الفهرس 
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Abstract
The present work was performed to investigate some pharmacodynamic and nephrotoxic aspects of Nigella sativa oil.
Concerning the pharmacodynamic studies, Nigella sativa oil at concentrations from 2.5 - 12.5 tg /ml bath produced slight inhibition in the force of contraction of guinea pig’s ileum, while concentrations from 25 - 100 μg/ml bath produced marked inhibition in the force and rate of contraction. Complete relaxation was produced by 150 lig /ml bath.
Nigella sativa oil in concentrations of 2.5 and 51.4 /ml bath produced slight inhibition in the force of contraction of isolated rabbit’s duodenum, but 7.5 and 10 lig /ml bath produced slight inhibition in the force and rate of contraction . Marked inhibition in the force and rate was produced by concentrations from 12.5 - 150 jig /ml bath , while 200 lig /ml bath coused complete relaxation. The site of action of Nigella sativa oil on the intestinal motility was proved to be myogenic in nature as a result of its calcium antagonistic effect.
Concentrations of Nigella sativa oil from 2.5 - 10 μg /ml bath produced slight inhibition in the force of contractions of isolated rat’s colon, but concentrations of 12.5, 25 and 50 lig /ml bath produced marked inhibition in the force of contraction. Very marked inhibition was produced by 100 μg/ml bath, while complete relaxtion was produced by concentration of 150 lig /ml bath .
Slight inhibition in the force of contraction of rat’s fundic strip was produced by concentrations of Nigella sativa from 10-50 lig /ml bath. Marked inhibition was produced by 100, 150 and 200 lig /ml bath, while very marked inhibition was produced by 250 i.tg /ml bath. This inhibitory action might be attributed to the possible anti-serotonin - like action of the oil as well as its direct action.
Nigella sativa oil in concentrations from 2.5 to 12.5 tg /ml bath produced slight inhibition in the force of uterine contractility in oestrus and non-oestrus stages of the sex cycle and slight inhibition in the force and rate of contractions at early and late stages. Marked inhibition in both the force and frequency of spontaneous uterine motility in all stages of the sex cycle was produced by the concentrations of 25, 50, 100 and 150 jig /ml bath . Complete relaxation of contractile uterine smooth muscle was produced by concentration of 150jig /ml bath in all stages of the sex cycle .
The inhibitory action of Nigella sativa oil on uterine muscle was proved to be direct in nature.
Nigella sativa oil in all tested concentrations didn’t induce any response on isolated guinea pig’s tracheal chain or isolated rabbit’s aortic strip. The oil blocked the stimulant effects of histamine and nor-adrenaline on isolated tracheal chain and the rabbit’s aortic strip, respectively. This effect is direct in nature.
Nigella sativa oil in concentrations from 2.5 - 12.5 jig /ml bath produced slight inhibation in the force of contraction of isolated guinea pig’s auricle. Marked inhibition was produced by concentration from 25 -200 lig /ml bath .
Nigella sativa oil in concentrations of 2.5, 5, 7.5 and 10 jig /ml cannula produced slight inhibition in the force of contraction of isolated rabbit’s heart. Marked inhibitory effect was produced by concentrations from 12.5-100 jag /ml cannula while very marked inhibition in the force of contraction was produced by 150 and 200 jig /ml cannula . This action of Nigella sativa oil was not attributed to 3 - adrenergic blocking or to cholinergic stimulant effects.
Nigella sativa oil at concentrations of 1000 and 2000 bath
caused slight blockade on the twitches of the isolated forg’s gastrocnemius muscle . Marked blockade was induced by 4000 pig /ml bath. The effect was attributed to the local anaesthetic activity of the oil on the sciatic nerve as well as its calcium antagonistic effect.
Concentrations lower than 50011g /m1 bath Nigella sativa oil had no effect on isolated forg’s rectus abdominis muscle in the presence of acetilcholine ( 2.5 lig /ml bath ). Concentration of 1000 and 2000 l_tg /ml bath caused slight blockade on the contracture of frog’s rectus abdominis muscle. Marked and complete blockade were induced by 3000 and 4000 )„tg /ml bath respectively. The blocking effect might be attributed to the calcium antagonistic activity of the oil.
