Theobroma cacao L. beans have long been used for food and medicinal purposes. However, up to 52%-76% of Theobroma cacao L. fruit comprises its husk, which are regarded as waste and oftentimes thrown away. In fact, cocoa pod husks actually possess a high antioxidant capacity. Antioxidants can be used to fight free radicals that are produced by environmental pollution. In order to simulate the effects of pollution, H2O2 and cigarette smoke extract models were used respectively. However, the antioxidant properties are limited on the skin due to poor penetration. Hence, in order to increase the topical penetration, cocoa pod husk extract (CPHE) was also formulated into niosomes thereafter. CPHE was characterised using total phenolic content, total flavonoid content and three antioxidant assays. After that, cytotoxicity and cytoprotective assay were conducted on HaCaT cells, which represent the skin epidermis. CPHE was then formulated into niosomes subjected to stability and penetration studies for three months. CPHE was shown to contain 164.26 ± 1.067 mg GAE/g extract in total phenolic content and 10.72 ± 0.32 mg QCE/g extract in total flavonoid content. In addition, our results showed that CPHE possesses similar antioxidant capacity through 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, around eight-fold less through ABTS assay and approximately twelve-fold less through Ferric reducing power (FRAP) assay. The extract also showed comparable cytoprotective properties to that of standard (ascorbic acid). The niosome formulation was also able to increase the penetration compared to unencapsulated extract, as well as possess a good stability profile. This showed that CPHE, in fact, could be repurposed for other uses other than being thrown away as waste.
Javanese turmeric (Curcuma xanthorrhiza Roxb.) is known for its diverse pharmacological activities due to its rich phytoconstituents, including curcuminoids and xanthorrhizol. Typically, these compounds are extracted using organic solvents, which pose health and environmental risks. Therefore, safer and more environmentally friendly green extraction methods are being developed. This study investigated the effect of ultrasound-assisted extraction (UAE) combined with natural deep eutectic solvents (NADES) based on choline chloride and organic acids (lactic, malic, and citric acid) to find the best combination for extracting curcuminoids and xanthorrhizol from Javanese turmeric. Results showed that UAE using choline chloride and malic acid (1:1) (ChCl-MA) yielded the best results. The Box-Behnken Design optimized water addition, solvent-to-powder ratio, and extraction time, with optimal conditions being 25 % water addition, a 20 mL/g ratio, and a 15-minute extraction time. This method yielded 4.58 mg/g of curcuminoids and 12.93 mg/g of xanthorrhizol. Furthermore, the ChCl-MA NADES with UAE extraction showed more cytoselective activity towards the HeLa cancer cell line compared to the non-cancer HaCaT cell line. In contrast, traditional ethanol extraction was non-selective, as indicated by similar cell viability reductions in both HeLa and HaCaT cells at 6.25 ppm. Collectively, this study is the first to report the optimal NADES combination with UAE, based on salts and organic acids, for the extraction of Javanese turmeric rhizomes with selective cytotoxic effects against cancer cells. These findings may contribute to the development of novel, naturally derived anticancer agents using green extraction techniques.