Chemical Composition, Antibacterial Activity, and Antibiotic Potentiation of Boswellia sacra Flueck. Oleoresin Extracts from the Dhofar Region of Oman

Table 4

Combinational effects of the B. sacra oleoresin extracts and conventional antibiotics measured as the sum of the fractional inhibition concentrations (ΣFIC).

Extract component			Antibiotic component	Gastrointestinal pathogens					Autoimmune inflammatory trigger bacteria
				E. coli	E. faecalis	S. aureus	S. newport	S. sonnei	P. mirabilis	K. pneumoniae	A. baylyi	P. aeruginosa
Najdi	Method 1	M	Pen	—	3.71	—	1.64	3.62	1.93	1.75	—	—
			Erth	4.5	1	—	—	1	1	—	1.3	—
			Chl	1	4.5	1	0.5	1	1.56	1.12	2.4	1.12
			Cip	0.76	2.02	0.5	0.51	0.99	3	2.63	1.03	1
			Tet	0.73	14.7	5	4.06	0.53	1	0.38	0.47	—
		W	Pen	—	1.69	—	2.11	—	2.2	2.27	2.65	—
			Erth	—	1.85	—	—	—	1.49	—	1.87	—
			Chl	.	1.29	1.82	1.34	—	1.53	1.37	1.52	—
			Cip	—	1.04	0.77	0.97	—	2.28	1.93	0.96	—
			Tet	—	3.72	2.26	2.46	—	1.06	1.46	0.75	—
	Method 2	M	Pen	—	2.68	—	3.27	2.44	3.15	2.18	2.1	—
			Erth	5.1	1.27	—	—	1.36	1.15	—	1.73	—
			Chl	0.86	4.13	1.09	0.46	0.91	1.81	1.36	1.88	1.47
			Cip	0.68	1.72	0.44	0.58	0.58	1.96	1.95	1.09	1
			Tet	1.47	5.63	6.36	3.74	1.02	0.96	0.47	0.35	—
		W	Pen	—	2.25	—	2.78	2.88	2.87	—	1.96	—
			Erth	3.11	1.83	—	—	1.7	1.29	—	1.58	—
			Chl	2.76	1.14	2.14	1.36	2.25	1.41	—	1.37	—
			Cip	1.04	1.07	1.26	0.92	0.86	1.03	—	1.05	—
			Tet	1.74	2.73	2.49	1.49	2.37	1.82	—	0.89	—
	Method 3	M	Pen	—	2.11	—	1.88	1.83	2.7	2.81	2.83	—
			Erth	4.1	1.83	—	—	1.28	1.2	—	1.55	—
			Chl	1.36	5.01	1.47	0.5	0.67	1.34	1.59	2.06	1.63
			Cip	0.92	1.45	0.48	0.65	0.52	1.45	1.38	1.36	0.95
			Tet	0.86	4.79	4.16	2.66	1.46	0.83	0.5	0.5	—
		W	Pen	—	3.08	—	2.92	—	2.25	3.17	3.4	—
			Eryth	2.92	1.54	—	—	—	1.86	—	1.72	—
			Chl	1.46	2.09	1.37	2.4	—	1.17	1.84	2.62	—
			Cip	1.17	1.46	1.66	1.22	—	1.19	1.5	1.19	—
			Tet	3.31	3.02	2.17	2.86	—	1.59	1.29	1.05	—
Sahli	Method 1	M	Pen	—	3.26	—	1.87	—	2.48	2.2	1.72	—
			Erth	—	1	—	—	—	1	—	0.81	—
			Chl	—	3.5	1	1.12	—	0.65	1.12	2.5	—
			Cip	—	1.01	0.51	0.88	—	2.02	5.26	1.03	—
			Tet	—	0.21	1.06	0.43	—	1	0.71	0.19	—
		W	Pen	—	2.81	—	2.13	—	—	—	—	—
			Erth	—	1.94	—	—	—	—	—	—	—
			Chl	—	1.62	—	1.88	—	—	—	—	—
			Cip	—	0.93	—	1.47	—	—	—	—	—
			Tet	—	2.77	—	2.16	—	—	—	—	—
	Method 2	M	Pen	—	2.09	—	2.5	1.74	3.17	2.82	1.68	—
			Erth	4.5	1.16	—	—	1.16	1.05	—	0.92	—
			Chl	1	2.67	1.21	1	1.31	0.85	1.62	1.92	2.81
			Cip	1.52	1.28	0.73	0.63	0.85	1.74	4.31	1.37	1
			Tet	0.81	0.42	1.47	0.25	0.88	0.96	0.92	0.36	—
