Flourensia cernua: Hexane Extracts a Very Active Mycobactericidal Fraction from an Inactive Leaf Decoction against Pansensitive and Panresistant Mycobacterium tuberculosis

Table 3

Yields and mycobactericidal activity of F. cernua ground dry leaves extracts obtained by successive extraction with solvents of increasing polarity using different extraction methods.

Extraction method	n-Hex			EtOAc			EtOH
	Extract (yield^a)	MBC^b (μg/mL)		Extract (yield^a)	MBC^b (μg/mL)		Extract (yield^a)	MBC^b (μg/mL)
		SMtb^c	RMtb^d		SMtb^c	RMtb^d		SMtb^c	RMtb^d
StMC	F (9.0%)	50	12.5	G (4.8%)	50	12.5	H (16.6%)	100	50
SXH	I (9.5%)	50	25	J (4.1%)	50	25	K (12.1%)	100	50
UsMC	L (11.5%)	50	25	M (3.9%)	100	50	N (5.5%)	100	100
SkMC	O (12.5%)	50	25	P (5.5%)	100	50	Q (17.1%)	100	50

n-Hex: n-hexane, EtOAc: ethyl acetate, EtOH: ethanol. StMC: still maceration, SXH: Soxhlet extraction, UsMC: ultrasound-assisted maceration, SkMC: shake-assisted maceration. ^aExpressed as the percentage of 15 g dry ground of F. cernua leaves. ^bMycobactericidal activity was expressed as the minimal bactericidal activity (MBC) that killed 100% of mycobacteria. ^cSMtb M. tuberculosis H37Rv strain sensitive to all five fist-line antituberculosis drugs; ^dRMtbCIBIN/UMF15:99, resistant to the above drugs. In this experiment, rifampin and ofloxacin were included as internal standards. These showed the same MBC than those determined in the experiments from Table 1.