Investigation of antidiabetic properties of shikonin by targeting aldose reductase enzyme: In silico and in vitro studies

Shikonin mitigates diabetic testicular dysfunction by improving oxidative, apoptotic, and metabolic functions in rats

Type 2 diabetes mellitus (T2DM) is a health concern worldwide, leading to high blood sugar levels and adversely affects various organ systems, including reproductive organs. The present study was conducted by the need to address the fact that T2DM exerts deleterious effects on male fertility via decreasing the circulating testosterone levels and increasing oxidative stress, apoptosis, and metabolic dysregulation in germ cells. The study purposes to explore the protective effect of Shikonin, a bioactive compound, on T2DM-induced reproductive damage. A high-fat diet along with streptozotocin (50 mg/kg) was administered for the induction of T2DM in male albino rats. The five experimental groups included, control, T2DM, T2DM+Shikonin (0.5 mg/kg), Only Shikonin (0.5 mg/kg), and T2DM+Metformin (50 mg/kg) were established for 4 weeks. Notably, Shikonin-treated diabetic rats exhibited significantly (p < 0.0001) increased body weight, Gonadosomatic index (GSI), Testosterone, and antioxidant response reflected in the significant increase (P < 0.05) in superoxide dismutase and catalase levels, while decreasing malondialdehyde. Histological analysis revealed improved testicular health in T2DM rats treated with Shikonin compared to those treated with Metformin. Shikonin treatment led to a further reduction in pro-apoptotic signaling (cytochrome c, caspase 9, and caspase 3) and improved metabolic disturbances by modulating levels of Fibroblast Growth Factor21 (FGF21) and Lactate Dehydrogenase C (LDHC) in T2DM rats. Compared with metformin, Shikonin showed the potential to offer more protective effects on male reproductive health while effectively managing diabetes, hence revealing its dual role. These findings disclose the significant (P < 0.05) potential of Shikonin in protecting reproductive health against T2DM-induced oxidative stress and apoptosis, hence giving a promising avenue for the therapeutic management of diabetes-induced reproductive complications. The study emphasizes the necessity for future human trials to assess the long-term effects and dosing of Shikonin as a therapeutic option for managing T2DM and its reproductive complications.

Phytochemical Composition and Inhibitory Effects of Curcuma angustifolia Leaves Extracts Against α-Amylase and α-Glucosidase Enzymes Associated With Hyperglycaemia: In Vitro and In Silico Analysis

Curcuma angustifolia Roxb. is a plant known for its therapeutic properties and has been employed conventionally to treat various ailments. The current research aimed to determine the phytochemical compounds and to explore the antihyperglycemic effects of C. angustifolia leaves through in vitro and in silico methods. The phytochemicals in the methanolic extract of leaves of C. angustifolia were detected using Fourier-transform infrared, gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry techniques. The antihyperglycemic potential of the different solvent extracts was evaluated using in vitro assays. The methanolic extract demonstrated comparatively higher inhibitory effects on both α-amylase and α-glucosidase enzymes, with the effects varying according to the concentration, and the half maximal inhibitory concentration values were 592.57 ± 0.64 and 267.11 ± 0.82 µg/ml, respectively. 2-p-Nitrophenyl-oxadiazol-1,3,4-one-5 was identified as a potential compound that could exhibit antihyperglycemic effects via molecular docking. 2-p-Nitrophenyl-oxadiazol-1,3,4-one-5 was found to have optimal physicochemical characteristics needed for drug-likeness based on in silico absorption, distribution, metabolism, excretion, and toxicity assessment. The prediction of activity spectra for substances prediction findings suggested that 2-p-nitrophenyl-oxadiazol-1,3,4-one-5 displays potent anti-diabetic activity, which aligns with the docking results. The findings suggested that the methanol extract of the leaves of C. angustifolia exhibits notable antihyperglycemic properties. Therefore, it could also be investigated to purify the active compound with antihyperglycemic effects.

