Inhibitory effect of alliin from Allium sativum on the glycation of superoxide dismutase

Role of methylglyoxal and glyoxalase in the regulation of plant response to heavy metal stress

KEY MESSAGE

Methylglyoxal and glyoxalase function a significant role in plant response to heavy metal stress. We update and discuss the most recent developments of methylglyoxal and glyoxalase in regulating plant response to heavy metal stress. Methylglyoxal (MG), a by-product of several metabolic processes, is created by both enzymatic and non-enzymatic mechanisms. It plays an important role in plant growth and development, signal transduction, and response to heavy metal stress (HMS). Changes in MG content and glyoxalase (GLY) activity under HMS imply that they may be potential biomarkers of plant stress resistance. In this review, we summarize recent advances in research on the mechanisms of MG and GLY in the regulation of plant responses to HMS. It has been discovered that appropriate concentrations of MG assist plants in maintaining a balance between growth and development and survival defense, therefore shielding them from heavy metal harm. MG and GLY regulate plant physiological processes by remodeling cellular redox homeostasis, regulating stomatal movement, and crosstalking with other signaling molecules (including abscisic acid, gibberellic acid, jasmonic acid, cytokinin, salicylic acid, melatonin, ethylene, hydrogen sulfide, and nitric oxide). We also discuss the involvement of MG and GLY in the regulation of plant responses to HMS at the transcriptional, translational, and metabolic levels. Lastly, considering the current state of research, we present a perspective on the future direction of MG research to elucidate the MG anti-stress mechanism and offer a theoretical foundation and useful advice for the remediation of heavy metal-contaminated environments in the future.

Antiglycoxidative properties of amantadine – a systematic review and comprehensive in vitro study

An important drug used in the treatment of Parkinson’s disease is amantadine. We are the first to perform a comprehensive study based on various glycation and oxidation factors, determining the impact of amantadine on protein glycoxidation. Sugars (glucose, fructose, galactose) and aldehydes (glyoxal, methylglyoxal) were used as glycation agents, and chloramine T was used as an oxidant. Glycoxidation biomarkers in albumin treated with amantadine were generally not different from the control group (glycation/oxidation factors), indicating that the drug did not affect oxidation and glycation processes. Molecular docking analysis did not reveal strong binding sites of amantadine on the bovine serum albumin structure. Although amantadine poorly scavenged hydroxyl radical and hydrogen peroxide, it had significantly lower antioxidant and antiglycation effect than all protein oxidation and glycation inhibitors. In some cases, amantadine even demonstrated glycoxidant, proglycation, and prooxidant properties. In summary, amantadine exhibited weak antioxidant properties and a lack of antiglycation activity.

The Allium triquetrum L. Leaves Mitigated Hepatotoxicity and Nephrotoxicity Induced by Lead Acetate in Wistar Rats

The aim of this study was to scrutinize the possible mitigating role of leaves' Allium triquetrum L. against the toxicity of lead acetate on liver and kidney markers of Wistar rat. Lead acetate (Pb) and leaves' aqueous extracts (L) were orally administrated for 3 weeks. Rats were divided into the control, Pb group (500 mg/kg body weight/day), positive controls L (2g, 3g, 4g/kg BW/day), along with three combined groups of the same doses (Pb-L1, Pb-L2, Pb-L3). The levels of plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total proteins (TP), albumin (ALB), urea, creatinine (Cr), and uric acid (UA), as well as the hepatic and the renal malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase (GPx), were estimated. Results exhibited a significant increase in plasma AST, ALT, ALP, urea, creatinine, uric acid, and MDA levels of the Pb group compared to the control, with the exception of TP, ALB, GSH levels, and GPx activities that were significantly diminished, though the co-administration of garlic extracts (Pb-L) revealed a significant decrease in all mentioned markers, excluding the TP, ALB, GSH, and GPx levels. Likewise, Pb caused histological injuries in the hepatic and renal tissues of rats, while the co-administration of leaves' wild garlic has reduced such effect. Thought, the Pb-L has attenuated the Pb-induced toxicity in a dose-dependent manner. In conclusion, the aqueous extracts of A. triquetrum have the potential to alleviate Pb hepatotoxicity and nephrotoxicity through the modulation of most biomarkers in Wistar rat.

