Chemotypic diversity and neuroactive potential of Valeriana jatamansi Jones: a systematic review on phytochemistry, pharmacology and standardisation challenges

Valeriana jatamansi (Indian valerian), a vital but endangered Himalayan plant, exhibits extreme chemical heterogeneity that undermines its clinical reliability and current pharmacopoeial standards. This systematic review (1979–May 2026; 312 studies) delineates five distinct chemotypes (OPLS-DA > 92%) defined by compositional extremes of patchouli alcohol (0.4–63.7%), maaliol (2.9–53.8%), valepotriates (1.8–2.4% Dry Weight), bornyl esters (10–20%) or sesquiterpenes (50–80%), driving 15–35% batch bioactivity variability. Mechanistically, valepotriates positively modulate GABA_A receptors (EC50 3–10 μM), while 6-methylapigenin targets the benzodiazepine site (IC50 0.3 μM). A meta-analysis of 12 Randomized Controlled Trials (RCTs) (n > 1500) confirms clinically meaningful improvements in insomnia (PSQI Δ3.8 ± 1.2 > MCID) and anxiety (SMD = −0.72). Crucially, this chemical diversity is therapeutically exploitable. We propose a chemotype-directed multi-marker bioactivity index combined with DNA barcoding to reduce batch variability below 10%, addressing IUCN ‘Vulnerable’ status (40–70% population decline) and transforming a conservation crisis into a foundation for evidence-based, sustainable phytomedicine.