Kinetics of α-amylase and α-glucosidase inhibitory potential of Zea mays Linnaeus (Poaceae), Stigma maydis aqueous extract: An in vitro assessment

Effect of Phenol and Alkylamide Interaction on α-Glucosidase Inhibition and Cellular Antioxidant Activity during In Vitro Digestion: Using Szechuan Pepper (Zanthoxylum genus) as a Model

Although recent evidence indicated significant phenol and alkylamide interaction in aqueous solutions, the gastrointestinal digestion influence of the combination remains unclear. This study aims to investigate phenol and alkylamide interaction during in vitro digestion, focusing on bioaccessibility and bioactivity, including α-glucosidase inhibition and cellular antioxidant activity. Additionally, the structural mechanism of phenol and alkylamide interaction during in vitro digestion was explored. The results indicated that the presence of phenols and alkylamides significantly increased or decreased their respective bioaccessibility, depending on the Zanthoxylum varieties. Furthermore, although antagonistic phenol/alkylamide interaction was evident during α-glucosidase inhibition, cellular oxidative stress alleviation, and antioxidant gene transcription upregulation, this effect weakened gradually as digestion progressed. Glycoside bond cleavage and the methylation of phenols as well as alkylamide isomerization and addition were observed during digestion, modifying the hydrogen bonding sites and interaction behavior. This study provided insights into the phenol/alkylamide interaction in the gastrointestinal tract.

Corn stigma ameliorates hyperglycemia in zebrafish and GK rats of type 2 diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Cornstigma (CS), derived from the stigma and style of gramineous plant Zeamays. The medicinal use of CS can be traced back to DianNanMateriaMedica. LingnanMedicinalPlantsCompendium records its effectiveness in ameliorating diabetes. Diabetes is a metabolic disorder characterized by hyperglycemia and the consequent chronic complications of kidney, heart, brain and other organs, which pose a significant threat to human health. CS has shown great potential in relieving hyperglycemia associated with diabetes. However, the mechanism of CS in treating diabetes remains unclear.

AIM OF THE STUDY

To explore the pathogenesis of diabetes and the mechanism of CS improving hyperglycemia in diabetes.

MATERIALS AND METHODS

We measured apigenin and luteolin contents in CS by UPLC/MS/MS method. Selecting Wistar rats as normal group, and GK rats as model group. For rats, we detected glucose and lipid metabolism indicators, including GHb, AST, ALT, U-Glu, UA, U-TP, U-ALB, and ACR after treatment. For zebrafish, we utilized alloxan and sucrose to establish the diabetes model. Measuring zebrafish blood glucose is employed to evaluate the hypoglycemic capability of CS. In order to explore the mechanism of CS in treating diabetes, we sequenced the transcriptome of zebrafish, compared differentially expressed genes of normal, diabetic, and CS-treated group, and validated multiple enrichment pathways by PCR.

RESULTS

CS can improve blood glucose levels in both GK rats and diabetic zebrafish. For rats, CS partially restored glucose and lipid metabolism indicators. Transcriptome data from zebrafish showed a close correlation with steroid biosynthesis. The RNA-Sequencing was consistent with PCR results, indicating that CS downregulated gene (fdft1,lss,cyp51) expression concerned with steroid biosynthesis pathway in the diabetes model.

CONCLUSION

CS effectively improved blood glucose levels, regulated glucose and lipid metabolism by suppressing gene expression in steroid biosynthesis pathway, and ameliorated hyperglycemia. Our research provides valuable insights for CS in the treatment of diabetes, and proposes a new strategy for selecting clinical medications for diabetes.

Exploring the hypoglycaemic efficacy of bio-accessed antioxidative polyphenolics in thermally processed Cucumis dipsaceus fruits - An in vitro and in silico study

Inhibition of breakdown of dietary carbohydrates, by controlling the postprandial activity of diabetic enzymes through fruit polyphenolics can help downregulate the effects of Type 2 Diabetes Mellitus (T2DM). The study focuses on deciphering the induction of hyperglycaemic control by bio-accessed anti-oxidative polyphenols of Cucumic dipsaceus fruits. Chiefly, we examined the antioxidant activity of bio-accessed polyphenols of C. dipsaceus fruits (DPPH: ME (GDE)-66.26 %; ABTS: FE (IDE)-1963.83 µM TEAC/mg extract; Phosphomolybdenum reduction: FE (IDE)- 64.95 mg AAEAC/g extract). To add more significance, the anti-diabetic activity was predetermined by in silico docking analyses (Pseudojervine - -5.43; Squalene- -10.41) and was concurrently confirmed by in vitro studies (α amylase inhibition: ME (GDE) - 69.58 %; α glucosidase inhibition: FE (UDE)- 88.67 %). A higher bio-accessibility of rutin (37.92 mg/g ODE) and gallic acid (8.36 mg/g ODE) was observed after quantification by HPLC, which confirmed the correlation between anti-diabetic activity and C. dipsaceus fruit phenolic compounds.

A novel heat-stable angiotensin-converting enzyme zinc-binding motif inhibitory peptide identified from corn silk

ETHNOPHARMACOLOGICAL RELEVANCE

Hypertension is the most common and chronic severe health problem globally. Corn silk (CS), the silky fibers of corn (Zea mays L.), has a long history of traditional usage as a remedy for edema and hypertension.

AIM OF THE STUDY

The aim of the study was to explore the underlying mechanism by which CS exerts its anti-hypertensive effects and investigate the presence of bioactive molecules in CS aqueous extract.

MATERIALS AND METHODS

We analyzed the effects of boiling water extract of CS on angiotensin-converting enzyme (ACE) activities, the critical enzyme involved in the regulation of blood pressure. ACE inhibitory peptides from CS extract were identified using proteomics and bioinformatics tools. The binding interfaces between these peptides and ACE were defined by hydrogen-deuterium exchange mass spectrometry (HDX-MS). Subsequently, the anti-hypertensive effects of peptides were further investigated in spontaneously hypertensive rats (SHR).

RESULTS

Our data showed that CS extract exhibited dose-dependent inhibition of ACE activity. Liquid chromatography-tandem mass spectrometry identified a heat-stable peptide bank with 1313 distinct peptide fragments within the CS boiling water extract. Among these, CS-1 (LVPGWTKPICIGR) was selected through PeptideRanker and BIOPEP-UWM analyses. In vitro ACE inhibitory assays confirmed that CS-1 exhibited dose-dependent ACE inhibition, with IC50 values of 10.32 ± 0.41 μmol/L (using HHL as the substrate) and 13.74 ± 1.87 μmol/L (using ZFHL as the substrate). Oral administration of CS-1 led to a significant dose-dependent reduction in blood pressure, with the maximal decrease (42.33 ± 13.08 mmHg) occurring 0.5 h after ingestion. HDX-MS analysis revealed that CS-1 interacted with the zinc-binding motif of ACE, and hydrogen bond interactions were predicted between CS-1 and specific residues, including His361 in the N-domain, as well as His382, Gly386, and His387 in the C-domain of ACE. These findings suggested that the interaction of CS-1 with the residues in the zinc-binding motif of ACE led to ACE activity inhibition and a subsequent decrease in blood pressure in rats.

