Synergistic Anti-Inflammatory Effect of a Polyherbal Formulation and Palm Oil on Induced Inflammatory Models in Albino Wistar Rats

Introduction: Palm oil obtained from the mesocarp of the fruit of Elaeis guineensis is locally used to treat inflammations either alone or in combination with herbs. The present study aimed to test the basis of using palm oil (PO) as an anti-inflammatory agent and the synergistic effect of the Aqueous Extract polyherbal Formulation (AEPHF) comprising Zingiber officinale, Curcuma longa, and Allium sativum. Materials and Methods: A total of 162 adult Wistar rats were used to investigate three anti-inflammatory models for eight weeks. Each model contained 54 rats (27 male and 27 female rats), with an average weight of 119 to 170 g. In the acute and sub-acute anti-inflammatory studies, 0.2 ml of carrageenan solution 1%, egg albumin, and formalin were injected subcutaneously into the paw of the rats respectively. Group 1 distilled H2O (2 ml/kg), Group 2, 10 mg/kg of ibuprofen, Group 3, 50 mg/kg of AEPHF, Group 4, 50 mg/kg of AEPHF + 2ml/kg of PO, Group 5, 50 mg/kg of AEPHF + PO topically, Group 6, 100 mg/kg of AEPHF, Group 7, 100 mg/kg of AEPHF + 2 ml/kg of PO, Group 8, 100 mg/kg of AEPHF + PO topically, Group 9, 2 ml/kg of PO and PO topically. The diameters of the paws were recorded at intervals of 0, 0.5, 1, 2, and 3 hours (for acute inflammatory study using egg albumin and carrageenan), as well as at 0, 3, 5, and 7 days (for sub-acute inflammatory study using formalin). Results: The results indicated that the treatment groups had significantly less paw diameter compared to the control group (p<0.01). Group 8, which distilled 100 mg/kg of AEPHF and PO topically, had the best effect compared to other treatment groups. Conclusion: An increase in the dose of AEPHF revealed subsequent increases in anti-inflammatory actions. 100 mg/kg of AEPHF and PO topically proved to be the most potent in the three models of inflammations. However, further research should be carried out to determine the mechanism of action of the anti-inflammatory effect of the plant using laboratory animals.