In vitro antioxidant and antiproliferative activity of three rosemary (Rosmarinus officinalis L.) extract formulations

Abstract

Summary Antioxidant and antiproliferative activities of three rosemary extract formulations (VivOX 20, VivOX 40 and Inolens 50) with different contents of carnosic acid, carnosol and methylcarnosol were tested in vitro. Electron spin resonance measurements revealed that Inolens 50 extract that contained highest amount of carnosic acid was the most potent scavenger of hydroxyl (concentration of extract where 50% of its maximal scavenging activity is observed, that is, EC50, 109.54 μg mL−1), superoxide anion (EC50 = 7.94 μg mL−1) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) (EC50 = 27.4 μg mL−1)‐free radicals. Comparison of the radar charts of standard antioxidants and rosemary extracts showed similarity between antioxidant characteristics of Inolens 50 and chlorogenic and caffeic acids. Tested rosemary extracts exhibited significant (P ≤ 0.01) antiproliferative effect in cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT‐29) cell lines. In both MCF7 and HeLa cell lines, the extracts yielded very low IC50 values (concentration of extract needed to inhibit cell growth by 50%), the most pronounced being for Inolens 50 in MCF7 (IC50 = 9.95 μg mL−1) and VivOX 20 in HeLa cell line (IC50 = 10.02 μg mL−1). The obtained results may provide support for the use of tested rosemary extracts as nutraceuticals and phytopharmaceuticals.

Anticancer Effects of Rosemary (Rosmarinus officinalis L.) Extract and Rosemary Extract Polyphenols

“…Yi, et al (2011) examined the anti-tumorigenic effect of several culinary and medicinal herbs on SW480 colon cancer cells and found RE to significantly decrease cell growth at a concentration of 31.25 µg/mL (48 h), with an IC50 of approximately 71.8 µg/mL [16]. Cell proliferation was dramatically decreased and cell cycle arrest was induced in HT-29 and SW480 cells using extracts that were standardized to CA (25%–43%) or to total polyphenol content (10 µM) [17,18,19]. Cell growth of SW620 and DLD-1 colon cancer cells was significantly inhibited by RE at 30 µg/mL (48 h), with an IC50 as low as 34.6 µg/mL.…”

“…There is a discrepancy seen in the reported IC50 values which may be attributed to the different extraction methods used for the preparation of rosemary extract; supercritical CO 2 [30] and ethanol extraction [29]. Furthermore, MCF-7 cells were used in 2 additional studies and while both were found to inhibit cell proliferation, the IC50 values varied greatly from 187 µg/mL [31] to 9.95–13.89 µg/mL (RE standardized to 25%–43% CA) [18]. In agreement with the aforementioned studies, the RE resulting in a higher IC50 value was obtained from an alcohol based, methanol extraction [31].…”

“…At 0.08% RE enhanced the sensitivity of A2780 and cisplatin-resistant A2780CP70 cell lines to growth inhibition by cisplatin treatment, suggesting that RE may be of use in combination with cisplatin or potentially other chemotherapeutic drugs in patients who have developed an acquired resistance [34]. In HeLa cervical cancer cells, RE inhibited cell proliferation with an IC50 of 23.31 µg/mL (72 h) [35] and RE standardized to CA (25%–43%) inhibited cell proliferation with an IC50 of ~10 µg/mL (48 h) [18], suggesting that standardized extracts containing higher concentrations of CA may have greater anticancer effects. Furthermore, in human ovarian cancer cells SK-OV3 and HO-8910 rosemary essential oil (0.0625%–1%) inhibited cell viability with an IC50 of 0.025% and 0.076% in each cell line respectively (48 h) (Table 3) [36].…”

“…Many studies have examined the anti-proliferative and colony forming abilities of RE in vitro in colon [15,16,17,18,19,20,24,25,26], pancreas [27], breast [18,29,31,32], prostate [33], cervical [18,35], bladder [31], ovarian [34], lung [39] and leukemia [29,40,41,42] cell lines however, little is known concerning the underlying mechanism. RE was shown to have an inhibitory effect on AKT1 mRNA and protein expression, a protein involved in the PI3K/Akt survival signaling pathway, in a leukemic cell line [42] however, no measure of Akt activity was mentioned.…”

Polyphenols from the Mediterranean herb rosemary (Rosmarinus officinalis) for prostate cancer

“…Carnosic acid, which is the most abundant diterpene, has been shown to be well absorbed orally in rats (90 mg/kg) with a maximum serum concentration of 126 μM and an absolute oral bioavailability of 65.1% (Piscopo, 2009). The anti-oxidant properties are seen through its ability to chelate iron, scavenge peroxyl free radicals and inhibit lipid peroxidation (Đilas et al, 2012). Carnosol is a derivative of carnosic acid containing a lactone ring.…”