Populus tremuloides.- American aspen  P. alba.- White poplar, P. nigra.- Black poplar    Family: Salicaceae       
P. alba and P. nigra are Europen species. P. tremuloides is North American.

PART USED: Bark
TASTE: Bitter ODORLESS
ACTIONS
GROUP: The Musculo-Skeletal System- Antirheumatics.
1. Antirheumatic.[1] Anti-inflammatory.[1,3]
2. Astringent.[1,3]
3. Cholagogue.[1]
4. Anodyne.[1,3]
5. Diuretic.[3] Urinary tonic.
6. Antiseptic.[1]
7. Bitter tonic.[2] Stimulant.[3]
INDICATIONS
1. Rheumatic disorders, especially rheumatoid arthritis.[1] Muscular and arthrodial rheumatism.[1] Neuralgias including sciatica.[2]
2. Uterine or vaginal weakness.[2] Dysmenorrhea.[2] Leukorrhea.[2]
3. Debility and Anorexia with stomach or liver disorders.[1,3] Dyspepsia.[2] Diarrhea.[1]
4. Cystitis.[1,3] Bladder catarrh.[2] Dysuria.[2] Bladder problems during pregnancy or after operations.[2]
5. The common cold.[1] Influenza.[2]
6. Wounds.[2] Ulcers.[2] Burns.[2] Eczema.[2]
7. Jaundice.[2]
SPECIFIC INDICATIONS: Rheumatoid arthritis.[1]
COMBINATIONS
- Rheumatoid arthritis, with Cimicifuga and Menyanthes.
- Anorexia with Gastrointestinal tract weakness, with Berberis and Chelone.
PREPARATIONS:   3X /day
Dried bark  1-4 g,[1,2,3] or by decoction[1] 1:20.[2]
Fluid extract  1:1 in 25% alcohol  1-4 ml.[1,3]
      
ORIGIN: Britain and Europe.
DESCRIPTION: Bark- occurs as curved or flattened pieces or may be shredded. The outer layer is usually removed, leaving a dull brown surface. The inner surface is smooth and varies in color from nearly white to brown.
References
Inner Path can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.
Constituents
Research
The salicylates are well known for their antiinflammatory activity.[1]
References
[1] Martindale. The Extra Pharmacopoeia, 27th Ed. Pub. The Pharmaceutical Press (1977) UK

Phenolic Compounds from Populus alba L. and Salix subserrata Willd. (Salicaceae) Counteract Oxidative Stress in Caenorhabditis elegans
Nora Tawfeek, Mansour Sobeh, Dalia I Hamdan, Nawaal Farrag, Mariana Roxo, Assem M El-Shazly, Michael Wink
Abstract
Utilizing bioassay- and TLC-guided column chromatography, fifteen secondary metabolites from Populus alba and eight compounds from Salix subserrata were isolated, including a novel plant metabolite salicyl ether and characterized using ultralviolet light (UV) absorbance, mass spectrometry (MS), 1H-, 13C-NMR (nuclear magnetic resonance), heteronuclear single quantum coherence spectroscopy (HSQC) and heteronuclear multiple bond correlation (HMBC). The extracts, their sub-fractions and the isolated compounds exhibited promising antioxidant activities in vitro in DPPH and FRAP assays. Also, the extracts of P. alba leaf (PL), shoots (PS), and S. subserrata leaf (SL) demonstrated substantial antioxidant activities in vivo in the multicellular model organism Caenorhabditis elegans. For the first time, the isolated secondary metabolites, aromadendrin, tremuloidin, salicin, isorhamnetin-3-O-ß-d-rutinoside, gallocatechin, triandrin, and chrysoeriol-7-O-glucuronide were investigated. They exhibited substantial antioxidant activities in vivo. Salicin, isorhamnetin-3-O-ß-d-rutinoside and gallocatechin, in particular, protected the worms against a lethal dose of the pro-oxidant juglone (80 µM), decreased the endogenous reactive oxygen species (ROS) level to 45.34%, 47.31%, 68.09% and reduced juglone- induced hsp-16.2::GFP (green fluorescence protein) expression to 79.62%, 70.17%, 26.77%, respectively. However, only gallocatechin induced higher levels of sod-3 expression. These findings support the traditional use of Populus alba and Salix subserrata for treating inflammation especially when ROS are involved.
Molecules 2019 May 24;24(10):1999. doi: 10.3390/molecules24101999. PMID: 31137712 PMCID: PMC6571762 DOI: 10.3390/molecules24101999 pubmed.ncbi.nlm.nih.gov  

Antioxidant phenolic glycosides from the bark of Populus ussuriensis Kom
Chuan-Ling Si 1, Shu-Ming Li, Zhong Liu, Jin-Kyu Kim, Young-Soo Bae
Abstract
Study on the EtOAc soluble fraction from the bark of Populus ussuriensis Kom. resulted in the isolation of three phenolic glycosides, including populoside (1), 7-O-r-coumaroylsalirepin (2) and 7-O-caffeoylsalirepin (3), among which 3 is a new compound. The structures of these compounds were elucidated on the basis of spectroscopic evidence. Phenolic glycosides 1-3 exhibited excellent antioxidant activity, evaluated in the ABTS* radical scavenging assay.
Nat Prod Res 2011 Sep;25(15):1396-401. doi: 10.1080/14786410802267700. Epub 2011 Jul 8. PMID: 19662569 DOI: 10.1080/14786410802267700 pubmed.ncbi.nlm.nih.gov