In Vitro and In Vivo
Multiple in vitro studies suggest that Ginkgo extract may have anticancer effects. The main active compound of Ginkgo extract, ginkgolide B, inhibited human ovarian cancer cell growth alone and in combination with cis-diaminodichloroplatinum (CDDP), and was less toxic to normal ovarian epithelial cells.5
Another study demonstrated that Ginkgo extract was synergistic with CDDP and etoposide in human gastric cancer cells.6 Treatment with Ginkgo extract of the seed coat inhibited the growth, migration, and invasion, as well as increased apoptosis, of human pancreatic cells.7 Ginkgo extract also induced apoptosis of estrogen-negative human breast cancer cells and inhibited aromatase in hormone-dependent breast cancer cells.8,9
Adding Ginkgo extract to rats with mammary tumors treated with tamoxifen modestly improved efficacy compared with rats treated with tamoxifen alone.10
Despite the multiple positive reports of in vitro efficacy of Ginkgo extract, few in-human studies are published. Two single-arm phase 2 trials that treated patients with pancreatic or colorectal cancer with Ginkgo extract in combination with 5-fluorouracil (5-FU) demonstrated an overall response rate of 9.4% and 6.3%, respectively.11,12 The extract was well tolerated, with adverse events related to 5-FU treatment.
A single-arm trial treated 32 patients with advanced hepatocellular carcinoma with increasing doses of Ginkgo extract (60 mg, 120 mg, or 240 mg once daily) plus sorafenib (400 mg twice daily).13 Partial response occurred in 3 patients, stable disease in 21, and progressive disease in 8. The overall survival was 11.6 months, with a median time to progression of 2.5 months.