Category: antimicrobial

Baical Skullcap – additional uses for aerial parts

On By philrasmIn Antibiotic Resistance, antimicrobial, Herbal Medicine, UncategorizedLeave a comment

Baical Skullcap

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 in a large number of Traditional Chinese Medicine formulations used to treat numerous disease conditions. These include allergic diseases, respiratory tract infections, pneumonia, colitis, hepatitis, dementia, Parkinson’s disease and cancer.

Scutellaria baicalensis is botanically related to Scutellaria lateriflora (commonly known as Skullcap or American Skullcap in western Herbal Medicine), best known for its anxiolytic and sedative properties.  However, the root of Baical skullcap is the plant part traditionally used, whereas for American Skullcap it is the aerial parts (leaves and stems).

Over 50 compounds have been isolated and identified from Baical skullcap, including flavonoids, terpenoids, volatile oils and polysaccharides. Flavonoids including baicalein and its metabolite baicalin and wogonin, are key active phytochemicals.  These occur in highest levels within the root, and virtually all research on this impressive plant has involved use of root-derived preparations.

Research on aerial parts

While not well known, other parts of Baical skullcap, are also sometimes used for therapeutic purposes.

Improved cognition in vascular dementia and in animal models of Alzheimer’s disease, and prevention of cerebral ischaemia reperfusion injury, have previously been reported in rats following administration of concentrated flavonoid extracts made from stems and leaves of Scutellaria baicalensis (1-5). While required dosages were large, favourable results using these animal models for common age-related conditions are encouraging. They also highlight potential applications in both veterinary and human medicine, for parts of the plant normally regarded as waste products from root farming operations. These have a different phytochemistry to the root, with the flavonoid scutellarin being predominant.

Poultry industry applications

The poultry industry is a huge global operation, but as it has grown and poultry farms become larger, challenges in relation to animal health and husbandry have also increased.

Most chicken farms around the world still rely heavily on regular use of antibiotics for disease prevention and control, and sometimes also to promote growth. However, such widespread use can lead to deposition of antibiotic residues in the soil and waterways, and the promotion of microbial mutations and antibiotic resistance. These are serious consequences for the environment, animal and human health(6).  Since 2006, the European Union has banned the use of antibiotics as growth promoters in farm animals. Their use in Australia and New Zealand, is also now limited to sick animals only.

Bacterial and viral infections nevertheless remain challenging for poultry farmers, and can lead to substantial losses in laying hens or in those farmed for meat.  Despite improvements in housing and management practices in recent years, infections such as salmonella or bird flu remain a constant threat.

A recent study by Chinese researchers, has now found the normally discarded tops of Baical skullcap to offer promise in helping farmers to manage respiratory tract pathogens in poultry.

Recent research

The study, conducted by agricultural researchers and veterinarians in Beijing, investigated the effects of an ethanolic extract of the stems and leaves of Scutellaria baicalensis, on respiratory symptoms in diseased laying hens.

Three groups of 60 diseased laying hens were randomly selected. One group was given a diet supplemented with dried Baical skullcap stem and leaf powder, another with a hydroethanolic extract of the stem and leaf, and one the usual diet only, for a period of 12 days.

After the 12 day supplementation period, hens given the Baical skullcap extract had a marked improvement in respiratory tract symptoms such as coughing, a runny nose and labored breathing. Subsequent biopsies revealed a significant improvement in lung tissue lesions and inflammation. Baical skullcap supplementation was also associated with a significant upward trend in the egg production rate starting 3 days after supplementation commenced, as well as improvements in egg quality(7).

Previous work

Earlier work in Europe found a combination of turmeric and baical skullcap given as a feed additive to chickens decreased gut inflammation and improved the health of chickens with the pathogen Salmonella enteritidis(8). Salmonella is a serious pathogen in chickens which can affect both meat and egg production and quality.

Another recent Chinese study found a combination of baical skullcap with flowers of Lonicera japonica (Japanese honeysuckle, a noxious weed in Aotearoa New Zealand)(9), to mitigate the negative effects of Clostridia perfringens infection in chickens. This is another gastrointestinal pathogen causing reduced growth and mortality in poultry, also normally treated with antibiotics. Mechanisms of action were related to improvement in intestinal barrier function, leading to a positive influence on the growth performance of challenged birds(10).

Economic and environmental benefits

Potential applications to develop animal feed products containing readily available and cheap or free plant materials to manage chicken diseases naturally rather than through agrichemicals, are made apparent by this recent research.

While above ground parts of medicinal plants where the root is harvested are usually returned to the land in the form of mulch or as some form of compost, an ability to utilize these also to produce valuable medicines, is preferential.

