Toxicity of Cymbopogon proximus (Maharaib) Oil Extract to Newzealand Rabbits
Medani AB*, Samia MAE2, Ahmed EA2
1Department of Pharmacology & Toxicology, Nile College, Sudan
2Department of Pharmacology & Toxicology, University of Khartoum, Sudan
Submission: March 10, 2016 ; Published: March 29, 2016 ;
*Corresponding author: Medani AB, Assistant Professor of Pharmacology & Toxicology, Nile College, Faculty of Pharmacy, Khartoum, Sudan, Tel: +249912369706; Email: amna_medani@ yahoo.com
How to cite this article: Medani A, Samia M, Ahmed E . Toxicity of Cymbopogon proximus (Maharaib) Oil Extract to Newzealand Rabbits. Open Acc J of Toxicol. 2016;1(2): 555556. DOI: 10.19080/OAJT.2016.01.555556
The clinical, pathological, hematological and biological changes in Newzealand rabbits groups given daily oral doses of 0.1, 0.25 and
0. 5 ml/kg body weight/day of Cpmbopogon proximus oil extract were investigated in experiment duration for 21 days. Other than the dose co-related mortality rates, the clinical signs were observed daily after dosing to be low appetite and nervous signs including restlessness and increased consciousness. Pulmonary excretion of the oil extract led to bloody spots on the lungs, lymphocyte infiltration, congestion and edema. Renal glomeruli manifested lymphocyte infiltration in addition to shrinkages and easinophilic material in the medulla, if considered with the corticomedullary generalized necrosis and the significant changes in urea, they may explain the renal dysfunction. Hepatic malfunction was manifested by significant changes in serum alkaline phosphatase and aspartate transferases accompanied by the congested fatty changed livers. The direct physical effect of the extracted oil was detected by the catarrhal inflammation of the intestines. There was no significant hematological change except for the slight changes in RBCs and MCVs in rabbits given the highest dose. Future work for Cymbopogon proximus oil extract was forwarded and practical implications of the result were highlighted.
From the very early history, man is still depending in his struggle against illness on herbal remedies. This suggests the importance of research against poisoning especially in rural areas where the only remedy is traditional health care. Cymbopogon proximus, a member from the lemon-grass genus, also known as gavatichaha in the Marathi language (gavat = grass; chaha = tea) and is used as an addition to tea, and in preparations such as kadha, which is a traditional herbal 'soup' used against coughs and colds . It has medicinal properties and is used extensively in Ayurvedic medicine. It is supposed to help with relieving cough and nasal congestion. AWL  was used in folkloric medicine against stomach aches and as an antispasmodic . It is also suitable for use with poultry, fish, beef, and seafood (Figure 1) in Sudan [4-7]. Lemongrass oil is used as a pesticide and a preservative [8,9]. Lemongrass has exhibited analgesic effects in mice and rat studies [10-12]. In a pharmacological study in mice, anti-inflammatory properties of lemongrass oil were examined with 5 |il of lemongrass oil per subject, intra peritoneally . Lemongrass oil has shown antiviral activity against herpes simplex virus type-1 (HSV-1) in vitro .There were two studies conducted to determine the hypoglycemic properties of lemongrass (Cymbopogon proximus) in alloxan-induced diabetic rats [15,16]. In Costarica, Maharaib was used as an antihypertensive drug . Lemongrass oil also demonstrated vasorelaxation on isolated, perfused, mesenteric artery preparation and appears to be mediated by nitric oxideindependent and non-postanoid mechanisms [18,19]. An oral infusion of up to 208 times the corresponding human dose of lemongrass and oral citral up to 200mg/kg in rats showed no effect on the central nervous system (CNS) as a depressant, hypnotic, neuroleptic, anti-convulsant or anxiolytic . In Egypt it was used for schistosomiasis  and as an expectorant.It was proven to have anti hyperglycemic effects on rats if given intragastric in Eygpt . Its antibacterial activity against Pseudomonus aeuriginosa and Staphylococcus aureus in vitro was proven by Farouk  who also showed its antibacterial effects on Bacillus subtilis and Eschericia coli. All the above mentioned pharmacological uses of lemon grass were not well supported by toxicological data on the way to avoid adverse, toxic or fatal effects of the traditionally used herb. This study enlightens the dark about one genus of lemongrass that is called in Sudan Maharaib.
Twenty Sixth month old Newzealand rabbits of both sexes were obtained and health-followed over an adaptation period of 2 weeks. They were then weighed and allotted into four equal groups starting with group (1), the un-dosed control. The herb Cymbopogon proximus was then extracted into an oil and orally given to group (2),(3) and (4) at doses of 0.1, 0.25 and 0.5 ml/ kg/day respectively for four weeks. Clinical signs and mortality (Table 1) were recorded .Blood samples prior to experiment and then at a week interval after dosing started for serum constituents (GOT, GGT, ALP, urea, creatinine, total protein, albumin, calcium and phosphorus) and hematological data (Hb, PCV, RBCs, MCV and MCVH).Specimens of tissues from rabbits were taken for histopathological examination.
