Ma Chi Xian (Purslane or Portulaca)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Ma Chi Xian?

  15–60 g of the dried herb in decoction, and the dose can be doubled where the fresh juice is used — the range recorded here. That is a wide range even by materia medica standards, and it reflects what purslane is: a bulky, watery aerial herb that is also a food, so the material is far less concentrated than a root or a bark and the quantities are correspondingly larger.

  • 15–60 g dried in decoction. The part used is the aerial plant — our record gives the pharmaceutical Latin as Herba Portulacae Oleraceae.
  • Fresh juice — the dosage can be doubled when the fresh pressed juice is used rather than the dried herb.
  • External use — applied topically as a poultice or wash for damp-heat sores and lesions; the fresh mashed herb is the traditional form.
  • As a food — purslane is eaten raw in salads and cooked as a vegetable in many cuisines, and culinary quantities are not measured as doses. Note that cooking method affects oxalate content (see the safety questions below).

  Source: Sacred Lotus sources & references (recorded dosage, including the fresh-juice note and the pharmaceutical Latin); preparation conventions per materia medica consensus, cross-referenced against multiple online sources. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Ma Chi Xian (purslane)?

  Two recorded traditional cautions, and one modern one that matters more for a plant people eat freely: it is contraindicated in pregnancy and in cold from Spleen and Stomach deficiency, and it is high in oxalates.

  • Pregnancy — contraindicated, per the traditional record carried here.
  • Cold from Spleen and Stomach deficiency — contraindicated. A cold, sour, downward-moving herb given in 15–60 g doses does not suit a cold, weak digestion, and loose stool from deficiency is not the dysentery this herb addresses.
  • Oxalates — the practical one. Purslane is genuinely high in oxalate, and this is documented for purslane itself rather than inferred from other leafy greens. Anyone who has been advised to limit dietary oxalate — a history of calcium-oxalate kidney stones, existing kidney impairment, or malabsorption — should treat purslane as a high-oxalate food and take medical advice before eating it in quantity. See the safety question below for the published case reports.
  • Cooking changes the oxalate load. A 2025 analysis found total oxalate highest in fresh purslane and progressively lower in blanched and pickled samples, so culinary processing measurably reduces it (PMID 41304577). Oxalate content also varies markedly by genotype (PMID 26510561).
  • Seed preparations are a separate matter — an evaluation in the traditional Iranian medicine literature investigated adverse events reported after an aqueous extract of purslane seed (itching, tachycardia, anxiety, breathlessness, severe nausea) and proposed catecholamine and niacin constituents as the likely explanation (PMID 24187878). Chinese medicine uses the aerial herb, not the seed extract, so this is not directly transferable — but it is on record and worth knowing.

  Source: Sacred Lotus sources & references (recorded contraindications); oxalate and processing data per PMID 41304577, PMID 26510561, PMID 24683365; seed-extract adverse events per PMID 24187878. Neutral reference facts, not usage instructions, and not a substitute for medical advice.

Chinese Herb Toxicity & Overdose

• Is purslane safe? Can it damage the kidneys?

  Purslane is not classified as a toxic herb and is eaten as a vegetable worldwide, but there is a specific, documented risk at very high intake: oxalate nephropathy. This is not a theoretical concern extrapolated from spinach — it has been reported for purslane by name in the clinical literature.

  • Documented oxalate content. A nutritional review reports purslane leaf oxalate at roughly 671–869 mg per 100 g fresh weight (PMID 24683365). That places it firmly in the high-oxalate category among leafy vegetables.
  • Published case reports. A 2023 report in BMC Nephrology describes two elderly patients who developed acute kidney injury attributed to oxalate nephropathy after high dietary consumption of purslane; one renal biopsy showed acute tubulointerstitial injury with tubular oxalate deposition. Both required haemodialysis and both recovered (PMID 37443012). A separate 2022 case report describes acute kidney injury with oxalate crystals on biopsy after a patient ate a large quantity of purslane, with renal function returning to normal after stopping the plant, rehydration and dialysis (PMID 35346825).
  • What that means in proportion. These are case reports involving large intakes, not a signal against eating purslane as a salad vegetable. They do mean that “it is just a weed you can eat” is an incomplete description, and that people with kidney impairment, a stone history, or malabsorption have a real reason for caution.
  • Processing reduces it. Blanching and pickling both lowered total oxalate content relative to fresh purslane in a 2025 study (PMID 41304577).

