Rosehip seeds of different species of roses are known to contain many active ingredients including potentially antimicrobial ones, the present study compared the antimicrobial potential of Rosa indica hip seeds’ methanolic (RME) and diethyl ether extracts (REE). From 150 g of rosehip seeds, 5.13 g of REE or 9.23 g of RME was obtained. Of the 162 strains of microbes tested, 24 and 159 strains were not inhibited by RME and REE, respectively at ≤50 mg mL-1 concentration. The minimum inhibitory concentration (MIC) of RME was for Gram-positive bacteria 13.99± 11.59 mg mL-1 followed by Gram-negative bacteria 32.85± 19.31 mg mL-1, and Candida 43.75± 12.5 mg mL-1 strains. The minimum MIC (0.1 mg mL1 ) of RME was for one strain each of Streptococcus anginosus, Bacillus brevis, Moraxella bovis and M. ovis. Only one strain each of M. ovis, Staphylococcus aureus, and Candida albicans were susceptible to REE at ≤50 mg mL-1 concentration. Of the 162, 12 (7.41%) strains (of Aeromonas trota, Staphylococcus aureus, S. xylosus, Proteus mirabilis, Flexibacter spp. Kocuria rosea, Streptococcus pyogenes, S. anginosus, M. bovis, Bacillus brevis) were inhibited at ≤1.66 mg mL-1 concentration of RME. There was wide variability in the MIC of rosehip extracts for strains of the same species and different species of microbes. The MIC of RME was minimum (13.05± 15.34 mg mL-1) for strains of buffalo origin and was maximum (40.63± 18.75 mg mL-1) for strains from lions. The MIC of RME for E. coli of dog origin (38.64± 13.06 mg mL-1) was almost similar to the MIC of RME (37.50± 16.14 mg mL1 ) for Escherichia coli strains from other sources. The study concluded that Rosa indica hip seeds had a wide spectrum of antimicrobial activity against 138 strains of 64 species of Introduction Roses of many different species of genus Rosa are native to many countries/ regions and are used in day-to-day activities for several purposes. Rose petals are of high culinary, decorative, and essence value while rosehips often go waste despite their high therapeutic potential. Rosehip extract (from whole rose fruit, rosehip) and rosehip seed extract (from seeds of rose present in rosehips) are acclaimed for several health benefits specially to cure inflammatory acne and acne scars due to their richness in vitamin A, C, and E, and essential fatty acids like omega-6 [1-3]. Phenolic compounds and antioxidant activity of rosehip oil/ extracts and its ability to scavenge free radicals helps skin to maintain its tone and thus acting as an antiaging agent [4,5]. The important problems treated or predicted to be treated with rosehip oil (RHO), rosehip seed oil (RHSO) and other extracts include rheumatism and rheumatoid arthritis [1,6,7-11], cancer [4,12,13], osteoporosis [1], hyperlipidaemia [14], obesity [14,15], renal problems [16], hepatic problems [17], neurological damage [18-20], skin diseases [21-23], diarrhoea [1] and peptic ulcers [24]. Though the antimicrobial potential of RHO/ RHSO and extracts of seeds and flowers are reported in Rosa canina [25- 27], R. rugosa [28-29], R. damascene [30], R. multiflora [31], R. pisocarpa, R. nutkana and R. woodsii [32] against strains of potentially pathogenic bacteria and fungi, little is understood about the antimicrobial potential of Rosa indica RHO/RHSO. The present study was undertaken to determine the antimicrobial potential of methanolic and ether extracts of rosehip seeds of Rosa indica against 158 strains of potentially pathogenic bacteria and 4 strains of yeasts. Materials and Methods Preparation of rosehip seed methanolic (RME) and diethyl ether (REE) extracts Ripened rosehips (orange-red in colour) were harvested in May 2020 from Rosa indica plants left unpruned after flowering in spring (due to lockdown implemented to contain COViD-19) at ICAR-IVRI, Izatnagar campus. Rosehip seeds were collected Volume 1 Issue 1 J Herb Med Plants SCIENTIFIC EMINENCE GROUP | www. scientificeminencegroup.com Page 2 after cutting the rosehips. Seeds were dried at 60o C for 24 h and ground mechanically. A total of 300 g rosehip seed powder was divided into two equal parts into 1.0 L Borosil neutral glass screwcapped bottles and in one bottle 500 mL HPLC grade methanol (SD Fine Chemicals Ltd. India) and in other bottle, 500 mL of HPLC grade diethyl ether (SD Fine Chemicals Ltd. India) was added, and after tightening the caps both the bottles were kept at 30o C on shaking platform (60 rpm) for 24 h. Then contents of the bottles were filtered through Whatman filter paper No. 1 to collect the liquids separately and transferred to two glass bowls of 1 L capacity each, and incubated at 45o C for 48 h to evaporate methanol and diethyl ether, and have the concentrated extract free of solvents. Extracts were collected and stored at 4o C in amber-coloured glass bottles till tested for their antimicrobial potential. Microbial strains used in the study A total of 155 strains (Table 1) of bacteria (101 Gram-negative of 30 species of 21 genera, and 54 Gram-positive bacteria of 33 species belonging to 9 genera), 4 strains of Candida (C. albicans 2, C. tropicalis 1, C. famata 1) isolated from veterinary (buffaloes 14, cattle 16, dogs 55, birds 16, sheep 3, goat 1, lions 6, pig 1, pythons 3, sloth bears 2, spotted deer 1, tigers 10) and human [12] clinical cases, environmental (air 17, water 2) clinical samples (Table 2) and three reference strains (DH5α Escherichia coli, and Staphylococcus aureus ATCC 29312 and ATCC 43300) available in the repository of Division of Epidemiology, ICAR-IVRI, Izatnagar were revived and confirmed to identity through morphological, culture, staining and biochemical characterization [33,34]. Further, strains were confirmed by MALDI-ToF MS (MALDI Biotyper Sirius system, Bruker Daltonics). During the study, all strains were maintained in semisolid nutrient agar till tested for their susceptibility. microbes and methanol was a better solvent than diethyl ether for extraction of antimicrobial ingredients.