The main purpose of this article is to present the latest research related to selected biological properties of carvacrol, such as antimicrobial, anti-inflammatory, and antioxidant activity. As a monoterpenoid phenol, carvacrol is a component of many essential oils and is usually found in plants together with its isomer, thymol. Carvacrol, either alone or in combination with other compounds, has a strong antimicrobial effect on many different strains of bacteria and fungi that are dangerous to humans or can cause significant losses in the economy. Carvacrol also exerts strong anti-inflammatory properties by preventing the peroxidation of polyunsaturated fatty acids by inducing SOD, GPx, GR, and CAT, as well as reducing the level of pro-inflammatory cytokines in the body. It also affects the body's immune response generated by LPS. Carvacrol is considered a safe compound despite the limited amount of data on its metabolism in humans. This review also discusses the biotransformations of carvacrol, because the knowledge of the possible degradation pathways of this compound may help to minimize the risk of environmental contamination with phenolic compounds.

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Infectious diseases are a primary driver of bee decline worldwide, but limited understanding of how pathogens are transmitted hampers effective management. Flowers have been implicated as hubs of bee disease transmission, but we know little about how interspecific floral variation affects transmission dynamics. Using bumblebees ( Bombus impatiens), a trypanosomatid pathogen ( Crithidia bombi) and three plant species varying in floral morphology, we assessed how host infection and plant species affect pathogen deposition on flowers, and plant species and flower parts impact pathogen survival and acquisition at flowers. We found that host infection with Crithidia increased defaecation rates on flowers, and that bees deposited faeces onto bracts of Lobelia siphilitica and Lythrum salicaria more frequently than onto Monarda didyma bracts . Among flower parts, bracts were associated with the lowest pathogen survival but highest resulting infection intensity in bee hosts. Additionally, we found that Crithidia survival across flower parts was reduced with sun exposure. These results suggest that efficiency of pathogen transmission depends on where deposition occurs and the timing and place of acquisition, which varies among plant species and environmental conditions. This information could be used for development of wildflower mixes that maximize forage while minimizing disease spread.

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Thymoquinone, a monoterpene molecule is chemically known as 2-methyl-5-isopropyl-1, 4-benzoquinone. It is abundantly present in seeds of Nigella sativa L. that is popularly known as black cumin or black seed and belongs to the family Ranunculaceae . A large number of studies have revealed that thymoquinone is the major active constituent in N. sativa oil this constituent is responsible for the majority of the pharmacological properties. The beneficial organoprotective activities of thymoquinone in experimental animal models of different human diseases are attributed to the potent anti-oxidant and anti-inflammatory properties. Thymoquinone has also been shown to alter numerous molecular and signaling pathways in many inflammatory and degenerative diseases including cancer. Thymoquinone has been reported to possess potent lipophilicity and limited bioavailability and exhibits light and heat sensitivity. Altogether, these physiochemical properties encumber the successful formulation for the delivery of drug in oral dosages form and restrict the pharmaceutical development. In recent past, many efforts were undertaken to improve the bioavailability for clinical usage by manipulating the physiochemical parameters. The present review aimed to provide insights regarding the physicochemical characteristics, pharmacokinetics and the methods to promote pharmaceutical development and endorse the clinical usage of TQ in future by overcoming the associated physiochemical obstacles. It also enumerates briefly the pharmacological and molecular targets of thymoquinone as well as the pharmacological properties in various diseases and the underlying molecular mechanism. Though, a convincing number of experimental studies are available but human studies are not available with thymoquinone despite of the long history of use of black cumin in different diseases. Thus, the clinical studies including pharmacokinetic studies and regulatory toxicity studies are required to encourage the clinical development of thymoquinone.

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Mechanical and ethological isolation between species is widespread in angiosperms with specialized animal-pollinated flowers, being recorded in 29 species groups belonging to 27 genera and 16 families. Mechanical isolation occurs in two forms. (i) The common type, designated the Salvia type, operates when two or more species of flowers are adapted for different groups of pollinators with different body sizes and shapes. (ii) In the Pedicularis type two flower species have the same species of pollinator but pick up pollen from different parts of the pollinator's body. Four forms of ethological isolation are recognized. (i) In the Aquilegia type, which is widespread, ethological isolation is a side effect of mechanical isolation. (ii) The flower-constancy type, as the name suggests, is based on flower-constant foraging behavior. (iii) In the Ophrys type, floral scents attract male bees or wasps and play a role in their mating behavior; different species of flowers, often orchids, have different scents and attract different sets of hymenopteran species. (iv) The monotropy type occurs in plants pollinated by hymenopterans with species-specific or group-specific flower preferences for nutritive purposes (monotropic and oligotropic bees and fig wasps). Three modes of origin of floral isolation are confirmed by evidence: (i) mechanical and ethological isolation arising as a by-product of allopatric speciation, (ii) ethological isolation developing by selection for reproductive isolation per se, and (iii) mechanical isolation arising as a by-product of character displacement. Mode of origin i accounts for the Salvia and Aquilegia types of isolation in nine known species groups and for the Ophrys type in one group. Mode of origin ii accounts for the flower-constancy type of ethological isolation in two species groups. Mode of origin iii explains mechanical isolation in two groups. Sympatric origin of floral isolation by hybrid speciation and by flower constancy has been proposed, but these modes are undocumented and improbable.

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