Biophysical, Biochemical, and Molecular Docking Investigations of Anti-Glycating, Antioxidant, and Protein Structural Stability Potential of Garlic

Garlic has been reported to inhibit protein glycation, a process that underlies several disease processes, including chronic complications of diabetes mellitus. Biophysical, biochemical, and molecular docking investigations were conducted to assess anti-glycating, antioxidant, and protein structural protection activities of garlic. Results from spectral (UV and fluorescence) and circular dichroism (CD) analysis helped ascertain protein conformation and secondary structure protection against glycation to a significant extent. Further, garlic showed heat-induced protein denaturation inhibition activity (52.17%). It also inhibited glycation, advanced glycation end products (AGEs) formation as well as lent human serum albumin (HSA) protein structural stability, as revealed by reduction in browning intensity (65.23%), decrease in protein aggregation index (67.77%), and overall reduction in cross amyloid structure formation (33.26%) compared with positive controls (100%). The significant antioxidant nature of garlic was revealed by FRAP assay (58.23%) and DPPH assay (66.18%). Using molecular docking analysis, some of the important garlic metabolites were investigated for their interactions with the HSA molecule. Molecular docking analysis showed quercetin, a phenolic compound present in garlic, appears to be the most promising inhibitor of glucose interaction with the HSA molecule. Our findings show that garlic can prevent oxidative stress and glycation-induced biomolecular damage and that it can potentially be used in the treatment of several health conditions, including diabetes and other inflammatory diseases.

Role of Ajwa Date Fruit Pulp and Seed in the Management of Diseases through In Vitro and In Silico Analysis

Simple Summary

Most diseases result in an imbalance of antioxidant defense, inflammatory responses, and membrane permeabilization. The current therapeutic modules of disease prevention are not fully effective and have some adverse effects on physiological parameters. In this vista, medicinal plants and their active compounds have proven to be effective against disease prevention and treatment. Ajwa dates have high nutritional value and are reported to possess antioxidant, anti-inflammatory, and antitumor properties. In the current in vitro study, Ajwa fruit pulp and seed extract were found to have strong antioxidant properties, stabilize the RBC membrane, and have a good protective capacity against protein denaturation. Besides this, the seed extract prevents glucose-mediated browning of BSA as well as inhibiting the development of cross-amyloid and AGEs formations. Molecular docking results confirm the interaction between functional residues of antioxidant enzymes and components of Ajwa fruit pulp and seed contents. Therefore, the consumption of Ajwa dates can be beneficial in disease prevention and treatment. However, more detailed study is required based on pharmacological aspects to determine the mechanisms of action of Ajwa dates’ components in disease prevention.

Abstract

This study investigated the health-promoting activities of methanolic extracts of Ajwa date seed and fruit pulp extracts through in vitro studies. These studies confirmed potential antioxidant, anti-hemolytic, anti-proteolytic, and anti-bacterial activities associated with Ajwa dates. The EC₅₀ values of fruit pulp and seed extracts in methanol were reported to be 1580.35 ± 0.37 and 1272.68 ± 0.27 µg/mL, respectively, in the DPPH test. The maximum percentage of hydrogen peroxide-reducing activity was 71.3 and 65.38% for both extracts at 600 µg/mL. Fruit pulp and seed extracts inhibited heat-induced BSA denaturation by 68.11 and 60.308%, heat-induced hemolysis by 63.84% and 58.10%, and hypersalinity-induced hemolysis by 61.71% and 57.27%, and showed the maximum anti-proteinase potential of 56.8 and 51.31% at 600 μg/mL, respectively. Seed and fruit pulp inhibited heat-induced egg albumin denaturation at the same concentration by 44.31 and 50.84%, respectively. Ajwa seed showed minimum browning intensity by 63.2%, percent aggregation index by 64.2%, and amyloid structure by 63.8% at 600 μg/mL. At 100 mg/mL, Ajwa seed extract exhibited good antibacterial activity. Molecular docking analysis showed that ten active constituents of Ajwa seeds bind with the critical antioxidant enzymes, catalase (1DGH) and superoxide dismutase (5YTU). The functional residues involved in such interactions include Arg72, Ala357, and Leu144 in 1DGH, and Gly37, Pro13, and Asp11 in 5YTU. Hence, Ajwa dates can be used to develop a suitable alternative therapy in various diseases, including diabetes and possibly COVID-19-associated complications.

