Crocin is a glycosyl ester of crocetin acid and is classified as a water-soluble carotenoid. It is abundant in Gardenia jasminoides (Ellis GJE.) GJE is a natural ingredient widely used to impart an orange-yellow hue to traditional Vietnamese products such as cakes, jelly, and fish sauce. Crocin, a key bioactive compound in Gardenia, has been used in medicine for its antioxidant, anticancer, and memory-enhancing properties. In this study, we introduced an effective strategy for the extraction of crocin pigments derived from Gardenia. The pretreatment of Gardenia is crucial in the extraction process, with the most effective method involving freeze-drying Gardenia followed by grinding with liquid nitrogen to enhance the extraction efficiency. Second, this study focused on optimizing crocin extraction using ultrasound-assisted methods by evaluating key parameters, including ultrasonic amplitude, extraction time, materialto- solvent ratio, and solvent concentration. The crocin content reached 95.04±0.81 mg ․ g–1dw. Finally, the optimal ultrasound-assisted extraction conditions were determined using response surface methodology, ensuring the maximum extraction efficiency of crocin (ultrasonic amplitude (60.41%), extraction time (5.95 min), solvent concentration (41.48%), and material/solvent ratio (2.7 g/100 mL). The maximum concentration of crocin from Gardenia was determined to be 97.05±1.00 mg ․ g–1dw.

Crocin is a carotenoid that may protect cells against oxidative stress by scavenging free radicals particularly superoxide anions. It has been reported that oocyte maturation is influenced by the free radicals generated during in vitro culture (IVC) process. The objective of study was to examine the effect of crocin in in vitro maturation (IVM) medium as an antioxidant on oocyte maturation and embryonic development after parthenogenesis (PA). Cumulus-oocyte complexes (COCs) were collected from ovaries of prepubertal gilts. The basic medium for IVM was medium-199 containing 10% pig follicular fluid, cysteine, pyruvate, epidermal growth factor, kanamycin, insulin, and hormones. Oocytes were treated for 44 hours with crocin at 0, 25, 50, and 100 μg/ml during IVM. Oocytes reached the metaphase II stage were induced for PA and cultured for 7 days in porcine zygote medium-3. Nuclear maturation of oocytes was not influenced by various concentrations of crocin (89.0, 87.3, 84.3, and 94.1% for control, 25, 50, and 100 μg/ml crocin, respectively). IVM oocytes treated with 50 μg/ml crocin showed a higher (P<0.05) intraoocyte glutathione (GSH) contents than untreated oocytes (1.00 vs. 1.29 pixels/oocyte). Blastocyst formation of PA embryos treated with 50 (42.9%) and 100 μg/ml crocin (43.8%) was significantly higher (P<0.05) than oocytes treated with 25 μg/ml crocin (30.5%) but not different from that (35.2%) of untreated oocytes. In summary, crocin increases cytoplasmic maturation in terms of intraoocyte GSH content which may be beneficial for later embryonic development by protecting from harmful effect of reactive oxygen species. Further studies are needed to determine whether the beneficial effect of crocin treatment during IVC would be shown in embryonic development after in vitro fertilization and somatic cell nuclear transfer.

Crocin is a carotenoid that may protect cells against oxidative stress by scavenging free radicals particularly superoxide anions. It has been reported that oocyte maturation is influenced by the free radicals generated during in vitro culture (IVC) process. The objective of study was to examine the effect of crocin in in vitro maturation (IVM) medium as an antioxidant on oocyte maturation and embryonic development after parthenogenesis (PA). Cumulus-oocyte complexes (COCs) were collected from ovaries of prepubertal gilts. The basic medium for IVM was medium-199 containing 10% pig follicular fluid, cysteine, pyruvate, epidermal growth factor, kanamycin, insulin, and hormones. Oocytes were treated for 44 hours with crocin at 0, 25, 50, and 100 μg/ml during IVM. Oocytes reached the metaphase II stage were induced for PA and cultured for 7 days in porcine zygote medium-3. Nuclear maturation of oocytes was not influenced by various concentrations of crocin (89.0, 87.3, 84.3, and 94.1% for control, 25, 50, and 100 μg/ml crocin, respectively). IVM oocytes treated with 50 μg/ml crocin showed a higher (P<0.05) intraoocyte glutathione (GSH) contents than untreated oocytes (1.00 vs. 1.29 pixels/oocyte). Blastocyst formation of PA embryos treated with 50 (42.9%) and 100 μg/ml crocin (43.8%) was significantly higher (P<0.05) than oocytes treated with 25 μg/ml crocin (30.5%) but not different from that (35.2%) of untreated oocytes. In summary, crocin increases cytoplasmic maturation in terms of intraoocyte GSH content which may be beneficial for later embryonic development by protecting from harmful effect of reactive oxygen species. Further studies are needed to determine whether the beneficial effect of crocin treatment during IVC would be shown in embryonic development after in vitro fertilization and somatic cell nuclear transfer.