Investigating the Role of Shikonin in Enhancing Osteogenesis and Angiogenesis for the Treatment of Osteoporosis

Osteoporosis, characterized by an increased risk of fractures, represents a significant global public health issue. Natural compounds have emerged as promising candidates for addressing this condition. Shikonin, derived from Lithospermum erythrorhizon as a purple-red naphthoquinone pigment, exhibits a diverse array of biological activities, including antibacterial, anti-inflammatory, and anticancer properties. Despite the well-documented bone-protective properties of shikonin, the precise molecular mechanisms underlying its role in the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) into osteoblasts, along with its implications on angiogenesis, are not fully elucidated. Our study showcases shikonin's ability to stimulate the differentiation of BMSCs into osteoblasts, leading to an upregulation of osteoblast-specific marker genes such as OC, Runx2, BMP2, and ALP. Furthermore, shikonin intervention triggers the upregulation of phosphorylation of p38, ERK, and JNK in the MAPK signaling pathway. Furthermore, shikonin has been shown to enhance the migration and angiogenic capabilities of human umbilical vein endothelial cells (HUVECs). Notably, the augmentation of HUVEC migration by shikonin can be counteracted by the addition of a JNK inhibitor. Furthermore, our findings indicate that shikonin effectively improves osteoporosis in aged mice by promoting osteoblast differentiation. In summary, our study elucidates the molecular mechanisms through which shikonin exerts its beneficial effects in the treatment of osteoporosis, highlighting its potential as a novel therapeutic option for both the prevention and management of this condition.

Insights into the Sources, Structure, and Action Mechanisms of Quinones on Diabetes: A Review

Quinones, one of the oldest organic compounds, are of increasing interest due to their abundant presence in a wide range of natural sources and their remarkable biological activity. These compounds occur naturally in green leafy vegetables, fruits, herbs, animal and marine sources, and fermented products, and have demonstrated promising potential for use in health interventions, particularly in the prevention and management of type 2 diabetes (T2DM). This review aims to investigate the potential of quinones as a health intervention for T2DM from the multidimensional perspective of their sources, types, structure-activity relationship, glucose-lowering mechanism, toxicity reduction, and bioavailability enhancement. Emerging research highlights the hypoglycemic activities of quinones, mainly driven by their redox properties, which lead to covalent binding, and their structural substituent specificity, which leads to their non-covalent binding to biocomplexes. Quinones can improve insulin resistance and regulate glucose homeostasis by modulating mitochondrial function, inflammation, lipid profile, gastrointestinal absorption, and by acting as insulin mimetics. Meanwhile, increasing attention is being given to research focused on mitigating the toxicity of quinones during administration and enhancing their bioavailability. This review offers a critical foundation for the development of quinone-based health therapies and functional foods aimed at diabetes management.

Bioaccessibility and Functional Food Potential of Equisetum telmateia Ehrh. Against Diabetes-Induced Kidney Disorders

Various species from the genus Equisetum are recorded as food and folk medicine against both kidney complications and diabetes. Equisetum telmateia Ehrh. is documented as a folk remedy in Türkiye against several kidney disorders. This study was designed to evaluate the possible protective mechanisms of E. telmateia EtOH extract (ETE) against kidney disorders and diabetes through different routes, such as the prevention of ROS formation, inhibitory potential against various DM-related enzymes, and a reduction in the amount of the mediators leading to disorders in both systems at the cellular level. The objective was to achieve advanced precision for in vitro results while considering the effect of GIS on oral consumption. Both phytochemical and bioactivity studies were conducted before and after simulated digestion. The results showed that ETE is a rich source of flavonoids and phenolic acids. In addition, it has significant antioxidant and enzyme inhibitory potential. Treatment also yielded promising results at the cellular level for both antioxidative and inhibitor proteins, which may play a role in the pathogenesis of kidney disorders and diabetes. Following the in vitro digestion procedure, both the number of phytochemical ingredients and bioactivity parameters showed a considerable decreasing trend; however, the results are still significant enough to justify the traditional utilization of the genus Equisetum. This investigation demonstrated that ETE has noteworthy potential as a functional food for protection against diabetic kidney disease.

