Evaluation of the Procurement Time of Kalmegh [Andrographis paniculata (Burm.f.) Nees], through HPLC, Macro- and Microscopic Studies

Abstract

Aim: This study was conducted to validate the most suitable collection time for Kalmegh [Andrographis paniculata (Burm.f.) Nees] by comparing the high-performance liquid chromatography (HPLC) estimation of andrographolide in different seasons and pharmacognostical study of aerial parts of the plant. In Ayurvedic texts, procurement time of A. paniculata has not been mentioned; hence, this study was performed to validate the most suitable time of collection of the plant. Materials and methods: The aerial part of Kalmegh [Andrographis paniculata (Burm.f.) Nees] was collected from the Regional Ayurveda Research Institute (RARI) garden from the same locations in the different seasons described in Ayurveda, i.e., Shishir or winter season (Jan to Feb), Vasant or spring season (Mar to Apr), Grishm or summer season (May to June), Varsha or rainy season (Jul to Aug), Sharad or autumn season (Sept to Oct), and Hemant or early winter season (Nov to Dec). The source of the collected plant materials was authenticated at National Vrkshayurveda Research Institute (NVARI), Jhansi Herbarium acronym code “JHS” (Accession no. 23598). Identification, comparative macroscopic and microscopic along with powder microscopy, of the aerial parts of A. panniculata in each season was carried out, in addition to the extraction of different solvents such as methanol, alcohol, and hydroalcoholic through Soxhlet, and its comparative quantitative analysis of the extracted material in all six seasons through HPLC for the different seasons at Captain Srinivas Murthy Regional Ayurveda Drug Development Institute, Chennai. Results: Extractive value of Andrographis paniculata (Burm.f.) Nees was found to be maximum, i.e., 1.3787 g (27.57%) of Varsha Ritu sample in methanol extract. The marker compound, andrographolide is high, i.e., 2.0312 to 2.2093 (% w/w) in Varsha ritu, through the HPLC analysis. The drug shows floral parts, i.e., pollen grains, epidermis of petals, fragments of trichome from the anthers in powder microscopy in Shishir, Sharad, and Hemant Ritu samples, whereas in Vasant, Grishm, and Varsha Ritu are devoid of floral parts. Conclusion: The study finds that the best procurement season for A. paniculata Nees. is Varsha Ritu for better therapeutic results in terms of assay of andrographolide.