Bio chemical and physical properties of bee propolis with respect to different geographical regions

Abstract

The present study was conducted at G.B.P.U.A and T. Pantnagar, Uttarakhand, India, during 2021- newline22. The purpose of this study was to find out the impact of different geographical regions, bee species and newlineconcentration of ethanol on the bio-chemical and physical properties of bee propolis. Moreover, samples newlinewere also evaluated for their antioxidant, antibacterial and acaricidal activity. In addition to these newlineobjectives, the chemical profile of propolis samples was also studied. newlineThe criteria for this study was to analyze the different bio-chemical and physical parameters of newlinepropolis samples viz. total phenols, flavonoids, tannin, wax, balsam, resin, moisture, and pH. Moreover newlinethe propolis samples were also characterized biochemically by quantifying its antioxidant activity. newlineEthanolic extracts of propolis samples were evaluated for in-vitro efficacy against Melissococcus plutonius newlineand field efficacy against Varroa destructor in Apis mellifera L. colony. In addition to that, structural newlinecharacterization of raw propolis as well as its ethanolic extract was also carried out by using FTIR- newlinespectroscopy. newlineWith respect to different geographical regions and bee species, the total phenols, flavonoids, tannin, newlinewax, balsam, resin, moisture, and pH content in the propolis samples, were ranged from 126.931-216.063 newlinemg gallic acid eq/g and 16.287-199.303 mg gallic acid eq/g, 14.076-40.604 mg quercetin eq/g and 7.030- newline55.600 mg quercetin eq/g, 14.248-49.536 mg catechin eq/100g and 1.850-44.037 mg catechin eq/100g, newline16.470- 60.683% and 23.453-53.244%, 1.231-3.466% and 3.403-29.219 %, 36.547-56.458% and 45.621- newline55.535%, 4.663-7.360 % and 5.375-8.211 %, 4.264-5.200 and 4.650-5.085, respectively. newlineAs per the antioxidant activity of propolis, IC50 value ranged between 0.015-0.306 mg/ml and newline0.038-1.720 mg/ml with respect to the samples collected from different geographical regions and bee newlinespecies. Moreover, an average IC 50 value of 0.114, 0.076, 0.075 mg/ml and 1.061, 0.803, 0.773 mg/ml was newlinerecorded in the samples collected from different geographical regions and bee species when extracted with newline50%, 75%, 100% ethanol. newlineFTIR spectroscopy of raw propolis as well as its extracts revealed that all samples contain phenols newlineand flavonoids. Spectra confirmed the significant differences among the samples with respect to their newlinegeographical region of collection and extraction process. newlineIn-vitro antibacterial activity of propolis samples from different geographical regions, in terms of newlinediameter of inhibition zone, at two different concentrations i.e. 200 mg/ml and 100 mg/ml against M. newlineplutonius was obtained 8.600-21.333 mm and 7.000-16.333 mm, respectively. However, in-vitro newlineantibacterial activity of propolis samples from different bee species at two different concentrations i.e. 200 newlinemg/ml and 100 mg/ml against M. plutonius was obtained 10.125-17.375 mm and 7.500-12.125 mm, newlinerespectively. newlineLikewise, field efficacy of propolis extracts against Varroa destructor found that all samples newlinepossessed acaricidal activity with highest per cent of corrected mite mortality observed in the colony newlinetreated with propolis extract from Alwar Rajasthan at seven days after both topical applications i.e. 69.66 newlineand 69.44%, respectively. However lowest activity was observed in the Ramnagar (54.24%) and Jeolikote newline(46.78%) propolis extract at seven days after first and second topical applications, respectively. newlineAmong all other samples of propolis, the sample collected from Rajasthan and Apis mellifera newlinecolony revealed the best results due to the presence of high amount of total phenols, flavonoid, tannin, newlinebalsam, resin, and antioxidant, antibacterial and acaricidal activity, although the wax content was found in newlinehigh amount in the sample of Jeolikote and sample from the colony of T. iridipennis. Among different newlineconcentrations of ethanol, 75% was found significantly more capable of extracting the soluble biochemical newlineconstituents of propolis. Thus it was concluded, geographical regions, bee species and concentration of newlineextraction solvent had significant influence on biochemical and physical properties of bee propolis. newline