Study on biological activities of herbs’ decoction combining Scutellaria barbata, Hedyotis diffusa and Ehretia asperula

Background: Cancer is a leading cause of death worldwide. Nowadays, cancer is often treated with different methods, such as surgery, radiation therapy, and chemotherapy. However, these methods have lots of side effects for patients, so natural products are often combined with them to diminish those side effects. According to oriental medicine, there are many folk remedies to support cancer treatment. Each different type of cancer has corresponding remedies. In particular, to support the liver cancer treatment, some medicinal herbs were used, such as Scutellaria barbata, Hedyotis diffusa, Ehretia asperula. The aim of the study: Determining the biological activities of herbal decoctions combining Scutellaria barbata, Hedyotis diffusa, and Ehretia asperula, which were tested on two different weight ratio recipes (denoted R1 and R2). Materials and methods: Mixing Scutellaria barbata, Hedyotis diffusa, and Ehretia asperula into dry mixtures and then collecting the decoction. Testing antioxidant activity by the reducing power assay and the DPPH free radical scavenging assay. Evaluating antibacterial activity by the agar well diffusion assay and cytotoxic ability by the sulforhodamine B assay. Results: R1 decoction, which had a higher ratio of E. asperula, showed greater antioxidant, antibacterial, and cytotoxic capacity than R2 decoction. In the reducing power assay, R1 decoction's optical density value was 2.80, while the other was 2.23 at 0.7% concentration. In the DPPH free radical scavenging assay, the EC50 values of R1 and R2 decoctions were 0.022% and 0.035%, respectively. Both R1 and R2 decoctions had antimicrobial activities against Bacillus subtilis at 100% concentration, as shown by the diameters of inhibition growth zones of 11.33 mm and 7.40 mm, respectively. In the Sulforhodamine B assay, R1 decoction's IC50 was 0.47%, and R2 decoction's IC50 was 0.66%. Conclusion: In the same condition, R1 decoction had better tested biological activities than R2 decoction.