>> Ginkgo Biloba
1. J Pharm Biomed Anal. 2005 Feb 23;37(2):287-95. Assays of physical stability and antioxidant activity of a topical formulation added with
different plant extracts.
Di Mambro VM, Fonseca MJ. Department of Pharmaceutical Science, Faculty of Pharmaceutical Sciences of Ribeirão
Preto, USP, Av. do Café s/n, 14040-903 Ribeirão Preto, SP, Brazil. email@example.com.
"In the present investigation the changes on physical stability (pH, viscosity, flow index and tixotropy) of topical formulations were evaluated
following inclusion of different plant extracts containing flavonoids. Also, the antioxidant effect of these plant extracts alone and after addition in
the formulation was evaluated using chemiluminescence and the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH(.-)) assays, as well as
the inhibition of lipid peroxidation. Formulation added with dl-alpha-tocopherol was used to compare the physical stability and antioxidant activity.
Formulations with plant extracts showed pseudoplastic behavior with decreasing on viscosity and tixotropy. The Glycyrrhiza glabra (GG) and
Ginkgo biloba (GB) extracts alone and the formulations containing these extracts showed great antioxidant and free radical scavenging
activities while the other extracts studied (mixture of Glycyrrhiza glabra, Symphytum officinale L and Arctium majus root, Nelumbium speciosum
and soybean) showed lower activity. The results suggest that GG and GB extracts may be used in topical formulations in order to protect skin
against damage caused by free radical and reactive oxygen species. PMID: 15708669 [PubMed - indexed for MEDLINE]"
2. J Pharm Pharmacol. 1999 Dec;51(12):1435-40. In-vivo and in-vitro assessment of the free-radical-scavenger activity of Ginkgo flavone
glycosides at high concentration.
Hibatallah J, Carduner C, Poelman MC. Département de Dermopharmacie et Biophysique Cutanée, Faculté des
Sciences Pharmaceutiques et Biologiques, Paris, France.
"Free radicals are involved in numerous skin diseases, especially inflammatory reactions and photosenescence. To identify possible free-radical
scavenging by an original terpene-free Ginkgo biloba extract containing 33% Ginkgo flavone glycosides, mostly quercetin and kaempferol
derivatives, we studied its activity by means of in-vitro and in-vivo experiments, using superoxide dismutase (SOD) as a positive control. By
means of an in-vitro electron-spin resonance (ESR) assay we compared the activity of the Ginkgo extract with that of its two aglycones,
quercetin and kaempferol. Quercetin and Ginkgo extract had significant antioxidant properties without pro-oxidant effect. In contrast, kaempferol,
above an optimum antioxidant concentration, behaved as a pro-oxidant. The in-vivo experiments were conducted on an anti-inflammatory model.
The cutaneous blood flux which reflects the skin inflammatory level was recorded by means of a laser Doppler perfusion imager. The data
confirmed the free-radical-scavenging property of both Ginkgo extract and SOD. The Ginkgo extract significantly inhibited (37%) cutaneous
blood flux to the same extent as SOD. These data confirmed the antioxidant property of Ginkgo extract. A complementary spin-trapping technique
would enable identification of the free radicals involved. This Ginkgo extract should be useful for protection of the skin against free radicals.
PMID: 10678500 [PubMed - indexed for MEDLINE]"
3. Skin Pharmacol. 1997;10(4):200-5. Effects of flavonoids of Ginkgo biloba on proliferation of human skin fibroblast.
Kim SJ, Lim MH, Chun IK,
Won YH. Department of Dermatology, Chonnam University Medical School, Kwangju, Korea.
"Ginkgo biloba studies have focused on the anti-inflammatory effects of the major components, ginkgolide and bilobalide, whereas little is known
about their effect on fibroblasts. This study demonstrated the enhancing effects of Ginkgo L. extracts, especially the flavonoid fractions:
quercetin, kaempferol, sciadopitysin, ginkgetin, isoginkgetin, on the proliferation of normal human skin fibroblast in vitro measured by MTT (3-[4,5
-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide) assay and direct hemocytometer cell count. Furthermore, increased production of
collagen and extracellular fibronectin were documented by radioisotope (2,3-3H-proline) incorporated collagen assay, procollagen type I C-
peptide assay and by immunoturbidimetric assay. These proliferative effects suggest another useful pharmacologic application of Ginkgo L.
extracts in addition to their well-known anti-inflammatory effect. PMID: 9413894 [PubMed - indexed for MEDLINE]"