		W	Pen	—	—	—	1.66	—	2.8	2.13	3.7	—
			Erth	—	—	—	—	—	2.16	—	2.87	—
			Chl	—	—	—	1.24	—	1.49	1.07	1.4	—
			Cip	—	—	—	1.27	—	1.27	1.73	1.06	—
			Tet	—	—	—	0.78	—	1.08	1.38	1.35	—
	Method 3	M	Pen	—	3.06	—	1.88	1.31	2.48	2.68	3.15	—
			Erth	5.14	1.18	—	—	1.96	1.32	—	0.75	—
			Chl	0.97	2.06	1.36	1.63	2.87	0.77	2.14	1.38	2.4
			Cip	1.14	0.98	0.74	0.92	0.73	1.59	4.16	0.92	1
			Tet	1.16	0.41	1.19	0.44	1.16	1	0.92	0.47	—
		W	Pen	—	—	—	1.46	—	—	2.82	3.35	—
			Erth	—	—	—	—	—	—	—	1.54	—
			Chl	—	—	—	2.79	—	—	1.59	1.36	—
			Cip	—	—	—	1.62	—	—	1.69	0.98	—
			Tet	—	—	—	1.23	—	—	1.48	1.06	—
Houjari	Method 1	M	Pen	—	2.31	—	3.65	2.48	1.95	1.86	1.36	—
			Erth	4.5	1	—	—	1.13	1	—	0.54	—
			Chl	1	3.51	1.06	1	1.13	2.5	1.12	1.6	2.81
			Cip	2.03	2.02	0.51	0.51	0.83	1.87	2.94	0.59	1
			Tet	0.55	0.65	1.06	3.56	0.75	1	0.51	0.49	—
		W	Pen	—	3.62	—	2.6	1.82	3.16	2.51	—	—
			Erth	2.97	2.18	—	—	2.43	1.65	—	—	—
			Chl	1.46	1.23	1.47	1.82	1.59	1.18	1.77	—	—
			Cip	0.88	1.17	1.06	1.44	1.64	0.98	1.25	—	—
			Tet	1.87	2.14	2.18	1.52	2.83	1.13	1.47	—	—
	Method 2	M	Pen	—	3.62	—	2.78	3.16	2.41	2.2	2.02	—
			Erth	4.21	0.98	—	—	1.48	0.92	—	0.75	—
			Chl	0.76	2.26	0.98	1.25	1.72	1.87	1.35	1.83	2.2
			Cip	1.26	1.53	0.62	0.86	0.73	1.19	2.16	0.74	0.95
			Tet	0.83	0.92	1.83	2.43	1.07	1	0.75	0.38	—
		W	Pen	—	2.83	—	1.89	2.77	—	—	3.16	—
			Erth	2.46	1.95	—	—	1.42	—	—	1.85	—
			Chl	1.25	1.07	—	1.65	1.86	—	—	1.49	—
			Cip	0.96	1	—	1.1	2.19	—	—	1.11	—
			Tet	1.48	1.89	—	3.16	3.4	—	—	1.32	—
	Method 3	M	Pen	—	3.16	—	1.47	1.96	1.78	2.92	1.83	—
			Erth	5.67	1.22	—	—	2.01	0.96	—	1.06	—
			Chl	0.93	1.83	0.94	2.62	1.83	2.43	1.16	1.48	2.54
			Cip	1.05	1.29	0.57	0.98	0.79	1.76	0.97	0.86	1
			Tet	0.59	0.85	1.38	1.74	1.24	0.95	0.78	0.48	—
		W	Erth	—	3.2	—	—	—	2.97	2.25	2.89	—
			Erth	—	2.07	—	—	—	1.48	—	1.84	—
			Chl	—	2.49	—	—	—	1.92	1.08	1.11	—
			Cip	—	1.88	—	—	—	1	1.07	0.94	—
			Tet	—	1.45	—	—	—	1.46	1.83	1.27	—

Synergistic ∑FIC values (0–≤0.5) are shown in bold; additive values (>0.5-≤1.0) are shown in italics; indifferent values (>1.0–≤4.0) are shown in normal text; antagonistic interactions (>4.0) are shown in underlined. Method refers to the extraction method used; M = methanolic extract; W = aqueous extract; areas with “—”indicate combinations that were not tested as the antibiotic MIC ≥ 2.5 μg/mL or if extract MIC was ≥2000 μg/mL. Pen = penicillin; Erth = erythromycin; Chl = chloramphenicol; Cip = ciprofloxacin; Tet = tetracycline.