Benefits
Intensely bitter taste from amarogentin
Amarogentin, the main bitter compound of this plant, is described as the most bitter compound isolated to date. In cell-based assays it switched on the human bitter taste receptor TAS2R50, the same receptor that andrographolide from andrographis activates. Whether swertia changes digestion in people has not been tested in the studies cited here.
Blood sugar handling in rat studies
In rats, the xanthone swerchirin given by mouth lowered blood sugar, with about 23 mg/kg needed for a 40% fall, and a swerchirin-rich fraction at 50 mg/kg cut it by about 60% within 7 hours while emptying insulin stores from the pancreas. An ethanol extract also lowered glucose in alloxan-treated rats. None of this has been tested in people.
Liver cell protection in rodent toxin models
In mice given a high paracetamol dose, a swertia extract at 100 to 200 mg/kg by mouth kept liver enzymes and antioxidant markers closer to normal. A methanol extract protected rat livers from carbon tetrachloride, and purified amarogentin at 100 mg/kg eased chemically induced liver scarring in mice. These are animal toxin models only.
Stomach lining in rat models
In rats, an ethanol extract of Swertia chirata reduced stomach lining damage from indomethacin and other irritants, lowered stomach secretion, and helped preserve the protective mucus layer and sulfhydryl content of the stomach wall. It also relaxed guinea pig gut tissue in a dish. No human stomach studies are cited here.
Mechanism of action
Bitter taste receptor activation
Amarogentin activates the human bitter receptor TAS2R50 in cell assays. Bitter receptors sit on the tongue and in the gut, which is the usual rationale for digestive bitters, but this was shown in engineered cells, not in people taking swertia.
Insulin release from pancreatic islets
A swerchirin-containing fraction increased glucose-stimulated insulin release from isolated rat islets and depleted insulin granules in treated rats, and serum from treated rats raised glucose uptake by muscle tissue. These are rat and tissue findings.
Fast clearance and low oral absorption of key compounds
In rabbits given intravenous doses, amarogentin was cleared quickly while mangiferin lingered longer, and giving them inside the whole extract did not change this. A review of swertiamarin reports rapid absorption but low oral bioavailability because of first-pass metabolism, so blood levels after oral use in people are unknown.
Clinical trials
Randomized, open-label, assessor-blinded, multicenter trial of AYUSH 64, a 500 mg tablet of aqueous extracts (100 mg each) of Alstonia scholaris bark, Picrorhiza kurroa rhizome and Swertia chirata whole plant, plus 200 mg of Caesalpinia crista seed powder, sponsored by its developer, the Indian government's CCRAS. (Chopra et al. 2023, PLoS One)
140 hospitalized adults in India with mild to moderate COVID-19, randomized to standard care alone or standard care plus AYUSH 64 (2 tablets twice daily for 12 weeks).
In the per-protocol analysis (134 people), mean time to clinical recovery was 6.45 days with AYUSH 64 versus 8.26 days with standard care alone (P = 0.003). Mild, mostly digestive adverse events occurred in both groups. The design was open label with no placebo, and the trial tested the whole formula, so it shows nothing about swertia on its own.
Animal study of swerchirin, a xanthone isolated from the hexane fraction of Swertia chirayita, given by mouth to rats. (Bajpai et al. 1991, Planta Med)
Male albino rats under fasted, fed, glucose-loaded and tolbutamide-pretreated conditions. No humans.
Swerchirin lowered blood sugar under all conditions tested; the dose giving a 40% fall (ED50) was 23.1 mg/kg. The authors said possible use in people needed further study.
Animal and tissue study of a crude swerchirin-containing hexane fraction of Swertia chirayita. (Saxena et al. 1993, Indian J Exp Biol)
Fed rats given a single oral dose of 50 mg/kg, plus isolated rat islets and rat muscle tissue. No humans.
Blood glucose fell by about 60% at 7 hours, with marked loss of insulin granules from the pancreas. The fraction increased glucose-stimulated insulin release from isolated islets, and serum from treated rats raised muscle glucose uptake. The authors concluded it acts by releasing insulin.
Comparative animal screening of 95% ethanol extracts of 30 traditional plants, including Swertia chirayita, at 250 mg/kg one to three times daily. (Kar et al. 2003, J Ethnopharmacol)
Alloxan-treated albino rats with raised blood sugar. No humans.
All tested extracts lowered blood glucose within 2 weeks. Swertia chirayita ranked ninth of the 24 ranked samples for glucose lowering. The abstract gives no glucose values for individual plants.
Animal study testing extracts of Andrographis paniculata and Swertia chirayita, each given by mouth, against acute paracetamol liver injury. (Nagalekshmi et al. 2011, Food Chem Toxicol)
Swiss albino mice given paracetamol 150 mg/kg, then extract at 100 to 200 mg/kg. No humans.
Paracetamol raised liver enzymes and bilirubin, damaged liver tissue and lowered antioxidant enzymes. Both extracts brought these markers back toward control values in a dose-dependent way. The two herbs were tested separately, so this does not show a combined effect.
Animal metabolomics study of purified amarogentin given by mouth to mice with carbon tetrachloride induced liver fibrosis. (Zhang et al. 2018, J Pharm Biomed Anal)
C57BL/6 mice in control, model and amarogentin (100 mg/kg) groups. No humans.
Liver tissue and blood markers in the amarogentin group were much closer to controls than in the untreated model group, and nine serum metabolites linked to amino acid and fatty acid metabolism separated the groups. The abstract gives no numeric marker values.
Animal study of an ethanol extract of Swertia chirata in rat models of chemically induced stomach injury. (Rafatullah et al. 1993, Drugs Exp Clin Res)
Rats given indomethacin or other irritants, pylorus-ligated rats, and isolated guinea pig ileum. No humans.
The extract reduced stomach lining damage, lowered gastric secretion, prevented ethanol-induced loss of stomach wall mucus and restored sulfhydryl content, and reduced acetylcholine-driven gut contraction. The abstract gives no doses or group sizes.