ABSTRACT
Phyllanthus amarus, also known as “stone breaker”, “carry me seed” is an upright annual herb which usually grows not more than 60 cm tall with small leaves and yellow flowers. It is known in different part of Nigeria as “Ebeiyekezupe in Bini and “Iyeke” in Urhobo. Over the years, there has been convincing evidence of the therapeutic use of P. amarus to treat several diseases such as hypertension, jaundice, diabetes, kidney problems and urogenital diseases. Several reports of the use of this plant in both traditional and modern medicine has emerged, however, little is known about its immunomodulatory effects, hence this study was carried out to determine its immunomodulatory effects on Wistar albino rats and also its antibacterial efficacy on some selected clinical isolates of medical relevance.
The leaves of the plant P. amarus were collected from a farmland at Ughelli in Ughelli North Local Government Area of Delta State, Nigeria. The leaves were identified and authenticated in the Department of Plant Biology and Biotechnology, University of Benin and a voucher specimen (Code No. UBH-P406) was deposited. five hundred grsms of the grounded plant material were extracted by soaking for 24 hours and 72 hours respectively using 900 mL of distilled water and 800mL ethanol, it was then filtered, concentrated and crude extracts were preserved in a sample bottle at 4oC. Preliminary phytochemical analysis was carried out on the leaves of P. amarus using aqueous and ethanol solvent according to standard laboratory procedures. The antibacterial activity of the leaves of P. amarus was investigated by evaluating the effects of the extract against the growth of Staphylococcus aureus, Shigella sp., Salmonella sp., and Escherichia coli using the agar well diffusion technique. A total of thirty-six (36) adult male Wistar rats weighing between 150 g and 250 g were used for this study. They were divided into six groups, A, B, C, D, E and F of six rats each. Group A was control, Group B, C and D received 25mg/kg, 50mg/kg and 100mg/kg of the ethanol extract respectively while Group E and F received 25mg/kg and 50mg/kg of the aqueous extracts were administered intraperitoneally for a period of twenty-eight (28) days. The possible effects associated with the administration of the aqueous and ethanol on the haematological parameters and histotoxicological effects on liver and kidney was also studied in Wistar albino rats. After the last day of immunization, twenty four hours later the animals were weighed, anaesthesized under chloroform vapour, blood drawn for haematological parameters and organs harvested for histopathology at University of Benin Teaching Hospital.
The result of this study revealed that P. amarus contained some phytochemicals and antioxidant such as alkaloid (10.67%), Saponin (7.33%), Tannin (87.8 µ/ml), flavonoids ( 8.17 µ/ml) and carotenoids (192.93 µ/ml). However, anthocyanins was not detected in both the aqueous and ethanol extract. The bacterial isolates were resistant to the various concentrations of the ethanol extract. There was no significance difference in the weights of the rats. Among the hematological parameters examined the lymphocytes count had a significant increase from 77.70±1.70 in the control to 87.40±6.20 at 100mg/kg of the ethanol extract. The white blood cells count also increased from 16.05±1.05 for control to 17.50±4.80 at 100 mg/kg of the ethanol extract and the red blood cells count increased from 4.65±0.25 in the control to 5.28±0.08 at 100mg/kg of the ethanol extract. There was increase in the concentration of lymphocytes observed in the spleen of the experimental animals compared to the control while the histopathology revealed mild hepatitis and splenitis at the highest concentration of the ethanol extract. There was no observable pathological effects observed in the kidneys. The results of this study suggests that P. amarus had a potential of stimulating immune response with no observable toxic effect, the result also revealed that the plant may not be a good antibacterial agent. Furthe it is r recommended that P. amarus leaves should be consumed at moderate concentration to improve immune response in animals