CONCLUSIONS

A novel heat-stable ACE inhibitory peptide, which interacted with the zinc-binding motif of ACE and reduced blood pressure in SHR, was identified in the CS extract. The presence of ACE inhibitory peptides in the CS extract supports its traditional use in ethnopharmacology for hypertension.

An evaluation of the antioxidant potential and in vitro enzyme inhibition profile of selected bryophytes from Northeast Anatolia (Türkiye)

Interest in the use of bryophytes in pharmaceutical, cosmetic, and food industrial applications is growing worldwide due to their secondary metabolites. In this study, n-hexane crude extracts and further fractions (aqueous, ethyl acetate and n-butanol) of aqueous ethanol (80:20, ethanol:H2O, v/v) were obtained from five different bryophytes (Pellia epiphylla, Conocephalum conicum, Porella platyphylla, Plagiomnium cuspidatum and Mnium spinulosum) collected from Trabzon, Türkiye. The total phenolic compound (TPC) content, antioxidant capacity (AC) and enzyme inhibition activity (acetylcholine esterase, butyrylcholine esterase, tyrosinase, α-amylase and α-glucosidase) of the extracts and fractions were species-specific and varied significantly between the crude extracts and fractions. Among the different bryophytes, Porella platyphylla and Pellia epiphylla in n-butanol and Plagiomnium cuspidatum and Mnium spinulosum in ethyl acetate fraction exhibited the highest TPC contents and AC values. The contents of phenolic acids liberated in free, ester and glycoside forms were also species-specific. p-Hydroxybenzoic acid (p-HBA) in free form in P. cuspidatum and P. platyphylla, p-coumaric acid (p-CoA) in ester form and m-hydroxybenzoic acid (m-HBA) in glycoside form in M. spinulosum were the major phenolic acids in the bryophytes. The n-hexane extracts of the bryophytes, in particular M. spinulosum, had IC50 values ​​almost 100 times lower than acarbose. This suggests that M. spinulosum in particular may represent a possible candidate for the production of new antidiabetic agents.Communicated by Ramaswamy H. Sarma.

Waste to Medicine: Evidence from Computational Studies on the Modulatory Role of Corn Silk on the Therapeutic Targets Implicated in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance and/or defective insulin production in the human body. Although the antidiabetic action of corn silk (CS) is well-established, the understanding of the mechanism of action (MoA) behind this potential is lacking. Hence, this study aimed to elucidate the MoA in different samples (raw and three extracts: aqueous, hydro-ethanolic, and ethanolic) as a therapeutic agent for the management of T2DM using metabolomic profiling and computational techniques. Ultra-performance liquid chromatography-mass spectrometry (UP-LCMS), in silico techniques, and density functional theory were used for compound identification and to predict the MoA. A total of 110 out of the 128 identified secondary metabolites passed the Lipinski's rule of five. The Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analysis revealed the cAMP pathway as the hub signaling pathway, in which ADORA1, HCAR2, and GABBR1 were identified as the key target genes implicated in the pathway. Since gallicynoic acid (-48.74 kcal/mol), dodecanedioc acid (-34.53 kcal/mol), and tetradecanedioc acid (-36.80 kcal/mol) interacted well with ADORA1, HCAR2, and GABBR1, respectively, and are thermodynamically stable in their formed compatible complexes, according to the post-molecular dynamics simulation results, they are suggested as potential drug candidates for T2DM therapy via the maintenance of normal glucose homeostasis and pancreatic β-cell function.

Cheminformatics identification of modulators of key carbohydrate-metabolizing enzymes from C. cujete for type-2 diabetes mellitus intervention

Purpose

The therapeutic use of oral hypoglycaemic agents in the management of type-2 diabetes mellitus (T2DM) is without adverse effects; thus, calls for alternative and novel candidates from natural products in medicinal plants.

Method

The study explored molecular docking and molecular dynamics (MD) simulation approaches to identify key antidiabetic metabolites from Crescentia cujete.

Results

Molecular docking results identified four and/or five best compounds against each target enzyme (alpha-glucosidase, dipeptidyl peptidase-IV, aldose reductase, and protein tyrosine phosphatase-1B (PTP-1B)) implicated in diabetes. The resulting complexes (except against PTP-1B) had higher docking scores above respective standards (acarbose, Diprotin A, ranirestat). The MD simulation results revealed compounds such as benzoic acid (-48.414 kcal/mol) and phytol (-45.112 kcal/mol) as well as chlorogenic acid (-42.978 kcal/mol) and naringenin (-31.292 kcal/mol) had higher binding affinities than the standards [acarbose (-28.248 kcal/mol), ranirestat (-21.042 kcal/mol)] against alpha-glucosidase and aldose reductase, respectively while Diprotin A (-45.112 kcal/mol) and ursolic acid (-18.740 kcal/mol) presented superior binding affinities than the compounds [luteolin (-41.957 kcal/mol and naringenin (-16.518 kcal/mol)] against DPP-IV and PTP-1B respectively.

Conclusion

While isoflavone (alpha-glucosidase), xylocaine (DPP-IV), luteolin (aldose reductase,) and chlorogenic acid (PTP-1B) were affirmed as the best inhibitors of respective enzyme targets, luteolin, and chlorogenic acid may be suggested and proposed as probable candidates against T2DM and related retinopathy complication based on their structural stability, compactness and affinity for three (DPP-IV, aldose reductase, and PTP-1B) of the four targets investigated. Further studies are warranted in vitro and in vivo on the antihyperglycaemic effects of these drug candidates.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01249-7.