  Suspected kidney injury is a medical matter and requires medical assessment. Nothing here describes a treatment.

  Sources: PMID 24683365, PMC 3934766, DOI 10.1155/2014/951019 (oxalate and nutrient composition); PMID 37443012, PMC 10347717, DOI 10.1186/s12882-023-03236-9 (purslane-induced oxalate nephropathy, case report and literature review); PMID 35346825, DOI 10.1016/j.trim.2022.101589 (oxalate nephropathy case report); PMID 41304577, PMC 12656633, DOI 10.3390/plants14223426 (effect of culinary processing on oxalate). Reference note, not a safety guarantee.

Herb-Drug Interactions

• Does Ma Chi Xian interact with medications?

  No well-established clinical herb–drug interactions are documented for purslane. Three areas warrant awareness on precautionary grounds rather than evidence. Its high potassium content (around 494 mg per 100 g, PMID 24683365) is worth noting alongside potassium-sparing diuretics, ACE inhibitors or angiotensin-receptor blockers, and in advanced kidney disease. Its oxalate load is relevant to anyone on treatment for calcium-oxalate stones or with reduced renal function. And a randomised trial of purslane extract in non-alcoholic fatty liver disease recorded within-group falls in fasting blood glucose and lipids (though no significant difference against placebo), so patients on glucose- or lipid-lowering medication are reasonably monitored (PMID 33880813). None of these is a demonstrated clinical interaction. (Flagged for practitioner confirmation.)

  Sources: PMID 24683365 (potassium and oxalate composition); PMID 33880813, DOI 10.1002/ptr.6972 (randomised trial). Precautionary reference, not documented clinical interactions.

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Ma Chi Xian (Portulaca oleracea)?

  Yes, and a great deal of it — but the bulk is nutrition and preclinical pharmacology, and the one well-conducted human trial we located returned a null result against placebo. Purslane is one of the most heavily reviewed edible medicinal plants in the literature, with at least four substantial review-level surveys published since 2015.

  • Review coverage — a 2017 review in the Journal of Ethnopharmacology covers botany, traditional uses, phytochemistry, pharmacology, pharmacokinetics and safety, and documents the plant’s long use for dysentery across both Chinese and European traditions (PMID 28495602). A 2015 review summarises phytochemistry and pharmacological effects (PMID 25692148); a 2022 review in Heliyon covers bioactive phytochemicals and ethnopharmacological potential (PMID 35028454); and a 2024 review updates the same ground (PMID 37739100). A 2024 review focuses specifically on purslane polysaccharides and immunomodulatory effects (PMID 39490030).
  • Composition — the recurring constituent classes are alkaloids, flavonoids, polysaccharides, omega-3 fatty acids (chiefly alpha-linolenic acid), and a high mineral and vitamin content. Nutritional and cytotoxicity profiling shows composition depends substantially on harvesting stage and plant part (PMID 31398846), and on genotype (PMID 26510561).
  • The human trial — and what it found. A randomised, double-blind trial gave 74 patients with non-alcoholic fatty liver disease 300 mg of purslane hydroalcoholic extract or placebo daily for 12 weeks. Several markers fell significantly within the purslane group compared with their own baseline, but no significant difference was found between the purslane and placebo groups for liver enzymes, lipid profile, glycaemic indices, steatosis grade or blood pressure. The authors concluded the extract had no significant effect at that dose and duration (PMID 33880813). Reported honestly, this is a negative trial.
  • What is not established — no controlled human trial of Ma Chi Xian for its traditional Chinese medicine indications was located. The traditional use rests on materia medica consensus and long practice, not on clinical trial evidence.

