Acaricidal activity of alkaloid fractions of Leucas indica Spreng against Rhipicephalus (Boophilus) annulatus tick.

The acaricidal activity from alkaloid and non-alkaloid fractions of Leucas indica were studied against Rhipicephalus (Boophilus) annulatus tick using adult immersion test under laboratory conditions. For this purpose, the engorged female R.(B.) annulatus tick were exposed to two fold serial dilutions of alkaloid extract (50 mg/ml, 25 mg/ml, 12.5 mg/ml, 6 mg/ml and 3 mg/ml) using 'dipping method' in vitro. The efficacy was assessed by measuring the percentage of adult mortality, inhibition of fecundity and hatching rate. The alkaloid fraction of the extract produced concentration dependent delayed adult tick mortality. The extract at a concentration of 50 mg/ml demonstrated 66.67 per cent mortality and 55.16 per cent inhibition of fecundity. Nicotine was identified as one of the compounds of alkaloid fraction. However, it did not reveal any acaricidal activity when tested in vitro at concentrations ranging from 62.5-1000 µg/mL. Hence, the acaricidal action of L. indica is not due to nicotine. Non alkaloid fraction also did not reveal any acaricidal effects against R. (B.) annulatus tick.

Acaricidal effect of Cassia fistula Linn. leaf ethanolic extract against Rhipicephlaus (Boophilus) annulatus.

The present study evaluates the acaricidal properties of crude ethanolic extract of Cassia fistula leaves for controlling Rhipicephalus (Boophilus) annulatus based on adult immersion test (AIT). The percentage of adult mortality, inhibition of fecundity and hatching of ova laid were studied at different concentrations of the extract ranging from 50 to 100 mg / ml. The results were compared using one-way ANOVA. The extract produced complete inhibition of hatching of eggs at concentrations above 80 mg / ml of the extract. Mortality of adult engorged female ticks and inhibition of fecundity were concentration dependent. The LC50 value of extract against R. (B.) annulatus was 97.1 mg / ml.

Plumbago zeylanica action on blood coagulation profile with and without blood volume reduction.

Plumbago zeylanica (PZ) is extensively used in Indian systems of medicine for its medicinal properties. The structure of its active principle is similar to that of vitamin K. Its effect on blood coagulation profile after chronic administration has not been reported so far. The PZ extract (2 mg/kg body weight) and napthoquinone (2 mg/kg body weight) given to individual groups were screened for its effect on bleeding time (BT), clotting time (CT), prothrombin time (PT), platelet count and platelet adhesion in albino rats after 1-day, 15-day and 31-day treatment. There was no change in the platelet count in the treated groups when compared to the control levels. But the platelet adhesion was significantly decreased after PZ and also napthaquinone-treated animals in both with and without blood volume reduction after 15th as well as 31st day. Since the napthoquinone-treated group also showed similar response the changes observed after PZ treatment may be due to this component. Even at a lower dosage level (2 mg/kg body weight), the chronic PZ administration prolongs the bleeding time by altering platelet adhesiveness and the coagulation.

Serotonin turnover in discrete regions of young rat brain after 24 h REM sleep deprivation.

The present study has attempted to elucidate the alteration of serotonin turnover after 24 h REM sleep deprivation in different regions in brain of young rat. Sleep deprivation was induced by the inverted flower pot technique. Results of this study show increased serotonin turnover after 24 h REM sleep deprivation in all the brain regions except in the hypothalamus. The decreased 5-HT ratio shows increased serotonin in the hypothalamus after 24 h sleep deprivation. This study indicates increased activity of serotonergic neurons in the hypothalamus after 24 h sleep deprivation. This also indicates that the hypothalamus plays a role in the immediate compensatory mechanism during 24 h REM sleep deprivation in young rats.

Biogenic amine changes in brain regions and attenuating action of Ocimum sanctumin noise exposure.

Broadband white noise exposure (100 dB) in wistar strain male albino rats significantly increased the levels of dopamine (DA), serotonin (5-HT) and 5-HT turnover in many of the discrete brain regions (cerebral cortex, cerebellum, hypothalamus, hippocampus, pons-medulla and corpus striatum) during sub-chronic noise exposure (4 h daily for 15 days). In acute (4 h for 1 day) and chronic noise exposures (4 h daily for 30 days) the levels were significantly altered only in certain regions. The turnover study of serotonin clearly indicates that neurotransmitter level alone cannot be an indicator, as in some brain regions the rate of synthesis matched with the degradation in order to maintain the normal levels. The intraperitoneal administration of 70% ethanolic extract of Ocimum sanctum(OS) at the dosage of 100 mg/kg body weight to animals subjected to noise exposure has prevented the noise induced increase in neurotransmitter levels without affecting the normal levels. This indicates that OS can be a probable herbal remedy for noise induced biogenic amine alterations.