Indigenous Medical System has played a prominent role, in addition to the other Asian medical systems such as Ayurveda, Siddha and Unani in the control of disease in Sri Lanka from time immemorial. Medicinal herbs are mainly used for treating patients in Indigenous Systems of Medicine as well as in other Asian Medical Systems. Among hundreds of medicinal plants used only a limited number have been subjected to toxicity and pharmacological evaluation.

"Kaluduru" (Nigella Sativa) is one of the main plants used in Indigenous Medical practice. In Vatikaprakarana, this is used as the Pharmacopoeia by Indigenous medical practitioners for preparing orally used medicines in the form of pills or pastes known as Guli and Kalka, eighty percent (80%) of the recipes contains “Kaluduru” (1). There is a good number of medicines which contain "Kaluduru" as a main ingredient in the book which is considered to be one of the authentic books written on indigenous Treatment known as Deshiya Chikitsa (2). In all these recipes and prescription, seeds of "Kaluduru" is used.

"Kaluduru" seed contains 25% of oil. It is taken for granted that medicinal value is based on, these oil susbtances. Recently "Kaluduru" oil has been introduced to drug market by the name of BARAKA Black Seed Oil.

It has been shown that there are no toxic effects when Nigella sativa seed oil was given to mouse in the dose of 10.0 ml/kg intragastricaly (3). It has been also reported that the powder of Nigella seed does not produce any toxic effects at the dose of 2 8 gm/kg when given to rabbit by gastric intubation (4). the LD 50 of the Ethanol extract given by intraperitoneal route for mice has been reported as 0.561 gm/kg (5). But according to another group of scientists LD 50 was 2.1 gm/kg for mice under same condition (6).

Ethanol extract of Nigella seed given 50.0 gm/kg intraperitoneally has shown antitoxic activity on cisplastin induced toxicity in mice (7).

Besides that, extracts of Nigella seeds has shown Antibacterial, Antifungal and Antiyeast activities.

8 weeks old blister Strain male rats weighing approximately 150-200 g were obtained. They were provided with food and water and libitum for 2 weeks for acclimatization. The food and water withdrawn 18 hours before administration of the drug.

The animals were divided into 2 groups of 8 each. The first group formed the control group and given distilled water orally. The second group was treated with the drug orally at a single dose of 1.07 ml/kg.

All the rats were observed for physiological and behavioral responses and any toxicity symptoms for first 2 hours and then for 6 hours. The animals were sacrificed after 24 hours and blood samples were collected from the jugular vein. S.G.O.T and S.G.P.T. assay were done according Reitman and Frankle method.

Albino rats (wister strain) of either sex were obtained. The animals were 6- 8 weeks old and average weight is
120-150 g. All the rats were provided with food and water ad libitum for 2 weeks for acclimatization.

The animals were divided into 3 groups; the control group (N=4) the treated group I (N=8) and the treated group II (N=8).

The different doses were administered orally to rats treated group I (0.0010714 ml/g) and treated group II (0.010714 ml/g) for 7 consecutive days. The control group received an equal amount of distilled water for the same number of days.

All the rats were observed for physiological and behavioral responses and for morality. Food consumption and water intake was recorded at the beginning and throughout the study.

The rats were fasted for 18 hours on the end of 8th day and they were sacrificed on 9th day. The blood samples were collected from the jugular vein and subjected to blood counting; S.G.O.T. ; S.G.P.T. and serum cholesterol assays.

Eight weeks old LC.R.C. albino mice weighing approximately 40 g were obtained. They were housed in cages and were provided with food and water ad libitum for one week for acclimatization.

The food and water were withdrawn 18 hours before the administration of graded doses of the extract orally to different groups of mice. And control groups of animals were maintained which received same amount of distilled water orally.

The animals, were observed continuously for the first 2 hours and then for 6 hours for any toxic symptoms. Finally the number of survivors was noted after 24 hours. The toxicological effect was assessed on the basis of mortality; expressed as LD 50. The L.D 50 values of drug by oral were calculated from the graph by the method of Miller and Tainter.

After oral administration, no toxicity symptoms or acute mortality was observed at the dose of 1.07 ml/kg; in the drug treated group of the rats. The animals did not show any changes in the general behavior or other physiological activities.

There were no significant differences in regard to S.G.O.T. and S.G.P.T. between control and treated groups.

The LD 50 of the drug given by orally was 22.4 ml/kg

No death was recorded during the treatment period either in the control or in the drug treated groups. The animals did not show any changes in the general behaviour or other physiological activities.

There was no significant differences of the body weight of rats between control and treated groups. Further no differences between initial and final body weight of the animals.

There were no sex based differences in any of the following parameters. Therefore the average values from both sexes are presented. The parameters did not vary from the control. The heamatological analysis is shown in table 6,7 and 8.

There was no significant changes in S.G.O.T. and S.G.P.T. levels (Table 3 4) and blood cholesterol (Table 5) when compared with the control.

Serum Glutamate Oxaloacetate Transaminase
Concentration in the control group and treated group after single dose of BARAKA Black Seed Oil are shown in table 1. Serum glutamate pyruvate transaminase concentration for the same group are shown in table 2. Both the concentration of enzymes have not significantly increased following orally administration of Baraka Black Seed Oil 1.07 ml/kg body weight.

Serum glutamate oxaloacetate transaminase concentration in two treated groups and the control groups are shown in table 3. Serum glutamate pyruvate transaminase concentration for the same group are shown table 4. Both the concentration were not significantly increased after giving two dose of the oil of Nigella Sativa for consecutive seven days. The larger dose is equal to nearly a hundred times of the human dose, according to body weight.

Serum cholesterol level of the two treated groups and the control group are shown in table 5. Serum cholesterol has not significantly increased in both the treated groups with two doses of Baraka Black Seed Oil when compared with the control group.

R.B.C. count of the control group and the treated group are shown in table 6. The mean values have not significantly changed in treated group when compared with the control group.

W.B.C. total count of treated groups and the control groups are shown in table 7. There is no any significant change in total count or differential count of W.B.C. in rat blood following orally administration of Baraka Black Seed Oil even at the dose of 0.010714 ml/g B.W. for consecutive seven days.

The present results confirm that BARAKA Black Seed Oil does not produce any toxic effect in rat according to the given conditions and parameters. As the LD 50 of Baraka Black Seed oil for rat was 22.4 ml/kg, it would be a safe drug even for human beings.