Anti-inflammatory and phytochemical evaluation of Combretum aculeatum Vent growing in Sudan

Abstract

Ethnopharmacological relevance: Combretum aculeatum Vent was traditionally used in Sudan, Eretria and Ethiopia as anti-inflammatory in case of skin inflammation, catarrh, wounds, scorpion stings and snake bites. Nevertheless, there is no scientific information regarding this activity.

Aim of study: The present study aimed to evaluate the phytochemical constituents and the scientific basis for the traditional use of Combretum aculeatum Vent through studying its anti-inflammatory properties for the first time to illustrate the putative mechanisms behind this bioactivity.

Materials and methods: the ethanolic extract was partitioned by petroleum ether, methylene chloride, ethyl acetate, and n-butanol saturated with water. The petroleum ether fraction was saponified and the saponifiable and unsaponifiable fractions were analyzed on GC/MS. The different fractions were subjected to phytochemical investigation to isolate pure compounds. In-vivo anti-inflammatory activity of the ethanolic extract was evaluated using carrageenan induced rat paws edema method at doses of 200, 400 and 600 mg/kg and proved based on histopathological and biochemical parameters.

Results: Five known compounds were isolated for the first time from the aerial parts of Combretum aculeatum Vent: quercetin, vitexin, isorhamnetin 3-O-β-glucoside, isovitexin and rutin, in addition to two previously isolated ones: β-sitosterol and its glucoside. The ethanolic extract evidenced in-vivo anti-inflammatory activity by oral intake of 400 mg/kg of the ethanolic extract significantly (P ≥ 0.05) decreased the paw edema (only 32±1.9% increase in paw weight after 4 h) compared to indomethacin (28.6±2.5%). Moreover, it significantly suppressed the serum malondialdehyde (MDA) and nitric oxide (NO) and increased the GSH to be 11.76±0.85, 5.13±0.62 μmol/mL and 5.66±0.28 μM/mL, respectively. It diminished the serum cytokines TNF-α, IL-6 and IL-1β levels to be 39.1±1.2, 32.6±1.1 and 37.5±1.2 pg/mL, respectively. Results are accompanied by histopathological examination.

Conclusion: Overall, the results herein presented significant anti-inflammatory properties traditionally ascribed to Combretum aculeatum Vent. Moreover, the biochemical mechanisms associated to this action were highlighted, introducing new prospects for the development of effective anti-inflammatory herbal medicinal products.

Keywords: Anti-inflammatory; Combretaceae; Combretum aculeatum; Phytochemical.