ANTIPYRETIC ACTIVITY OF ANNONA PLANTS LEAVES ON BREWER'S YEAST INDUCED FEBRILE RATS

Objective: To evaluate and compare the in vivo antipyretic activity of the methanolic extracts of selected three Annona plant leaves.Methods: The acute oral toxicity determined by OECD class method and the in vivo antipyretic activity was determined by brewer's yeast inducedpyrexia method.Results: The results showed that the methanolic extract of leaves of Annona plants are non-toxic and possessed significant antipyretic effect whichmay be attributed to the presence of flavonoids and saponins in the extracts.Conclusion: This study provides evidences for the antipyretic activity of Annona squamosa, Annona reticulata and Annona muricata possess antipyreticactivity at the tested doses 100 and 200 mg/kg body weight without any side effects, which could partly contribute to its ethno medical use.Keywords: Annona squamosa L, Annona reticulata L, Annona muricata L, Antipyretic activity, Brewer's yeast

Discovery of unusual pulsations in the cool, evolved Am stars HD 98851 and HD 102480

The chemically peculiar (CP) stars HD 98851 and HD 102480 have been discovered to be unusual pulsators during the ``Naini Tal Cape Survey'' programme to search for pulsational variability in CP stars. Time series photometric and spectroscopic observations of these newly discovered stars are reported here. Fourier analyses of the time series photometry reveal that HD 98851 is pulsating mainly with frequencies 0.208 mHz and 0.103 mHz, and HD 102480 is pulsating with frequencies 0.107 mHz, 0.156 mHz and 0.198 mHz. The frequency identifications are all subject to 1 d$^{-1}$ cycle count ambiguities. We have matched the observed low resolution spectra of HD 98851 and HD 102480 in the range 3500-7400 \AA with theoretical synthetic spectra using Kurucz models with solar metallicity and a micro-turbulent velocity 2 km s$^{-1}$. These yield $T_{eff}=7000\pm250$ K, log $g=3.5 \pm 0.5$ for HD 98851 and $T_{eff} = 6750 \pm 250$ K, log $g = 3.0 \pm 0.5$ for HD 102480. We determined the equivalent H-line spectral class of these stars to be F1 IV and F3 III/IV, respectively. A comparison of the location of HD 98851 and HD 102480 in the HR diagram with theoretical stellar evolutionary tracks indicates that both stars are about 1-Gyr-old, 2-$M_{\odot}$ stars that lie towards the red edge of the $\delta$ Sct instability strip. We conclude that HD 98851 and HD 102480 are cool, evolved Am pulsators. The light curves of these pulsating stars have alternating high and low amplitudes, nearly harmonic (or sub-harmonic) period ratios, high pulsational overtones and Am spectral types. This is unusual for both Am and $\delta$ Sct pulsators, making these stars interesting objects.Comment: 9 pages, 6 Figures, Accepted for publication in MNRA

In Vitro Characterization of a Multifunctional Staphylokinase Variant with Reduced Reocclusion, Produced from Salt Inducible E. coli GJ1158

The thrombolytic therapy with clinically approved drugs often ensues with recurrent thrombosis caused by thrombin-induced platelet aggregation from the clot debris. In order to minimize these problems, a staphylokinase (SAK)-based bacterial friendly multifunctional recombinant protein SRH (staphylokinase (SAK) linked with tripeptide RGD and dodecapeptide Hirulog (SRH)) was constructed to have Hirulog as an antithrombin agent and RGD (Arg-Gly-Asp) as an antiplatelet agent in the present study. This multifunctional fusion protein SRH was expressed in osmotically inducible E. coli GJ1158 as soluble form and purified with a yield of 0.27 g/L and functionally characterized in vitro. SRH retained the fibrinolytic activity and plasminogen activation rate comparable to the parental counterpart SAK. The antithrombin activity of SRH was significantly higher than SAK. The platelet rich clot lysis assay indicated that SRH had enhanced platelet binding activity and T50% and C50 of SRH were significantly lower than that of SAK. Furthermore, SRH inhibited the ADP-induced platelet aggregation in dose-dependent manner while SAK had no significant effect on platelet aggregation. Thus, the current study suggests that the SAK variant produced from osmotically inducible GJ1158 is more potent thrombolytic agent with antithrombin and antiplatelet aggregation activities for reduction of reocclusion in thrombolytic therapy

Characterization of a Multifunctional Staphylokinase Variant with Reduced Reocclusion, Produced from Salt Inducible E. coli GJ1158

The thrombolytic therapy with clinically approved drugs often ensues with recurrent thrombosis caused by thrombin-induced platelet aggregation from the clot debris. In order to minimize these problems, a staphylokinase (SAK)-based bacterial friendly multifunctional recombinant protein SRH (staphylokinase (SAK) linked with tripeptide RGD and dodecapeptide Hirulog (SRH)) was constructed to have Hirulog as an antithrombin agent and RGD (Arg-Gly-Asp) as an antiplatelet agent in the present study. This multifunctional fusion protein SRH was expressed in osmotically inducible E. coli GJ1158 as soluble form and purified with a yield of 0.27 g/L and functionally characterized in vitro. SRH retained the fibrinolytic activity and plasminogen activation rate comparable to the parental counterpart SAK. The antithrombin activity of SRH was significantly higher than SAK. The platelet rich clot lysis assay indicated that SRH had enhanced platelet binding activity and T 50% and C 50 of SRH were significantly lower than that of SAK. Furthermore, SRH inhibited the ADP-induced platelet aggregation in dose-dependent manner while SAK had no significant effect on platelet aggregation. Thus, the current study suggests that the SAK variant produced from osmotically inducible GJ1158 is more potent thrombolytic agent with antithrombin and antiplatelet aggregation activities for reduction of reocclusion in thrombolytic therapy

Survey for roAp stars in the Northern sky from Naini Tal

Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of them were discovered at SAAO indicating that a systematic survey also is needed in the northern sky. Therefore, a project has been initiated at the Uttar Pradesh State Observatory in Naini Tal with the objective to find and study new roAp stars in the northern sky. The test observing campaigns were made during 1997 and 1998 from UPSO at Naini Tal. A brief report of these efforts is presented here. The initial results were encouraging and qualified the site, the telescope and the instrument as the right combination needed for the success of the project. Though these preliminary observations did not yield new roAp stars, they did lead to the discovery of delta Scuti pulsations in two chemically peculiar stars, HD 13079 and HD 13038