Orobanche cernua Loefling Attenuates Ultraviolet B-mediated Photoaging in Human Dermal Fibroblasts.[Pubmed: 29446095]

UV radiation is the primary cause of skin photoaging, which results in an increase in matrix metalloproteinases and degradation of collagen. Developing new natural antioxidant as photoprotective agents has become a popular area of research. Orobanche cernua Loefling is a parasitic plant that is rich in phenylethanoid glycosides (PhGs). This study investigated the photoprotective effects of the ethanolic extract of Orobanche cernua Loefling (OC) and its principal component acteoside on UVB-induced photoaging as well as their underlying molecular mechanisms in normal human dermal fibroblasts (NHDFs). Biological testing demonstrated that OC and acteoside possessed significant photoprotective activities, reducing MMP and IL-6 levels while improving type-I procollagen synthesis in UVB-irradiated NHDFs. Further study showed that the protective mechanisms were the improvement of transcription factor Nrf2-mediated antioxidant defensive system, suppression of MAPK/AP-1 and activation of the TGF-β/Smad pathway. Together, our results suggested that OC might be a promising antiphotoaging agent against UV radiation-induced skin damage.

A new phenylethanoid glycoside from Orobanche cernua Loefling.[Pubmed: 26358786]

A novel phenylethanoid glycoside, 3'-O-methyl isocrenatoside (1), along with two known compounds, methyl caffeate (2) and protocatechuic aldehyde (3), were isolated from the fresh whole plant of Orobanche cernua Loefling. All the isolated compounds (1-3) were elucidated on the basis of spectroscopic analysis including IR, MS and NMR data. The cytotoxic activities of these compounds were evaluated. Results showed that 3'-O-methyl isocrenatoside (1) and methyl caffeate (2) exhibited significant cytotoxicity, with IC50 values of 71.89, 36.97 μg/mL and 32.32, 34.58 μg/mL against the B16F10 murine melanoma and Lewis lung carcinoma cell lines, respectively.

Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth.[Pubmed: 26252191]

Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL - mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work.

Aspergillus alliaceus, a new potential biological control of the root parasitic weed Orobanche.[Pubmed: 23686407]

During extensive surveys in fields heavily infested by broomrape in the Trakya Region-Turkey, a different new fungus, Aspergillus alliaceus, was isolated from the infected broomrape. It is aimed to investigate whether or not it is really a pathogen for Orobanche. The fungi was exposed to a greenhouse environment in order to assess its pathogenicity and virulence against Orobanche cernua. In addition, infection tests on Orobanche seeds were also performed under laboratory conditions. The fungus was subjected using two different methods, exposure to a liquid culture with conidial solution and a sclerotial solid culture with fungal mycelia. Cytological studies were carried out at light, TEM and SEM levels. The results show that the sclerotial solid culture with fungal mycelia quickly caused necrosis and was more effective than the other type. It also greatly diminished attachments, tubercles, and caused the emergence of shoots and an increase in the total shoot number of Orobanche. In addition, both when the fungi was exposed to both soil and used to contaminate sunflower seeds, its pathogenicity was more effective. Consequently, it was determined that A. alliaceus was an effective potential biological control of broomrape throughout its life cycle from dormant seed to mature plant.

Strigolactone analogues and mimics derived from phthalimide, saccharine, p-tolylmalondialdehyde, benzoic and salicylic acid as scaffolds.[Pubmed: 22082666]

A series of new strigolactone (SL) analogues is derived from simple and cheap starting materials. These SL analogues are designed using a working model. The first analogue is a modified Nijmegen-1, the second contains saccharin as substituent (bio-isosteric replacement of a carbonyl in Nijmegen-1 by a sulfonyl group) and the third one is derived from p-tolylmalondialdehyde. These new SL analogues are appreciably to highly active as germination stimulants of seeds of Striga hermonthica and Orobanche cernua. The SL analogue derived from saccharin is the most active one. A serendipitous and most rewarding finding is that the compound obtained by a direct coupling of saccharin with the chlorobutenolide exhibits a high germination activity especially towards O. cernua seeds. Two other SL mimics are obtained from benzoic and salicylic aid by a direct coupling reaction with chlorobutenolide, both of them are very active germinating agents. These SL mimics represent a new type of germination stimulants. A tentative molecular mechanism for the mode of action of these SL mimics has been proposed.