Aerial parts contain sesquiterpene glycosides.
The leaves and dried juice contain lacticin, lactucopicrin (sesquiterpene lactones); flavonoids (mainly based on quercetin); coumarins (cichoriin and aesculin); N-methyl-beta-phenethylamine; triterpenes include taraxasterol and beta-amyrin. The sesquiterpene lactones have a sedative effect.
The Wild Lettuce also contains hyoscyamine, while the dried sap is devoid of it. Morphine content has been found in low concentrations, too low to have pharmacological effect.
(Natural Medicines Comprehensive Database, 2007.)
The oil of seeds is used for arteriosclerosis.

Lagenaria siceraria
(Mol.) Standl.
Synonym L. vulgaris Ser.
L. leucanth Rusby.
Cucurbita siceraria Mol.
Family Cucurbitaceae.
Habitat Throughout India.
English Bitter Bottle-Gourd.
Ayurvedic Katu-tumbi, Tumbini,
Ikshavaaku. Tiktaalaavu, Pindaphalaa.
Unani Kaddu-e-tallth (bitter var.). Siddha/Tamil Suraikai.
Action
Pulp—purgative, emetic. Leaf—used in jaundice.
Cucurbita lagenaria Linn. is equated with Lauki or Sweet Bottle-Guard, used all over India as a vegetable.
Cucurbita siceraria Mol. is equated with Titalauki or the Bitter Bottle- Gourd. Bitter fruits yield 0.013% of a solid foam containing cucurbitacin B,D,G and H, mainly cucurbitacin B. These bitter principles are present in the fruit as aglycones. Leaves contain cucurbitacin B, and roots cucurbitacins B, D and traces of E. The fruit juice contains beta-glycosidase (elaterase).
Plants which yield non-bitter fruits contain no bitter principles or elaterase; their roots are not bitter.
Lagerstroemia flos-reginae
Retz.
Synonym L. speciosa (L.) Pers.
L. reginae Roxb.

Lagg era alata Sch.- Bip. ex Oliver. 359

Encyclopedia of Ayurvedic Medicinal Plants

A Candle of Medicinal Herb’s Identification and Usage