Exploring plant-based alpha-glucosidase inhibitors: promising contenders for combatting type-2 diabetes

Objective: This systematic review aimed to provide comprehensive details on the α-G inhibitory potential of various bioactive compounds derived from natural sources.Methods: A comprehensive literature search was conducted using various databases and search engines, including Science Direct, Google Scholar, SciFinder, Web of Science, and PubMed until May, 2023.Results and conclusions: The enzyme alpha-glucosidase (α-G) is found in the brush border epithelium of the small intestine and consists of duplicated glycoside hydrolase (GH31) domain. It involves the conversion of disaccharides and oligosaccharides into monosaccharides by acting on alpha (1 → 4) and (1 → 6) linked glucose residue. Once absorbed, glucose enters the bloodstream and elevates postprandial glucose, which is associated with the development of type 2 Diabetes (T2D). Epidemic obesity, cardiovascular disease, and nephropathy are linked to T2D. Traditional medicinal plants with α-G inhibitory potential are commonly used to treat T2D due to the adverse effects of currently used α-G inhibitors miglitol, acarbose, and voglibose. Various bioactive compounds derived from natural sources, including lupenone, Wilforlide A, Baicalein, Betulinic acid, Ursolic acid, Oleanolic acid, Katononic acid, Carnosol, Hypericin, Astilbin, lupeol, betulonic acid, Fagomine, Lactucaxanthin, Erythritol, GP90-1B, Procyanidins, Galangin, and vomifoliol retain α-G inhibitory potential for regulating hyperglycaemia.

Theoretical Studies for the Discovery of Potential Sucrase-Isomaltase Inhibitors from Maize Silk Phytochemicals: An Approach to Treatment of Type 2 Diabetes

A theoretical analysis of the potential inhibition of human sucrase-isomaltase (SI) by flavonoids was carried out with the aim of identifying potential candidates for an alternative treatment of type 2 diabetes. Two compounds from maize silks, maysin and luteolin, were selected to be studied with the structure-based density functional theory (DFT), molecular docking (MDock), and molecular dynamics (MD) approaches. The docking score and MD simulations suggested that the compounds maysin and luteolin presented higher binding affinities in N-terminal sucrase-isomaltase (NtSI) than in C-terminal sucrase-isomaltase (CtSI). The reactivity parameters, such as chemical hardness (η) and chemical potential (µ), of the ligands, as well as of the active site amino acids of the NtSI, were calculated by the meta-GGA M06 functional in combination with the 6-31G(d) basis set. The lower value of chemical hardness calculated for the maysin molecule indicated that this might interact more easily with the active site of NtSI, in comparison with the values of the acarbose and luteolin structures. Additionally, a possible oxidative process was proposed through the quantum chemical calculations of the electronic charge transfer values (∆N) between the active site amino acids of the NtSI and the ligands. In addition, maysin displayed a higher ability to generate more oxidative damage in the NtSI active site. Our results suggest that maysin and luteolin can be used to develop novel α-glucosidase inhibitors via NtSI inhibition.

Synthesis and potential antidiabetic and lipid-lowering activities of putative asperidine B and its desmethyl analogue

Putative asperidine B is an unnatural 2,6-disubstituted piperidin-3-ol and a structural isomer of (+)-preussin, a well-known pyrrolidin-3-ol alkaloid. This work reports the first enantioselective synthesis of putative asperidine B and its desmethyl analogue via a chiron approach starting from d-isoascorbic acid as well as evaluation of their free-radical scavenging, antidiabetic, and anti-hyperlipidemic activities. Both putative asperidine B and its desmethyl analogue markedly reduced the total reactive oxygen species (ROS) without cytotoxicity in hepatocellular carcinoma (HepG2) cells. The desmethyl analogue was a potent inducer for two antioxidant gene expression, glutathione peroxidase and superoxide dismutase, whereas putative asperidine B only induced superoxide dismutase. In addition, putative asperidine B exerted potent antidiabetic activity via α-glucosidase inhibition (IC50 = 0.143 ± 0.001 mg/mL) comparable to that of acarbose, an antidiabetic drug. Consistent with the parent asperidine B (preussin), both putative asperidine B and its desmethyl analogue inhibited cholesterol absorption in the intestinal Caco-2 cells. These novel and promising antioxidant, antidiabetic, and lipid-lowering effects of piperidin-3-ols could offer a starting point for this class of compounds for obesity and diabetic drug discovery.

Bioactive compounds of corn silk and their role in management of glycaemic response

Management of glycaemic response is perhaps the most critical part of antidiabetic therapy. Hypoglycaemia is an avoidable complication caused by conventional drugs used in the treatment of diabetes. It triggers commonly during the intensification of anti-hyperglycemic therapy used to render glycemic control in diabetic patients. The commercial oral hypoglycaemic drugs, insulin, herbal medicines and plant extracts are therefore used as a part of the treatment of diabetes. The demand for treating diabetes, through herbal and plant resources is due to their lesser adverse reactions and better phytochemical benefits. Corn silk has been shown to have anti-allergic, anti-inflammatory, and anti-hypertensive effects when extracted in various solvents. Corn silk has medicinal characteristics and has long been used as a traditional medicine in many nations, although the mechanism of action is unknown. The hypoglycaemic effects of corn silk are investigated in this review. The phytochemical components present in corn silk-like flavonoids, phenolics, terpenoids, tannins, sterols, and alkaloids are phytochemical components that have hypoglycemic activity and a mechanism for lowering blood glucose levels. There is a lack of a homogenized database on the hypoglycemic properties of corn silk thus the present review attempts to critically analyse it and provide specific recommendations of its doses.

By-Products of Zea mays L.: A Promising Source of Medicinal Properties with Phytochemistry and Pharmacological Activities: A Comprehensive Review

Zea mays (Z. mays) is one of the main cereal crops in the world, and it's by-products have exhibited medicinal properties to explore. This article intends to review the chemical compositions and pharmacological activities of by-products of Z. mays (corn silks, roots, bract, stems, bran, and leaves) which support the therapeutic potential in the treatment of different diseases, with emphasis on the natural occurring compounds and detailed pharmacological developments. Based on this review, 231 natural compounds are presented. Among them, flavonoids, terpenes, phenylpropanoids, and alkaloids are the most frequently reported. The by-products of Z. mays possess diuretic effects, hepatoprotective, anti-diabetic, antioxidant, neuroprotective, anti-inflammatory, anti-cancer, plant protection activity, and other activities. This article reviewed the phytochemistry and pharmacological activities of Z. mays for comprehensive quality control and the safety and effectiveness to enhance future application.

