Effect of flavonoid-rich fraction of Pleiocarpa mutica leaves on phospholipase A2 activity

Pleiocarpa mutica (Apocynaceae) is a pharmaceutical plant investigated to identify the usefulness and efficacy of the shrubs in the treatment of various ailments. Also, flavonoids are polypenolic compounds frequently found in nature and are divided into flavones, anthocyanidins, isoflavones, catechins, flavonols, chalcones, and flavonones based on the structure of their chemicals. Hence, fresh leaves of Pleiocarpa mutica were collected from Ugbene-Ajima, Uzo-Uwani Local Government Area, Enugu State, Nigeria. The extraction of a flavonoid-rich fraction of P. mutica leaves was conducted by dissolving a certain amount of crude extract in 20 mL of 10% H₂SO₄ in a tiny flask and then heating the mixture in a water bath for 30 minutes at 100 °C to initiate hydrolysis. However, quantitative phytochemical analysis of the P. mutica flavonoid-rich fraction was carried out by utilizing standard conventional protocols. Newly drawn human blood samples were centrifuged for 10 minutes at 3,000 rpm, with the supernatant (plasma) being disposed of. After being measured and reconstituted as a 40% (v/v) suspension with phosphate-buffered saline, the red blood cells were rinsed three times with an equivalent volume of normal saline. The fraction substantially (p < 0.05) reduced the activity of phospholipase A₂ in a concentration-dependent approach when compared to the standard drug (prednisolone), with a range of 0.2 mL to 1.0 mL reducing the amount of the enzyme by 47.58% to 63.61%. These results showed that the flavonoid-rich fraction of Pleiocarpa mutica leaves is potent in curtailing the inflammatory response through inhibition of phospholipase A₂ activity.