Table 3.

In vivo efficacy of plant‐derived natural products that target specific phases of the viral life cycle

Life cycle stage	Extract/compound	Virus	Model	Results	Reference
Attachment/Fusion	BanLec H84T (Lectin)	HIV	Bone‐marrow‐liver‐thymus humanized mouse model; 75 μg, prophylactic vaginal administration	Prophylactic treatment with H84T significantly (P ≤ 0·05) reduced the incidence of infection, with no HIV infection detected in the H84T treatment group compared to 50% of the control group	Swanson et al. (2015)
	Griffithsin (Lectin)	SARS‐CoV	Mouse, 10 mg kg−1 day−1, intranasal administration	All mice in the griffithsin treatment group survived SARS‐CoV infection compared to 30% survival in the no treatment group. Lung viral titres and weight loss were also significantly (P ≤ 0·05) reduced by griffithsin treatment	O’Keefe et al. (2010)
RNA replication	Calanolide A (Coumarin)	HIV	Human, phase 1 clinical trial of healthy volunteers (n = 47); escalating doses for 5 days	Transient mild to moderate adverse effects were observed. Adverse effects and laboratory abnormalities were non‐dose dependent. Absorption profiles and plasma levels of calanolide A varied significantly	Eiznhamer et al. (2002)
Protein synthesis	Celgosivir (Iminosugar)	DENV	Mouse; 33 mg kg−1 three times daily, oral gavage	Significant reduction (P ≤ 0·05) in viral RNA load. Marginal but non‐significant (P > 0·05) reduction in infectious viral load	Sayce et al. (2016)
		DENV	Human phase 1b trial of dengue fever patients (n = 50); initial dose 400 mg, followed by 200 mg every 12 h for 4·5 days	Celgosivir was generally well tolerated. Treatment marginally but non‐significantly (P > 0·05) reduced viral load compared to the control (−1·86 vs −1·64 virological log10 reduction). No significant differences (P > 0·05) in fever burden or haematological and biochemical markers were observed	Low et al. (2014)
	UV‐4B (Iminosugar)	IAV	Mouse; single dose 100–1000 mg kg−1, oral gavage	Significant dose‐dependent reduction in mortality at doses; >250 mg kg−1 produced a 30–70% survival compared to 10% in the control group	Warfield et al. (2020)
		DENV	Mouse; single dose 250–1000 mg kg−1, oral gavage	Significant dose‐dependent reduction in mortality at doses, with 25–70% survival compared to 10% in the control group	Warfield et al. (2020)
Maturation	Luteolin (Flavonoid)	DENV	Mouse; 100 mg kg−1, oral, four times per day	A significant (P ≤ 0·05; twofold) reduction in viraemia compared to the control was observed 3 days post‐infection	Peng et al. (2017)
	Bevirimat (Triterpenoid)	HIV	Human phase I and II clinical trial of HIV patients (n = 24); single dose of 75, 150 or 250 mg, oral administration	Significant reductions in HIV viral RNA load were observed in 150 and 250 mg groups (0·46–0·47 log10 reductions) compared to the placebo (0·15 log10 reduction). No significant adverse effects were reported	Smith et al. (2007)