Garlic Extract: Inhibition of Biochemical and Biophysical Changes in Glycated HSA

Glycation of various biomolecules contributes to structural changes and formation of several high molecular weight fluorescent and non-fluorescent, advanced glycation end products (AGEs). AGEs and glycation are involved in various health complications. Synthetic medicines, including metformin, have several adverse effects. Natural products and their derivatives are used in the treatment of various diseases due to their significant therapeutic qualities. Allium sativum (garlic) is used in traditional medicines because of its antioxidant, anti-inflammatory, and anti-diabetic properties. This study aimed to determine the anti-glycating and AGEs inhibitory activities of garlic. Biochemical and biophysical analyses were performed for in vitro incubated human serum albumin (HSA) with 0.05 M of glucose for 1, 5, and 10 weeks. Anti-glycating and AGEs inhibitory effect of garlic was investigated in glycated samples. Increased biochemical and biophysical changes were observed in glycated HSA incubated for 10 weeks (G-HSA-10W) as compared to native HSA (N-HSA) as well as glycated HSA incubated for 1 (G-HSA-1W) and 5 weeks (G-HSA-5W). Garlic extract with a concentration of ≥6.25 µg/mL exhibited significant inhibition in biophysical and biochemical changes of G-HSA-10W. Our findings demonstrated that garlic extract has the ability to inhibit biochemical and biophysical changes in HSA that occurred due to glycation. Thus, garlic extract can be used against glycation and AGE-related health complications linked with chronic diseases in diabetic patients due to its broad therapeutic potential.

Antidiabetic Medicinal Plants Used in Democratic Republic of Congo: A Critical Review of Ethnopharmacology and Bioactivity Data

Several studies have been conducted and published on medicinal plants used to manage Diabetes Mellitus worldwide. It is of great interest to review available studies from a country or a region to resort to similarities/discrepancies and data quality. Here, we examined data related to ethnopharmacology and bioactivity of antidiabetic plants used in the Democratic Republic of Congo. Data were extracted from Google Scholar, Medline/PubMed, Scopus, ScienceDirect, the Wiley Online Library, Web of Science, and other documents focusing on ethnopharmacology, pharmacology, and phytochemistry antidiabetic plants used in the Democratic Republic of Congo from 2005 to September 2021. The Kew Botanic Royal Garden and Plants of the World Online web databases were consulted to verify the taxonomic information. CAMARADES checklist was used to assess the quality of animal studies and Jadad scores for clinical trials. In total, 213 plant species belonging to 72 botanical families were reported. Only one plant, Droogmansia munamensis, is typically native to the DRC flora; 117 species are growing in the DRC and neighboring countries; 31 species are either introduced from other regions, and 64 are not specified. Alongside the treatment of Diabetes, about 78.13% of plants have multiple therapeutic uses, depending on the study sites. Experimental studies explored the antidiabetic activity of 133 plants, mainly in mice, rats, guinea pigs, and rabbits. Several chemical classes of antidiabetic compounds isolated from 67 plant species have been documented. Rare phase II clinical trials have been conducted. Critical issues included poor quality methodological protocols, author name incorrectly written (16.16%) or absent (14.25%) or confused with a synonym (4.69%), family name revised (17.26%) or missing (1.10%), voucher number not available 336(92.05%), ecological information not reported (49.59%). Most plant species have been identified and authenticated (89.32%). Hundreds of plants are used to treat Diabetes by traditional healers in DRC. However, most plants are not exclusively native to the local flora and have multiple therapeutic uses. The analysis showed the scarcity or absence of high-quality, in-depth pharmacological studies. There is a need to conduct further studies of locally specific species to fill the gap before their introduction into the national pharmacopeia.

Health Promoting Effect of Phyllanthus emblica and Azadiractha indica against Advanced Glycation End Products Formation