  Note on oxalate figures. Published oxalate values for purslane vary widely between studies, partly because of genuine genotype and growing-condition differences and partly because of differences in extraction and reporting method — a 2024 methods paper was written specifically to address inconsistency in how oxalic acid is extracted and quantified in purslane matrices (PMID 39157815). The figure quoted in our safety section (roughly 671–869 mg per 100 g fresh weight, PMID 24683365) is the most commonly cited range; some other studies report values on a scale that is not directly comparable. The safe reading is that purslane is reliably a high-oxalate food, while any single numeric value should be treated as approximate.

  Sources: PMID 28495602, DOI 10.1016/j.jep.2017.05.004 (traditional uses, phytochemistry and pharmacology review); PMID 25692148, PMC 4321094, DOI 10.1155/2015/925631 (phytochemistry and pharmacological effects review); PMID 35028454, PMC 8741462, DOI 10.1016/j.heliyon.2021.e08669 (bioactive phytochemicals review); PMID 37739100, DOI 10.1016/j.jep.2023.117211 (2024 review); PMID 39490030, DOI 10.1016/j.carres.2024.109298 (polysaccharides and immunomodulation); PMID 31398846, PMC 6720689, DOI 10.3390/antiox8080293 (nutritional value by harvesting stage and plant part); PMID 26510561, DOI 10.1007/s11130-015-0511-8 (genotype variation, omega-3); PMID 33880813, DOI 10.1002/ptr.6972 (randomised controlled trial, NAFLD); PMID 39157815, PMC 11326941, DOI 10.1016/j.mex.2024.102863 (oxalic acid quantification methods). Research context, not a therapeutic claim.

Chinese Herb Notes

• Is purslane really one of the richest plant sources of omega-3?

  Yes — among green leafy vegetables, purslane is repeatedly described in the nutrition literature as the richest source of the omega-3 fatty acid alpha-linolenic acid (ALA). This is a statement about the plant’s composition, not a health claim, and it is worth being precise about what it does and does not mean.

  • What is actually measured. A nutritional review of purslane reports alpha-linolenic acid at around 4 mg per gram of fresh weight, alongside a high mineral profile (potassium roughly 494 mg per 100 g, magnesium 68 mg, calcium 65 mg) and notable alpha-tocopherol and ascorbic acid content (PMID 24683365). A separate study of six purslane genotypes confirmed the plant as an alternative source of omega-3 fatty acids while finding that fatty-acid and organic-acid content varies substantially between genotypes (PMID 26510561).
  • What ALA is. Alpha-linolenic acid is the plant-form omega-3. It is not the same molecule as the long-chain marine omega-3s EPA and DHA, and human conversion of ALA into those is limited. “Richest leafy-vegetable source of omega-3” therefore means richest source of ALA specifically.
  • Scale matters. Fresh purslane is mostly water. A meaningful ALA intake means eating a real vegetable-sized portion, not a garnish — and that portion also carries the oxalate load discussed below.
  • Chinese medicine does not use it for this. The traditional indications are dysenteric disorders, heat-toxin and bleeding. The omega-3 content is a modern nutritional finding about a food, and it is offered here as composition information because readers ask about it, not as a rationale for the traditional use.

  Where does Ma Chi Xian sit among the toxin-resolving herbs?

  • It is sour, which is rare in this group — most of the herbs that clear heat and eliminate toxins are bitter and cold. The sour flavour brings an astringent, consolidating quality, which is consistent with its orientation to dysentery with blood and to bleeding generally rather than to systemic heat.
  • It is directed downward and outward — Large Intestine and Liver channels, and both intestinal and skin indications, rather than the Lung/upper-burner focus of some of its category-mates.
  • It is a food first — unlike most of the group, this is a vegetable people eat by the bowlful, which sets both its large dose range and its safety profile.

  Formulas: no formula record on this site lists Ma Chi Xian among its ingredients, which is consistent with its traditional use as a single herb, taken in quantity or applied fresh, rather than as a component of the named classical prescriptions. (Traditional context, not treatment advice.)

  Source: Sacred Lotus sources & references (herb identity, category and channel data; formula-ingredient records checked and none found containing this herb); composition per PMID 24683365, PMC 3934766, DOI 10.1155/2014/951019 and PMID 26510561, DOI 10.1007/s11130-015-0511-8; cross-referenced against multiple online sources and materia medica consensus.