Chilca

Chilca is used across the folk medicine of Venezuela, Colombia, Ecuador, Peru and Bolivia ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. The main medicine is the fresh leaf, and the main preparation is a poultice.

The leaves are crushed, warmed and laid over sore muscles, sprains, bruises and rheumatic joints. In Ecuador the leaves are applied as a plaster over bone fractures to reduce swelling ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. In Bolivia chilca is mainly an anti-inflammatory: the leaves are mashed, heated with urine and applied to bruises, dislocations and sprains, including by physiotherapists and chiropractors ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

In the Canta province of Peru, a decoction of the leaves and bark is used for headache and muscle pain, painful areas are massaged with the fresh leaves, and cooled leaf water is used to wash wounds ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. Elsewhere the leaves are mixed with animal fat as an ointment for wounds, or used in steam baths ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

Taken internally, a leaf infusion is used for diarrhoea, flatulence, heartburn, stomach pain and insomnia ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. A 5% infusion is taken as a tonic, for diabetes and digestion, and for liver disease ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. A decoction of the flowers and leaves is taken for cough and bronchitis, and decoctions are also used for rheumatism, ulcers and intestinal worms ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

In a comparison of four Bolivian Baccharis species, hexane, dichloromethane, ethanol and water extracts were tested in mouse immune cells (peritoneal macrophages) for their effect on COX-1, 5-lipoxygenase, COX-2, nitric oxide and TNF-α ^{1Reference 1Abad MJ et al. · 2006Anti-inflammatory activity of four Bolivian Baccharis species (Compositae)View study →}. Most of the extracts were active in all the assays ^{1Reference 1Abad MJ et al. · 2006Anti-inflammatory activity of four Bolivian Baccharis species (Compositae)View study →}.

For B. latifolia, the review of this work reports that the hexane and dichloromethane extracts inhibited COX-1 more strongly than the reference drug indomethacin, with a significant effect on the 5-lipoxygenase product LTC₄ ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. COX-2 was inhibited by 98.8% (hexane), 100% (dichloromethane) and 98.1% (water extract), similar to the reference drug ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

A Colombian study found the dichloromethane extract active at 300 mg/kg in the mouse-ear edema model ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

The leaves contain the flavonoids quercetin and rutin, which are known COX and lipoxygenase inhibitors, but no single compound from chilca has been tested.

Gap: No study has tested the fresh-leaf poultice, and there is no human or standardised-preparation data.

The activity here belongs to the essential oil of the aerial parts. Of 15 Asteraceae essential oils, those of B. latifolia and Achyrocline alata were the only ones active against the mould Aspergillus fumigatus; the chilca oil’s MIC was 157.4 µg/mL ^{4Reference 4Zapata B et al. · 2010Antifungal activity, cytotoxicity and composition of essential oils from the Asteraceae plant familyView study →}. Neither oil harmed Vero cells, and neither was active against Candida yeasts ^{4Reference 4Zapata B et al. · 2010Antifungal activity, cytotoxicity and composition of essential oils from the Asteraceae plant familyView study →}.

An Ecuadorian oil showed moderate activity against the skin fungi Trichophyton rubrum and T. mentagrophytes ^{8,11Reference 8Valarezo E et al. · 2013Chemical composition, antifungal and antibacterial activity of the essential oil from Baccharis latifolia (Ruiz & Pav.) PersView study →Reference 11Armijos C et al. · 2022Poorly investigated Ecuadorian medicinal plantsView study →}. It was inactive against a panel of common bacteria, including Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

Against the honeybee pathogen Paenibacillus larvae, the chilca oil was active, but unlike the other oils tested it did not break down the bacterial membrane ^{5Reference 5Pellegrini MC et al. · 2017Chemical composition, antimicrobial activity and mode of action of essential oils against Paenibacillus larvaeView study →}.

The oil is mostly limonene, at about 34% ^{2,8Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →Reference 8Valarezo E et al. · 2013Chemical composition, antifungal and antibacterial activity of the essential oil from Baccharis latifolia (Ruiz & Pav.) PersView study →}.

Gap: These results are for the essential oil, not the fresh-leaf poultice or an infusion. There is no infection model or human data.

In human neutrophils, the leaf methanol extract reduced the production of reactive oxygen species triggered by phorbol ester (PMA) by 55% ^{2,3Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →Reference 3Pérez-García F et al. · 2001Activity of plant extracts on the respiratory burst and the stress protein synthesisView study →}.

This is a test of the cells’ oxidative burst, not a chemical radical-scavenging test. The leaves contain quercetin and rutin, flavonoids with strong antioxidant activity, and total flavonoid content differs between leaf types and varies with soil chemistry ^{7Reference 7Enríquez S et al. · 2018Flavonoid contents in leaves of Baccharis latifolia according to the type of leaf and its dependence on the physicochemical properties of soilsView study →}.

Gap: One cell assay, with no ORAC or DPPH data and nothing in animals.

A Peruvian survey collected 51 plants used locally for liver and digestive complaints and tested 61 ethanol extracts against the liver-cancer cell line Hep3B ^{6Reference 6Carraz M et al. · 2015Antiproliferative activity and phenotypic modification induced by selected Peruvian medicinal plants on human hepatocellular carcinoma Hep3B cellsView study →}. The B. latifolia leaf extract was one of 14 extracts that significantly slowed the cells’ growth, at concentrations of 50 µg/mL or less ^{6Reference 6Carraz M et al. · 2015Antiproliferative activity and phenotypic modification induced by selected Peruvian medicinal plants on human hepatocellular carcinoma Hep3B cellsView study →}. These active extracts were not toxic to normal human liver cells (primary hepatocytes) in the same study ^{6Reference 6Carraz M et al. · 2015Antiproliferative activity and phenotypic modification induced by selected Peruvian medicinal plants on human hepatocellular carcinoma Hep3B cellsView study →}.

A review of this work reports that the chilca extract was also active against three other liver-cancer cell lines, HepG2, PLC/PRF/5 and SNU-182 ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

Gap: Cell lines only. No animal data, no isolated active compound, and nothing on internal use.

Andean folk medicine uses a leaf infusion of about 5% as a tonic for diabetes and digestion, and recommends it for liver disease ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. No glucose-uptake, α-glucosidase or animal study has been published for B. latifolia, and no clinical study.

Gap: No experimental or clinical data.

Toxicity. In acute toxicity studies in rodents, the extract caused slight depression and loose stools, with no change in weight and no tissue damage ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. A repeated-dose oral study in rats caused no deaths, but changed the relative weights of the spleen and kidneys and caused kidney tissue injury, which the authors read as a slight toxic response ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}. The Colombian handbook of medicinal plants lists no contraindications ^{2Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}.

Use on the skin. The traditional poultice and wash are applied to the skin. There are no human safety studies of internal use.

Possible interactions. Leaf extracts block the COX enzymes ^{1,2Reference 1Abad MJ et al. · 2006Anti-inflammatory activity of four Bolivian Baccharis species (Compositae)View study →Reference 2Sequeda-Castañeda LG et al. · 2015Phytochemical and therapeutic use of Baccharis latifolia (Ruiz & Pav.) PersView study →}, so chilca could in theory add to the effects of NSAIDs or blood thinners. Its traditional use for diabetes suggests care alongside blood-sugar-lowering drugs. None of these interactions has been studied.

Essential oil. The limonene-rich essential oil is a different product from the leaf. Oxidised citrus-type monoterpene oils can sensitise the skin.