclusionThrough this study, a conclusion could be made that WEM mitigates hyperglycemia, IR, and inflammation through the interactions among TLR2 signalling pathway, insulin signalling pathway and TNF-α.

Consumption of Biscuits with a Beverage of Mulberry or Barley Leaves in the Afternoon Prevents Dinner-Induced High, but Not Low, Increases in Blood Glucose among Young Adults

“…Moreover, the simultaneous intake of mulberry or barley leaves significantly attenuated the biscuit-induced increase in glucose level during snack time. This finding aligns with that of previous reports [12,24,25], and further contributes to claims of the efficacy of dietary fibers and alpha-glucosidase in inhibiting increases in blood sugar incurred by high-glycemic foods [15,26,27].…”

Mining Novel Specific Rumen Bacteria to Enhance the Bioactive Function of Mulberry Leaf in Promoting Host Antioxidant Activity and Immunomodulatory

“…IFN-γ is involved in the initiation and regulation of the immune response [38]. It was found that water extracts of mulberry leaf mitigate in ammation through the interactions among insulin signalling pathway and TNF-α [39]. However, the current study did not nd the changes of serum glucose and TNF-α, but with increased serum IFN-γ concentration shown in the current study.…”

Plant Extracts for Type 2 Diabetes: From Traditional Medicine to Modern Drug Discovery

“…Mice were treated with 30, 90 and 270 mg/kg doses for 7 days, in combination with insulin, which resulted in synergistically reduced FBG levels. Tian et al demonstrated that Morus alba L. water extract alleviated insulin resistance and diabetic status through the insulin signaling pathway, in which elevations of IRS1 and insulin receptor (InsR) were shown [ 105 ]. This extract neutralized the inflammation by reducing TNF-α, toll-like Receptors 2 (TLR2), and critical messengers of TLR2 signaling, such as myeloid differentiation primary-response protein 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF6) and NF-κB p65.…”

“…Eight studies with various experiment models, including TSOD mice, leptin-deficient ob/ob mice, ICR mice, Kunming mice, and SHRSP.ZF rats and patients were reported. Cassia siamea Lam ( Senna siamea ) (Fabaceae) ethanolic extract [ 113 ], Morus alba L. water extract [ 105 ] and Vernonia cinerea water extract [ 114 ] activated the PI3K/Akt signaling pathway, indicating the facilitation of glucose transport and metabolism. Additionally, significant anti-inflammatory and antioxidant activities were observed in Allium sativum L [ 119 ], Apis mellifera L. [ 120 ] and Morus alba L. water extract [ 105 ], poplar buds from Populus [ 107 ], and Vernonia cinerea water extract [ 114 ].…”