Morphological Analysis and Comparison of Asiaticoside Content in <i>Centella asiatica</i> Grown in Different Regions of Malaysia

Background: Centella asiatica L. Urban is a medicinal plant that contains Secondary Metabolites (SMs) such as terpenoids that not only function in environment adaptation but importantly give potential wide medicinal value specifically asiaticoside such as brain tonic and anti-inflammatory. This very reason causes a rise in market demand which may lead to plant overexploitation considering that the plant grows very slowly in natural settings and only produces a small amount of SM. Previous studies have reported a few factors including soil composition, lighting and temperature that may affect the growth of the plant and its SM production. Aim: This study aimed to compare the asiaticoside accumulated in C. asiatica grown in different regions and the factors that may affect its accumulation. Methods: In this study, the High-Performance Liquid Chromatography (HPLC) method was used to identify and compare the asiaticoside content in C. asiatica from Sungai Buloh, Bukit Cerakah and Sungkai and the concentration was then calculated by utilisation of calibration curve. Field Emission Scanning Electron Microscopy (FESEM) was used to analyse the plant cell morphology and pH measurements of soil were conducted. Results: The crude extract obtained from pegaga of Sg. Buloh with clayey and acidic soil exhibited the highest asiaticoside content followed by Bukit Cerakah and Sungkai. Other factors such as the optimal light intensity, photoperiod, temperature, soil fertility and soil water status were also key factors that significantly enhanced the asiaticoside production. Conclusion: This study demonstrates that distinct growing conditions particularly the type and acidity of soil play a vital role in the production of SM. However, further studies are necessary to explore the soil nutrients and the simultaneous effects of multiple environmental factors on the biosynthesis of SM to ensure favourable plant cultivation and maximise SM production.