NZ Native Plants

Watch Part 1 of the Webinar here. 
Watch Part 2 of the Webinar here. 

Part 1 Notes:

Native Plants:

• Manuka (Leptospermum scoparium)
• Koromiko (Hebe salicifolia; H stricta)
• Kawakawa (Macropiper excelsum)
• Tanekaha (Phyllocladus trichomanoides)

Rongoā Māori

• Relatively good health of Māori upon European arrival suggests effective use of traditional medicine (Rongoā Māori).
• Most usage topical, but preparations also taken internally.
• Interest in traditional medicine including Rongoā and use of NZ native plants is now increasing.
• Encouraging and facilitating research in traditional medicine is a key objective of World Health Organisation Traditional Medicine Strategy 2014-2023.

WHO Strategy

• Aims to support Member States in developing proactive policies and implementing action plans that will strengthen the role traditional medicine plays in keeping populations healthy.
• More priority given than previous strategy on prioritizing health services and systems.
• These include traditional and complementary medicine products, practices, and practitioners.

Manuka (Leptospermum scoparium)

• Various parts used for a large number of medicinal complaints.
• Called "tea tree" after leaves used by Captain Cook’s crew and early migrants as an English tea substitute.
• Around 85 Leptospermum spp found throughout Australia, Southeast Asia, and New Zealand.
• Mānuka Honey and Mānuka essential oil popular in past 25 years.

Phytochemistry

• Triterpene acids and derivatives, including ursolic acid acetate
• Tannins, ellagic acid, and O-methyl ethers of ellagic acid
• Volatile oil - predominantly sesquiterpene hydrocarbons, oxygenated sesquiterpenes, monoterpenes, and triketones, including leptospermone
• Flavonoids, including methylated and methoxylated flavones
• Dihydroxyacetone (DHA) – in nectar of flowers 

Topical Traditional Uses

• Infusions, poultices, vapor baths, lotions, and ointments
• Wounds, cuts, sores, and skin diseases
• Decoction of bark used as mouthwash and gargle
• Inflammatory conditions such as sprains, strains, swellings, broken limbs, and rheumatism

Traditional Uses (continued)

• Bark infusion reportedly used as a sedative
• Bark, leaves, and seeds used for diarrhea and dysentery
• Bark burned slowly in closed huts post-childbirth (antimicrobial, astringent, haemostatic)
• Decoctions and infusions used to allay fevers, and vapor inhaled for colds
• Leaf infusions drunk for urinary problems and diuretic properties

Antimicrobial Properties

• Leaf extracts combined with Phyllocladus trichomanoides (Tanekaha) active against oral pathogens (Strep mutans, Strep mitis, Actinomyces naeslundii)
• Volatile oil has antimicrobial properties (especially against Gram-positive bacteria)
• Mānuka Honey proven healing and antimicrobial properties, particularly against Staph aureus and E. coli
• Synergistic antimicrobial activities for Mānuka Honey with various antibiotics (rifampicin, oxacillin, gentamycin, clindamycin)

Mānuka Honey

• Used for centuries as wound dressings
• Most antibacterial activities attributable to high osmolality and/or liberation of hydrogen peroxide
• ‘Active’ Mānuka honey contains additional non-peroxide antimicrobial activities
• Higher polyphenolic content than other honeys

Digestive System Activities

• Seed capsules used to relieve colic
• Tannin-rich herbs widely used for dysentery and diarrhea
• Powerful astringent and antimicrobial effects produced by infusions and hydroethanolic liquid extracts
• Oil has spasmolytic, anti-inflammatory, and antimicrobial activities

Nervous System Activities

• Early settlers reported use of bark infusion as a sedative
• Methylated and methoxylated flavones isolated from ethanolic extracts
• Found to act as agonists at benzodiazepine GABA-A receptors
• Locomotion studies in rats confirmed sedative and anxiolytic activities

Insecticidal and Herbicidal

• Smoke from mānuka fires used by Māori to rid cloaks of lice
• Leptospermone has powerful insecticidal activity
• Oil lures trialed in the U.S. to attract borer beetles affecting trees
• Herbicidal activity reported for triketone-rich Mānuka oil

Koromiko (Hebe salicifolia / Hebe stricta)

• Plantaginaceae family
• Low spreading shrub with glossy green leaves
• Many Hebe species grow in New Zealand
• Leaves and young shoots used

Topical Uses

• Leaves bruised and applied as poultice or lotion for sores, ulcers, venereal disease
• Used for menorrhagia, postpartum haemorrhage
• Decoction used for haemorrhoids
• Mouthwash for dental infections

