The experiment was conducted to know the effect of aging on Andrographolide content in Kalmegh to establish the best harvesting time. The trial was conducted at the agronomy farm of Natural Remedies Pvt. Ltd. at Bangalore.

Normally the leaves contain 2.5-3% w/w of andrographolide. But there are many factores, which influence phytochemical profile of a plant drug. The age of plant at the time of collection is one such factor.

In this trial, the seeds were soaked in water overnight. The nursery bed was prepared before sowing and care was taken to avoid deep sowing. Nursery was maintained under uniform shade for better growth of seedling. After 6 weeks of sowing, they are transplanted at spacing of 15x15cm and land is supplied with 75Kgeach of Nitrogen, Phosphorus and 50 Kg potassium per hectare and other cultural operations were carried out.

The plant samples were collected at the age of 30,60,90,120,150 days respectively after sowing. They were dried at 60ºC in hot air oven and grounded to fine powder. Crude drug was extracted and evaporated to dryness. Then it was dissolved to a known volume and analyzed by High Power Liquid Chromatography (HPLC). The result obtained were the increasing trend in plant height, number of branches, fresh weight and dry weight at all stages. The number of leaves at 90,120 & 150 days were significantly high as compared to 30 days. There was a reduction in number of leaves per plant at 150 days as compared to 120 days due to fall of aged leaves.

The andrographolide content in leaves was maximum at 90 days and minimum at 150 days may be attributed to increase in stem portion and loss of leaves due to aging. Even though there was a higher andrographolide content at 90 days after sowing, the dry matter content was very less as compared to the plants at age of 120 days. Hence, harvesting at 120 days could be beneficial.