Preparation, characterization and evaluation of hydrogels from different fractions of diverse medicinal plants for management of pain and inflammation

ABSTRACT

Damage to body tissue either deeply or superficially causes pain sensation in response to which Inflammation occurs which is a normal protective natural response of the body to a variety of hostile agents. Different treatment options, including conventional and herbal therapies, are available for pain and inflammation. This study was designed to evaluate the polyherbal n-hexane and methanolic extracts and their hydrogel formulations prepared from commonly available medicinal plants for their analgesic and anti-inflammatory potential. Cinnamomum verum J. (bark), Moringa oleifera L. (leaves), Nigella sativa L. (seed), and Trigonella foenum graecum L. (seed) were collected and purchased from the vicinity and local market of Multan Punjab, Pakistan. After drying, extraction was carried out by maceration separately with two different solvents (methanol and n-hexane). An equal quantity of all methanolic and n-hexane extracts was used to formulate polyherbal methanolic and n-hexane extracts separately. Then 1%, 3%, and 5% pH-based hydrogel formulations of methanolic and n-hexane polyherbal extract were prepared. All prepared six formulations were evaluated for pH, rheological study, spreadability, extrudability, stability study, texture, color, and for toxicological study. Then analgesic and anti-inflammatory potential of methanol and n-Hexane polyherbal extracts at (200, 400 and 800.0 mg/kg) in comparison with diclofenac sodium (100 mg/kg) and prepared gel formulations (1%, 3%, and 5%) were also evaluated in comparison to diclofenac sodium 1% gel (standard drug). Both polyherbal extracts and their gel formulations have significant analgesic and anti-inflammatory potential but methanolic extract and its hydrogel have slightly more potential as compared to n-hexane extracts and its prepared hydrogel. Results also revealed that their gel formulations have more significant analgesic and anti-inflammatory potentials as compared to extracts. All pH-based gels have good texture, spreadability, extrudability, stability, and are safe to use. It is concluded that methanolic polyherbal extract and hydrogel prepared from methanolic extract have more analgesic and anti-inflammatory potential as compare to n-Hexane extract and hydrogel prepare from n-Hexane extract.

KEYWORDS:

• Inflammatory
• hydrogel
• Carbopol
• solvent-based extraction
• carrageenan

Abbreviations

G; hydro-gel formulation without polyherbal extract, MG 1%; hydro-gel formulation with 1 g of polyherbal methanolic extract, MG 3%; hydro-gel formulation with 3 g of polyherbal methanolic extract, MG 5%; hydro-gel formulation with 5 g of polyherbal methanolic extract, MNTC; Moringa oleifera, Nigella sativa, Trigonella foenum graecum and Cinnamomum verum, NG 1%; hydro-gel formulation with 1 g of polyherbal n-hexane extract, NG 3%; hydro-gel formulation with 3 g of polyherbal n-hexane extract and NG 5%; hydro-gel formulation with 5 g of polyherbal n-hexane extract, PME; polyherbal methanolic extract, PNE; polyherbal n-hexane extract, Sample M 1; polyherbal methanolic extract 200 mg/kg, Sample M 2; polyherbal methanolic extract 400 mg/kg, Sample M 3; polyherbal methanolic extract 800 mg/kg, Sample N 1; polyherbal n-hexane extract 200 mg/kg, Sample N 2; polyherbal n-hexane extract 400 mg/kg, Sample N 3; polyherbal n-hexane extract 800 mg/kg

Acknowledgments

The authors are thankful to the Dean of Faculty of Pharmacy, Baha Uddin Zakariya University Multan, for providing necessary facilities to carry out this research work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethical approval and consent to participate

According to national research council guidelines, all procedures and techniques of this study were performed. Laboratory animals were approved by the bio-ethical committee of Baha Uddin Zakariya University Multan vide letter No BZ-237-PH-10/1 were also used in their accordance.