Table 4.

Summary of clinical trials of T. vulgaris preparations.

Pharmacological activity	Type of study	Models	Plant part/material	Type of Extract/compound	Doses	Controls	Mechanisms	Results	References
Adipogenetic and anti-aging	in vitro	Humans	Leaves and flowers	ThymLec gel 2% prepared from leaf and flower extract (1.0%–3.0%) + water, propanediol, glycerine +5.0%–13.4%) lecithin (additive) + benzyl alcohol, potassium sorbate, tocopherol (preservatives)	2 mg/cm2 of the facial skin applied with 2% concentration (20 mg/g w/w), gently spreading, twice a day (morning and evening).	Placebo (formulation containing the same vehicle of ThymLec gel) and Benchmark 2%	ThymLec topical application leads into the adipogenesis and lipid production, further augmenting cell volume and better remodelling of face oval features. ThymLec modulates the PPAR-γ signalling pathway, increasing adiponectin production and adipocyte lipid accumulation.	Reduction of area (7.0%), depth, and length (10.2%) of the perioral wrinkles on day 60, whereas benchmark produced a reduction of 5.4% and 7.5%, respectively in case of humans. Length of the nasolabial lines (8.9%), Crow's feet wrinkles' area (8.9%), breadth (3.9s%), and length (11.1%) were also decreased. Face oval remodelling evaluation resulted in the reduction of total face volume (4.9 fold) in comparison with benchmark on day 60. In vitro adiponectin synthesis increased in 3T3-L1 embryonic fibroblasts treated with ThymLec 2% (122% at 0.0195% concentration) and (137% at 0.039% concentration).	[79]
Anti-dysmenorrhea	in vitro	Humans	Not defined	Essential oil	25 drops of essential oil	Ibuprofen, Placebo (Ibuprofen 200mg + oil 25 drops)	Anti-prostaglandin and antispasmodic activity of T. vulgaris L.	Pain intensity mean values reached lowest point (6.57–1.14 VAS) in case of oil consumers' group in comparison with placebo (6.13–3.45) and ibuprofen (5.3–1.48) (p < 0.05). No significant results were obtained in case of bleeding control by both oil and placebo. Oil was able to reduce clinical symptoms like lower abdominal pain, nausea, mood swing, and fainting after 48 h of consumption (p < 0.05).	[80]
Anti-bronchitis	in vitro	Humans	Whole plant extract	Dry powder extract	160 mg oral dose along with 60 mg primrose (P. vulgaris) root extract for 11 days	Placebo tablet without ingredients	Not defined	The extract reduced the cough symptoms on day 9 with an efficacy of 73.7% in comparison with placebo (day 11; 57.8%) (p < 0.0001). Reduction of bronchitis severity score was observed only after 4 days in case of extract (-6.2) in comparison with placebo (-4.1) (p < 0.05). The extract also reduced minor symptoms like disturbance in sleeping, rising body temperature, chest pain, and difficulty in breathing.	[12]