Table 1.

Summary of research work of importance of natural products for male fertility.

	Product	Effect	Reference
Positive	Date palm (Phoenix dactylifera L.) fruit extract (DPFE)	DPFE can be applied as an effective protecting agent to reduce the deleterious effects of formaldehyde	[42]
	Matricaria chamomilla extract	Reduces the adverse effect of formaldehyde on the reproductive system of male rats. The antioxidants also protect Leydig cells from free radicals that interfere with steroidogenesis	[43]
	Tribulus terrestris Linn.	Improvement of sperm motility and efficiency	[44–46]
	Cistanche tubulosa, echinacoside, and water methanol extract Loranthus micranthus	Effect on the increase in testosterone levels and the enzymes CYP11A11, CYP17A1, 3β-HSD, 17β-HSD	[47, 48]
	Acacia hydaspica ethyl acetate extract, mature garlic extract, diallyl sulfide, water methanol extract Loranthus micranthus, methanol extract of Carissa opaca leaves, Teucrium polium extract, and Thymus algeriensis extract	Reduction of oxidative stress, reduction of free radicals (NO, TBRAS), increase of oxidative enzymes (SOD, CAT, GSH, GST, and GPx), and reversal of infertility caused by oxidative stress	[47, 49–54]
	Echinacea purpurea ethanol extract, Lycium barbarum polysaccharide, and white tea	Restoration of reproductive function and blood glucose levels in mice with STZ-induced diabetes	[55–57]
	Gosha-Jink-Gan	Potentially restores spermatogenesis	[58, 59]
	Saikokaryukotsuboreito	Improves spermatogenesis and testosterone levels	[60, 61]
	Wuzi Yanzong	Reduces oligoasthenozoospermia by regulating sex hormones	[62]
	Apis mellifera	Antioxidant, antihyperglycemic, and antidiabetic	[63,64]
	Barley, royal jelly	Decrease in free radicals and increase in antioxidant enzymes	[65,66]
	Cinnamon, Ficus asperifolia water extract	Reduction of oxidative stress and control of lipid components, improving fertility	[67, 68]
Negative	Olea europaea water-alcohol extract and permethrin	Decline in reproductive function even at doses as low as 50 and 35 mg/kg, respectively	[69, 70]
	Tripterygium glycoside extract	Inhibition of the activity of hormone receptors critical in the fertilization process	[71]
	The dose of Ricinus communis L. water extract was higher than 100 mg/ml, and the dose of ethanol extract from Spondias mombin L. and red cultivar Allium cepa methanol extract exceeded 100 mg/kg	Adverse fertility	[72–74]