Oxidative stress is linked with inflammation, diabetic complications, and advanced glycation end products formation. Intake of flavonoid-rich foods has been reported to have a beneficial effect on human health. The aim of this study was to verify the therapeutic potential of Phyllanthusemblica and Azadiractha indica against glycation and other oxidative stress-induced complications such as inflammation using in vitro study. Ethanol extracts of Phyllanthus emblica fruit pulp and dried leaf of Azadiractha indica were prepared to investigate in vitro anti-inflammatory and anti-glycating potentials. In a DPPH assay, the EC50 value of extract of P. emblica and A. indica was found to be 1532.36 ± 0.17 and 1380.61 ± 0.27 µg/mL, respectively. The FRAP value of P. emblica and A. indica extract was 86.6 and 32.12 µg ascorbic acid/100 mg dry weight of the extract. The maximum percentage of H2O2 scavenging activity was 71.30% and 67.38%, respectively. Extracts of P. emblica and A. indica showed maximum inhibition of heat-induced BSA denaturation by 62.42% and 53.00%, heat-induced denaturation of egg albumin, by 50.84%% and 44.31%, and heat-induced hemolysis by 54.44% and 50.21%. Both extracts (600 µg/mL) significantly reduced the browning, structural changes, aggregation, and AGEs formation. Our biophysical studies confirmed the AGEs formation was inhibiting the potential of extracts. Thus, our findings confirm that these extracts are a rich source of antioxidants and may be utilized to prevent the oxidative stress-induced destruction of biomolecules, glycation, and in the therapy of a variety of health problems, including inflammation. Further, a combination of extracts of P. emblica and A. indica may be extremely useful in preventing and treating health problems.

Profile of urinary amino acids and their post-translational modifications (PTM) including advanced glycation end-products (AGEs) of lysine, arginine and cysteine in lean and obese ZSF1 rats

Heart failure with preserved ejection fraction (HFpEF) is associated with high mortality and has an increasing prevalence associated with the demographic change and limited therapeutic options. Underlying mechanisms are largely elusive and need to be explored to identify specific biomarkers and new targets, which mirror disease progression and intervention success. Obese ZSF1 (O-ZSF1) rats are a useful animal model, as they spontaneously develop hypertension, hyperlipidemia and glucose intolerance and finally HFpEF. The urinary profile of amino acids and their metabolites of post-translational modifications (PTM), including the advanced glycation end-products (AGEs) of lysine, arginine and cysteine, are poorly investigated in HFpEF and ZSF1 rats. The aim of the present study was to characterize the status of free amino acids and their metabolites of PTM and glycation in lean ZSF1 (L-ZSF1) and O-ZSF1 rats in urine aiming to find possible effects of glucose on the excretion of native and modified amino acids. In the urine of twelve L-ZSF1 and twelve O-ZFS1 rats collected at the age of 20 weeks, we measured the concentration of native and modified amino acids by reliable previously validated stable-isotope dilution gas chromatography-mass spectrometry (GC–MS) approaches. Serum glucose was 1.39-fold higher in the O-ZSF1 rats, while urinary creatinine concentration was 2.5-fold lower in the O-ZSF1 rats. We observed many differences in urinary amino acids excretion between L-ZSF1 and O-ZSF1 rats. The creatinine-corrected homoarginine excretion was twofold lower in the O-ZSF1 rats. We also observed distinct associations between the concentrations of serum glucose and urinary amino acids including their PTM and AGE metabolites in the L-ZSF1 and O-ZSF1 rats. Our study shows that PTM metabolites and AGEs are consistently lower in the L-ZSF1 than in the O-ZSF1 rats. Serum malondialdehyde (MDA) concentration was higher in the O-ZSF1 rats. These results suggest that hyperglycemia, hyperlipidemia and elevated oxidative stress in the O-ZSF1 rats favor PTM methylation of arginine and lysine and the glycation of lysine and cysteine. The area under the receiver operation characteristic (ROC) curve values were 0.996 for serum glucose, 0.951 for urinary creatinine, 0.939 for serum MDA, 0.885 for N^ε-carboxyethyl-lysine, 0.830 for carboxyethyl-cysteine, and 0.792 for monomethyl-lysine. Non-invasive measurement of methylation and glycation products of arginine, lysine and cysteine residues in proteins in urine of L-ZSF1 and O-ZSF1 rats may be useful in studying pathophysiology and pharmacology of HFpEF.

