Purpose: King of bitters, Andrographis paniculata (Burm.f.) Wall. ex Nees, is a herb native to Southeast Asian countries especially India and China, and has been used in traditional and modern medicine. It has been found to possess antimicrobial, antihyperglycemic, cardiovascular, anticancer, hepatoprotective, anti-inflammatory amongst other remarkable pharmacological activities. The major bioactive chemical compound – Andrographolide; abundant in the leaves and stems of the plant is responsible for these pharmacological activities. The genus Andrographis has about 28 species most of which possess no medicinal value. This study is aimed at identifying A. paniculata using DNA barcodes and improving the yield of andrographolide via enzymatic treatment.
Methods: The DNA of Andrographis paniculata leaves was obtained using the Qiagen kit, the psbA-trnH and rbcL DNA barcode regions were amplified using RT-PCR. Presence of amplified regions was confirmed using gel electrophoresis and the amplicons were sequenced. A blast N search was performed on the sequenced DNA. The constituents of A. paniculata dried leaves was extracted using methanol; followed by treatment with or without β glucosidase. The concentrated extract obtained was dried and partitioned using ethyl acetate. The ethyl acetate fraction was concentrated, and the residue dissolved in methanol. Andrographolide content was then determined using High Performance Liquid Chromatography (HPLC).
Results: The psbA-trnH and rbcL DNA regions were successfully amplified having 358 and 604 bp respectively. Blast N search on both DNA barcode sequences obtained gives accession numbers JQ922119.1 and JQ922118.1 that corresponds with the psbA-trnH and rbcL genes of A. paniculata voucher MICET P00101 respectively. The mean andrographolide yield was 9.4±0.11mg/g and 8.9±0.13mg/g dry weight for the treatment and control groups respectively; statistical analysis shows a significant difference.
Conclusion: The Andrographis paniculata plant provided was successfully identified and enzymatic treatment improved andrographolide yield from the plant.