Honeysuckle flower (Lonicera japonica, Flos Lonicerae Japonicae, Chinese: 銀花, Pinyin: Jin Yin Hua)

Japanese honeysuckle is an invasive vine that is predominantly found in Asia, but you can find it in other parts of the world due to its invasive nature. Chances are you could find at least one species of honeysuckle in the country you live in. Do be careful as I don’t know whether all of them have medicinal benefits.

The flowers of this plant are quite rare as there are not that many present on the plant and they shrink upon drying. That’s why you can expect the price of this herb to be somewhere between 3-6 USD per 50 g/1.76 oz.

Lonicera japonica

Honeysuckle flowers are a staple of Chinese medicine, not to mention they are very well-researched and edible. Don’t confuse it with Ren Dong Teng (Caulis Lonicerae), which is the stem of the japanese honeysuckle.

Constituents (more than 140 of them):

essential oil, polysaccharides, organic acids (chlorogenic, caffeic, hexadecanoic, myristic, isochlorogenic and its isomers), flavones (hyperoside, corymbosin, quercetin-3-O-ß-D-glucoside, luteolin-7-O-α-D-glucoside, biflavones, luteolin-7-O-ß-galactoside), saponins (mainly hederagenin and oleanone type), iridoids (loganin, sweroside, secoxyloganin, secologanin, kingiside, ketologanin, 7α-morroniside, 7ß-morroniside, secologanoside, lonijaposides A-L, secoiridoid glycosides, loniceracetalides A-B), lonijaposides A1-A4, B1-B2, shuangkangsu, inorganic elements (Fe, Mn, Cu, Zn, Ti, Sr, Mo, Ba, Ni, Cr, Pb, V, Co, Li) 1

Antiviral properties:

  • Active against pneumonia, RSV, HIV-1 (HIV-1 RT), HSV-1, cytomegalovirus, SARS, pseudorabies, Newcastle virus, respiratory viruses, enterovirus 71, herpes zoster, influenza virus A, B and A3 (shuangkangsu), hepatitis B (caffeoylquinic acids) 1,2

Antibacterial properties:

  • Active against: MRSA, MRSH, MRSE, HLAR, Listeria monocytogenes, B. subtilis, B. cereus, S. aureus, Salmonella enteritidis, Salmonella typhimurium, E. coli, Enterobacter aerogenes, Streptococcus hemolyticus, Bacillus dysenteriae, B. comma, B. typhosus, B. paratyphosus, B. tuberculosis, B. adhaerens, Pseudomonas aeruginosa, Klebsiella pneumoniae, S. mutans, Bacteroides melanogenicus, Haemophilus actinomycetemcomitans, Actinomyces viscosus, Salmonella paratyphi, Diplococcus intracellularis, Mycobacterium tuberculosis, C. albicans 1,2
  • Eliminates R plasmid from Pseudomonas aeruginosa 1
  • May contain derivates of thymol (7-acetyl-8,9-dihydroxy thymol-and 7,8-dihydroxy-9-buyryl thymol) with strong antibiotic effects 3

Antifungal properties:

  • Active against: Aspergillus spp., Penicillium citrinum, Saccharomyces cerevisiae, Cryptococcus neoformans, Fusarium moniliforme, C. albicans 2

Anti-inflammatory properties:

  • Inhibits COX-1, COX-2, COX-2 protein expression and COX-2 mRNA (H2O) 1
  • Inhibits secretion of TNF-α, expression of mRNA tryptase and ERK phosporylation (inhibits activation of mast cells) 1
  • Inhibits activity of myeloperoxidase 1
  • Ochnaflavone- anti-inflammatory effects, COX-2 and LTC4 inhibitor 1
  • May decrease IFN-γ, IL-12, IL-17, IL-6 and protect against colitis-induced histological damage of the colon 4

Anti-cancer properties:

  • polysaccharides inhibit sarcoma (through regulation of Bcl-2/Bax pathway) 5
  • Japoflavone D- modulates apoptosis of liver cancer and protects liver cells 6
  • Cytotoxic to Ehrlich ascites cancer cells, sarcoma, liver cancer (both ethanol and water) 5
  • Cytotoxic towards lung cancer (induces apoptosis through activation of AIF and distribution of HSP27) (ethanol) 5
  • Polyphenols (mainly protocatechuic and chlorogenic acids)- active against liver cancer, they block cell cycle in G2/M phase and induce apoptosis (reduce CDK1, CDC25C, cyclin-B1, PARP, procaspase 3 and 9, inhibit PI3k/Akt, activate MAPKs) 5
  • Hydnocarpin – against colon cancer (inhibits Wnt/ß-catenin signalization, antiproliferative effects) 5
  • Essential oil – potential against glioma and liver cancer 5
  • 7’’-methylagathisflavone and 7,7’’-dimethyllanaraflavone, ochnaflavone- active against cancer (colon, lung, breast, ovaries, kidney, leukemia, lymphoma), ochnaflavone modulates expression of proteins responsible for cell cycle of cancer, it also increases caspases 3,8,9 and activates PARP cleavage 5

