Antioxidant and anti-inflammatory (in-vitro) properties of extract and fractions of Syzygium guineense leaves

The medicinal plant Syzygium guineense is an ethno-medicinal African plant commonly used for treating inflammatory and oxidative stress-related conditions. It is rich in phytochemicals such as flavonoids, tannins, and saponins, which are known for their therapeutic properties. The leaves of S. guineense are particularly noted for their antioxidant and anti-inflammatory effects. This study aimed to evaluate the in vitro antioxidant and anti-inflammatory activities of crude extract and various solvent fractions of S. guineense leaves. The leaves were extracted with ethanol and subsequently fractionated using solvents of varying polarity, including n-hexane, chloroform, ethyl acetate, n-butanol, and water. Antioxidant activity was assessed using DPPH radical scavenging and ferric-reducing antioxidant power (FRAP) assays. Anti-inflammatory activity was determined through inhibition of protein denaturation using the egg albumin denaturation method. The n-hexane fraction exhibited the highest antioxidant activity in both DPPH (100%) and FRAP (85.6%) assays, closely comparable to ascorbic acid. Anti-inflammatory assays showed that at 5 mg/ml concentration, the n-hexane and crude fractions had the highest inhibition of protein denaturation (90±0.13and 89±0.19 respectively). These findings demonstrate a strong correlation between the phytochemical constituents of S. guineense and its biological activities. The extract and fractions of S. guineense leaves possess significant antioxidant and anti-inflammatory properties, suggesting their potential as natural therapeutic agents. Further studies are recommended to isolate and characterize the bioactive compounds responsible for these effects.