دراسة حياتية وجزيئية لكفاءة بعض المستخلصات النباتية ضد الأصابة بطفيلي قمل الرأس في الإنسان Pediculus humanus capitis

Biological and molecular study of the efficacy of some plant extracts as against Pediculus humanus capitis infestation in humans

Abstract
A survey study was conducted to investigate the epidemiology and spread of the Pediculus humanus capitis parasite for the period from December/2021 to May/2022 among students of a number of primary schools in some districts of Babil Governorate, which included the center of the city of Hilla and some districts (Abu Gharq District, Al-Hashmiyah District, Al-Kifl District) Through it, 2575 students in two age groups of 6-8 and 10-12 years were examined. It was found through the physical examination that there is a wide spread of Pediculus humanus capitis among primary school children, especially in the rural areas of the governorate, with the increasing rates of infection among females, where the infection rate reached 20% among females. While the infestation rate did not exceed 18% in males, and age had a clear impact on the number of infestation, as it was found that the age group 6-8 was the most infested with head lice. There was also a fluctuation in infestation rates throughout the year, and by tracking the infestations for a period of six months, it was found that they reached It peaked during the months of November and December at a rate of 32%, after which these percentages gradually decreased to nearly half during the months of February and March, as it exceeded 17%. A clear decrease was also found in the last two months of the study, which are April and May, when the average Infected with parasite 8.75%
The current study included conducting laboratory experiments to find out the effectiveness of three methods of extraction (alcoholic, aqueous, volatile oil) for two types of plants, lavender and sage, and knowing the effect of the synergistic action between the two plants in combating Pediculus humanus capitis in humans.
The volatile oil of the two plants showed a positive effect in killing adults from the parasite, as it had the highest killing rates among the extracts, especially when the parasites were treated with covering the dishes, as the killing rates were 100% within 10 minutes when treated with lavender oil and 15 minutes for sagebrush at concentration (15ppm).
The effect of the killing rate when lifting the lids off the dishes was also observed, as there was a decrease in the efficiency of the oils in the fight against the parasite
The time showed an important effect in estimating the effectiveness of the volatile oil on the parasites. The longer the time, the higher the parasite mortality rates.
It was found that the synergistic action of the alcoholic extract of lavender and sage plants is comparable to ((Dimethicone), which is the treatment that was used from the pharmacy, as the death rate of all parasites inside the dish did not exceed five hours at a concentration of 10%
It was also shown through the results that the cold water extract was the least effective extract in combating Pediculus humanus capitis in humans. The death rates for all parasites exceeded 12 hours at the highest concentration taken, which is 10%. Its effectiveness increases with increasing hours of treatment, but it gave somewhat positive results in killing when it was tested. Synergistic action of the aqueous extract of the two plants together, lavender and sage
With regard to the molecular study, 12 samples were taken from the four studied regions after isolating their DNA to detect the Cox1 gene by polymerase chain reaction.
The results of the isolates that indicated the presence of six DNA variants were obtained compared with the index sequences of the Pediculus humanus capitis (GenBank) acc. no. MK913649.1 Three of them showed a change in the level of amino acids, while the other three showed a silent effect.
Meanwhile, the other five samples showed no detectable DNA differences compared to the same reference sequences Through the evolutionary tree, it was found that our examined samples were suitable in the immediate vicinity of different strains of the same sequence of species recorded from different places in Australia and America.
The adjacent phylogenetic distances in this tree also indicated a distinct biodiversity of Pediculus humanus capitis sequences.