A new study has found that, in mouse models of prostate cancer, a compound extracted from sandalwood oil was effective in slowing the onset and growth of tumors and resulted in cell death. Further research will explore whether the extract can be used to treat prostate cancer in humans.
While early detection and treatment have improved outcomes for men with prostate cancer, standard treatments such as radio- and chemotherapy can be less effective against advanced forms of the disease – time, then, to look for alternative therapies. Researchers from Florida Atlantic University’s (FAU) Schmidt College of Medicine have turned to nature for such a treatment, testing whether a sandalwood oil extract could be effective against prostate cancer.
“Identifying agents that have the ability to selectively target cancerous cells and delay onset and progression of prostate cancer is greatly needed,” said Ajay Bommareddy, the lead and corresponding author of the study.
For many centuries, sandalwood oil derived from the Santalum album or Indian sandalwood tree has been used worldwide for its health benefits and medicinal applications. The oil is primarily comprised of santalol, which is a mixture of alpha- and beta-santalol. Previous studies, including by FAU researchers, have found that alpha-santalol is effective in suppressing the growth of human cancer cells and inducing programmed cell death, or apoptosis.
After isolating 95% pure alpha-santalol from sandalwood oil, the researchers administered it by intraperitoneal injection to mouse models of prostate cancer. Control mice were given a saline solution. The body weights of the mice were recorded weekly and, after treatment for 20 weeks, vital organs were collected and weighed. A portion of the prostate tumor tissues from the treatment and control groups was analyzed.
The researchers found no difference in body weight between treatment and control groups, indicating that alpha-santalol was well-tolerated. Compared to controls, the extract reduced the incidence of visible prostate tumors. Only one out of the nine mice (11%) in the treated group developed tumors, whereas five out of nine (56%) control mice did. The average wet weight of the treated mice’s prostate glands was 52.9% lower than that of untreated mice.
When they compared the area occupied by healthy tissue in alpha-santalol-treated mice, it was 53% compared to 12% in control mice. This indicated that the extract protected the healthy tissue and delayed progression from prostatic intraepithelial neoplasia (PIN), a pre-cancerous condition where some prostate cells have started to look and behave abnormally, to poorly differentiated carcinoma, a high-grade form of cancer, where they are very abnormal. These results are significant, the researchers say, because prostate cancer mortality is mainly attributable to advanced stages of the disease.
The expression of Ki-67, a widely used prognostic marker for tumor cell proliferation and growth, was reduced by 74.42% in treated mice compared with controls. Further, the number of apoptotic – that is, dying – cells was higher in alpha-santalol-treated animals.
“Although our cellular studies provided important mechanistic insights, relevant in vivo models are vital for developing novel chemo-preventive agents for clinical use and to determine if alpha-santalol offers protection against prostate cancer development,” Bommareddy said. “Prior to this new study, alpha-santalol’s in vivo efficacy against prostate cancer had not yet been established.”
Further research is needed to explore the feasibility of using alpha-santalol as an anti-tumor agent in the treatment of prostate cancer.
The study was published in the journal Phytomedicine Plus.
Source: FAU
