Dendrobium is used in Chinese Medicine for stomach ailments, and to promote the production of body fluid, and to reduce body heat. See Chinese Herbs for more listings

Dendrobium Research Update
Antiplatelet aggregation principles of Dendrobium loddigesii.
J Nat Prod. 1994 Sep;57(9):1271-4.
The MeOH extract of the stem of Dendrobium loddigesii was found to inhibit the aggregation of rabbit platelets induced by arachidonic acid and collagen. Two active compounds, moscatilin [1] and moscatin [2], were isolated. Moscatilin diacetate [3] also exhibited antiplatelet aggregation activity.

[Studies on the chemical constituents of Dendrobium loddigesii rolfe]
Yao Xue Xue Bao. 1991;26(4):307-10.
According to IR, UV, MS and NMR spectra of the compounds isolated from the fresh stem of Dendrobium loddigesii Rolfe (a Chinese medicine), 3 constituents were identified. They are shihunidine, shihunine and dendrophenol (4,4'- dihydroxy-3,3',5-trimethoxybibenzyl). Chemical reactions showed that shihunidine was derived from shihunine during isolation. Shihunidine and shihunine were shown to be inhibitors of Na+, K+-ATPase of the rat kidney.