Tag: New Zealand Herbs

Baical Skullcap – useful for anxiety, neurological & mood disorders

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Baical Skullcap

The root of Scutellaria baicalensis (known as Baical skullcap or Huangqin) is an important plant medicine in China, Russia, Mongolia, Korea and Japan.  It is a prominent constituent of many Traditional Chinese Medicine formulations, including those used for allergic diseases, respiratory tract infections, pneumonia, colitis, hepatitis, dementia, Parkinson’s disease and cancer (1).

Scutellaria baicalensis is botanically related to Scutellaria lateriflora (commonly known as Skullcap or American Skullcap). This skullcap species is better known in western herbal medicine, particularly for its anxiolytic and sedative properties(2). 

Over 50 compounds have been isolated and identified from Baical skullcap, including flavonoids, terpenoids, volatile oils and polysaccharides. Most research implicates various flavonoids including baicalein (5,6,7-trihydroxyflavone) and its metabolite baicalin and wogonin, as being key active phytochemicals(3). 

Neurological effects

Neuroprotective effects have been reported for Baical skullcap as well as baicalin, baicalein and wogonin in a range of animal models and in vitro systems(4-6). These include protection against damage to dopamine neurons in the striatum, hippocampus and substantia nigra, suggesting a potential role in Parkinson’s disease(7, 8). Alleviation of both abnormal motor behavioural and depression-like behavior in rodent models of Parkinson’s disease, has also been reported for baicalein(9, 10).

Mitigation of brain injury in the acute stage of ischaemic stroke, and a lessening of subsequent motor dysfunction and cognitive impairment, has been reported following Baical skullcap administration in several rodent studies (5, 11-14). Improved cognition in aged rats, vascular dementia and in animal models of Alzheimer’s disease, are other reported outcomes following administration of concentrated flavonoid extracts made from this plant (15, 16). These include those also extracted from its stem and leaf, as per my herbblurb article posted in April, on additional uses for the aerial parts of Baical skullcap(17). Antioxidant, anti-inflammatory, mitochondrial protective and gut microbiome modulatory effects, seem to be contributory to these various neuroprotective actions(5, 13, 18-20). 

These are impressive findings. The potential applications of Baical skullcap as part of the clinical management of ischaemic stroke in humans, a leading cause of mortality and disability, are of great interest, and clinical studies are warranted.

Effects in anxiety and depression

Anxiolytic effects have been shown in animal studies for Baical skullcap and some of its flavonoid constituents(21-23). Baicalein, baicalin and wogonin are positive modulators of the benzodiazepine binding site of GABAA receptors, the same sites of action of benzodiazepine drugs such as diazepam, a possible mechanism of action in anxiety disorders(21, 24-26). Unfortunately however, human studies involving its use as a single herb rather than as part of a formulation, are lacking.

Behavioural studies have also revealed a potential for Baical skullcap to alleviate prenatal stress-induced anxiety and depression-like behaviours in the offspring of mice. Mechanisms of action were related at least partially through protecting placental barrier function, reversing an overactive hypothalamic-pituitary-adrenal (HPA) axis, and reducing neurodevelopmental dysfunction(27).

I recently presented on antidepressant herbs apart from St Johns Wort, to a practitioner audience, something I’ve done several times in the past, and which I regard as a very important subject(28). Depression is a very common human illness, and as in many countries, antidepressant prescribing rates in Aotearoa New Zealand have been increasing in recent decades.  Given that as with individual drug treatments, only 60-65% of patients respond to the well researched St John’s Wort, there exists a need to research and increase our knowledge on additional herbal interventions that may be helpful as part of the management of mood disorders.  

Baical skullcap is also an ingredient in many traditional Chinese medicine formulae used to treat a range of nervous system conditions, including depression(29).  It is also sometimes combined with another widely used Chinese medicinal plant, Bupleurum (Bupleurum chinense) in these formulations(30). Favourable effects have also been shown for its root and flavonoids in animal models of depression(19), although this in itself doesn’t necessarily indicate antidepressant properties in humans.