Phytochemical analysis, identification of bioactive compounds using GC-MS, in vitro and in silico hypoglycemic potential, in vitro antioxidant potential, and in silico ADME analysis of Chlorophytum comosum root and leaf

Chlorophytum comosum is a plant with medicinal potential traditionally used to treat different diseases. The present study aimed to determine the bioactive compounds, hypoglycemic and antioxidant potential of C. comosum root and leaf. The ethyl acetate extracts of C. comosum root and leaf were analyzed by GC-MS to determine the bioactive compounds. The hypoglycemic potential of the extracts was evaluated by α-amylase, α-glucosidase, glucose diffusion inhibitory assays, and glucose adsorption assay. The ethyl acetate extract of C. comosum root inhibited α-amylase, α-glucosidase, and glucose diffusion in a concentration-dependent manner with IC50 values of 205.39 ± 0.15, 179.34 ± 0.3 and 535.248 μg/mL, respectively, and the leaf extract inhibited α-amylase and α-glucosidase enzymes with IC50 values of 547.99 ± 0.09, and 198.18 ± 0.25 μg/mL respectively. C. comosum root and leaf extracts also improved glucose adsorption. Heptadecanoic acid and dodecanoic acid were identified as potential compounds with hypoglycemic properties through molecular docking. The extracts were also assessed for their antioxidant activity using DPPH, ABTS, and FRAP assays. C. comosum root and leaf extracts were also able to scavenge DPPH radicals with IC50 values of 108.37 ± 0.06 and 181.79 ± 0.09 µM and ABTS radicals with IC50 values of 126.24 ± 0.13 and 264.409 ± 0.08 µM, respectively. The root and leaf extracts also reduced the ferricyanide complex to ferrocyanide with higher reducing powers of 2.24 ± 0.02 and 1.65 ± 0.03, respectively. The results showed that the ethyl acetate extract of C. comosum root has significant antioxidant and hypoglycemic potential compared to the leaf extract. Thus, it can also be studied to isolate the potential compounds with antihyperglycemic activities.

Role of Alkannin in the Therapeutic Targeting of Protein-Tyrosine Phosphatase 1B and Aldose Reductase in Type 2 Diabetes: An In Silico and In Vitro Evaluation

Alkannin is a plant-derived naphthoquinone that is isolated from the Boraginaceae family plants. In our previous studies, we found that shikonin, which is the R-enantiomer of alkannin, has potent antidiabetic activity by inhibiting the action of the aldose reductase (AR) enzyme and the protein-tyrosine phosphatase 1B (PTP1B). Therefore, in this study, we aim to explore the antidiabetic effect of alkannin targeting PTP1B and AR by employing in silico and in vitro techniques. For in silico, we used different parameters such as ADMET analysis, molecular docking, MD simulation, Root Mean Square Deviation (RMSD), protein-ligand mapping, and free binding energy calculation. The in vitro evaluation was done by assessing the inhibitory activity and enzyme kinetics of PTP1B and AR inhibition by alkannin. The in silico studies indicate that alkannin possesses favorable pharmacological properties and possesses strong binding affinity for diabetes target proteins. Hydrogen bonds (Val297, Ala299, Leu300, and Ser302) and hydrophobic interactions (Trp20, Val47, Tyr48, Trp79, Trp111, Phe122, Trp219, Val297, Cys298, Ala299, Leu300, and Leu301) are established by the compound, which potentially improves specificity and aids in the stabilization of the protein-ligand complex. The results from in vitro studies show a potent dose-dependent PTP1B inhibitory activity with an IC50 value of 19.47 μM, and toward AR it was estimated at 22.77 μM. Thus, from the results it is concluded that a low IC50 value of alkannin for both PTP1B and AR along with favorable pharmacological properties and optimal intra-molecular interactions indicates its utilization as a potential drug candidate for the management of diabetes and its end complications.

Recent Studies of Artificial Intelligence on In Silico Drug Absorption

Absorption is an important area of research in pharmacochemistry and drug development, because the drug has to be absorbed before any drug effects can occur. Furthermore, the ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) profile of drugs can be directly and considerably altered by modulating factors affecting absorption. Many drugs in development fail because of poor absorption. The research and continuous efforts of researchers in recent years have brought many successes and promises in drug absorption property prediction, especially in silico, which helps to reduce the time and cost significantly for screening undesirable drug candidates. In this report, we explicitly provide an overview of recent in silico studies on predicting absorption properties, especially from 2019 to the present, using artificial intelligence. Additionally, we have collected and investigated public databases that support absorption prediction research. On those grounds, we also proposed the challenges and development directions of absorption prediction in the future. We hope this review can provide researchers with valuable guidelines on absorption prediction to facilitate the development of newer approaches in drug discovery.