Antioxidant properties (mainly due to luteolin, caffeic acid, protocatechuic acid, derivates of quercetin, isorhamnetin and luteolin):

  • polysaccharides increase activity of GSH-Px, CAT, increase SOD, decrease MDA 1

Hepatoprotective properties (mainly flavones):

  • decrease elevated liver and spleen indices, improve histopathological changes of liver, inhibit expression of TNF-α in liver tissue, reduce NO and iNOS expression (ethanol) 1
  • japoflavones C-D – hepatoprotective and active against liver cancer 6,7
  • May prevent nonalcoholic steatohepatitis and alleviate fibrosis and hepatic inflammation 8

Antihyperlipidemic properties:

  • decreases cholesterol and atherosclerotic accumulation index 1

Diabetes:

  • May decrease total cholesterol, triglycerides, LDL-C, VLDL-C, increase HDL-C, improves oxidative stress in liver, decreases sugar and insulin in serum 9
  • Potent inhibitor of α-glucosidase/maltase (methanol) 10
  • May improve diabetic nephropathy through reduction of inflammation and mitigation of glomerular pathological changes, reduction of accumulation and infiltration of macrophages and T cells in kidney tissue 11

Neuroprotective properties:

  • Inhibits NF-κB, iNOS, COX-2, IL-1ß, MCP-1, MMP-9, through suppression of phosphorylation of ERK 1/2, JNK, JAK1(STAT)1/3, PI3K/Akt and MAPKs 12
  • Protects neurons from glutamate neurotoxicity 13
  • Polysaccharides LJW0F2 and LFA03-a may inhibit aggregation of ß-amyloid plaques and induce neurite growth to help combat Alzheimer’s disease 14,15

Cardioprotective:

  • Caffeoylquinic acids protect cardiomyocytes from apoptosis and necrosis through inhibiting generation of ROS 16
  • Rutin inhibits apoptosis of heart tissue that may occur during ischemia-reperfusion injury and reduces possible infarct size 17

Chondroprotective:

  • 8,4′-di-O-methylquercetin-3′-O-β-galactosyl-3-O-β-glucopyranoside may be beneficial for for rheumatoid arthritis and joint inflammation 18

Immunomodulatory:

  • May improve proliferation of splenocytes and enhance humoral immunity 2
  • Polysaccharides have immunomodulatory properties and may help with immunosuppression 19
  • May be capable of reversing apoptosis of lymphocytes during sepsis and improve production of cytokines 20,21

Misc:

  • potential lipase inhibitor (ethanol) 1
  • improves wound healing 22
  • protects against UV-radiation 2
  • may inhibit platelet aggregation 2
  • may promote growth of probiotic bacteria in the colon at small doses 2
  • protects against gout as LJP-1 polysaccharide decreases uric acid in serum, inhibits xanthine oxidase, decreases IL-1ß, IL-6 23

Toxicity: Non-toxic (LD50 of injections was found to be 53 g/kg while LD50 of orally administered extract was found to be higher than 15 g/kg) 2

Personal experience: The flowers have comparable properties in water and alcohol. Tincture of the flowers is okay, but not required. When preparing an infusion, feel free to cover your cup as to help more of the essential oil to stay in the water.

