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Response to “Molecular and cellular assessment of Gingko biloba extract as a possible ophthalmic drug”, by G. Thiagarajan, S. Chandani, S. Harinarayana Rao, A.M. Samuni, K. Chandrasekaran and D. Balasubramanian [Experimental Eye Research 75 (2002) pp. 421–430]
Experimental Eye Research 77 (2003) 117 www.elsevier.com/locate/yexer
Letter to the Editors
Response to “Molecular and cellular assessment of Gingko biloba extract as a possible ophthalmic drug”, by G. Thiagarajan, S. Chandani, S. Harinarayana Rao, A.M. Samuni, K. Chandrasekaran and D. Balasubramanian [Experimental Eye Research 75 (2002) pp. 421 – 430] Robin Richard Socci* Department of Pharmacology/Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA Received 7 February 2003; accepted 3 March 2003
I am writing in response to a recent publication by Thiagarajan and colleagues on the use of standardized Ginkgo biloba extract as a possible ophthalmic drug (Exper Eye Res, 2002; 421 –430). They described the use of the standardized extract of Ginkgo biloba (EGb761), an efficient antioxidant with cytoprotective action, to retard selenite-induced cataract formation in an in vivo rat model. This extract is produced by the Beaufourt-Ipsen Company of France and contains 24% flavonol glycosides and 6% terpene lactones. Their report highlights the importance of the flavonoid fraction in the antioxidant activity, as well as the importance of both flavonoids and terpenes for the cytoprotective action. In addition, by showing the components of EGb761 cross the blood-aqueous barrier in the selenite-induced cataract rat model, they demonstrated that a non-ocular route of administration is available. The authors correctly indicate the dried leaf preparation of Ginkgo biloba has components, i.e., alkylphenols, which
have been shown to have deleterious effects. However, by stating the over-the-counter forms of Ginkgo biloba available in drug and natural food stores are of the dried leaf preparation, they fail to mention the EGb761 extract is available commercially in certain over-the-counter brands. In a search on the Internet using ‘EGb761’ as a keyword, I found health-related websites, such as Health World Online, as well as those of health food stones, i.e., www. gnc.com, indicating the brands containing this standardized extract. For physicians who decide to use EGb761 extract as part of their treatment of glaucoma or other ocular diseases, this over-the-counter brand information is important in advising their patients about what is available. In addition, both the physician and the patient should be aware of potential interactions between this extract and the other medications that the patient maybe taking.
* R.R. Socci, PhD, Department of Pharmacology/Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA. E-mail address: [email protected] (R.R. Socci). 0014-4835/03/$ - see front matter q 2003 Elsevier Science Ltd. All rights reserved. DOI:10.1016/S0014-4835(03)00066-6
Letter to the Editors
Response to “Molecular and cellular assessment of Gingko biloba extract as a possible ophthalmic drug”, by G. Thiagarajan, S. Chandani, S. Harinarayana Rao, A.M. Samuni, K. Chandrasekaran and D. Balasubramanian [Experimental Eye Research 75 (2002) pp. 421 – 430] Robin Richard Socci* Department of Pharmacology/Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA Received 7 February 2003; accepted 3 March 2003
I am writing in response to a recent publication by Thiagarajan and colleagues on the use of standardized Ginkgo biloba extract as a possible ophthalmic drug (Exper Eye Res, 2002; 421 –430). They described the use of the standardized extract of Ginkgo biloba (EGb761), an efficient antioxidant with cytoprotective action, to retard selenite-induced cataract formation in an in vivo rat model. This extract is produced by the Beaufourt-Ipsen Company of France and contains 24% flavonol glycosides and 6% terpene lactones. Their report highlights the importance of the flavonoid fraction in the antioxidant activity, as well as the importance of both flavonoids and terpenes for the cytoprotective action. In addition, by showing the components of EGb761 cross the blood-aqueous barrier in the selenite-induced cataract rat model, they demonstrated that a non-ocular route of administration is available. The authors correctly indicate the dried leaf preparation of Ginkgo biloba has components, i.e., alkylphenols, which
have been shown to have deleterious effects. However, by stating the over-the-counter forms of Ginkgo biloba available in drug and natural food stores are of the dried leaf preparation, they fail to mention the EGb761 extract is available commercially in certain over-the-counter brands. In a search on the Internet using ‘EGb761’ as a keyword, I found health-related websites, such as Health World Online, as well as those of health food stones, i.e., www. gnc.com, indicating the brands containing this standardized extract. For physicians who decide to use EGb761 extract as part of their treatment of glaucoma or other ocular diseases, this over-the-counter brand information is important in advising their patients about what is available. In addition, both the physician and the patient should be aware of potential interactions between this extract and the other medications that the patient maybe taking.
* R.R. Socci, PhD, Department of Pharmacology/Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA. E-mail address: [email protected] (R.R. Socci). 0014-4835/03/$ - see front matter q 2003 Elsevier Science Ltd. All rights reserved. DOI:10.1016/S0014-4835(03)00066-6