Documenting the therapeutic potential of encapsulated cardamom essential oil

Abstract

Proposed study was an effort to investigate the antimicrobial and nutraceutical worth of black and green cardamom extracts. For the purpose, cardamom powders were analyzed followed by the supercritical fluid extraction, GC-MS quantification, estimation of antimicrobial and antioxidant potential of the extracts. Afterwards, encapsulation of cardamom essential oils in guar gum and whey protein isolates blends and finally bio-evaluation trial was carried out for the management of hypercholesterolemia, liver and renal malfunctioning. In present study, supercritical fluid extraction technique was used to obtain high extraction efficiency. In terms of antioxidant potential, black cardamom showed higher amount of polyphenols than green cardamom as 1325.03±7.69 and 934.72±6.94 mg GAE/100g for TPC, 208.63±10.36 and 192.45±9.62 μmol Fe2+/g for FRAP, 172.58±6.14 and 143.96±7.38 μM Trolox/g for ABTS, 63.57±3.48 and 56.81±2.01 % for DPPH assays. However, total flavonoids contents were present in greater amount in green cardamom compared to black cardamom investigated as 215.74±6.32 and 168.25±5.26 mg CE/g. GC-MS quantification indicated that 1,8-cineole (44.24% and 28.71%) and α-terpinyl acetate (12.25% and 38.4%) were the principle components in black and green cardamom essential oils which were responsible for pungency and pleasant aroma, respectively. Moreover, antimicrobial evaluation revealed that green cardamom extract exhibited more inhibitory effects than black cardamom extract on the growth of microorganisms, quorum sensing inhibition of C. violaceum and biofilm formation inhibition of S. typhimurium and E. coli. The results related to encapsulation of black and green cardamom supercritical fluid extracts showed that encapsulation efficiency, entrapment capacity and moisture content ranged between 63.54% to 84.72%, 5.77% to 7.08% and 5.81% to 6.33% in freeze dried capsules. On the basis of encapsulation efficiency, one from black and one from green cardamom encapsulates were used for cupcakes development and in the preparation of nurtaceutical diets. Cupcakes containing green cardamom (Elettaria cardamomum) extract produced good aroma while taste was good with the cupcakes prepared from black cardamom (Amomum subulatum) extract. The diets contained green cardamom (D1) and black cardamom (D2) encapsulated essential oils were prepared alongside control (Do) for comparison purpose. Bio-evaluation study conducted on male Sprague Dawley rats, accordingly two different studies were designed on the basis of diets i.e. study I (rats fed on normal diet) and study II (rats were given high cholesterol diet). The body weights of experimental rats were significantly effected with diets in both studies. Black cardamom encapsulated extract (D2) instigated highest reduction in weight gain during the study period. Likewise, D2 imparted maximum decrease in total cholesterol levels in study I and II, by 4.42% and 12.53% whereas LDL by 6.75% and 14.08% respectively. However, levels of HDL and triglycerides were effected non-significantly by diets in study I but effects were significant in study II. Likewise, D2 instigated maximum reduction in urea and creatinine levels in study I and II i.e. 8.63% and 19.25% and 9.2% and 20.46%. Furthermore, diets resulted improved antioxidant status by increasing glutathione levels and decreasing thiobarbituric acid reactive substances (TBARS). Amongst diets, black cardamom encapsulated extract (D2) was proved more effective for glutathione contents enhancement during the investigation in study II. The restoration/stabilization of liver function tests towards normal ranges proved the safety of resultant therapeutic diets. From the current explorations, results concluded that diets supplemented with encapsulated black and green cardamom essential oils were efficient tool to mitigate lifestyle related disorders.