Evaluation of the Organ Microscopy, Chemical Composition and Anti-inflammatory Potentials of Methanolic Leaf Extract and Fractions of Diaphananthe bidens

Aim: The study aims to investigate high-pressure liquid chromatographic (HPLC)-based chemical composition and anti-inflammatory activity of methanolic leaf extract and fractions of D. bidens.

Study Design: The study is a laboratory-based research involving collection, identification and preparation, of plants, extraction, characterization and evaluation of the anti-inflammatory potential of D. bidens.

Place and Duration of Study: Department of Pharmacognosy and Traditional Medicine, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Nigeria between January 2016 and June 2019.

Methodology: Powdered leaves of D. bidens was macerated in methanol and the obtained crude extract was fractionated using n-hexane, ethylacetate, butanol, and water respectively. The acute toxicity profile of the extract was determined. Spectroscopic factors of the plant were assayed using HPLC-DAD and the anti-inflammatory activity of the extract and its fractions were evaluated.

Results: Acute toxicity study showed that the crude extract has an LD50 > 5,000 mg/kg. HPLC-DAD analysis revealed the presence of compounds including apigenin monoglycoside, quercetin 3-O-(6''O-acetyl) galactopyranoside, kaempferol 3-O-(6" O-malonyl) glucoside, genistein 8-C-glucoside, while anti-inflammatory study showed that the extract and fractions inhibited cellular activities of inflammatory mediators (86 – 97 %) in comparison with the diclofenac (53 %); thus, supporting its ethnomedicinal use in the treatment of inflammation.

Conclusions: Methanolic extract of D. bidens has wide margin of safety. It has sufficient deposit of flavonoids which might be responsible for its strong anti-inflammatory activity that is comparable with diclofenac.