Anti-inflammatory, analgesic, antioxidant, and alpha-amylase inhibitory effects of the hydroethanolic leaf extract of Aleuritopteris bicolor (Roxb.) Fraser-Jenk

Abstract

Aleuritopteris bicolor (Roxb.) Fraser-Jenk. is used in traditional medicine in Nepal to treat a variety of ailments. This study aimed to investigate qualitative phytochemical screening, quantitative phytochemical analysis (total phenolic and flavonoid content estimation), in vitro antioxidant activity, alpha-amylase inhibitory activity of Aleuritopteris bicolor (Roxb.) Fraser-Jenk. leaves from Nepal. Furthermore, this study examined the analgesic (tail flick and hot plate test method) and anti-inflammatory (carrageenan-induced paw edema) activities of Aleuritopteris bicolor leaves in an acute pain and inflammation rat model. The Aleuritopteris bicolor extract exhibited flavonoid (405.95 ± 0.28 mg QE/g) and phenolic content (20.98 ± 0.20 mg GAE/g). Aleuritopteris bicolor showed free radical scavenging activity with IC50 value in difference antioxidant methods (IC50:9.87 µg/mL, DPPH scavenging assay; 249.59 µg/mL, Hydrogen peroxide; 72.98 µg/mL, Nitric oxide assay), and significant Ferric reducing power assay (0.51 ± 0.004). It increased analgesic activity by 38.89% (hot plate test) and 16.84% (tail-flick test) at 250 mg/kg, reduced inflammation by 36.44% at 180 min (500 mg/kg), and inhibited alpha-amylase activity (IC50:59.31 µg/mL). Aleuritopteris bicolor exhibits significant analgesic, anti-inflammatory, and hypoglycemic potential, making it a promising candidate for further pharmacological exploration. This study marks the first scientific study of the in vivo analgesic and anti-inflammatory effects from the leaf extract of Aleuritopteris bicolor till date.

Fig 1. Schematic representation of the details experimental protocol of A. bicolor leaves.

Fig 2. TLC profiling of the A. bicolor leaves extract.

I; TLC spot of A. bicolor extract observation under short UV 254 nm, II; long UV 365 nm, III; TLC spot sprayed with 10% H₂SO₄/Heat, (IV) 10% FeCl₃, (V) DPPH.

Fig 3. Analgesic activity of A. bicolor extract.

(A) Hot plate method. (B) Tail flick test. Pain reaction time (paw licking) expressed as mean ± standard error of mean, n = 6 rats per group, Data differed statistically significantly at ^*p < 0.05, ^#p < 0.001 when compared with the control group.

Fig 4. Anti-inflammatory activity of A. bicolor extract by implementing the carrageenan- induced paw edema model.

(A) Inflammatory index (edema volume in ml) and (B) Percentage inhibition of paw edema (%). Value expressed as mean ± standard error of mean, n = 6 rats per group. Data differed statistically significantly at *p < 0.05, ^#p < 0.001 when compared with the control group.