Liposomal Ellagic Acid Alleviates Cyclophosphamide-Induced Toxicity and Eliminates the Systemic Cryptococcus neoformans Infection in Leukopenic Mice

Cryptococcus neoformans infections rose sharply due to rapid increase in the numbers of immunocompromised individuals in recent years. Treatment of Cryptococcosis in immunocompromised persons is largely very challenging and hopeless. Hence, this study aimed to determine the activity of ellagic acid (EA) in the treatment of C. neoformans in cyclophosphamide injected leukopenic mice. A liposomal formulation of ellagic acid (Lip-EA) was prepared and characterized, and its antifungal activity was assessed in comparison to fluconazole (FLZ). The efficacy of the drug treatment was tested by assessing survival rate, fungal burden, and histological analysis in lung tissues. The safety of the drug formulations was tested by investigating hepatic, renal function, and antioxidant levels. The results of the present work demonstrated that Lip-EA, not FLZ, effectively eliminated C. neoformans infection in the leukopenic mice. Mice treated with Lip-EA (40 mg/kg) showed 70% survival rate and highly reduced fungal burden in their lung tissues, whereas the mice treated with FLZ (40 mg/kg) had 20% survival rate and greater fungal load in their lungs. Noteworthy, Lip-EA treatment alleviated cyclophosphamide-induced toxicity and restored hepatic and renal function parameters. Moreover, Lip-EA treatment restored the levels of superoxide dismutase and reduced glutathione and catalase in the lung tissues. The effect of FLZ or EA or Lip-EA against C. neoformans infection was assessed by the histological analysis of lung tissues. Lip-EA effectively reduced influx of inflammatory cells, thickening of alveolar walls, congestion, and hemorrhage. The findings of the present study suggest that Lip-EA may prove to be a promising therapeutic formulation against C. neoformans in immunocompromised persons.

Metabolic Changes in Different Tissues of Garlic Plant during Growth

The accumulation, distribution, and transportation of nutrients in different tissues of garlic during growth are unclear. Thereby, five tissues (leaf, pseudostem, bulb wrapper, clove skin, and clove) collected at 7 weeks were subjected to metabolomics analysis. A total of 84 biomarkers were identified during garlic plant growth. Most organosulfur compounds, amino acids, and dipeptides were upregulated in the clove, while a reversed trend was observed in other tissues. In addition, nucleotides and alkaloids increased because of senescence in the last 2 weeks except for the clove. The results also indicated that the garlic plant at an early stage is an ideal vegetable that is rich in nutrients. When the leaves began to wither, most nutrients were transported from other tissues to cloves, and the content of 7 total flavor precursors and 20 total amino acids in the clove increased by 113% and 65% after week 5, respectively. Therefore, delayed harvest may improve the nutritional quality of garlic bulbs.

Hepatoprotective Effects of Garlic Extract against Carbon Tetrachloride (CCl4)-Induced Liver Injury via Modulation of Antioxidant, Anti-Inflammatory Activities and Hepatocyte Architecture

The current study aims to explore the hepatoprotective mechanisms of garlic extract through in vivo and in vitro assays. The in vitro investigation of antioxidant and anti-inflammatory potential showed maximum 67.5% of free radical scavenging and 71.36% albumin denaturation inhibition by 600 μg/mL garlic extract. To explore the hepatoprotective activity by in vivo experiments, the animals were orally intoxicated with 150 μL of CCl4 (1:1 v/v in olive oil) and treated with garlic extract (75 mg/kg b.w.) 3 times/week, for eight successive weeks. The administration of garlic extract significantly ameliorated CCl4 induced increment in amounts of serum Alanine aminotransferase (ALT), Alkaline phosphatase (ALP) and Aspartate transaminaseas (106.7, 116.3, 136.4 U/L) as compared to disease control which showed increased level (140.5, 156.2, 187.6 U/L). Besides, significant reduction of Superoxide dismutase (SOD), Glutathione peroxidases (GPx), and Glutathione (GSH) (29.3, 48.4, and 25.9 U/mg protein) was noticed in CCl4 induced animals, respectively. Likewise, garlic extract treatment facilitated a significant increment in all tested antioxidant enzymes levels (41.6, 63.3, and 32.5 U/mg protein), respectively. Additionally, Tumor necrosis factor⍺ (TNF-⍺), C-reactive protein (CRP), Interleukin-1β (IL-1β), Interleukin 6 (IL-6) and ICAM-1 (Intercellular Adhesion Molecule 1) level (63.79, 580.2, 18.3, 63.74 and 148.4 pg/mL) were increased significantly in CCl4-induced group, while garlic extract treatment decreased these pro inflammatory marker levels (40.24, 460.4, 15.4, 45.14, and 125.3 pg/mL). The animals exposed to CCl4 showed various types of alterations like lymphocytes infiltration, edema and congestion, while the animals treated with garlic extract plus CCl4 showed amelioration of the hepatocytes architectures. Thus, our finding advocates that the consumption of garlic can be a potential therapeutic remedy in the inhibition of liver ailments.