Internal Uses

• Used in Rongoā Māori
• Treatment for diarrhoea, dysentery, stomach-ache, venereal disease, kidney, and bladder complaints
• Teething in infants

Antidiarrheal Properties

• Effective remedy for diarrhoea
• Recognized in British medicine
• Used during WWII for soldiers in the Middle East

Kawakawa (Macropiper excelsum)

• Used topically for skin conditions, wounds, and bruises
• Internal uses for digestive aid, colds, coughs, and bronchitis
• Cytotoxic amides isolated from kawakawa fruits tested for anticancer effects
• Effects on intestinal nutrient uptake studied

Tanekaha (Phyllocladus trichomanoides)

• High tannin content, used as a red-brown dye
• Used for skin diseases, burns, haemorrhoids
• Internal uses for diarrhoea, dysentery, dysmenorrhea
• Possible liver benefits

Dosage and Preparations

• Hydroethanolic liquid extracts, teas, and topical applications

Summary of Potential Uses

• Topical applications for wounds, ulcers, burns
• Mouthwash for oral hygiene
• Digestive and urinary system support
• Anxiety and insomnia treatment potential

Part 2 Notes

Native Plants:

• Akeake (Dodonaea viscosa)
• Hoheria (Hoheria populnea)
• Horopito (Pseudowintera axillaris; Pseudowintera colorata)
• Kanuka (Kunzea ericoides)
• Kohekohe (Dysoxylum spectabile)

Rongoā Māori

• Traditional medicine played a significant role in Māori health before European arrival.
• Most usage was topical, but internal preparations were also common.
• Interest in Rongoā and native plant use is increasing.
• WHO Traditional Medicine Strategy 2014-2023 encourages research in this field.

Akeake (Dodonaea viscosa)

• Found in tropical and subtropical regions worldwide.
• Indigenous to Australia (Hopbush) and widely used medicinally.
• Contains saponins, diterpenoids, flavonoids, tannins, sterols, and essential oils.

Traditional Uses

• Internal: Fever reduction, pain relief, gastrointestinal spasms, pulmonary infections.
• Topical: Used for wounds, burns, eczema, insect bites, and rheumatic pain.
• Antimicrobial: Effective against Streptococcus, Staphylococcus, E. coli, and Candida.
• Anti-inflammatory: Used for joint pain and inflammatory conditions.
• Gastroprotective: Used for ulcers and stomach ailments.
• Anti-cancer potential: Contains dodoviscin A, which may inhibit tumor growth.
• Anti-diabetic: Flavonoids show glucose-lowering potential.

Hoheria (Hoheria populnea)

• Native to New Zealand, known as lacebark.
• Fast-growing tree with mucilage-rich leaves and bark.
• Used for burns, wounds, ulcers, and dry skin.
• Internally used for coughs, bronchitis, and gastrointestinal inflammation.
• Pharmacology: Demulcent, gastroprotective, expectorant, febrifuge, anti-inflammatory.

Horopito (Pseudowintera axillaris, Pseudowintera colorata)

• Peppery leaves used traditionally for pain relief and infections.
• Contains polygodial, a sesquiterpene dialdehyde with antimicrobial and analgesic properties.
• Used for stomach pain, colds, chest infections, and fungal infections.
• Anti-inflammatory and potential anti-allergic effects.

Kanuka (Kunzea ericoides)

• Similar to mānuka but with different essential oil composition.
• Contains α-pinene, flavonoids, acyl-phloroglucinols, and tannins.
• Antibacterial and antifungal properties.
• Used for herpes, fungal infections, oral mucositis, and skin conditions.

Kohekohe (Dysoxylum spectabile)

• Found in coastal forests of New Zealand.
• Related to medicinal Dysoxylum species used in SE Asia and the Pacific.
• Used for diarrhea, heavy menstruation, tuberculosis, and chest infections.
• Tonic and astringent properties similar to quinine.
• Potential anticancer properties based on related species research.

Dosage and Preparations

• Various plants prepared as liquid extracts, teas, ointments, and essential oils.
• Caution with high doses due to tannin content affecting mineral absorption.

Case Studies

• Use of herbal treatments for gastrointestinal issues, respiratory conditions, and anxiety.
• Traditional preparations still effective in modern herbal medicine practices.

References & Further Reading

• Māori Healing and Herbal, Murdoch Riley
• New Zealand Medicinal Plants, SG Brooker, RC Cambie, RC Cooper
• Various scientific studies on the pharmacological effects of native plants.

This summarizes the medicinal uses and pharmacological properties of key New Zealand native plants, supporting their relevance in both traditional and modern herbal medicine.