Evaluation of the efficacy of Abelmoschus manihot (L.) on diabetic nephropathy by analyzing biomarkers in the glomeruli and proximal and distal convoluted tubules of the kidneys

Exploring the role of NLRP3 inflammasome in diabetic nephropathy and the advancements in herbal therapeutics

Diabetic nephropathy (DN), a prevalent complication of diabetes mellitus (DM), is clinically marked by progressive proteinuria and a decline in glomerular filtration rate. The etiology and pathogenesis of DN encompass a spectrum of factors, including hemodynamic alterations, inflammation, and oxidative stress, yet remain incompletely understood. The NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome, a critical component of the body's innate immunity, plays a pivotal role in the pathophysiology of DN by promoting the release of inflammatory cytokines, thus contributing to the progression of this chronic inflammatory condition. Recent studies highlight the involvement of the NLRP3 inflammasome in the renal pathology associated with DN. This article delves into the activation pathways of the NLRP3 inflammasome and its pathogenic implications in DN. Additionally, it reviews the therapeutic potential of traditional Chinese medicine (TCM) in modulating the NLRP3 inflammasome, aiming to provide comprehensive insights into the pathogenesis of DN and the current advancements in TCM interventions targeting NLRP3 inflammatory vesicles. Such insights are expected to lay the groundwork for further exploration into TCM-based treatments for DN.

Identification of the main flavonoids of Abelmoschus manihot (L.) medik and their metabolites in the treatment of diabetic nephropathy

Introduction: Huangkui capsule (HKC) is made from the ethanol extract of Abelmoschus manihot (L.) Medik [Malvaceae; abelmoschi corolla] and received approval from the China Food and Drug Administration (Z19990040) in 1999. Currently, HKC is used for treatment of the patients with diabetic nephropathy (DN) in China. The bioactive chemical constituents in HKC are total flavonoids of A. manihot (L.) Medik (TFA). The present study aims to identify the primary flavonoid metabolites in HKC and TFA and their metabolism fates in db/db mice, the animal model for the study of type 2 diabetes and DN. Methods: HKC (0.84 g/kg/d) and TFA (0.076 g/kg/d) or vehicle were respectively administered daily via oral gavage in db/db mice for 4 weeks. The metabolism fate of the main metabolites of HKC in serum, liver, kidney, heart, jejunum, colon, jejunal contents, colonic contents, and urine of db/db mice were analyzed with a comprehensive metabolite identification strategy. Results and Discussion: In db/db mice administered with HKC and TFA, 7 flavonoid prototypes and 38 metabolites were identified. The related metabolic pathways at Phases I and II reactions included dehydroxylation, deglycosylation, hydrogenation, methylation, glucuronidation, sulphation, and corresponding recombined reactions. Quercetin, isorhamnetin, quercetin sulphate, quercetin monoglucuronide, and isorhamnetin monoglucuronide presented a high exposure in the serum and kidney of db/db mice. Thereby, the present study provides a pharmacodynamic substance basis for better understanding the mechanism of A. manihot (L.) Medik for medication of DN.

Atorvastatin ameliorated myocardial fibrosis in db/db mice by inhibiting oxidative stress and modulating macrophage polarization

BACKGROUND

People with diabetes mellitus (DM) suffer from multiple chronic complications due to sustained hyperglycemia, especially diabetic cardiomyopathy (DCM). Oxidative stress and inflammatory cells play crucial roles in the occurrence and progression of myocardial remodeling. Macrophages polarize to two distinct phenotypes: M1 and M2, and such plasticity in phenotypes provide macrophages various biological functions.

AIM

To investigate the effect of atorvastatin on cardiac function of DCM in db/db mice and its underlying mechanisms.

METHODS

DCM mouse models were established and randomly divided into DM, atorvastatin, and metformin groups. C57BL/6 mice were used as the control. Cardiac function was evaluated by echocardiography. Hematoxylin and eosin and Masson staining was used to examine the morphology and collagen fibers in myocardial tissues. The expression of transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1β),M1 macrophages (iNOS+), and M2 macrophages (CD206+) were demonstrated by immunohistochemistry and immunofluorescence staining. The levels of TGF-β1, IL-1β, and TNF-α were detected by ELISA and real-time quantitative polymerase chain reaction. Malondialdehyde (MDA) concentrations and superoxide dismutase (SOD) ac-tivities were also measured.

RESULTS

Treatment with atorvastatin alleviated cardiac dysfunction and decreased db/db mice. The broken myocardial fibers and deposition of collagen in the myocardial interstitium were relieved especially by atorvastatin treatment. Atorvastatin also reduced the levels of serum lactate dehydrogenase, creatine kinase isoenzyme, and troponin; lowered the levels of TGF-β1, TNF-α and IL-1β in serum and myocardium; decreased the concentration of MDA and increased SOD activity in myocardium of db/db mice; inhibited M1 macrophages; and promoted M2 macrophages.

CONCLUSION

Administration of atorvastatin attenuates myocardial fibrosis in db/db mice, which may be associated with the antioxidative stress and anti-inflammatory effects of atorvastatin on diabetic myocardium through modulating macrophage polarization.