While much less researched than its Asian cousin, Scutellaria lateriflora has also been reported to have a mood enhancing effect after two weeks treatment, in a British crossover study involving 43 healthy participants(31).

Recent clinical trial

A six week placebo-controlled clinical trial involving 180 participants with mild to moderate depression who took Baical skullcap with or without saffron, recently took place in Belgium(32).

This trial selected participants aged between 18 and 75 presenting with a depressive episode according to the DSM-5 definition, experiencing mild to moderate depressive symptoms using the Beck Depression Inventory, and having had a depressive episode within the last two years. Those with other mental health conditions or those taking any psychotropic treatment, were excluded.

Four treatment arms were used. The first group (n=42) took an extract of Baical skullcap alone, the second (n=43) a Saffron extract alone, the third (n=48) a combination of these two phytomedicines, and the fourth (n=47) a placebo capsule daily, for 42 days. The Saffron used was standardised for its content of crocins and safranal, and the Baical skullcap was standardised for baicalin.

Participants were assessed prior to commencing treatment, then after three and six weeks of treatment, and at two weeks following the end of treatment. Primary outcomes were the standardized depression scale measured using the Beck Depression Inventory and Hamilton Depression score. Subjects also completed other questionnaires assessing positive and negative affects, anxiety levels, quality of life, and wellbeing levels.

Improvements occured in both mood and sleep in all four groups, particularly between the 21 day and 42 day treatment period. While differences between groups in terms of the depression measurements weren’t statistically significant, anxiety levels were decreased with all three treatment but not the placebo group. Scores for Emotional Assessment, a self-rated scale describing feelings and emotions, were also improved but maintained at 56 days only for the Baical skullcap and combined Baical skullcap and Saffron treated groups. Minimal adverse effects were reported across all treatment groups. 

While this study failed to reveal evidence of an antidepressant effect for Baical skullcap, Saffron also failed to achieve this to statistical significance, despite several trials having reported such effects for it already (33). Methodological issues such as low participant numbers and/or the dosages used being too low, may have been contributory. The study did however, produce data suggesting an anti anxiety or anxiolytic effect, and overall improvement in self rated feelings and emotions. Given the link  between chronic and poorly controlled anxiety and a predisposition to depression, further studies with larger numbers and using different dosages are recommended.

This is one of the first well designed clinical trials published in an English language journal implicating an anxiolytic and possible antidepressant effect for Baical skullcap.

References:

  1. Zhao T, Tang H, Xie L, Zheng Y, Ma Z, Sun Q, Li X. Scutellaria baicalensis Georgi. (Lamiaceae): a review of its traditional uses, botany, phytochemistry, pharmacology and toxicology. J Pharm Pharmacol. 2019 Sep;71(9):1353-1369. 
  2. Shen J, Li P, Liu S, Liu Q, Li Y, Sun Y, He C, Xiao P. Traditional uses, ten-years research progress on phytochemistry and pharmacology, and clinical studies of the genus Scutellaria. J Ethnopharmacol. 2021 Jan 30;265:113198. 
  3. Wang ZL, Wang S, Kuang Y, Hu ZM, Qiao X, Ye M. A comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensis. Pharm Biol. 2018 Dec;56(1):465-484.
  4. Si L, An Y, Zhou J, Lai Y. Neuroprotective effects of baicalin and baicalein on the central nervous system and the underlying mechanisms. Heliyon. 2024 Dec 10;11(1):e41002. 
  5. Seo HW, Ha TY, Ko G, Jang A, Choi JW, Lee DH, Chang KA. Scutellaria baicalensis Attenuated Neurological Impairment by Regulating Programmed Cell Death Pathway in Ischemic Stroke Mice. Cells. 2023 Aug 23;12(17):2133.
  6. Huynh DL, Ngau TH, Nguyen NH, Tran GB, Nguyen CT. Potential therapeutic and pharmacological effects of Wogonin: an updated review. Mol Biol Rep. 2020 Dec;47(12):9779-9789. 
  7. Lee HJ, Noh YH, Lee DY, Kim YS, Kim KY, Chung YH, Lee WB, Kim SS. Baicalein attenuates 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y cells. Eur J Cell Biol. 2005 Nov;84(11):897-905
  8. Zhao WZ, Wang HT, Huang HJ, Lo YL, Lin AM. Neuroprotective Effects of Baicalein on Acrolein-induced Neurotoxicity in the Nigrostriatal Dopaminergic System of Rat Brain. Mol Neurobiol. 2018 Jan;55(1):130-137.
  9. Gao L, Li C, Yang RY, Lian WW, Fang JS, Pang XC, Qin XM, Liu AL, Du GH. Ameliorative effects of baicalein in MPTP-induced mouse model of Parkinson’s disease: A microarray study. Pharmacol Biochem Behav. 2015 Jun;133:155-63. 
  10. Zhao X, Kong D, Zhou Q, Wei G, Song J, Liang Y, Du G. Baicalein alleviates depression-like behavior in rotenone- induced Parkinson’s disease model in mice through activating the BDNF/TrkB/CREB pathway. Biomed Pharmacother. 2021 Aug;140:111556.
  11. Li M, Meng Z, Yu S, Li J, Wang Y, Yang W, Wu H. Baicalein ameliorates cerebral ischemia-reperfusion injury by inhibiting ferroptosis via regulating GPX4/ACSL4/ACSL3 axis. Chem Biol Interact. 2022 Oct 1;366:110137. 
  12. Shang Y, Cheng J, Qi J, Miao H. Scutellaria flavonoid reduced memory dysfunction and neuronal injury caused by permanent global ischemia in rats. Pharmacol Biochem Behav. 2005 Sep;82(1):67-73. 
  13. Liang W, Huang X, Chen W. The Effects of Baicalin and Baicalein on Cerebral Ischemia: A Review. Aging Dis. 2017 Dec 1;8(6):850-867.
  14. Zhao S, Kong W, Zhang S, Chen M, Zheng X, Kong X. Pretreatment with scutellaria baicalensis stem-leaf total flavonoid prevents cerebral ischemia-reperfusion injury. Neural Regen Res. 2013 Dec 5;8(34):3183-92.
  15. Song HR, Cheng JJ, Miao H, Shang YZ. Scutellaria flavonoid supplementation reverses ageing-related cognitive impairment and neuronal changes in aged rats. Brain Inj. 2009 Feb;23(2):146-53.
  16. Ma S, Xu CC, Dong YC, Li CX, Shang YZ. Scutellaria Baicalensis Georgi Stem and Leaf Flavonoids Ameliorate the Learning and Memory Impairment in Rats Induced by Okadaic Acid. Comb Chem High Throughput Screen. 2025;28(2):263-277.
  17. Rasmussen PL, Baical Skullcap – additional uses for aerial parts. www.herbblurb.com April 7, 2025.