Extraction Optimization, Preliminary Identification, and Bioactivities in Corn Silk

For thousands of years, corn silk has been widely used as an antidiabetic, antioxidant, and antihyperlipidemic and for other effects, but there is a lack of studies that correlate the extracts of flavonoid composition with their biological activities. Thus, the objectives of this study were to optimize the conditions for extracting flavonoids, identify flavonoids, and correlate the flavonoid composition with the biological activities in corn silk. The response surface experiments showed that the highest flavonoid content was predicted at 45.321 min, 57.349°C, 26.089 mL/g, and 71.269%, respectively. The verification experiment results under these optimized conditions showed an ultrasonic time of 45 min, an ultrasonic temperature of 57°C, a liquid-to-material ratio of 26, and an ethanol volume fraction of 70%. No significant differences (the relative error is 4.378%) were observed between the theoretical and experimental TFC values, indicating that the developed models were accurate. Under these optimum extraction conditions, 20 major compounds were identified and quantified by UPLC-LTQ/Orbitrap MS. Furthermore, these optimum ethanol extracts of corn silk are effective against Bacillus subtilis and hypoglycemic activity compared with the traditional heating reflux extraction method. Six corn silk components seem to be the main contributors to the inhibitory effect against Bacillus subtilis and hyperglycemia activities. These results are useful for the application of corn silk in the food or pharmaceutical industry.

Modulation of gut microbiota and fecal metabolites by corn silk among high-fat diet-induced hypercholesterolemia mice

Corn silk (CS) is known to reduce cholesterol levels, but its underlying mechanisms remain elusive concerning the gut microbiota and metabolites. The aim of our work was to explore how altered gut microbiota composition and metabolite profile are influenced by CS intervention in mice using integrated 16S ribosomal RNA (rRNA) sequencing and an untargeted metabolomics methodology. The C57BL/6J mice were fed a normal control diet, a high-fat diet (HFD), and HFD supplemented with the aqueous extract of CS (80 mg/mL) for 8 weeks. HFD-induced chronic inflammation damage is alleviated by CS extract intervention and also resulted in a reduction in body weight, daily energy intake as well as serum and hepatic total cholesterol (TC) levels. In addition, CS extract altered gut microbial composition and regulated specific genera viz. Allobaculum, Turicibacter, Romboutsia, Streptococcus, Sporobacter, Christensenella, ClostridiumXVIII, and Rikenella. Using Spearman’s correlation analysis, we determined that Turicibacter and Rikenella were negatively correlated with hypercholesterolemia-related parameters. Fecal metabolomics analysis revealed that CS extract influences multiple metabolic pathways like histidine metabolism-related metabolites (urocanic acid, methylimidazole acetaldehyde, and methiodimethylimidazoleacetic acid), sphingolipid metabolism-related metabolites (sphinganine, 3-dehydrosphinganine, sphingosine), and some bile acids biosynthesis-related metabolites including chenodeoxycholic acid (CDCA), lithocholic acid (LCA), ursodeoxycholic acid (UDCA), and glycoursodeoxycholic acid (GUDCA). As a whole, the present study indicates that the modifications in the gut microbiota and subsequent host bile acid metabolism may be a potential mechanism for the antihypercholesterolemic effects of CS extract.

Enzyme inhibitory activities of phenolic compounds in pecan and the effect on starch digestion

Pecan has been widely recognized for its high phenolic content and related health benefits. Previous studies indicated that pecan consumption might be beneficial in treating type 2 diabetes mellitus (T2DM). The objective of this study was to investigate the enzyme inhibitory activities of pecan phenolic compounds (PPC) and the effect in starch hydrolysis by in vitro simulation digestion. PPC was extracted with a solvent mixture from pecan powder and freeze-dried. PPC was tested for the inhibitory effects on α-amylase and α-glucosidase via enzyme kinetics study. Static in vitro digestion trials were conducted to evaluate the effect of intake of PPC and pecan powder on starch digestion. PPC displayed a potent inhibition effect against α-amylase and α-glucosidase with IC₅₀ of 77.9 μg/mL and 9.02 μg/mL, respectively. Both PPC and pecan powder inhibited starch hydrolysis during in vitro digestion. However, the level of inhibition was lower than that from the catalytic kinetics study, and PPC exhibited a higher inhibition effect than pecan powder. The results confirmed the potential of PPC as a novel enzyme inhibitor for T2DM management. The information is helpful to promote the intake of pecan nuts for health-enhancing effects.

Extraction of Pectin from Orange Peel and Study of Its Protective Effect Against Loperamide-Induced Impaired Gastrointestinal Motor Functions and Oxidative Stress in Rats

Pectin is a polysaccharide attached to carbohydrates. These are substances exclusively of plant origin. The aim of the present study is to evaluate the laxative effects of orange peel pectin extract (OPPE) against constipation induced by loperamide (LOP) in rats. Rats were equally divided into six groups and treated daily 1 week as follows: Control, LOP (3 mg/kg, body weight [b.w.], Per Os [p.o.]), LOP+yohimbine (2 mg/kg, b.w., i.p.), and LOP+OPPE (6.25, 12.5, and 25 mg/kg, b.w., p.o.). At the end of the experiment, the effects of OPPE were assessed by fecal parameters (numbers, weight, and water content), gastrointestinal transit, gastric emptying, serum metabolic parameter changes, intestinal and colon mucosa oxidative stress, and the histological examination. The defecation test showed that administration of LOP (3 mg/kg, b.w., p.o.) leads to the production of remarkable constipation. Indeed, the number and water content of stools decreased (25.50 [n/24 h] and 29.86%) significantly (P < .05). Acute pretreatment with OPPE significantly and dose dependently accelerated the stool moistening and allowed an increase of stool weight (2.85, 3.61, 3.93 [g/24 h/rat]) as well as the frequency of defecation (47.36, 54.54, and 56.26 [n/24 h]). OPPE also significantly (P < .05) and dose dependently increased the intestinal motility (70.78%, 73.33%, and 75.01%) and gastric emptying. LOP-induced reduction (P < .05) of intestinal secretion was accompanied by a colonic and small bowel oxidative stress status and histological changes, which was attenuated by OPPE treatment. The findings of this study indicate that OPPE possesses an important role in the gastrointestinal motility regulation, and thus lend pharmacological credence to the suggested use of the natural pectin for the treatment, management, and/or control of constipation.

