traditionally used to manage tumours in Ghana

ETHNOPHARMACOLOGICAL RELEVANCE

Cancer stands as one of the leading causes of death worldwide according to the World Health Organization (WHO), and it has led to approximately 10 million fatalities in 2020. Medicinal plants are still widely used and accepted form of treatment for most diseases including cancer in Ghana. This review presented Cryptolepis nigrescens (Wennberg) L. Joubert. and Bruyns., Prosopsis africana (Guill. and Perr.) Taub. and Pterygota macrocarpa K. Schum. as medicinal plants that are traditionally used to treat tumour growth, amongst other diseases, in the Ashanti region of Ghana.

AIM OF REVIEW

This paper aims to present a comprehensive review on the botanical description, ecological distribution, ethnomedicinal uses, phytochemical composition and ethnopharmacological relevance of C. nigrescens, P. africana and P. macrocarpa.

MATERIALS AND METHODS

The review covers works published between 1962 and 2023 from various countries. Published books, thesis, scientific and medical articles on C. nigrescens, P. africana and P. macrocarpa were collected from the following databases: 'Scopus', 'Science Direct', 'Medline', 'PubMed', 'Research Gate' 'Google Scholar, and 'Springer link' using the keywords.

RESULTS

Phytochemical analysis of C. nigrescens, P. africana and P. macrocarpa revealed the presence of some prominent bioactive compounds such as convallatoxin, 7,3,4-trihydroxy-3-methoxyflavanone and dioxane, respectively. Plant extracts and isolated compounds of these medicinal plants exhibited a wide range of ethnopharmacological activities including antimicrobial, anti-inflammatory, antioxidant, analgesic, cytotoxic, antimalarial, antipyretic, haematinic, hepato-protective, aphrodisiac and antihypertensive properties.

CONCLUSION

The present review on C. nigrescens , P.africana and P. macrocarpa provided a credible summary of the ethnopharmacological research conducted on these medicinal plants till date. The data also highligted the potential therapeutic profiles of these plants in Ghana that could serve as foundation for future studies. Additionally, the information significantly supported the traditional and commercial use of these plants among the people.

The function of wing bullae in mayflies (Insecta: Ephemeroptera) reveals new insights into the early evolution of Pterygota

BACKGROUND

Mayflies are basal winged insects of crucial importance for the understanding of the early evolution of Pterygota. Unlike all other insects, they have two successive winged stages, the subimago and the imago. Their forewings feature so-called bullae, which are desclerotized spots in the anterior main veins. Up to now, they have been considered to play a major role in wing bending during flight.

RESULTS

We investigated bullae by multiple methods to reveal their structure and arrangement and to gain new information on the evolution of insect flight. Bullae are mostly present in the anterior negative wing veins, disrupting the otherwise rigid veins. High-speed videography reveals that mayfly wings do not bend during flight. Likewise, different arrangements of bullae in different species do not correlate with different modes of flying. Observations on the moulting of subimagines unravel that they are essential for wing bending during the extraction of the imaginal wing from the subimaginal cuticle. Bullae define predetermined bending lines, which, together with a highly flexible wing membrane enriched with resilin, permit wing bending during subimaginal moulting. Bullae are only absent in those species that remain in the subimaginal stage or that use modified modes of moulting. Bullae are also visible in fossil mayflies and can be traced back to stemgroup mayflies of the Early Permian, the 270 million years old Protereismatidae, which most probably had bullae in both fore- and hind wings.

CONCLUSIONS

Bullae in mayfly wings do not play a role in flight as previously thought, but are crucial for wing bending during subimaginal moulting. Thus, the presence of bullae is a reliable morphological marker for a subimaginal life stage, confirming the existence of the subimago already in Permian Protereismatidae. A thorough search for bullae in fossils of other pterygote lineages may reveal wheather they also had subimagines and at what point in evolution this life stage was lost. In mayflies, however, the subimago may have been retained due to selective advantages in connection with the transition from aquatic to terrestrial life or due to morphological requirements for a specialized mating flight.

Origin of insect wings, metamorphosis, pupae and the maj or insect orders

Although most discussions on the origin and evolution of insect wings and metamorphosis have assumed that the ancestors of winged insects were terrestrial, it now seems possible that they were actually aquatic. Changing the basic assumptions affects our interpretations of the origin of metamorphosis and our understanding of insect diversity. It is argued that the ancestors of winged insects were similar to primitive mayflies, developing from aquatic larvae into terrestrial adults, and that metamorphosis originated as an inevitable consequence of an amphibiotic life cycle. It is suggested that the first pupae resembled those of Megaloptera.

Revisiting the formation of midgut epithelium in Zygentoma (Insecta) from a developmental study of the firebrat Thermobia domestica (Packard, 1873) (Lepismatidae)

Zygentoma is an order of wingless insects, representing the sister group of Pterygota and constituting Dicondylia together with Pterygota. Contrasting views exist regarding midgut epithelium formation in Zygentoma. According to some reports, in Zygentoma, the midgut epithelium is entirely derived from yolk cells as in other wingless orders; however, according to other reports, the midgut epithelium is of dual origin in Zygentoma, similar to that in Palaeoptera of Pterygota, i.e., the anterior and posterior midgut epithelia are stomodaeal and proctodaeal respectively, whereas the middle part of the midgut originates from yolk cells. Aiming to provide a sound basis to evaluate the true image of midgut epithelium formation in Zygentoma, we examined the formation of the midgut epithelium in detail in Thermobia domestica, and concluded that the midgut epithelium is exclusively derived from yolk cells in Zygentoma, without the stomodaeal and proctodaeal elements involved in its formation. The participation of the anlagen differentiated at or around the stomodaeal and proctodaeal extremities in the formation of the midgut epithelium (bipolar formation) may be regarded as having first appeared not in Dicondylia but in Pterygota, of which the major part is represented by Neoptera with the midgut epithelium formed through bipolar formation.