Pharmacognostic Characterization of Rarely Used Herbs Described in Nighantus with Comparative Microscopy of Haritaki (Terminalia chebula) from Distinct Geographical Origins -A Comprehensive Review
Abstract
Background:
Nighantus represent the advanced evolution of Ayurvedic Materia Medica, expanding beyond
Bruhatrayi with elaborate descriptions of dravya rasa–guna–veerya–vipaka–prabhava and
morphological identifiers. Several drugs recorded in Dhanvantari, Raja, Kaiyadeva, Madanpala,
and Bhavaprakasha Nighantu remain underutilized today despite historically documented
therapeutic potency (1)(2). Scientific pharmacognostic profiling enables revitalization of such rare
herbs through botanical authentication, quality assurance, and standardization.
Aim & Objectives:
1. To critically compile and analyse pharmacognostic traits of lesser-used Nighantu herbs.
2. To perform a comparative pharmacognostic evaluation of Haritaki fruits collected from
the Western Ghats, Himalayas, & Eastern India.
3. To correlate classical morphological descriptors with modern anatomical microscopy and
powder analysis.
Materials & Methods:
An Ayurvedic review was conducted using Nighantu databases, Bruhatrayi, Nighantu
commentaries, and modern pharmacognostic indexes. Microscopy of authenticated Haritaki
samples included TS, maceration, powder microscopy under normal & polarized light, and
histochemical staining using safranin–fast green dual mode (3)(4). Comparisons were made
based on stone cell clusters, vessel structure, epidermal cuticle, tannin localization, and rosette
crystals (5)(6).
Key Review Findings:
Parpat, Ajagandha, Surasa, Shyonaka, and Svadupami/Swaduparni demonstrate specific
micro-characters such as prismatic crystals, glandular trichomes, unicellular hairs, parenchymal
mucilage and porous pith that enable unambiguous authentication.
Haritaki samples varied significantly: Western Ghats fruits contained abundant stone cells and
tannin masses; Himalayan fruits showed thin pericarp and sparse trichomes; Eastern region
fruits had dense sclereids and high rosette crystal population (7)(8)(9).
These differences validate the Ayurvedic doctrine Desha-Bheda (regional variations) and
influence potency, stability, and formulation value.
Conclusion:
Pharmacognostic standardization bridges ancient textual ethnobotany with modern scientific
validation. Rare Nighantu herbs warrant reintegration into clinical practice after histological
authentication. Haritaki demonstrates strong geoclimatic phytovariation, necessitating sourcespecific monograph development for future pharmacopeial inclusion.
Keywords
Nighantu dravyas, Pharmacognosy, Haritaki microscopy, rare herbs, tannin content, Terminalia chebula, stone cells, histochemical analysis