Chemical Group Profiling, In Vitro and In Silico Evaluation of Aristolochia ringens on α-Amylase and α-Glucosidase Activity

Diabetes mellitus (DM) has become a global scourge, and there is a continuous search for novel compounds as viable alternatives to synthetic drugs which are often accompanied by severe adverse effects. Aristolochia ringens is among the scientifically implicated botanicals effective in the management of several degenerative diseases including DM. The current study evaluated the inhibitory mechanism(s) of root extract of A. ringens on α-amylase and α-glucosidase in vitro and in silico, while its constituents were characterized using liquid chromatography-mass spectrometric technique. The extract had concentration-dependent inhibitory effect on the study enzymes, and the inhibition compared well with that of standard drug (acarbose) with respective IC₅₀ values of 0.67 mg/mL (α-amylase) and 0.57 mg/mL (α-glucosidase) compared with that of the extract (0.63 and 0.54 mg/mL). The extract competitively and uncompetitively inhibited α-amylase and α-glucosidase, respectively. Of the identified compounds, dianoside G (−12.4, −12.5 kcal/mol) and trilobine (−10.0, −10.0 kcal/mol) had significant interactions with α-amylase and α-glucosidase, respectively, while magnoflorine and asiatic acid also interacted keenly with both enzymes, with quercetin 3-O-glucuronide and strictosidine showing better affinity towards α-glucosidase. These observations are suggestive of involvement of these compounds as probable ligands contributing to antidiabetic potential of the extract. While studies are underway to demystify the yet to be identified compounds in the extract, the data presented have lent scientific credence to the acclaimed in vivo antidiabetic potential of the extract and suggested it as a viable source of oral hypoglycaemic agent.

Interactions between Phenols and Alkylamides of Sichuan Pepper (Zanthoxylum Genus) in α-Glucosidase Inhibition: A Structural Mechanism Analysis

The phenols and alkylamides in 26 varieties of Zanthoxylum pericarps (ZP) were comparatively identified, and the contribution of these key components to the inhibition of in vitro α-glucosidase (α-Glu) was confirmed using principal component analysis (PCA) and ingredient recombination models. Additionally, spectrophotometric assays, nuclear magnetic resonance (NMR), and molecular docking (MD) were employed to characterize the interactions among key components in ZP when exposed to α-Glu. Four phenols and hydroxy-α-sanshool (α-SOH), which were recognized as main ingredients, presented an antagonistic effect in the inhibition of α-Glu. ¹H NMR demonstrated chemical shifts of certain hydrogens in the B phenolic ring and tetraenyl group, indicating a possible p-π conjugation between phenols and α-SOH. In addition, using MD analysis, the phenol-binding sites were observed to be negatively affected when α-SOH initially interacted with α-Glu. The combined results of the NMR and MD clarified the structural mechanism behind phenol/α-SOH antagonistic behavior in α-Glu inhibition.

Extraction of Flavonoids from Corn Silk and Biological Activities In Vitro

When harvesting corn, corn silk was discarded as waste, including the compounds isolated and identified from corn silk such as flavonoids, sterols, alkaloids, polysaccharides, organic acids, volatile oils, trace elements, and multivitamins. It not only pollutes the environment but also wastes resources. In this paper, extraction methods commonly used for extracting flavonoids from corn silk were reviewed, such as reagent method, enzymatic method, microwave, supercritical CO2 extraction, ultrasonic, and microwave-assisted ultrasonic. Flavonoids are natural antioxidants and have application value in scavenging free radicals, inhibiting bacteria, and regulating blood lipids. The in vitro biological activities of flavonoids from corn silk extracted by different extraction methods were also compared.

Nutritional Properties and In Vitro Antidiabetic Activities of Blue and Yellow Corn Extracts: A Comparative Study

The objective of this research was to designate and identify the profile of fatty acids, sterols, and polyphenol compounds and to demonstrate the antidiabetic activity, in blue corn extracts (BCE) in comparison with the yellow variant of this raw material. All of the maize lines, including the blue corn, were grown in Europe (southwestern part of Poland) and not in the place of origin (South America). In the extracts of the blue corn variety, eight anthocyanin compounds were isolated. The compound found in the largest amount was pelargonidin, followed by cyanidin-3-glucoside and other glycoside derivatives. Unsaturated fatty acids were the main ones found in the lipid fraction of blue and yellow corn, including linoleic acid and oleic acid. Saturated fatty acids, such as stearic and palmitic acid, were present in smaller amounts. The blue corn’s sterol profile was similar to other varieties of this corn, with β-sitosterol and campesterol occurring in the largest amount, alongside smaller amounts of stigmastanol and stigmasterol. The blue corn variety was characterized by a high content of polyphenolic compounds, which show several biological activities, including antidiabetic activity. The strongest in vitro antidiabetic effect was found in the blue corn lines. Among the polyphenolic compounds in both the blue and yellow corn varieties, in the largest amounts, were caffeic acid, procyanidin B2, and gallic acid. Despite the known and proven biological activity of polyphenolic compounds, the fat fraction showed the highest in vitro antidiabetic activity in the BCE studied.

Maysin plays a protective role against α-Synuclein oligomers cytotoxicity by triggering autophagy activation

Parkinson's disease (PD) is a widespread neurodegenerative disorder characterized by the progressive loss of neurons. The accumulation of aggregated forms of the α-Synuclein (Syn) protein is the main cause of neurotoxicity in PD by disrupting cellular homeostasis until neuronal death. Scientific research is constantly looking for natural products as preventive agents against the progression of several neurodisorders due their safety and non-toxic nature. Neuroprotective phytochemicals include Maysin (Mys), the most abundant C-glycosilflavone in corn silk. In this work, the Mys protective role against damage by Syn amyloid aggregates - oligomers and fibrils - was investigated in SH-SY5Y human neuroblastoma cells obtaining novel and interesting information concerning the Mys molecular mechanism of action. Mys showed effectiveness in preventing the typical toxic events induced by Syn amyloid aggregates, i.e. oxidative stress and imbalance of intracellular calcium homeostasis. Mys exhibited a cytoprotective role, especially against Syn oligomers injury, activating an autophagic degradative process, thus playing a key role on several features of amyloid neurotoxicity. Therefore, Mys could be proposed for the first time to the scientific community as an interesting novel natural compound that might allow to develop alternative strategies to prevent the damage of Syn oligomers involved in Parkinson's disease.

Purgative/laxative actions of Globularia alypum aqueous extract on gastrointestinal-physiological function and against loperamide-induced constipation coupled to oxidative stress and inflammation in rats

BACKGROUND

Chronic constipation is a gastrointestinal functional disorder which affects patient quality of life. Therefore, many studies were oriented to search herbal laxative agents. In this study, we investigated the effect of Globularia alypum L. leaves aqueous extract (GAAE) against loperamide (LOP)-produced constipation.

METHODS

Animals were given LOP (3 mg/kg, b.w., i.p.) and GAAE (100, 200, and 400 mg/kg, b.w., p.o.) or yohimbine (2 mg/kg, b.w., i.p.), simultaneously, for 1 week. Gastric-emptying test and intestinal transit were determined. Colon histology was examined, and oxidative status was evaluated using biochemical-colorimetric methods.