Taste: very pleasant

References

  1. Shang, X., Pan, H., Li, M., Miao, X. & Ding, H. Lonicera japonica Thunb.: Ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine. J. Ethnopharmacol. 138, 1–21 (2011).
  2. Li, Y. et al. Lonicerae Japonicae Flos and Lonicerae Flos: A Systematic Pharmacology Review. Evid. Based. Complement. Alternat. Med. 2015, 905063 (2015).
  3. Yang, J. et al. Two thymol derivatives from the flower buds of Lonicera japonica and their antibacterial activity. Nat. Prod. Res. 32, 2238–2243 (2018).
  4. Park, J.-W. et al. Prophylactic effects of Lonicera japonica extract on dextran sulphate sodium-induced colitis in a mouse model by the inhibition of the Th1/Th17 response. Br. J. Nutr. 109, 283–292 (2013).
  5. Xu, J. P. Cancer inhibitors from Chinese natural medicines. Cancer Inhibitors from Chinese Natural Medicines (CRC Press, 2016). doi:10.1201/9781315366753
  6. Ge, L. et al. Novel flavonoids from Lonicera japonica flower buds and validation of their anti-hepatoma and hepatoprotective activity in vitro studies. Ind. Crops Prod. 125, 114–122 (2018).
  7. Wan, H. et al. Effects of a novel biflavonoid of Lonicera japonica flower buds on modulating apoptosis under different oxidative conditions in hepatoma cells. Phytomedicine 57, 282–291 (2019).
  8. Tzeng, T.-F., Tzeng, Y.-C., Cheng, Y.-J., Liou, S.-S. & Liu, I.-M. The Ethanol Extract from Lonicera japonica Thunb. Regresses Nonalcoholic Steatohepatitis in a Methionine- and Choline-Deficient Diet-Fed Animal Model. Nutrients 7, 8670–8684 (2015).
  9. Wang, D., Zhao, X. & Liu, Y. Hypoglycemic and hypolipidemic effects of a polysaccharide from flower buds of Lonicera japonica in streptozotocin-induced diabetic rats. Int. J. Biol. Macromol. 102, 396–404 (2017).
  10. Zhang, Z. et al. α-Glucosidase inhibitory activity by the flower buds of Lonicera japonica Thunb. J. Funct. Foods 5, 1253–1259 (2013).
  11. Tzeng, T.-F., Liou, S.-S., Chang, C. & Liu, I.-M. The Ethanol Extract of Lonicera japonica (Japanese Honeysuckle) Attenuates Diabetic Nephropathy by Inhibiting p-38 MAPK Activity in Streptozotocin-Induced Diabetic Rats. Planta Med. 80, 121–129 (2014).
  12. Kwon, S.-H., Ma, S.-X., Hong, S.-I., Lee, S.-Y. & Jang, C.-G. Lonicera japonica THUNB. Extract Inhibits Lipopolysaccharide-Stimulated Inflammatory Responses by Suppressing NF-κB Signaling in BV-2 Microglial Cells. J. Med. Food 18, 762–75 (2015).
  13. Weon, J. B. et al. Neuroprotective activity of the methanolic extract of Lonicera japonica in glutamate-injured primary rat cortical cells. Pharmacogn. Mag. 7, 284–8 (2011).
  14. Liu, Q. et al. Characterization of a pectin from Lonicera japonica Thunb. and its inhibition effect on Aβ42 aggregation and promotion of neuritogenesis. Int. J. Biol. Macromol. 107, 112–120 (2018).
  15. Wang, P. et al. A glucan isolated from flowers of Lonicera japonica Thunb. inhibits aggregation and neurotoxicity of Aβ42. Carbohydr. Polym. 110, 142–147 (2014).
  16. Wang, C., Wang, G., Liu, H. & Hou, Y.-L. Protective effect of bioactive compounds from Lonicera japonica Thunb. against H2O2-induced cytotoxicity using neonatal rat cardiomyocytes. Iran. J. Basic Med. Sci. 19, 97–105 (2016).
  17. Jeong, J. J. et al. Rutin from Lonicera japonica inhibits myocardial ischemia/reperfusion-induced apoptosis in vivo and protects H9c2 cells against hydrogen peroxide-mediated injury via ERK1/2 and PI3K/Akt signals in vitro. Food Chem. Toxicol. 47, 1569–1576 (2009).
  18. Xiao, Y., Li, B. & Liu, J. A new constituent against rheumatoid arthritis from the flower buds of Lonicera japonica. Phytochem. Lett. 29, 160–164 (2019).
  19. Zhou, X. et al. Immunomodulatory activity of a novel polysaccharide from Lonicera japonica in immunosuppressed mice induced by cyclophosphamide. PLoS One 13, e0204152 (2018).
  20. Kim, S.-J. et al. HS-23, a Lonicera japonica extract, reverses sepsis-induced immunosuppression by inhibiting lymphocyte apoptosis. J. Ethnopharmacol. 171, 231–239 (2015).
  21. Kim, S.-J. et al. HS-23, Lonicera japonica extract, attenuates septic injury by suppressing toll-like receptor 4 signaling. J. Ethnopharmacol. 155, 256–266 (2014).
  22. Chen, W.-C., Liou, S.-S., Tzeng, T.-F., Lee, S.-L. & Liu, I.-M. Wound repair and anti-inflammatory potential of Lonicera japonica in excision wound-induced rats. BMC Complement. Altern. Med. 12, 1273 (2012).
  23. Yang, Q. et al. Anti-hyperuricemic and anti-gouty arthritis activities of polysaccharide purified from Lonicera japonica in model rats. Int. J. Biol. Macromol. 123, 801–809 (2019).