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.