  18. Im AR, Kim YH, Uddin MR, Lee HW, Chae SW, Kim YH, Jung WS, Kang BJ, Mun CS, Lee MY. Scutellaria baicalensis Extracts and Flavonoids Protect Rat L6 Cells from Antimycin A-Induced Mitochondrial Dysfunction. Evid Based Complement Alternat Med. 2012;2012:517965.
  19. Wang C, Gao MQ. Research Progress on the Antidepressant Effects of Baicalin and Its Aglycone Baicalein: A Systematic Review of the Biological Mechanisms. Neurochem Res. 2024 Jan;49(1):14-28.
  20. He P, Qiao R, Liu C, Zhang W, Li H, He F. Neuroprotective Mechanisms of Baicalin in Ischemia Stroke. ACS Chem Neurosci. 2025 Jun 4;16(11):1978-1995. 
  21. Hui KM, Huen MS, Wang HY, Zheng H, Sigel E, Baur R, Ren H, Li ZW, Wong JT, Xue H. Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis Georgi. Biochem Pharmacol. 2002 Nov 1;64(9):1415-24. 
  22. de Carvalho RS, Duarte FS, de Lima TC. Involvement of GABAergic non-benzodiazepine sites in the anxiolytic-like and sedative effects of the flavonoid baicalein in mice. Behav Brain Res. 2011 Aug 1;221(1):75-82. 
  23. Warlick H 4th, Leon L, Patel R, Filoramo S, Knipe R, Joubran E, Levy A, Nguyen H, Rey J. Application of gabapentinoids and novel compounds for the treatment of benzodiazepine dependence: the glutamatergic model. Mol Biol Rep. 2023 Feb;50(2):1765-1784. 
  24. Liao JF, Wang HH, Chen MC, Chen CC, Chen CF. Benzodiazepine binding site-interactive flavones from Scutellaria baicalensis root. Planta Med. 1998 Aug;64(6):571-2.
  25. Wang H, Hui KM, Chen Y, Xu S, Wong JT, Xue H. Structure-activity relationships of flavonoids, isolated from Scutellaria baicalensis, binding to benzodiazepine site of GABA(A) receptor complex. Planta Med. 2002 Dec;68(12):1059-62. 
  26. Wang F, Xu Z, Ren L, Tsang SY, Xue H. GABA A receptor subtype selectivity underlying selective anxiolytic effect of baicalin. Neuropharmacology. 2008 Dec;55(7):1231-7.
  27. Li L, Zhang W, Sun C, Chai Z, Wang K, Zhou Q, Wang X. Scutellariae radix Ameliorates Prenatal Stress-Induced Anxiety-Like and Depression-Like Behavior in the Offspring via Reversing HPA Axis Hyperfunction and Ameliorating Neurodevelopmental Dysfunction. Dev Neurosci 2024 Dec 19:1-19.
  28. Rasmussen PL, Herbs other than St Johns Wort that can be useful in treating Depression. NZ Association of Medical Herbalists, NZAMH, Conference, Christchurch, New Zealand, 6-7 September 2025.  www.nzamh.org.nz/assets/ Conference-brochure-2025-final.pdf.
  29. Ma Y, Zhou X, Zhang F, Huang C, Yang H, Chen W, Tao X. The effect of scutellaria baicalensis and its active ingredients on major depressive disorder: a systematic review and meta-analysis of literature in pre-clinical research. Front Pharmacol. 2024 Mar 20;15:1313871. 
  30. Bing Y, Li Z, Liu L, Wang D, Liu K, Li J, Li S, Qu Z, Zou X. Preliminary exploration of the antidepressant mechanism of Bupleurum scorzonerifolium-Scutellaria baicalensis and its core SSa-Baicalin combination. J Ethnopharmacol. 2025 Sep 25;353(Pt B):120426.
  31. Brock C, Whitehouse J, Tewfik I, Towell T. American Skullcap (Scutellaria lateriflora): a randomised, double-blind placebo-controlled crossover study of its effects on mood in healthy volunteers. Phytother Res. 2014 May;28(5):692-8. 
  32. Dormal V. Nutrients. 2025 Feb 26;17(5):809.Wang C, Neurochem Res. 2024 Jan;49(1):14-28. doi: 10.1007/s11064-023-04026-3
  33. Chauhan S, Tiwari A, Verma A, Padhan PK, Verma S, Gupta PC. Exploring the Potential of Saffron as a Therapeutic Agent in Depression Treatment: A Comparative Review. Yale J Biol Med. 2024 Sep 30;97(3):365-381.

