Viscosine as a Potent and Safe Antipyretic Agent Evaluated by Yeast-Induced Pyrexia Model and Molecular Docking Studies.

The antipyretic potential of viscosine, a natural product isolated from the medicinal plant Dodonaea viscosa, was investigated using yeast-induced pyrexia rat model, and its structure-activity relationship was investigated through molecular docking analyses with the target enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGES-1). The in vivo antipyretic experiments showed a progressive dose-dependent reduction in body temperatures of the hyperthermic test animals when injected with viscosine. Comparison of docking analyses with target enzymes showed strongest bonding interactions (binding energy -17.34 kcal/mol) of viscosine with the active-site pocket of mPGES-1. These findings suggest that viscosine shows antipyretic properties by reducing the concentration of prostaglandin E2 in brain through its mPGES-1 inhibitory action and make it a potential lead compound for developing effective and safer antipyretic drugs for treating fever and related pathological conditions.

Antioxidant profile of constituents isolated from Polygonatum verticillatum rhizomes.

The purpose of the current study was to estimate the antioxidant profile of two compounds, diosgenin and santonin, isolated from Polygonatum verticillatum rhizomes. Stable free radical, 2, 2-diphenyl-1-picrylhydrazyl and reducing power assays were employed for this purpose. The results showed profound free radical scavenging effect of both diosgenin and santonin in a concentration-dependent manner. The calculated half maximal inhibitory concentration (IC50) values for both diosgenin and santonin was 65.80 and 50.03 µg/ml, respectively. Similarly, in reducing power assay, diosgenin and santonin exhibited marked quenching effect. The corresponding IC50 values for both the compounds were 62.10 and 46.40 µg/ml, respectively. In conclusion, both the isolated compounds have strong antioxidant potential, which is consistent with the results of the extracts of the plant.

First evidence of the analgesic activity of govaniadine, an alkaloid isolated from Corydalis govaniana Wall.

In this work, govaniadine, an alkaloid isolated from Corydalis govaniana Wall. was evaluated for its analgesic activity by writhing and hot-plate tests. Govaniadine did not display any toxic effects in mice up to 20 mg/kg during 24 h assessment study. The acetic acid-induced writhing was significantly reduced by pretreatment with govaniadine in a dose-dependent manner (1.25-5.0 mg/kg, intraperitoneally (i.p.)). Furthermore, molecular docking study has shown that this alkaloid binds the COX-2 enzyme. In the hot-plate test, govaniadine at dose of 2.5 and 5 mg/kg, i.p. displayed analgesic effect at all time points (30, 60, 90 and 120 min). The analgesic effect of govaniadine was significantly antagonised by naloxone administration. Our results demonstrate for the first time that the peripheral and central analgesic effects of govaniadine could be in part related to the involvement of COX-2 activity and by its interaction with the opioid system.

Antibacterial, Antifungal, Cytotoxic, Phytotoxic, Insecticidal, and Enzyme Inhibitory Activities of Geranium wallichianum.

The present study describes the phytochemical investigations of the crude extracts of rhizomes and leaves of Geranium wallichianum. The crude extracts were fractionated to obtain n-hexane, ethyl acetate, and n-butanol fractions, which were subjected to different biological activities and enzyme inhibition assays to explore the therapeutic potential of this medicinally important herb. The results indicated that the crude extracts and different fractions of rhizomes and leaves showed varied degree of antimicrobial activities and enzyme inhibitions in different assays. Overall, the rhizome extract and its different fractions showed comparatively better activities in various assays. Furthermore, the purified constituents from the repeated chromatographic separations were also subjected to enzyme inhibition studies against three different enzymes. The results of these studies showed that lipoxygenase enzyme was significantly inhibited as compared to urease. In case of chemical constituents, the sterols (2-4) showed no inhibition, while ursolic acid (1) and benzoic ester (6) showed significant inhibition of urease enzymes.