KEY RESULTS

GAAE ameliorates significantly gastric emptying (64% to 76.5%) and intestinal transit (66.65% to 84.73%). LOP negatively influenced defecation parameters and generated a stress situation. GAAE administration in contrast ameliorated those parameters and re-established oxidative balance.

CONCLUSION

GAAE showed a modest action against oxidative stress and decreased LOP effect and thereby can be considered a pharmacological agent in constipation.

Increment of Lysosomal Biogenesis by Combined Extracts of Gum Arabic, Parsley, and Corn Silk: A Reparative Mechanism in Mice Renal Cells

Gum Arabic (GA), parsley, and corn silk have been traditionally used for renal failure patients worldwide. This study aimed at probing the mechanism of the combined extracts, namely, GA (3 g/kg/day), parsley (1 g/kg/day), and corn silk (200 mg/kg/day), as nephroprotective agents in mice after amikacin (1.2 g/kg) single dose through exploration of their action on G-protein coupled receptors (GPR) 41 and 43 and the ensuing lysosomal biogenesis. Western blotting was employed for renal levels of bcl-2-associated X protein (BAX) and cytosolic cathepsin D; cell death markers, nuclear transcription factor EB (TFEB), and lysosomal associated membrane protein-1 (LAMP-1); and lysosomal biogenesis indicators. Liquid chromatography–mass spectrometry (LC-MS) and docking were also employed. After amikacin treatment, BAX and cathepsin D levels were upregulated while LAMP-1 and nuclear TFEB levels were inhibited. The combined extracts inhibited BAX and cytosolic cathepsin D but upregulated LAMP-1 and nuclear TFEB levels. Docking confirmed GPR modulatory signaling. The combined extracts showed GPR signal modulatory properties that triggered lysosome synthesis and contributed to reversing the adverse effects of amikacin on renal tissues.

Chemical profiling of secondary metabolites from Himatanthus drasticus (Mart.) Plumel latex with inhibitory action against the enzymes α-amylase and α-glucosidase: In vitro and in silico assays

ETHNOPHARMACOLOGICAL RELEVANCE

Himatanthus drasticus is an important medicinal plant whose latex is traditionally used in Northeast Brazil to treat various diseases, including diabetes. The use of α-amylase and α-glucosidase inhibitors can be an effective strategy to modulate levels of postprandial hyperglycemia via control of starch metabolism.

AIMS OF THE STUDY

This study aimed to verify if H. drasticus latex has inhibitory activity against enzymes linked to type 2 diabetes, besides chemically characterizing the metabolites responsible for such activities. In addition, in silico analysis was performed to support the traditional claim of possible antidiabetic activity of this latex.

MATERIALS AND METHODS

Latex from H. drasticus stems was sequentially partitioned with n-hexane (FHDH), CHCl₃ (FHDC) and EtOH (FHDHA). Wash extraction of the FHDHA fraction was performed to obtain the other extract fractions. The FHDHA was submitted to chromatography in a SPE C₁₈ cartridge using gradient elution with MeOH/H₂O to produce five fractions: FHDHA1, FHDHA2, FHDHA3, FHDHA4 and FHDHA5. The FHDHA1 was subjected to semi-preparative reverse phase HPLC. Lineweaver-Burk plots were used to investigate the kinetic parameters of α-amylase and α-glucosidase inhibitory activity. The interactions between plumieride and porcine pancreatic α-amylase and α-glucosidase were analyzed through an in silico molecular docking study.

RESULTS

Phytochemical identification of compounds present in the FHDHA fraction of H. drasticus latex was possible by 1H, 13C NMR analysis and mass spectrometry, and the results were compared with the literature. The identified compounds were α-ethyl glucoside, protocatechuic acid, 3-O-caffeoylquinic acid, 15-demethylplumieride acid, 5-O-caffeoylquinic acid, caffeic acid, vanillic acid, plumieride, and catechin. The inhibition results of the fractions tested against α-amylase and α-glucosidase showed inhibitory activities dependent on the increase of fractions and compound concentrations. The IC₅₀ results obtained from FHDHA, FHDHA1 and plumieride fractions against α-amylase were 36.46, 72.61, 33.87 μg/mL respectively. The IC₅₀ of plumieride was the closest to that of acarbose (22.52 μg/mL), a result similar to that obtained for α-glucosidase. The type of inhibition was competitive for both enzymes.

CONCLUSIONS

There was strong inhibition of α-amylase and α-glucosidase by FHDHA, FHDHA1 and plumieride, suggesting that these enzymes slow glucose absorption.

Ethnopharmacological review of medicinal plants used to manage diabetes in Morocco

Diabetes is a chronic metabolic disorder which affects millions of people every year. If diabetes is not controlled, it can cause serious damage and a number of health complications. The aim of this paper was to review published ethnobotanical and ethnopharmacological evidences of Moroccan plants with antidiabetic potentials. Publications describing the medicinal plants used for the treatment of diabetes in Morocco were searched from the databases, including Google Scholar, Elsevier, Medline, Web of Science, SCOPUS and Pubmed. Other literature source was also used including books and theses available in library. About 750 literature references were studied, and only 240 research publications based on data from different Moroccan provinces published until June 2019 were included in this review. In total, 255 plants species belonging to 70 families were reported. Compositae and Lamiaceae were mentioned as the most represented families. The frequently used plant species in the dwellers of most regions of Morocco are Trigonella foenum-graecum, Artemesia herba-alba, Nigella sativa, Olea europaea, Allium cepa and Marrubium vulgare. This review provides useful information and current scientific knowledge on the medicinal plants used to manage diabetes in Morocco. Medicinal plants reported should be submitted to chemical, pharmacological and clinical studies to identify pharmacologically active metabolites and to confirm their antidiabetic activity.

Inhibitory effect of Artocarpus lakoocha Roxb and oxyresveratrol on α-glucosidase and sugar digestion in Caco-2 cells

Long-term diabetic complications are exacerbated by post-prandial hyperglycemia which could be ameliorated by α-glucosidase inhibitor including oxyresveratrol. Puag-Haad is an aqueous extract from Artocarpus lakoocha Roxb. containing ~65% oxyresveratrol. Oxyresveratrol is an inhibitor of isolated yeast α-glucosidase enzyme but has not been tested on intact gut enterocytes where the enzyme is membrane-bound. Accordingly, differentiated Caco-2 cells that contain the native enzyme were used to test maltose hydrolysis in the present study. The results demonstrated that purified yeast α-glucosidase was non-competitively inhibited by oxyresveratrol (Ki 54.4 ± 0.7 μg/mL) and Puag-Haad (2.7 ± 0.1 μg/mL) compared to 153.8 ± 4.3 μg/mL acarbose, an anti-diabetic drug. In differentiated Caco-2 cells, both oxyresveratrol and Puag-Haad inhibited maltose hydrolysis with lesser potency compared to acarbose. Thus, although weaker than acarbose, oxyresveratrol and Puag-Haad do not inhibit pancreatic amylase which might be a therapeutic asset in preventing fermentation of unabsorbed carbohydrate causes abdominal bloating, flatulence, or diarrhea. Oxyresveratrol and Puag-Haad may help control postprandial hyperglycemia with low risk of gastrointestinal side effects.