An introduced botanical paradise seen on holiday in Aotearoa New Zealand

On By philrasmIn Uncategorized1 Comment

Achillea millefolium (Yarrow) was the first familiar medicinal plant to proudly show itself to me on the 1st day of a recent six day campervan trip from Christchurch to the west coast of Te Waipounamu (the South Island), of Aotearoa New Zealand. Growing and flowering prolifically along the roadside and beyond as we ventured inland towards Arthurs Pass, I wished I could have stayed another night in the campsite, and had the chance to harvest a decent batch.

Yarrow is a great plant to have nearby. So also apparently thought the Greek warrior Achilles, who is said to have applied its leaves and flowers topically to the sword and arrow wounds of his soldiers after battle, to close and heal their wounds. It is widely utilized in the traditional medicine of cultures from Europe to Asia to north America for numerous health conditions. They include spasmodic digestive and gynaecological complaints, and as a febrifuge and antimicrobial for fevers and infections(1). Relief from period pain was reported after drinking three cups of yarrow tea daily on days one to three of the menstrual cycle, in a clinical trial with 91 students aged 19-23(2).

Eschscholztia californica was a pretty poppy that called out with its bright yellow and orange flowers, in many roadside and dry gravelly patches throughout our journey. Related botanically to its opium-producing cousin, also seen in a couple of places thanks to the early Chinese goldminers of central Otago, Californian poppy is now a popular remedy for anxiety, insomnia and mild pain. My application of it however, has mainly been in patients withdrawing from substance dependency(3).

The amount of St John’s Wort (Hypericum perforatum) thriving in numerous locations in the Hawea, Wanaka and Queenstown districts and in other areas throughout our journey, was quite eye opening. I first wildcrafted and grew Hypericum as a student in the UK, and have dispensed it extensively within herbal formulations over the past 30 years.  A powerful antidepressant, antimicrobial and anti-inflammatory, with a multitude of applications both topically and internally.   

Mullein (Verbascum thapsus) was another one, appearing unexpectantly upon rounding many corners on sloping, dry hillbanks, with its distinctive upright stems poking towards the sky. As an invasive plant in many pastures and fields of rural New Zealand, with a rich content of polysaccharide hydrocolloids and other expectorant and anti-inflammatory phytochemicals, its long historical use as a lung tonic and for the management of upper respiratory tract infections, warrants more attention. While it’s a lot of work to harvest and dry the large lightweight leaves, it makes a great cough formula ingredient. The flowers and roots, also have established medicinal properties(4).

And then the rosehips. Through Lindis Pass into the upper Waitaki Valley as well as at the start of Arthurs Pass, fields and fields of them, dominated many parts of the landscape. Rosehips (Rosa canina) are probably best known for their vitamin C content, and in the 1940’s, locals from Otago and Southland wildcrafted the hips and sold them to the Greggs factory in Dunedin to manufacture syrups and powder forms. Rosehips were similarly wildcrafted in Britain during World War Two, and its syrup given to children and troops to prevent scurvy. 

Several clinical trials have reported efficacy of rosehip powder or extracts for the symptomatic treatment of osteoarthritis(5-7). Inhibitory effects against both cyclo-oxygenase 1 and 2 (COX-1 and COX-2) enzymes may contribute to these benefits(8, 9 ). Other traditional indications are for kidney stones, UTI’s and digestive ailments, and its oil is a popular application for skin health. Rosehips have antioxidant, anti-inflammatory, anti-obesity, anti-cancer, hepatoprotective, nephroprotective, cardioprotective, anti-aging, anti H. pylori, neuroprotective and antinociceptive activities(10).

Finally, heading back into Canterbury, the presence of Elder trees (Sambucus nigra), made themselves known upon the landscape. I made many batches of wine using Elder berries or flowers I wildcrafted when living in the U.K. many years ago, although it is a less common albeit somewhat invasive species here and prefers the cooler south rather than north island.  

Elder flowers are a great decongestant, and its berries rich in antioxidant anthocyanins and other anti-inflammatory polyphenols and vitamin C (11). Global demand greatly outstripped supply during the Covid-19 pandemic, due to its alleged antiviral properties (12, 13).