Wild fruits of the family Poaceae (Gramminae), Cymbopogon proximus (L) Spreng were purchased from the herbalist in Omdurman market (Figure 1) identified and deposited as herbarium specimens at the Medicinal and Aromatic Plants Research Institute, National Centre for Research, Khartoum, Sudan to be dried and crushed coarsely. They were then macerated in a percolator with distilled water for twelve hours. This liquid separated with filtration using cotton to give the appropriate concentrations of the extract. Using Clevenger Apparatus, the oil of the extract was distilled to be passed through anhydrous sodium sulfate.
Rabbits in group (2) in-tubated orally with 0.1 ml/Kg/ day of Cymbopogon proximus showed signs of depression and unthriftness. Rabbits in group (3) given oral doses of this herb at the rate of 0.25 ml/Kg/day, had manifested the same signs, but to a larger extend. Rabbits in group (4) receiving 0.5 ml/Kg/day of Maharaib oil extract orally showed a very low appetite and restlessness .The undosed control rabbits in group were normal. All rabbits were slaughtered after 21 days of dosing.
Rabbits of group (2) given oral doses of 0.1ml/Kg/day of Cymbopogon oil extract showed fatty changes in the liver (Figure 2), while those in group (3) dosed with 0.25 ml/Kg/day orally of the extract showed bloody spots on the lungs. Rabbits in group (4) receiving 0.5 ml/Kg/day of Maharaib oil extract orally manifested congested lungs and livers. Rabbits in the undosed control group showed no abnormalities.
The kidneys of the rabbits of group (2) given oral doses of 0.1 ml/Kg/day of Cymbopogon oil extract showed congestion and easinophilic material in the medulla in addition to lymphocyte infiltration in the medulla (Figure 3).The lungs showed edema, congestion and lymphocyte infiltration (Figure 4). Catarrhal inflammation was observed in the intestines and the livers clarified congestion, fatty changes and slight lymphocyte infiltration (Figure 5).
Changes in the activities ofALP,AST,GGT and the concentration of phosphrus, calcium, creatinine, urea, total protien and albumin in the serum of goats dosed with Cymbopogon proximus were entabulated (Table 2). There were no changes in the concentrations of total proteins, albumin, and phosphorus nor in the activity of GGT in rabbits of all groups compared to those in the undosed control group. Urea and calcium concentrations were higher (P<0.5-0.1) in the rabbits of group (4) receiving 0.5 ml/Kg/day of Maharaib oil extract orally ,while GOT activity was higher (P<0.05) in rabbits in group (4) and group (3) dosed with 0.25 ml/Kg/day orally. ALP activity showed higher values (P<0.05-0.01) in all the under-test rabbits compared to the control group of rabbits.
NS= Not Significant, P = Level of significance above or below control value
There were no changes in the rabbits of all groups in Hb, PCV and MCHC values if compared with the undosed group. Rabbits in group (4)receiving0.5 ml/Kg/day of Maharaib oil extract orally and those in group (3) dosed with 0.25 ml/Kg/day orally showed no differences in the MCH values relative to the control group,, while those in group (2) given oral doses of 0.1 ml/Kg/day of Cymbopogon oil extract showed lower values (P<0.05) .Rabbits in group (4) receiving 0.5 ml/Kg/day of Maharaib oil extract orally showed no significant values in RBCs count , but those of group (2) given oral doses of 0.1 ml/Kg/day of Cymbopogon oil extract and group (3)dosed with 0.25 ml/Kg/day orally showed higher values (PP<0.05) than the rabbits in the control group (1) (Table 3).
NS= Not Significant, P = Level of significance above or below control value
On acute exposure of Newzealand rabbits to doses of C. proximus as an oil extract, rabbits showed dose-related signs and were all slaughtered at the end of the experiment. This may indicate the non-fatal property ofthe under-test herb [24-27]. The unthriftness, restlessness, bloody spots on the lung, lymphocyte infiltration, congestion and edema might be probably due to Cymbopogon proximus poisoning as a volatile oil easily excreted via lungs which indicates it as a suggestive inflammatory inducer . The kidneys showed a lymphocyte infiltration in the glomeruli accompanied by shrinkage, hemorrhages and easinophilic material in the medulla and a generalized necrosis in both medulla and cortex which may be the cause of renal dysfunction. The presence of easinophilic material in the lumen of affected tubules and the increased changes in urea and calcium (P< 0.05-0.01) confirm the existence of nephrotoxicity . The necropsy found congestion in the liver of the under-test rabbits, the significantly elevated GOT values (P<0.05) and ALP activity (P<0.05-0.01) are indicative biomarkers of the hepatic insufficiency . The low appetite together with the catarrhal inflammation is pointing out C. proximus as an intestinal irritant [31,32]. Screening of the hematological picture suggested C. proximus as a non endotheliotioxic herb . This toxicological risk assessment of the acute doses of C. proximus clarified this popular herb as a dose dependant, non-fatal, non-endothelio toxic, asthma inducer and hepato-nephrotoxic substance.
As the economic capability of attaining chemical drugs is not always obtained for different uses of the society and as directed by the (WHO) and (UNIDO), people should utilize drugs of local material available at hand which should encourage further investigations to produce proper pharmaceutical preparations to eliminate any possibility of toxicity induced by raw local medicines by conducting experiments using different experimental animals. These trials should be supported by governmental and private bodies to enrich the field of traditional folk medicine with safety data. C. proximus as wild herb that is available for a wide range of believers for medicinal purposes should be investigated for more data and for long term accumulative uses.