The area of commercial cultivation of Baical skullcap in China alone is currently more than four times that of all Aotearoa New Zealand apple and pear orchards combined. This in itself speaks to the market potential of farming for the highly medicinal root.  With additional poultry industry applications being revealed for plant parts generally regarded as a waste byproduct, the case for increased research to further develop a sustainable and profitable scaled up medicinal plant cultivation industry here, continues to strengthen.

Refs:

  1. Cao Y, Liang L, Xu J, Wu J, Yan Y, Lin P, Chen Q, Zheng F, Wang Q, Ren Q, Gou Z, Du Y. The effect of Scutellaria baicalensis stem-leaf flavonoids on spatial learning and memory in chronic cerebral ischemia-induced vascular dementia of rats. Acta Biochim Biophys Sin (Shanghai). 2016 May;48(5):437-46.
  2. 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. doi: 10.3969/j.issn.1673-5374.2013.34.002.
  3. Zhang H, Liu QQ, Ding SK, Li H, Shang YZ. Flavonoids From Stems and Leaves of Scutellaria Baicalensis Georgi Improve Composited Aβ-Induced Alzheimer’s Disease Model Rats’ Memory and Neuroplasticity Disorders. Comb Chem High Throughput Screen. 2023;26(8):1519-1532. 
  4. 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
  5. Wang X, Xie Y, Bayoude A, Zhang B, Yu B. Discovering the Q-marker of scutellaria baicalensis against viral pneumonia integrated chemical profile identification, pharmacokinetic, metabolomics and network pharmacology. J Ethnopharmacol. 2025 Jan 31;340:119232.
  6. Rasmussen PL, ‘Antibiotics and their effects on Plants. www.herbblurb.com July 27, 2017.
  7. Wang X, Wu S, Guo N, Yu F, Xu X, Wang X, Yu X, Liu X, Dong H. Scutellaria baicalensis stem and leaf combat chicken-derived respiratory bacterial infection. Microb Pathog. 2025 May;202:107439. 
  8. Varmuzova K, Matulova ME, Gerzova L, Cejkova D, Gardan-Salmon D, Panhéleux M, Robert F, Sisak F, Havlickova H, Rychlik I. Curcuma and Scutellaria plant extracts protect chickens against inflammation and Salmonella Enteritidis infection. Poult Sci. 2015 Sep;94(9):2049-58.
  9. Rasmussen PL, ‘Honeysuckle and other useful weeds surrounding us. www.herbblurb.com January 24, 2019.
  10. Li S, Zhang K, Bai S, Wang J, Zeng Q, Peng H, Lv H, Mu Y, Xuan Y, Li S, Ding X. Extract of Scutellaria baicalensis and Lonicerae flos improves growth performance, antioxidant capacity, and intestinal barrier of yellow-feather broiler chickens against Clostridium perfringens. Poult Sci. 2024 Jul;103(7):103718.

PROMISING NEW FINDINGS FOR ROSEMARY

On By HerbBlurbIn Anti-inflammatory, antimicrobial, antioxidant, cancer, Herbal Medicine, Plant MedicineLeave a comment

The leaves and sprigs of Rosemary (Rosmarinus officinalis), have been widely used in food preparation and preservation and also for many medicinal purposes, almost as far back as human history began. As a popular plant that is easy to use and often readily accessible, its reputation as a meat preserver and an alleged hair restorer, are fairly well known in herbal folklore.

As with other long-esteemed herbaceous plants, rosemary’s diverse medicinal capabilities and their relevance to the needs of a modern-day world are being increasingly validated by modern research.  Rosemary is now known to have some powerful pharmacological actions, including antioxidant, hepatoprotective, anti-cancer, antimicrobial and potential antidepressant activities(1).

Further possible medicinal uses for this well-known plant have now emerged, following results from recent research.

Preservative actions have long been assigned to rosemary, and scientific evidence supporting an antimicrobial application is very encouraging(2,3). An ethanolic rosemary extract was recently reported to have promising antibacterial activity against different pathogenic bacteria, with particularly good activity against Klebsiella pneumoniae(4). The essential oil of rosemary also exhibits powerful bactericidal (bacteria killing) and anti-biofilm activity against Staphylococcus aureusand Staphylococcus epidermidis(5), common causes of infections such as UTI’s and those from medical devices such as catheters.

Another study by veterinarian researchers recently, found that rosemary essential oil improved the motility of sperm collected from roosters, during its storage at 4 degrees C. These benefits were particularly seen when low concentrations of 8.7 and 87 ug/ml of rosemary essential oil were used. This suggests potential uses in animal fertilisation, and in human fertility clinics and procedures(6). With declining rates of sperm counts and motility, anything that gives sperm a greater chance of successfully fertilising an egg, can only be a good thing. As such it is conceivable that humans (or prehumans) may become exposed to this remarkable herb even before conception itself in the future!