Plant leaves for wrapping zongzi in China: an ethnobotanical study

BACKGROUND

Zongzi, a common Chinese rice-pudding and one of the most symbolic foods in traditional Chinese festivals, is integral to both Chinese traditional culture and daily meals. Traditionally, the leaves of different plant species have been used to wrap zongzi. The variety of zongzi leaves (ZLs) can contribute to the zongzi-based cultural diversity. Given the cultural and dietary significance of zongzi, the ethnobotanical surveys were carried out, aiming to investigate the diversity of plant species and associated traditional botanical knowledge of ZLs, which could attract particular attention for their further studies.

METHOD

Both literature studies and field surveys were conducted in the study. The field investigations were carried out from May 2006 to June 2018 throughout China. Ethnobotanical information about ZLs was obtained by direct observation, semi-structured interviews, and key informant interviews.

RESULTS

In total, ZLs from 57 plant species were identified and recorded, belonging to 38 genera and 18 families. Several folk legends have been formed to explain the origin of using plant leaves to pack zongzi. Over time, Chinese people have developed diverse traditional botanical knowledge surrounding ZLs, especially regarding the zongzi flavor, antiseptic functions, and medicinal values. Based on the literature review, some species of ZLs such as the leaves of Corchorus capsularis and Vernicia fordii may even pose a potential threat to human health. Presently, in some regions of China, the traditional ZLs, such as Cocos nucifera, Tilia tuan, and Zizania latifolia, are being substituted by commercialized ZLs such as Phragmites australis and Indocalamus tessellatus.

CONCLUSION

A variety of traditional ZLs have been discovered in China. Although diverse traditional knowledge exists in China surrounding the usage of ZLs, some species may have the potential of threatening human health. Therefore, further explorations are necessary to comprehensively evaluate traditional ZLs, the results of which could help to conserve the cultural diversity of zongzi, to guarantee food safety, and to encourage the uses of plant leaves in food, medicine, and environmental management, for our human health.

Postprandial Glycemic and Insulinemic Effects of the Addition of Aqueous Extracts of Dried Corn Silk, Cumin Seed Powder or Tamarind Pulp, in Two Forms, Consumed with High Glycemic Index Rice

Several plant-based traditional ingredients in Asia are anecdotally used for preventing and/or treating type 2 diabetes. We investigated three such widely consumed ingredients, namely corn silk (CS), cumin (CU), and tamarind (TA). The aim of the study was to determine the effects of aqueous extracts of these ingredients consumed either as a drink (D) with high-glycemic-index rice or added to the same amount of rice during cooking (R) on postprandial glycemia (PPG), insulinemia (PPI), and blood pressure (BP), over a 3 h measurement period. Eighteen healthy Chinese men (aged 37.5 ± 12.5 years, BMI 21.8 ± 1.67 kg/m²) took part in a randomized crossover trial, each completing up to nine sessions. Compared to the control meal (plain rice + plain water), the addition of test extracts in either form did not modulate PPG, PPI, or BP. However, the extracts when added within rice while cooking gave rise to significantly lower PPI than when consumed as a drink (p < 0.01). Therefore, the form of consumption of phytochemical-rich ingredients can differentially modulate glucose homeostasis. This study also highlights the need for undertaking randomized controlled clinical trials with traditional foods/components before claims are made on their specific health effects.

Antihypertensive Effects of Corn Silk Extract and Its Novel Bioactive Constituent in Spontaneously Hypertensive Rats: The Involvement of Angiotensin-Converting Enzyme Inhibition

Corn silk tea has been used in folk medicine for anti-hypertensive healthcare. Angiotensin-converting enzyme (ACE) plays a crucial role on the homeostasis of blood pressure. However, effects of corn silk tea on ACE activity and the presence of ACE inhibitory constituents in corn silk are still unknown. Here we applied proteomics and bioinformatics approaches to identify corn silk bioactive peptides (CSBps) that target ACE from the boiling water extract of corn silk (CSE). CSE significantly reduced systolic blood pressure (SBP) levels in spontaneously hypertensive rats and inhibited the ACE activity. By proteomics coupled with bioinformatics analyses, we identified a novel ACE inhibitory peptide CSBp5 in CSE. CSBp5 significantly inhibited the ACE activity and decreased SBP levels in a dose-dependent manner. Docking analysis showed that CSBp5 occupied the substrate-binding channel of ACE and interacted with ACE via hydrogen bonds. In conclusion, we identified that CSE exhibited anti-hypertensive effects in SHRs via the inhibition of ACE, the target of most anti-hypertensive drugs. In addition, an ACE inhibitory phytopeptide CSBp5 that decreased SBP levels in rats was newly identified. Our findings supported the ethnomedical use of corn silk tea on hypertension. Moreover, the identification of ACE inhibitory phytopeptide in corn silk further strengthened our findings.

Inhibitory effect of saccharides and phenolic compounds from maize silks on intestinal α-glucosidases

Maize silks have been used in Mexico for centuries as a natural-based treatment for various illnesses, including obesity and diabetes. It has been shown in mice that intake of maize silk extracts reduces the levels of blood glucose. However, it is not clear how or what maize silk compounds are involved in such an effect. A hypothesized mechanism is that some maize silk compounds can inhibit carbohydrate hydrolyzing enzymes like α-glucosidases. This work aimed to assess the capability of both saccharides and phenolic compounds from maize silks to inhibit intestinal α-glucosidases. Results showed that saccharides from maize silks did not produce inhibition on intestinal α-glucosidases, but phenolics did. Maize silk phenolics increased the value of K_m significantly and decreased the V_max slightly, indicating a mixed inhibition of α-glucosidases. According to the molecular docking analysis, the phenolics maysin, methoxymaysin, and apimaysin, which had the highest predicted binding energies, could be responsible for the inhibition of α-glucosidases. PRACTICAL APPLICATIONS: The International Diabetes Federation (IDF) reported in 2017 that diabetes affects over 424 million people worldwide, and caused 4 million deaths. Non-insulin-dependent diabetes or type 2 diabetes mellitus (T2DM) accounts for ∼90% of cases. T2DM is characterized by insulin resistance and pancreatic β-cell failure. Therapy for T2DM includes the use of sulfonylureas, thiazolidinediones, biguanides, and α-glucosidase inhibitors. Regarding the α-glucosidase inhibitors, only few are commercially available, and these have been associated with severe gastrointestinal side effects. This work aimed to assess the capability of both saccharides and phenolic compounds from maize silks to inhibit intestinal α-glucosidases. Results from this work evidenced that maize silk polyphenols acted as effective inhibitors of intestinal rat α-glucosidases. Computational analysis of maize silk polyphenols indicated that maysin, a particular flavonoid from maize silks, could be responsible for the inhibition of α-glucosidases.

