Preliminary screening of hydrogel containing Martynia annua extract for anti-inflammatory activity

Objective: Aim of the present study was to investigate preliminary evaluation of hydrogel formulation of methanol fraction of Martynia annua for anti-inflammatory activity using different types of animal models. Materials and Methods: Five different hydrogel formulations containing extract and one control without extract were prepared according to standard method using different proportions of Carbopol 940 and sodium carboxymethyl cellulose (CMC). Prepared hydrogel was characterized for optimization and screened for anti-inflammatory activity using Xylene induced ear edema and Croton oil-induced ear edema in mice. Effect was observed by measurement of percent inhibition of ear edema and biochemical parameters, for example, nitric oxide level and myeloperoxidase (MPO) level. Results: Phytochemical screening showed that petroleum ether extract of M. annua showed the presence of sterols, terpenoids, and fatty oils while ethanol extract of showed the presence of glycosides, phenolic compounds, flavonoids, and amino acids. Results of all other evaluation parameters, for example, pH, viscosity, spreadability, and consistency were found suitable in optimized formulation as 1.5 g of Carbopol 940 and 1% of Sodium CMC for best drug release profile. Effect of MAMFH was observed greater percentage of edema inhibition (66.67%) and was comparable to standard group of treatment (65.59%). Results showed that MPO level of inflamed ears (inflamed control and treated only with gel base) was significantly higher in comparison with the non-inflamed control (P < 0.01), and with hydrogel formulations. The results showing the ability of croton oil to induce neutrophil influx into mice ear tissue. This may be reduced by treatment with extract hydrogels, as well as Voltaren Emulgel, reduced significantly (P < 0.05) the MPO levels in mice ears. Conclusion: Methanol fraction of M. annua was capable of inhibiting ear edema induced by xylene. It may be due to the ability of extract to either inhibit the synthesis, release or action of xylene involved in the inflammation. Methanol extracts was exhibits its anti-inflammatory action by inhibiting the synthesis, release or action of histamine. Significant activity may be due to presence of flavonoids in methanol extract fraction of M. annua leaves.