Rosemary also has a reputation for helping prevent cancer, and application of rosemary or its phenolic acid constituents carnosol and ursolic acid were first shown to inhibit skin cancer formation in 1994(7).  Such actions have since been extended to other forms of cancer cells, including most recently the growth of human colon adenocarcinoma(8), and three other gastrointestinal cancer cell lines(9).

Benefits on heart health are also associated traditionally with regular ingestion of this herb, and recent studies on rodents have provided some support for this.  Pre-treatment with an aqueous rosemary extract protected mice against cardiotoxicity and hepatotoxicity(10). Supplementation of the diet of rats with 0.02% rosemary for three months improved diastolic function, and reduced the degree of hypertrophy after a heart attack (myocardial infarction). These effects were associated with improved energy metabolism and decreased oxidative stress(11). Rosmarinic acid has also shown a cardioprotective effect against myocardial infarction and arrhythmia in rats(12).

Collectively, these recent studies support further investigations into the potential use of rosemary as adjuvant therapy with other cardiac drugs in those at risk of a heart attack, or to be taken immediately following such life-threatening cardiac events.

Finally, rosemary is also used in traditional medicine to alleviate rheumatic and abdominal pain. In a rat model of painful diabetic neuropathy, rosemary extract improved hyperglycemia, hyperalgesia and motor deficit(13). Triterpene constituents of an ethanolic extract also reduce abdominal pain in mice(14). These findings suggest rosemary may have analgesic and neuroprotective effects in painful diabetic neuropathy as well as abdominal pain in humans. Rosmarinic acid is likely to contribute to these effects, as other recent studies found it effective in a rat model of neuropathic pain(15-17). Analgesic properties have also previously been reported for rosemary essential oil (18).

Rosmarinic acid is a highly valued phenolic compound found not only in Rosemary, but also in many other well-known plants in the Lamiaceae and Boraginaceae families, such as Sage, Lemon balm, and Perilla (Perilla frutescens). Potentially beneficial pharmacological properties of this natural compound include anticancer, anti-angiogenic, anti-inflammatory, antioxidant, and antimicrobial activities(19,20). This has lead to increasing demands for it from the pharmaceutical industry. As a result, methods to chemically synthesise rosmarinic acid or produce it by biotechnological methods, are now being actively explored(19).

Beyond rosmarinic acid, however, the cumulative research into the diverse pharmacological actions of the reliable rosemary, show that other phenolic acids, triterpenoids, essential oil and other constituents, also seem to make powerful contributions to its many potential medicinal uses.

 

References:

  1. Andrade JM et al, Future Sci OA. 2018 Feb 1;4(4):FSO283.
  2. Ahn J et al, Food Microbiol. 2007 Feb;24(1):7-14
  3. Nieto G et al, Medicines (Basel).2018 Sep 4;5(3).
  4. Javed H 1stal, Pam J Pharm Sci 2018; 31(3):933-939.
  5. Jardak M et al, Lipids Health Dis. 2017 Oct 2;16(1):190.
  6. TouaziL et al, Vel World 2018; 11(5):590-597.
  7. Huang lT et al, Cancer Res.1994 Feb 1;54(3):701-8.
  8. Jaksevicius A, et al, Nutrients. 2017 Sep 21;9(10).
  9. Karimi N, Gastroenterol Hepatol Bed Bench. 2017 Spring;10(2):102-107.
  10. Hamed H et al, Appl Physiol Nutr Metab.2018 Apr 9. doi: 10.1139/apnm-2017-0786. [Epub ahead of print]
  11. Murino Rafacho BP, PLoS One. 2017 May 11;12(5):e0177521
  12. Javidanpour S et al, 2017 Dec;51(11-12):911-923.
  13. Rasoulian B et al, J Physiol Sci 2018; May 12 (epub ahead of print).
  14. Martinez AL et al, J Ethnopharmacol 2012; 142(1):28-34.
  15. Rahbardar GM et al, Biomed Pharmacother. 2017 Feb;86:441-449
  16. Rahbardar MGet al 2018 Feb 1;40:59-67
  17. Di Cesare Mannelli L et al,Sci Rep. 2016 Oct 7;6:34832.
  18. Raskovic A, et al, Eur Rev Med Pharmacol Sci. 2015 Jan;19(1):165-72.
  19. Swamy MK et al, Appl Micriobil Biotechnol 2018.
  20. Shekarchi M et al, Pharmacognosy Mag 2012; 8(29):37-41.