Phytochemical Screening, Antioxidant, and Antibacterial Activities from Leaf and Stem Extracts of Strobilanthes crispus (L.) Collected in Sarawak and Melaka

Abstract

Strobilanthes crispus (L.), commonly known as Pokok Pecah Beling, is a medicinal plant from Southeast Asia used for treating illnesses like diabetes, cancer, and hypertension. However, scientific research on this species for an early stage of drug discovery is still considered limited. This study aimed to screen the phytochemicals and determine the antioxidant and antibacterial activities of its leaf and stem extracts from two Malaysia locations: Sarawak and Melaka. The leaf and stem extracts were prepared using hexane, ethyl acetate, and methanol using maceration techniques. The antioxidant activity is analysed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, while antibacterial activity is tested using the disc diffusion method.  Results showed that methanol extracts from both regions contained alkaloids, flavonoids, tannins, terpenoids, and phenols, with Sarawak’s methanol stem extract demonstrating the highest antioxidant activity (94.14% scavenging activity, IC₅₀ = 115.13 ppm). These findings highlight S. crispus (L.) as a promising antioxidant source, especially in methanol extracts from Sarawak. Regarding antibacterial activity, the S. crispus (L.) extracts show no activity against selected bacteria, as no zone of inhibition was observed. Therefore, extract samples in this work only showed antioxidant potential. Further research is recommended to investigate the molecular mechanisms of its antioxidant activity and explore its potential therapeutic applications.