ABSTRACT
Haematotoxicity induced by benzene exposure has been associated with altered gene expressions of key inflammatory cytokines, such as Interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNF-α). Launaea taraxacifolia, a plant known for its traditional medicinal uses, has emerged as a subject of interest due to its reported anti-inflammatory properties. Therefore, the aim of this study was to determine the effects of aqueous leaf extracts of Launaea taraxacifolia on IL-6 and TNF-α gene expression in benzene induced haematotoxicity in albino Wistar rats. A total of sixty (60) adult male albino Wistar rats were divided into six (6) groups namely groups A, B, C, D, E and F, representing control, benzene group, cyclophosphamide group, benzene + 100mg/kg Launaea taraxacifolia, benzene + 200mg/kg Launaea taraxacifolia and benzene + 400mg/kg Launaea taraxacifolia respectively. Haematological parameters, blood cell morphology, mRNA expressions of IL-6 and TNF-α were determined using haematology autoanalyzer, manual method and polymerase chain reaction (PCR) respectively. Data obtained was analyzed by the Statistical Package for Social Science (SPSS) software. The comparison of haematological parameters amongst the study groups showed that the Total white blood cell count (TWBC μL) was significantly higher in group A (18.4±1.16) when compared to group C (10.89±0.43), D (14.61±0.33), E (14.56±0.31) and F (13.05±1.37) (p<0.05). Group B (18.59±0.48) had a significantly higher TWBC count when compared to group C (10.89±0.4298), D (14.61±0.3318), E (14.56±0.31) and F (13.05±1.37) (p<0.05). Lymphocyte count (%) was significantly lower in group C (59.6±3.655) when compared to groups A (85.15±0.71), B (86.3±1.46), D (89.19±0.96), E (87.79±1.331) and F (90.69±0.49) (p<0.05). Monocyte count, neutrophil count and basophil count was significantly higher in group C when compared to other groups (p<0.05). Platelet count was significantly lower in group A (489.8±22.7) when compared to groups B (605.8±41.23) and C (753.7±37.27) (p<0.05). Group B (605.8±41.23) had a significantly higher platelet count when compared to groups D (479.8±14.58), and F (475.4±23.06) (p<0.05). Platelet count of group C (753.7±37.27) was significantly higher than groups D (479.8±14.58), E (524.8±11.53) and F (475.4±23.06) (p<0.05). Blood morphology showed small and large lymphocytes and normal platelets in all groups. The mRNA expression of IL-6 in group B was significantly higher when compared to group A (p<0.05). The mRNA expression of IL-6 in groups C and D was significantly lower when compared to group B (p<0.05). The mRNA expression of IL-6 was significantly higher in groups E and F when compared to group A (p<0.05). There was a significant increase in the mRNA expression of TNF-α in group B when compared to group A (p<0.05). The mRNA expression of TNF-α in groups C, D, E and F was significantly lower when compared to groups A and B (p<0.05). This study concludes that the intervention of Launaea taraxacifolia resulted in dose dependent impacts on both white blood cell counts and platelet parameters in the relationship to benzene administration. Also, benzene exposure induced an increase in the mRNA expression of IL-6 and TNF-α. Co-administration of benzene and varying Launaea taraxacifolia concentrations subsequently reduced TNF-α while further increase was noted in IL-6 expression after administration of 200mg/kg with benzene.