ent-Kaurane Diterpenoids with Neuroprotective Properties from Corn Silk ( Zea mays)

Thirteen new ent-kaurane diterpenoids, stigmaydenes A-M (1-13), together with two known compounds (14, 15), were isolated from the crude extract of corn silk ( Zea mays). The structures of the compounds were confirmed by comprehensive spectroscopic analyses. The absolute configuration of compound 1 was defined by single-crystal X-ray diffraction. The absolute configurations of the compounds were also confirmed by comparison of experimental and calculated specific rotations. The compounds were evaluated for their neuroprotective effects against H₂O₂-induced SH-SY5Y cell injury, and compound 8 was active at 100 μM, as determined by flow cytometry (annexin V-FITC/PI staining) and Hoechst 33258 staining. The results suggested that compound 8 could protect neuronal cells from H₂O₂-induced injury by inhibiting apoptosis in SH-SY5Y cells.

KINETICS OF MODULATORY ROLE OF Cyperus esculentus L. ON THE SPECIFIC ACTIVITY OF KEY CARBOHYDRATE METABOLIZING ENZYMES

Background:

The continuous search for new lead compounds as viable inhibitors of specific enzymes linked to carbohydrate metabolism has intensified. Cyperus esculentus L. is one of the therapeutically implicated botanicals against several degenerative diseases including diabetes mellitus.

Materials and Methods:

This study evaluated the antioxidant and mechanism(s) of inhibitory potential of aqueous extract of C. esculentus on α-amylase and α-glucosidase in vitro. The extract was investigated for its radical scavenging and hypoglycaemic potentials using standard experimental procedures. Lineweaver-Burke plot was used to predict the manner in which the enzymes were inhibited.

Results:

The data obtained revealed that the extract moderately and potently inhibited the specific activities of α-amylase and α-glucosidase, respectively. The inhibition was concentration-related with respective IC₅₀ values of 5.19 and 0.78 mg/mL relative to that of the control (3.72 and 3.55 mg/mL). The extract also significantly scavenged free radicals and the effects elicited could be ascribed to its phytoconstituents.

Conclusion:

The respective competitive and non-competitive mode of action of the extract is due to its inhibitory potentials on the activities of α-amylase and α-glucosidase. Going forward, in addition to completely characterize the exact compound(s) responsible for the elicited activity in this study, pertinent attention will be given to the in vivo evaluation of the identified constituents.

THE PURVIEW OF PHYTOTHERAPY IN THE MANAGEMENT OF KIDNEY DISORDERS: A SYSTEMATIC REVIEW ON NIGERIA AND SOUTH AFRICA

BACKGROUND

The kidney is tasked with a number of metabolic functions in the body. In its role as a detoxifier and primary eliminator of xenobiotics, it becomes vulnerable to developing injuries. Currently, over 1 million people in the world are living on renal replacement therapies (RRTs). The case in sub-Sahara African countries like Nigeria and South Africa is not any better than the global trend.

MATERIALS AND METHODS

A systematic review of medicinal plants used in the treatment of kidney disorders was conducted. Information were gathered from published scientific journals, books, reports from national, regional and international institutions, conference proceedings and other high profile intellectual resources. MeSH words like 'prevalence of kidney disorders in Africa', 'renal replacement therapy', 'nephrotoxins or nephrotoxicants', 'nephroprotective plants', 'nephroprotective plants in Nigeria or South Africa' and 'nephroprotective phytocompounds' were used to retrieve information from online databases (Google, Pubmed, MEDLINE, Science Direct, Scopus and SID).

RESULTS

Interestingly, our findings revealed that phytotherapy has emerged and is being employed to protect renal functions and delay progression of renal pathological conditions into end episodes where the last resort is RRT. In fact, in recent times, Phytotherapists are not only interested in developing relatively safe, more affordable, easily accessible and potent nephroprotective formulations but also increasing awareness on the prevalence of the disease and educating the populace on the probable preventive measures. More importantly, efforts at scientifically elucidating the pharmacological efficacy of the identified nephroprotective plants yet to be validated must be intensified through informed expert opinions. Till date, there is paucity of information on the concept of nephroprotection in most developing countries where kidney disorder is a major threat. Although, the concept is just emerging in South Africa, evidences have given credence to its application in complementary and alternative system of medicine in Nigeria.

CONCLUSION

This review, therefore, reawaken researchers' consciousness in the continuous search for auspicious nephroprotective plants that could potentially be excellent candidates in developing new lead drugs to manage and treat renal disorders.

Membrane Stabilization and Detoxification of Acetaminophen-Mediated Oxidative Onslaughts in the Kidneys of Wistar Rats by Standardized Fraction of Zea mays L. (Poaceae), Stigma maydis

This study evaluated membrane stabilization and detoxification potential of ethyl acetate fraction of Zea mays L., Stigma maydis in acetaminophen-induced oxidative onslaughts in the kidneys of Wistar rats. Nephrotoxic rats were orally pre- and posttreated with the fraction and vitamin C for 14 days. Kidney function, antioxidative and histological analyses were thereafter evaluated. The acetaminophen-mediated significant elevations in the serum concentrations of creatinine, urea, uric acid, sodium, potassium, and tissue levels of oxidized glutathione, protein-oxidized products, lipid peroxidized products, and fragmented DNA were dose-dependently assuaged in the fraction-treated animals. The fraction also markedly improved creatinine clearance rate, glutathione, and calcium concentrations as well as activities of superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase in the nephrotoxic rats. These improvements may be attributed to the antioxidative and membrane stabilization activities of the fraction. The observed effects compared favorably with that of vitamin C and are informative of the fraction's ability to prevent progression of renal pathological conditions and preserve kidney functions as evidently supported by the histological analysis. Although the effects were prominently exhibited in the fraction-pretreated groups, the overall data from the present findings suggest that the fraction could prevent or extenuate acetaminophen-mediated oxidative renal damage via fortification of antioxidant defense mechanisms.