Araucaria heterophylla oleogum resin essential oil is a novel aldose reductase and butyryl choline esterase enzymes inhibitor: in vitro and in silico evidence

The essential oil isolated by hydrodistillation of the oleogum resin of Araucaria heterophylla has been analyzed by GC-MS. Twenty-four components accounting to 99.89% of the total detected constituents of this essential oil were identified. The major ones were: caryophyllene oxide (14.8%), ( +)-sabinene (12.07%), D-limonene (11.22%), caryophyllene (10.36%), α-copaene (8.00%), β-pinene (6.44%), trans-verbenol (5.88%) and α-pinene oxide (5.18%). The in vitro inhibitory activities of this oil against aldose reductase, BuCHE, COX-2 and SARS-CoV-2 Mpro enzymes were evaluated. This revealed promising inhibitory activity of the essential oil against both aldose reductase and BuCHE enzymes. The molecular docking study of the major components of the Araucaria heterophylla essential oil was carried out to correlate their binding modes and affinities for aldose reductase and BuCHE enzymes with the in vitro results. In conclusion, the in vitro inhibitory activity of the essential oil attributed to the synergistic effect between its components and the in silico study suggested that compounds containing epoxide and hydroxyl groups may be responsible for this activity. This study is preliminary screening for the oil to be used as antidiabetic cataract and Alzheimer's disease therapeutics and further investigations may be required.

Natural Plant-Derived Compounds in Food and Cosmetics: A Paradigm of Shikonin and Its Derivatives

Shikonin and its derivatives are the natural naphthoquinone compounds produced in the roots of the Boraginaceae family. These red pigments have been used for a long time in coloring silk, as food colorants, and in the Chinese traditional system of medicines The resurgence of public interest in natural and plant-based products has led to this category of compounds being in high demand due to their wide range of biological activities including antioxidant, antitumor, antifungal, anti-inflammatory ones. Different researchers worldwide have reported various applications of shikonin derivatives in the area of pharmacology. Nevertheless, the use of these compounds in the food and cosmetics fields needs to be explored more in order to make them available for commercial utilization in various food industries as a packaging material and to enhance their shelf life without any side effects. Similarly, the antioxidant properties and skin whitening effects of these bioactive molecules may be used successfully in various cosmetic formulations. The present review delves into the updated knowledge on the various properties of shikonin derivatives in relation to food and cosmetics. The pharmacological effects of these bioactive compounds are also highlighted. Based on various studies, it can be concluded that these natural bioactive molecules have potential to be used in different sectors, including functional food, food additives, skin, health care, and to cure various diseases. Further research is required for the sustainable production of these compounds with minimum disturbances to the environment and in order to make them available in the market at an economic price. Simultaneous studies utilizing recent techniques in computational biology, bioinformatics, molecular docking, and artificial intelligence in laboratory and clinical trials would further help in making these potential candidates promising alternative natural bioactive therapeutics with multiple uses.

Anemoside B4 Exerts Hypoglycemic Effect by Regulating the Expression of GLUT4 in HFD/STZ Rats

Anemoside B4 (B4) is a saponin that is extracted from Pulsatilla chinensis (Bge.), and Regel exhibited anti-inflammatory, antioxidant, antiviral, and immunomodulatory activities. However, its hypoglycemic activity in diabetes mellitus has not been evaluated. Here, we explored the effect of B4 on hyperglycemia and studied its underlying mechanism of lowering blood glucose based on hyperglycemic rats in vivo and L6 skeletal muscle cells (L6) in vitro. The rats were fed a high-fat diet (HFD) for one month, combined with an intraperitoneal injection of 60 mg/kg streptozotocin (STZ) to construct the animal model, and the drug was administrated for two weeks. Blood glucose was detected and the proteins and mRNA were expressed. Our study showed that B4 significantly diminished fasting blood glucose (FBG) and improved glucose metabolism. In addition, B4 facilitated glucose utilization in L6 cells. B4 could enhance the expression of glucose transporter 4 (GLUT4) in rat skeletal muscle and L6 cells. Mechanistically, B4 elevated the inhibition of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathways. Furthermore, we confirmed the effect of B4 on glucose uptake involved in the enhancement of GLUT4 expression in part due to PI3K/AKT signaling by using a small molecule inhibitor assay and constructing a GLUT4 promoter plasmid. Taken together, our study found that B4 ameliorates hyperglycemia through the PI3K/AKT pathway and promotes GLUT4 initiation, showing a new perspective of B4 as a potential agent against diabetes.