Dendrobium species of plants are apparently highly prized medicinal medicines, in regards to being a 'stomach tonic' and the candidum species is known for aiding body fluid excretion (saliva, tears). There are around 200 species of Dendrobium, although only a few have been used medicinally.
Dendrobium includes a variety of bioactives, including (species listed in brackets):
Sequesterpene aglycones such as copacamphane, picrotoxane, and alloaromadendrane (moniliforme stem) as well as dendrosides A, C, and F as well as vanilloloside
Dendrochrysanene (chrysanthum stem)
Batatasin III, gigantol, hircinol and 7-methoxy-9,10-dihydrophenanthrene-2,4,5-triol (draconis stem) which are associated with 'blood tonic' tea in Thailand. Gigantol and Hircinol are also found in other species (trigonopus)
Neutral polysaccharide (Densiflorum)
Chalcone, an aromatic ketone used in anthocyanin synthesis (sonia)
Possibly sucrose, due to presence of sucrose synthesis enzymes (officinale)
Nucleic acids (Adenosine, Uridine, Guanosine) and other acids (candidum)
Different species in the Dendrobium family appear to have widely different bioactives, and the exact species of the plant consuming is probably going to be very important to know
Currently, one of the few human studies on Dendrobium has been conducted in persons with Sjögren's syndrome (autoimmune syndrome where salivary and tear ducts are targeted) noted improvements in salivation. It was thought to help due to Sjögren's syndrome being characterized by abnormally low distribution of Aquaporin-5 in the salivary glands of these patients and previous animal models establishing that abolishment of AQP-5 results in a 65% reduction in salivation. This study, using a liquid form of Dendrobium Candidum at a 0.5g/mL concentration with 5mL aliquiots (so, 2.5g doses thrice a day for a weeks time) and it appeared to increase salivation rates by approximately 65% in persons with treatment relative to placebo. This increase in salivation was accompanied by a normalization of AQP-5, where the protein was not expressed at the apical membrane of Sjögren's patients but was after Dendrobium treatment, the increase was about 35% relative to placebo. In mice, Dendrobium reduced water intake suggesting it could aid dry mouth symptoms and it is suggested this may be due to the polysaccharide content and potentially have some cross-over with Dendrobium officinale.
Demonstrated in at least on human trial to increase salivation, but the trial was in persons with Sjögren's syndrome and may not apply to persons without
Anti-proliferative activities have been seen with the methanolic extract (and attributed to three phenanthrenes) of Dendrobium Nobile in vitro with immortalized rat HSC-T6 cells, which suggest anti-fibrotic activities of this extract in these isolated stellate cells. These three phenanthrenes, denbinobin (DEN), fimbriol-B (FIM) and 2,3,5-trihydroxy-4,9-dimethoxyphenanthrene (THDMP) were reassessed in HSC-T6 cells and noted that they were nontoxic to primary liver cells, yet caused a dose dependent reduction in HSC-T6 cells at 1-50uM attibuted to apoptosis. The growth inhibitory actions of these phenanthrenes was similar to EGCG from green tea catechins and has also been suggested to apply to Dendrobium huoshanense, another medicinal species.
Dendrobin, a phenanthrene isolated from Dendrobium moniliforme and Nobile, appears to have anti-cancer potential.
When Dendrobium Nobile has its phenanthrenes tested (showing efficacy in reducing liver fibrosis in vitro) they do not appear to significantly influence TNF-α production in stimulated macrophages by LPS although this inhibition has been noted in RAW 264.7 macrophages elsewhere with moderate potencies (9.6μM to 35.7μM). However, TNF-α induced inflammation (as well as PMA-induced) via NF-kB translocation has been demonstrated to be inhibited by Denbinobin, also in Nobile. This study was done in leukemic cells, and noted that Denbinobin inhibited NF-kB secondary to TAK1 inhibition, which prevented IKK and IκBα activation at 2.5uM. This inhibition of NF-kB has been noted previously in HIV-1 cells, and does not interfere with MAPK, ERK, JNK, or p38 signalling.
Oral administration of Dendrobum officinale polysaccharides to mice appears to beneficially influence cellular immunity and nonspecific immunity while a non-polysaccharide fragment exerts benefit to humoral immunity.
The huoshanense species, in a pilot study in youth (4-18), appears to benefit atopic dermatitis symptoms, and reduce circulating cytokines assocaited with atopic dermatitis.