Withania somnifera extracts induced attenuation of HIV-1: a mechanistic approach to restrict viral infection.

BACKGROUND: Several anti-retroviral drugs are available against Human immunodeficiency virus type-1, but have multiple adverse side effects. Hence, there is an incessant compulsion for effectual anti-retroviral agents with minimal or no intricacy. Traditionally, natural products have been the most successful source for the development of new medications. Withania somnifera, also known as Ashwagandha, is the utmost treasured medicinal plant used in Ayurveda, which holds the potential to give adaptogenic, immunomodulatory, and antiviral effects. However, its effect on HIV-1 replication at the cellular level has never been explored. Herein, we focused on the anti-HIV-1 activity and the probable mechanism of action of hydroalcoholic and aqueous extracts of Withania somnifera roots and its phytomolecules. METHODS: The cytotoxicity of the extracts was determined through MTT assay, while the in vitro anti-HIV-1 activity was assessed in TZM-bl cells against the HIV-1 strains of X4 and R5 subtypes. Results were confirmed in peripheral blood mononuclear cells, using the HIV-1 p24 antigen assay. Additionally, the mechanism of action was determined through the Time of Addition assay, which was further validated through the series of enzymatic assays, i.e. HIV-1 Integrase, Reverse transcriptase, and Protease assays. To explore the role of the identified active metabolites of Withania somnifera in antiretroviral activity, molecular docking analyses were performed against these key HIV-1 replication enzymes. RESULTS: The hydroalcoholic and aqueous extracts of Withania somnifera roots were found to be safer at the sub-cytotoxic concentrations and exhibited their ability to inhibit replication of two primary isolates of HIV-1 through cell-associated and cell-free assays, in dose-dependent kinetics. Several active phytomolecules found in Withania somnifera successfully established hydrogens bonds in the active binding pocket site residues responsible for the catalytic activity of HIV replication and therefore, signifying their role in the attenuation of HIV-1 infection as implied through the in silico molecular docking studies. CONCLUSIONS: Our research identified both the hydroalcoholic and aqueous extracts of Withania somnifera roots as potent inhibitors of HIV-1 infection. The in silico analyses also indicated the key components of Withania somnifera with the highest binding affinity against the HIV-1 Integrase by 12-Deoxywithastramonolide and 27-Hydroxywithanone, HIV-1 Protease by Ashwagandhanolide and Withacoagin, and HIV-1 Reverse transcriptase by Ashwagandhanolide and Withanolide B, thereby showing possible mechanisms of HIV-1 extenuation. Overall, this study classified the role of Withania somnifera extracts and their active compounds as potential agents against HIV-1 infection.

In-silico Studies Show Potent Inhibition of HIV-1 Reverse Transcriptase Activity by a Herbal Drug.

Acquired immunodeficiency syndrome (AIDS) is a life threatening disease of the human immune system caused by human immunodeficiency virus (HIV). Effective inhibition of reverse transcriptase activity is a prominent, clinically viable approach for the treatment of AIDS. Few non-nucleoside reverse transcriptase inhibitors (NNRTIs) have been approved by the United States Food and Drug Administration (US FDA) as drugs for AIDS. In order to enhance therapeutic options against AIDS we examined novel herbal compounds of 4-thiazolidinone and its derivatives that are known to have remarkable antiviral potency. Our molecular docking and simulation experiments have identified one such herbal molecule known as (5E)-3-(2-aminoethyl)-5-benzylidene-1, 3-thiazolidine-2,4-dione that may bind HIV-1RT with high affinity to cause noncompetitive inhibition. Results are also compared with other US FDA approved drugs. Long de novo simulations and docking study suggest that the ligand (5E)-3-(2-aminoethyl)-5-benzylidene-1, 3-thiazolidine-2,4-dione (CID: 1656714) has strong binding interactions with Asp113, Asp110, Asp185 and Asp186 amino acids, all of which belong to one or the other catalytic pockets of HIV-1RT. It is expected that these interactions could be critical in the inhibitory activity of the HIV-1RT. Therefore, this study provides an evidence for consideration of (5E)-3-(2-aminoethyl)-5-benzylidene-1, 3-thiazolidine-2,4-dione as a valuable natural molecule in the treatment and prevention of HIV-associated disorders.

Identification of potential herbal inhibitor of acetylcholinesterase associated Alzheimer's disorders using molecular docking and molecular dynamics simulation.

Cholinesterase inhibitors (ChE-Is) are the standard for the therapy of AD associated disorders and are the only class of approved drugs by the Food and Drug Administration (FDA). Additionally, acetylcholinesterase (AChE) is the target for many Alzheimer's dementia drugs which block the function of AChE but have some side effects. Therefore, in this paper, an attempt was made to elucidate cholinesterase inhibition potential of secondary metabolite from Cannabis plant which has negligible or no side effect. Molecular docking of 500 herbal compounds, against AChE, was performed using Autodock 4.2 as per the standard protocols. Molecular dynamics simulations have also been carried out to check stability of binding complex in water for 1000 ps. Our molecular docking and simulation have predicted high binding affinity of secondary metabolite (C28H34N2O6) to AChE. Further, molecular dynamics simulations for 1000 ps suggest that ligand interaction with the residues Asp72, Tyr70-121-334, and Phe288 of AChE, all of which fall under active site/subsite or binding pocket, might be critical for the inhibitory activity of AChE. This approach might be helpful to understand the selectivity of the given drug molecule in the treatment of Alzheimer's disease. The study provides evidence for consideration of C28H34N2O6 as a valuable small ligand molecule in treatment and prevention of AD associated disorders and further in vitro and in vivo investigations may prove its therapeutic potential.

Analyzing the interaction of a herbal compound Andrographolide from Andrographis paniculata as a folklore against swine flu (H1N1).

OBJECTIVE: To find new bioactive molecules for the treatment of swine flu. METHODS: The present study is an attempt to elucidate inhibition potential of andrographolide and its derivatives along with an associated binding mechanism through virtual screening and molecular docking simulation studies. RESULTS: Our findings revealed structural conformation changes in 150 loop, secondary sialic acid binding site residues of ACZ97474 {Neuraminidase (A/Blore/NIV236/2009(H1N1)}. Andrographolide have been identified as the highest binging energy of -10.88 Kcal/mol, 3 hydrogen bond interactions (Arg152, Lys150, and Gly197), total intermolecular energy of -12.07 Kcal/mol with bioactivity value (Ki) of 10.59 nmol/L, while the Food and Drug Admistraton approved drug Oseltamivir and Zanamivir have shown 2 and 4 hydrogen bond interactions with binding energies of -6.28 Kcal/mol and -7.73Kcal/mol, respectively, which is higher than andrographolide. The guanidine group of Arg152 has binding affinities to the hydrophilic nature of the inhibitors (-OH and =O groups), as identified by docking of andrographolide (CID: 5318517) on neuraminidase. CONCLUSIONS: Hence, andrographolide has the potential to inhibit neuraminidase activity of H1N1 and may be used as an alternative medicinal therapy for swine flu positive patient. With potent antiviral activity and a potentially new mechanism of action, andrographolide may warrant further evaluation as a possible therapy for influenza.