Cucurbitacin I

Benincasa hispida holds substantial ethnopharmacological values across traditional medicines in Asia. It has been used traditionally for the management of various pathological conditions, including obesity, ulcer, epilepsy, bleeding piles, hyperacidity, haemoptysis, dysuria, and urinary calculi. Preclinical studies have shown its nephroprotective potential in rodent models of acute and sub-chronic toxicity. However, its potential pharmacological targets and mechanisms underlying the ethnopharmacological aspects are not elucidated yet.

The present study aims to elucidate the molecular mechanism by which Benincasa hispida confers the protein against diabetic nephrotoxicity by modulating hyperglycemia-induced renal fibrosis and preventing the loss of podocytes, specialized glomerular cells essential for maintaining the integrity of the filtration barrier.

Q-Orbitrap LC-HRMS was employed to characterize phytochemical composition of the hydroalcoholic extract of Benincasa hispida (BH). It pharmacological effects were investigated in a mouse model of type 2 diabetes, which was developed through a high-fat diet with low doses of streptozotocin. The analyses included a thorough evaluation of the extract's impact on serum biochemical parameters, along with the identification of essential genes and proteins that govern kidney function, utilizing integrative transcriptomics, proteomics, qPCR, and immunohistochemical methods.

LC-HRMS analysis identified 28 phytochemicals in the BH extract, predominantly belonging to the category of flavonoids, phenolics, triterpenoids, cucurbitacins, sterol glycosides, coumarins, and others. The presence of catechin, naringenin, kaempferol, cucurbitacin E, cucurbitacin I, Dihydrocucurbitacin B, quercetin, myricetin, 3-hydroxyflavone, etc., demonstrates Benincasa hispida as a valuable source of bioactive chemicals. Blood serum of mice on a high-fat diet showed elevated glucose, triglycerides, total protein, urea, and cholesterol, and decreased creatinine, indicating metabolic dysregulation and chronic diabetic condition. BH treatment significantly restored these biochemical parameters towards normal level. In-depth integrated proteomics and transcriptomics analysis revealed differential expression of genes and proteins involved in cytoskeletal organisation, vesicle transport systems, extracellular matrix, and cell-cell adhesion showed differential in the kidneys of diabetic mice. Consistently, diabetic mice exhibited a notable decrease in podocyte cells, as demonstrated by the downregulation of gene expression specific to the podocyte cytoskeleton genes (cd2ap, actn4, and podxl), which are essential for maintaining glomerular filtration integrity. A notable increase in core histone proteins identified through proteomics has revealed genotoxicity and chromatin remodelling in diabetic mice. Immunohistochemical analysis of PARP1, H2AX, HDAC1, 5'-MC, TET1, and 5'-HMC proteins confirmed DNA damage and epigenetic alterations in the kidneys of diabetic mice, while BH treatment repaired DNA damage and restored epigenetic homeostasis. Additionally, our findings indicated that BH intervention significantly reduced renal inflammation and fibrosis by modulating key inflammatory and profibrotic mediators, such as CD200, TGF-β, and BCl3, which were activated under hyperglycemic condition. In this study, we identified three potential renal cell type-specific targets (S100A6, ACSM2, and TPD52) for the therapeutic action of BH, which require future validation.

The results of our investigation establish a scientific basis for the nephroprotective properties of Benincasa hispida in a mouse model of type 2 diabetes. The observed effects were associated with decreased genotoxicity and renal fibrosis, along with improved podocyte function.

Momordica spp. has been traditionally used to manage type 2 diabetes mellitus, but the mechanisms and metabolites remain unclear. This study evaluated the inhibitory potential of Momordica balsamina extracts on α-amylase and α-glucosidase in vitro, identifying cucurbitacin I and momordin Ic via high-performance liquid chromatography-photo diode array, and their inhibitory potential in silico. Ethyl acetate seed extract (14.46 µg/ml) and hexane fruit flesh extract (16.79 µg/ml) exhibited lower IC₅₀ values against α-amylase and α-glucosidase, respectively, compared to acarbose (reference standard). Comparatively, momordin Ic concentrations (36.57-605.98 µg/ml) were higher than cucurbitacin I (17.08-44.34 µg/ml). A 140 ns simulation showed that cucurbitacin I (-63.06 kcal/mol) and momordin Ic (-66.53 kcal/mol) exhibited stronger binding to α-amylase than acarbose (-36.46 kcal/mol), whereas cucurbitacin I (-38.08 kcal/mol) and momordin Ic (-54.87 kcal/mol) displayed weaker binding to α-glucosidase, relative to acarbose (-63.73 kcal/mol). Generally, momordin Ic demonstrated better thermodynamic properties, hence further in vitro and in vivo studies are needed to validate their antidiabetic potential.