Benefits
Gut bacteria composition in healthy adults
In a 4-week placebo-controlled pilot, healthy adults took 2,000 mg a day of manjistha tablets (9 analyzed in that group). Responses varied widely and no bacterial group changed in everyone; the herb groups trended toward a lower Firmicutes to Bacteroidetes ratio and more Akkermansia muciniphila. No digestive or other health outcome was shown.
Inflammation signaling in cell studies (mollugin)
Mollugin, a compound from the root, blocked TNF-alpha-triggered NF-kB activation in human colon cells and HeLa cells and lowered inflammatory messengers such as IL-8 and MCP-1 in colon cells. These are lab findings at set concentrations; whether oral manjistha reaches such levels in the body is unknown.
Skin-cell responses in lab and mouse studies
In cell studies, manjistha suppressed reactive oxygen species released by immune cells exposed to acne bacteria (Propionibacterium acnes). A root fraction slowed the growth of cultured skin cells (keratinocytes) and, applied as a gel to mouse tail skin, changed skin-layer structure. Neither tested oral manjistha in people.
Intestinal lining in a rat injury model
In rats given the painkiller indomethacin to injure the intestine, an oral root extract (300 or 600 mg/kg a day for 11 days, 6 rats per group) was followed by less visible tissue damage and blood LDH closer to normal than in untreated injured rats. There was no comparison drug, and this has not been tested in people.
IgE antibody production in mouse and cell studies
In peanut-sensitized mice, a water extract of the root given by mouth for 5 weeks lowered peanut-specific IgE by about 80% versus sham treatment, with lower reaction scores and histamine on challenge. It also cut IgE output by human B cells in culture. The authors said controlled clinical studies are needed before use in people.
Mechanism of action
Red anthraquinone pigments
The root's color comes from anthraquinones such as purpurin, alizarin and rubiadin. In cell and animal studies purpurin shows antioxidant, anti-inflammatory and antimutagenic activity, while rubiadin and alizarin from madder color made from the related plant Rubia tinctorum caused kidney tumors in rats, so this compound class raises safety questions as well as lab activity.
Mollugin and the NF-kB pathway
Mollugin, a naphthoquinone from the root, inhibited activation of NF-kB, a master switch for inflammatory genes, in cell lines by blocking IKK and IkB-alpha phosphorylation and p65 movement into the nucleus. This has been shown only in cells and in mice carrying human tumor cells.
Many compounds, little absorption data
Reviews list more than 100 compounds, mainly quinones and bicyclic hexapeptides, with reported antioxidant, anti-inflammatory and anti-platelet activity in preclinical work. Few pharmacokinetic studies exist, so how much of any compound reaches the body after an oral dose of the root is unknown.
Clinical trials
Double-blind, randomized, placebo-controlled pilot of 2,000 mg/day manjistha tablets, triphala tablets or placebo for 4 weeks, run by a university dermatology department; the registry entry (NCT03477825) also listed skin sebum output as a primary outcome. (Peterson et al. 2020, J Altern Complement Med)
31 healthy adults randomized to three arms; 29 completed and were analyzed (manjistha 9, triphala 9, placebo 11). The registry lists ages 18 to 60.
Gut bacteria responses were highly individual and no taxon changed uniformly. Both herb groups showed a trend toward a lower Firmicutes to Bacteroidetes ratio and higher Akkermansia muciniphila, and both reduced Rikenellaceae, mainly Alistipes. The abstract reports no significance values, no skin or digestion-questionnaire results and no adverse event data, and the health meaning of these shifts is unknown.
Animal study of an oral 70% ethanol root extract given once daily for 11 days, with indomethacin injected on days 8 and 9 to injure the intestine. (Pawar et al. 2011, Indian J Pharm Sci)
24 male Wistar rats in 4 groups of 6: normal, indomethacin only, and extract at 300 or 600 mg/kg plus indomethacin.
Extract-treated rats had less intestinal damage on macroscopic scoring, less inflammation on histology, and serum LDH closer to normal than indomethacin-only rats (significance threshold P<0.05). There was no comparison drug, the extract's constituents were not measured, and no human data exist.
Mouse and cell study of a water extract of Rubia cordifolia root given intragastrically at 2 or 4 mg twice daily for 5 weeks, plus tests in a human IgE-producing B-cell line. (López-Expósito et al. 2011, Chin Med)
Female mice sensitized to peanut, 5 to 8 per group; U266B1 human B cells in culture.
At 4 mg, peanut-specific IgE was 80.5% lower than in sham-treated mice (P = 0.027), the median anaphylaxis score was 0 versus 2 (P < 0.001), and plasma histamine was lower. In culture the extract inhibited IgE production (IC50 3.06 micrograms/mL) without reducing cell viability. The authors state that controlled clinical studies are required.
Medium-term multi-organ bioassay in which rats pretreated with five carcinogens were fed rubiadin or alizarin, components of madder color from the related species Rubia tinctorum, at 0.008% or 0.04% of the diet for 23 weeks. (Inoue et al. 2009, Cancer Sci)
Male F344 rats, 6 weeks old at the start.
Rubiadin at 0.04% increased atypical kidney tubules and induced kidney cell adenomas and carcinomas, and raised precancerous changes in the liver and large intestine; alizarin also increased kidney tumors, at a lower rate. The authors concluded that rubiadin likely plays a major role in madder color's carcinogenicity. Rubiadin also occurs in Rubia cordifolia; relevance to people is unknown.