Many other established or invasive medicinal plants were seen during our journey, though most of these didn’t cry out so much to me.  It was the ones that I don’t see as much in the north island where I live, that served to remind me of the enormous geographical and botanical diversity that is characteristic of the Aotearoa New Zealand landscape.

And of course the extent and variety of our own native species was absolutely awe-inspiring, as it has been every time I’ve travelled on the west coast. The dominance of rātā (Metrosideros robusta) with its beautiful red flowers blanketing out in so many locations from within the dominant native beech forests (Nothofagus spp), was truly stunning.

We live in a country where there are bountiful supplies of medicinal plants. From many perspectives including those based upon invasive plant and land management, biodiversity, sustainability, economics and ultimately health outcomes, we should use more of them.

References:

  1. Ali SI, Gopalakrishnan B, Venkatesalu V. Pharmacognosy, Phytochemistry and Pharmacological Properties of Achillea millefolium L.: A Review. Phytother Res. 2017 Aug;31(8):1140-116
  2. Jenabi E, Fereidoony B. Effect of Achillea Millefolium on Relief of Primary Dysmenorrhea: A Double-Blind Randomized Clinical Trial. J Pediatr Adolesc Gynecol. 2015 Oct;28(5):402-4.
  3. Rasmussen PL, A Role for Phytotherapy in the Treatment of Benzodiazepine and Opiate Drug Withdrawal; Part 2, Treatment Approaches to Opiate Withdrawal, and Conclusions. Eur J Herbal Med, 1997; 13-10.
  4. Gupta A, Atkinson AN, Pandey AK, Bishayee A. Health-promoting and disease-mitigating potential of Verbascum thapsus L. (common mullein): A review. Phytother Res. 2022 Apr;36(4):1507-1522. 
  5. Rasmussen PL, Rosehip for Osteoarthritis. Phytonews 24, February 2006; published by Phytomed Medicinal Herbs Ltd, Auckland, New Zealand. ISSN 1175-0251.
  6. Christensen R, Bartels EM, Altman RD, Astrup A, Bliddal H. Does the hip powder of Rosa canina (rosehip) reduce pain in osteoarthritis patients?–a meta-analysis of randomized controlled trials. Osteoarthritis Cartilage. 2008 Sep;16(9):965-72. 
  7. Gruenwald J, Uebelhack R, Moré MI. Rosa canina – Rose hip pharmacological ingredients and molecular mechanics counteracting osteoarthritis – A systematic review. Phytomedicine. 2019 Jul;60:152958. 
  8. Jäger AK, Eldeen IM, van Staden J. COX-1 and -2 activity of rose hip. Phytother Res. 2007 Dec;21(12):1251-2. 
  9. Rasmussen PL, Rosehip acts as a cyclo-oxygenase inhibitor. Phytonews 29, June 2008; published by Phytomed Medicinal Herbs Ltd, Auckland, New Zealand. ISSN 1175-0251.
  10. Ayati Z, Amiri MS, Ramezani M, Delshad E, Sahebkar A, Emami SA. Phytochemistry, Traditional Uses and Pharmacological Profile of Rose Hip: A Review. Curr Pharm Des. 2018;24(35):4101-4124.
  11. Stępień AE, Trojniak J, Tabarkiewicz J. Health-Promoting Properties: Anti-Inflammatory and Anticancer Properties of Sambucus nigra L. Flowers and Fruits. Molecules. 2023 Aug 24;28(17):6235.
  12. Wieland LS, Piechotta V, Feinberg T, Ludeman E, Hutton B, Kanji S, Seely D, Garritty C. Elderberry for prevention and treatment of viral respiratory illnesses: a systematic review. BMC Complement Med Ther. 2021 Apr 7;21(1):112.
  13. Boroduske A, Jekabsons K, Riekstina U, Muceniece R, Rostoks N, Nakurte I. Wild Sambucus nigra L. from north-east edge of the species range: A valuable germplasm with inhibitory capacity against SARS-CoV2 S-protein RBD and hACE2 binding in vitro. Ind Crops Prod. 2021 Jul;165:113438.