Nigella sativa oil in concentrations lower than 500 pig /m1 bath had no effect on isolated rat’s phrenic nerve hemidiaphragm. Slight inhibition in the force was produced by concentration of 1000 and 2000 1.1g/m1 bath, while marked and very marked inhibitions in the force were produced by 3000 and 4000 lig /ml bath respectively. Nigella sativa oil didn’t impair the stimulatory effects of prostigmine and acetylcholine. So the inhibitory effect might be attributed to the local anaesthetic and calcium antagonistic activities of the oil.
Intravenous injection of 15 mg/kg. b.wt of Nigella sativa oil produced slight hypotensive effect in anaesthetized dog. Marked hypotensive effect was produced by intravenous injection of Nigella sativa oil in a dose of 60 mg/kg. b.wt . Rate of respiration wasn’t be affected after bath injections. The hypotensive effect of Nigella sativa oil didn’t attributed to a adrenergic blocking effect, but it was blocked by atropine. So the hypotensive effect of the oil was attributed to its cholinomimetic activity.
Nigella sativa oil in the dose of 26 and 104 mg/kg. b.wt ( low and high doses ) didn’t affect electrocardiographic parameters of conscious rabbit within a period of 8 hours after oral administration of the oil .
Nigella sativa oil in a dose of 280 mg/kg. b.wt of mouse produced a significant analgesic effect 2.5 hours post-administration. This might be attributed to the presence of an opioid principle in the oil.
Nigella sativa oil in doses of 50 and 200 mg/kg. b.wt of rats produced a significant antipyretic effect. The effect produced 1.5 and 1 hour after administration of the high and low doses respectively .
Regarding the nephrotoxic effect , Nigella sativa oil produced a highly significant increase in the amount of urine voided per day of rats administrated 50 and 200 mg/kg. b.wt. This was attributed to the high glomerular filteration rate caused by Nigella sativa oil as a result of relaxation of the renal blood vessels.
Nigella sativa oil in doses of 50 and 200 mg/kg. b.wt caused a decrease in serum urea level and an increase in urea concentration in urine of the tested rats. The oil in both given doses increased urea clearance .
Doses of 50 and 200 mg/kg. b.wt Nigella sativa oil increased creatinine concentration in urine, while the concentration of creatinine in serum was decreased. The oil in both doses caused an increase in creatinine clearance. Elevated clearance of both urea and creatinine was attributed the diuretic effect of the oil and increase of their levels in urine as well as their low serum levels.
Doses of 50 and 200 mg/kg. b.wt Nigella sativa oil caused a decrease of glucose level in serum. Glucose was not detected in urine. The hypoglycaemic effect of the oil was attributed to increased insulin level end/ or to decreased gloconeogenesis.
Nigella sativa oil in a dose of 50 and 200 mg/kg. b.wt decreased serum total protein concentrations. Protein was not detected in urine. The hypoproteinaemic effect of the oil might be attributed to its possible hepatotoxicity.
Serum calcium level was decreased while urine calcium was increased after oral administration of 50 and 200 mg/kg. b.wt Nigella sativa oil to rats. The decrease in serum calcium is logic after hypoproteinaemia.
Nigella sativa oil in a dose of 50 and 200 mg/kg. b.wt decreased sodium level in serum, while the excreted soduim in urine was increased. Also, Nigella sativa oil produced an insignificant decrease in serum potassium of rats administered 50 and 200 mg/kg. b.wt. The same doses caused an insignificant increase in the urine potassium of tested rats. The obtained results concerning sodium and potassium were attributed to the diuretic effect of the oil.
Nigella sativa in the dose of 50mg./kg. b.wt. produced congestion in renal blood vessels and proliferation of glomerular tuft cells, while the dose of 200 mg./kg. b.wt. produced mild degenerativa changes in kidneys.