Table 2.

Summary of the main effects of the discussed herbal compounds on retinal ganglion cells and intraocular pressure.

Herbal compounds	In vitro or animal studies	Human studies	Effects on RGCs	Effects on IOP
Ginkgo biloba	2	2	Possible reduction of the damage induced by oxidant agents both in animal models and in NTG patients [30–33] No data on POAG patients	Not demonstrated
Scutellaria baicalensis Georgi	4	—	Strong capacity to protect RGCs from oxidative stress in animal and in vitro models [52–54, 56] No data on human models	Not demonstrated
Crocus sativus L.	1	2	Neuroprotective effects derived from antioxidant and anti-inflammatory effects both in animal models and in POAG patients [65] No data on NTG patients	Conflicting results from human studies on POAG patients [67, 68] No data on NTG patients
Coleus forskohlii	3	4	Not demonstrated	Conflicting results from studies on animal models, healthy people, and POAG patients [79–85] No data on NTG patients
Vaccinium myrtillus	1	3	Neuroprotective effects through retinal microcirculation improvement both in animal and human models [93]	Slight IOP reduction if administered orally in patients with ocular hypertension [94–96] No data on POAG and NTG patients
Ribes nigrum L.	—	3	Neuroprotective effects through ocular blood flow improvement in POAG patients [97, 98] No data on NTG patients	IOP decrease both in healthy people and POAG patients [99] No data on POAG patients
Erigeron breviscapus	—	1	Stimulating effects in POAG patients with IOP in a controlled range [102] No data on NTG patients	Not demonstrated
Salvia miltiorrhiza	1	1	Neuroprotective effects on animal model and POAG patients [104, 105] No data on NTG patients	Not demonstrated