Relative Free Radical Scavenging, Tyrosinase Inhibitory, and Anti-Inflammatory Potential of the Polar Peel decoctures of distinct Malus Species indigenous to Kashmir
Authors: Gupta Amit , Ahmad Shah Ashfaq , Rawat Akshita , Parihar Tanvi , Singh Yashaswi , Pandey Neha , Kumar Vijay 
Published: September 2023

Apple, (Malus domestica, Brokh), is a vital source of phenolic and polyphenolic compounds whose accumulation in the different parts of the fruit depends upon various intrinsic and extrinsic factors. This study aimed to perform a comparative evaluation of phenolics of peels of three red-skinned (“Delicious”, “Maharaji”, “Royal delicious”), and one yellow-skinned (“Golden Delicious”) apple varieties incorporating preliminary secondary metabolite perusal followed by estimation of Total phenol and total flavonoid contents. Secondary phytocompounds being usually polar in nature were extracted from peels via the Soxhlet and hot maceration processes using different menstruum systems of varied polarity. Comparative assessment of Free radical scavenging, anti-pigmentation, and anti-inflammatory properties of all the decoctures was analyzed thereafter.Free radical scavenging capacity was analyzed via 2, 2-diphenyl-1-picrylhydrazyl assay.Tyrosinase inhibitory activity was assessed by studying the in vitro impact of decoctures on the monophenolase and diphenolase reactions of the enzyme tyrosinase. The anti-inflammatory potential of the samples was assessed by inhibition of hypotonicity-induced HRBC membrane lysis. TPC/TFC estimation was analyzed via spectrophotometry. Methanol crude peel extracts of all apple species revealed rich phytochemical content as per TPC/TFC analysis. In a dose-dependent manner, all the crude peel extracts demonstrated considerable free radical scavenging capacity with DPPH assay. Maharaji methanolic decocture revealed potent free radical scavenging activity by showing the lowest IC50 value while Royal delicious acetone extract showed the highest IC50 value when collated with the potent reference antioxidant ascorbic acid with an IC50value of 114.62µg/ml. Polarextract of Malus domestica var Maharaji revealed significant tyrosinase inhibitory activity by revealing IC50 of 8460.65µg/mlon L-Tyrosine substrate and IC50 of 7830.46 µg/ml on L-DOPA substrate. Malus peel compounds turn out to be more effective in diphenolase reaction and kojic acid acts more effectively in the monophenolase one.At various concentrations, the percentage of membrane stabilization for methanolic extracts and the reference NSAID diclofenac sodium was determined.The highest level of membrane stabilization wasshown by methanolic Maharaji and delicious apple peel extracts (83.76 % and 72.32% at a dose of 200 mg/ml respectively) when juxtaposed with standard NSAID showing 98.58 % inhibition at a concentration of 25 mg/ml. Methanol extracts of Malus domestica var Maharaji out performed the other Malus peel extracts in terms of all the parameters analyzed, according to the current study. So, this study is giving the highest pharmaceutical priority to the Malus domestica var Maharaji when it comes to human-health benign bioactive compounds, oxidative stress-related diseases, pigmentation disorders, and inflammatory diseases.