Protective Effects of Ginger Extract against Glycation and Oxidative Stress-Induced Health Complications: An In Vitro Study

Protein glycation and oxidative stress lead to severe health complications in various diseases including diabetes mellitus. The intake of flavonoid-rich foods has been confirmed previously to have a positive effect on human health. Ginger is an important source of flavonoids and is one of the most widely used traditional medicines in many Asian countries. The aim of this study was to verify the therapeutic potential of methanolic extract from ginger against glycation and other oxidative stress-induced complications using in vitro study. In this study, quantitative estimations of antioxidant components such as total phenolic and flavonoids were determined by UV–visible spectrophotometry. The anti-inflammatory action of the ginger extract was checked by determining its protective action against the denaturation of proteins, anti-proteinase activity and its membrane stabilization effect. The anti-inflammatory action of ginger extract was found to be comparable with reference standard drugs. The antiglycating effect of ginger extract was investigated by placing bovine serum albumin (BSA) with glucose in the presence and absence of ginger extract for two weeks at 37 °C. The incubated samples were analyzed for the number of glycation products, secondary structural changes, aggregation and advanced glycation end products (AGEs) formation by checking browning intensity, determination of aggregation index and Congo red assays. Our findings demonstrated that ginger extract (600 µg/mL) significantly reduced the browning, secondary structural changes, aggregation and AGEs formation. Thus, it can be concluded from these results that ginger extract is a wealthy source of antioxidants and can be used to prevent the glycation and oxidative stress-induced damage of biomolecules in various health complications including inflammation.

Differential effect of biophenols on attenuation of AGE-induced hemoglobin aggregation

Despite most studied activities of natural biophenols rely on antioxidant properties, little clues explored their key structural components with regard to opposing action on glycation-induced aggregation. Herein, human hemoglobin (hHb)/fructose system used to decipher if structural peculiarities of two biophenols "chlorogenic acid (CGA) and curcumin (CUR)" are effective toward AGEs-bridged aggregate formation. Suppression in amyloid cross-β formation was monitored by CD spectroscopy, fluorescence microscopy, ANS and AGE fluorescence. Reduction in molten globule structure of modified-Hb by CGA was corroborated with helix structure, thiol group and lysine residues content estimation for native, glycated and biophenols treated samples. ThT and Congo red assays showed the cross-β breaking properties of CGA. Molecular docking outcomes revealed the positioning of CGA/CUR is driven by "aromatic interactions" with Trp β₁180 and Tyr α₂540. These interactions are modulated by the structural constraints such as number of hydroxyl groups and their methylation status directing the biophenols to the amyloidogenic core. The results are applicable to formulation of small-molecule nutraceuticals for treatment of conformational diseases.

Enhancement in the Catalytic Activity of Human Salivary Aldehyde Dehydrogenase by Alliin from Garlic: Implications in Aldehyde Toxicity and Oral Health

BACKGROUND

Lower human salivary aldehyde dehydrogenase (hsALDH) activity increases the risk of aldehyde mediated pathogenesis including oral cancer. Alliin, the bioactive compound of garlic, exhibits many beneficial health effects.

OBJECTIVE

To study the effect of alliin on hsALDH activity.

METHODS

Enzyme kinetics was performed to study the effect of alliin on the activity of hsALDH. Different biophysical techniques were employed for structural and binding studies. Docking analysis was done to predict the binding region and the type of binding forces.

RESULTS

Alliin enhanced the dehydrogenase activity of the enzyme. It slightly reduced the Km and significantly enhanced the Vmax value. At 1 µM alliin concentration, the initial reaction rate increased by about two times. Further, it enhanced the hsALDH esterase activity. Biophysical studies indicated a strong complex formation between the enzyme and alliin (binding constant, Kb: 2.35 ± 0.14 x 103 M-1). It changes the secondary structure of hsALDH. Molecular docking study indicated that alliin interacts to the enzyme near the substrate binding region involving some active site residues that are evolutionary conserved. There was a slight increase in the nucleophilicity of active site cysteine in the presence of alliin. Ligand efficiency metrics values indicate that alliin is an efficient ligand for the enzyme.

CONCLUSION

Alliin activates the catalytic activity of the enzyme. Hence, consumption of alliincontaining garlic preparations or alliin supplements and use of alliin in pure form may lower aldehyde related pathogenesis including oral carcinogenesis.