ฤทธิ์ทางชีวภาพและองค์ประกอบพฤกษเคมีของพญายอจากภูมิภาคต่างๆ ของประเทศไทย

Abstract

Phaya yo (Clinacanthus nutans), a medicinal plant belonging to the Acanthaceae family, has been grown in different parts of Thailand. This plant contains several phytochemicals which are defined as bioactive compounds. However, there is no report regarding the comparison of the phytochemical profile and bioactivities of C. nutans extract from different regions in Thailand up to date. In this present study, C.nutans extracts collected from totally 10 different parts of Thailand were determined for its genetic diversity and compared for the phytochemical components and their biological activities. The genetic diversity of fresh C. nutans leaves collected from the Northern, Central, and Northeastern regions of Thailand was investigated by sequence-related amplified polymorphism (SRAP) technique. The DNA fingerprint demonstrated that all 10 C. nutans samples had closely similarity with an average of 0.95 which could be divided into two major groups by the unweighted pair group method with arithmetic mean (UPGMA) analysis. The phytochemical analysis by using high-performance liquid chromatography (HPLC) was performed and used the representative phenolic compounds; the gallic acid and quercetin as the standards. The results indicated that all extracts had only low amounts of gallic acid and quercetin but varied among the extracts. The biological activity of C.nutans extracts was determined for the protective effect against lipopolysaccharide (LPS) induced cell death by cell viability assay, the antioxidant capacity by DPPH radical scavenging and the antibacterial activity by determining the broth dilution assay The results showed that all C. nutans extracts at highest test concentration (500 ug/ml) had no cytotoxicity and effectively inhibited LPS-induced cell death in bovine endothelial cells. All extract conferred the antioxidant activities against free radical scavenging DPPH with the ICso values ranging from 2.559 + 0.378 to 9.219 + 0.210. Moreover, all extracts could inhibit bacterial growth but the activities were varied among different bacteria species with MIC and MBC values of 31.25 and 250 mg/ml respectively. The findings of this study indicated that C. nutans from different regions of Thailand were closely related in genetic aspect concordant to the phytochemical profiles with similar patterns. However, the varied phytochemical quantity among these extracts was a major factor affecting their biological activities.