Marker-based standardization and investigation of nutraceutical potential of Indian propolis

OBJECTIVE： Propolis, a resinous material collected by honey bees from various plants, has been explored globally for its medicinal and nutritional properties. However, research over Indian propolis is at infancy. This study was designed to investigate nutraceutical potential of Indian propolis. METHODS： In the present study, propolis extract was standardized with respect to markers caffeic acid phenethyl ester, caffeic acid, galangin, luteolin, curcumin, apigenin, pinocembrin and quercetin by new high-performance thin-layer chromatographic （HPTLC） methods. The physico-chemical analysis, residues analysis and in vitro antioxidant activity analysis were performed. Nutraceutical value was examined in terms of fats, fibers, minerals, proteins, polysaccharides, total carbohydrates, and energy value. RESULTS： The developed HPTLC methods were found to be simple, reliable accurate, and the validation parameters were within the limits of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use guidelines. Macerated ethanolic extract of propolis （MEEP） was found to have polyphenolic content of （20.99 ＋ 0.24） mg/g and flavonoids content of （8.39 ＋ 0.04） mg/g. MEEP was found to comprise of （283.33 ＋ 51.31） g/kg fats, （30.07 ＋ 7.30） g/kg fibers, （102.56 ＋ 2.84） g/kg proteins and （389.36 ＋ 57.50） g/kg carbohydrate with a calorie value of （38 409.33 ＋ 6 169.80） kJ/kg. It was found that Indian propolis exhibited high nutraceutical value and showed absence of pesticides and heavy metals. The MEEP showed in vitro antioxidant activity with inhibitory concentration of （12.24 ＋ 4.64） pg/mL. CONCLUSION： The present work explores Indian propolis as a potential nutritious candidate. The proposed analytical methods can be applied in future screening of the quality of Indian propolis.

Investigation of the nutraceutical potential of monofloral Indian mustard bee pollen

OBJECTIVE： This study was designed to investigate the nutraceutical potential of monofloral Indian mustard bee pollen （MIMBP）. METHODS： The nutritional value of MIMBP was examined in terms of proteins, fats, carbohydrates, and energy value. Its chemical composition in terms of total polyphenol and flavonoid content was determined. MIMBP was screened for free flavonoid aglycones by developing and validating a high-performance liquid chromatography-photo diode array （HPLC-PDA） method. MIMBP was analyzed for in vitro antioxidant effect in terms of 2,2-diphenyl-l-picrylhydrazyl （DPPH） radical-scavenging activity. RESULTS： MIMBP was found to be comprised of proteins （（182.2±5.9） g/kg）, fats （（137.7±6.8） g/kg） and carbohydrates （（560.6±17.4） g/kg）, which result in its high energy value （（17 616.7±78.6） kJ/kg）. MIMBP was found to contain polyphenols （（18 286.1±374.0） mg gallic acid equivalent/kg） and flavonoids （（1 223.5±53.1） mg quercetin equivalent/kg）. The HPLC-PDA analysis revealed the presence of kaempferol （（65.4±0.5） mg/kg） and quercefin （（51.4±0.4） mg/kg） in MIMBP, which can be used as markers for determining the quality of bee pollen. The MIMBP extract showed DPPH free radical-scavenging activity with a half maximal inhibitory concentration of 54.79 μg/mL. CONCLUSION： The MIMBP was found to be a rich source of nutrients providing high caloric value, which makes it a candidate for a potential nutraceutical agent. The study also illustrated the high antioxidant content of MIMBP, especially in the principle polyphenols and flavonoids, which suggests its potential role in the prevention of free radical-implicated diseases. The DPPH-scavenging effect of MIMBP further confirmed its antioxidant potential. Additionally, we developed a simple, specific and accurate HPLC-PDA method for the identification and quantification of free flavonoid aglycones. This can be applied in future screenings of the quality of pollen collected by honeybees.