THE HUMAN HAIR FOLLICLE AS SENTINEL FOR DRUGS EVALUATION: DEMONSTRATION OF TETRACYCLINE ADHESION TO HAIR FOLLICLE AS PROPOSED MECHANISM IN DYSFUNCTIONAL HAIR LOSS

© 2020 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 324 THE HUMAN HAIR FOLLICLE AS SENTINEL FOR DRUGS EVALUATION: DEMONSTRATION OF TETRACYCLINE ADHESION TO HAIR FOLLICLE AS PROPOSED MECHANISM IN DYSFUNCTIONAL HAIR LOSS


INTRODUCTION
The hair follicle as sentinel was previously introduced in detecting changes in both in vitro and in vivo ethanol blood alcohol concentration [1]. The aim of this manuscript is to reintroduce the human hair follicle as sentinel, this time in vitro detecting effects from direct contact with a commonly used antibiotic, namely dry and liquid tetracycline (TET). A variety of in toto freshly plucked, human hairs were tested. The hair mainly consists of two parts, the follicle penetrating the skin and a visible part or shaft. The idea for these experiments resulted from experiments done in the early 1960's where the fluorescence property of TET was used in an attempt to identify gastric cancer cells, as we know ultraviolet light triggers fluorescence, thus the basis for that early research [2]. Recent reports of mitochondrial dysfunction in mitochondrial depleted mouse show "that hair loss and wrinkled skin after two months of doxycycline [which is a synthetic antibiotic derived from tetracycline (italics mine)] was reversed a month after doxycycline was stopped. Concluded was "that restoration of mitochondrial functions can reverse the skin and hair pathology…and alopecia was not due to loss of hair follicles or cessation of cycling; rather, the follicles were dysfunctional and could not produce normal hair shaft or completely lost this capability" [3]. Additional reports identified TET as a zinc chelator [4] and zinc transporters compounds, are prevalent in hair follicles [5]. Due to the body of evidence found in the aforementioned published reports, this author became intrigued as to the in vitro effect of liquid or dry TET on a human miniorgan a.k.a. the hair follicle [6]. Images and video recordings are introduced supporting the adhesive property of tetracycline on the human hair follicle as mechanism for the reported depletion of mitochondrial DNA.

METHODS
Tetracycline capsules (500 mg) were pierced at one end and the golden yellow powder transferred to a white glass dinner plate. The power was divided by a double edge razor blade into 10 piles each estimated to contain 100 mg each. The subdivision progressed until to piles of 5 mgs each were reached ( Figure 1).
Freshly plucked human hairs were placed on a glass slide and immersed in two drops of liquid tetracycline (TET). The liquid version was prepared diluting 5 mg of TET powder in 2 drops of water (delivered by medicine dropper).
The Single Slide Preparation (SSP) is where a sample is placed on a glass slide and covered with a given dry or liquid material. Changes caused during the time dependent evaporation process are recorded.
The Sandwich (SDW) is when material is trapped between two equal glass slides. On the top slide samples are placed to record effects of any radiated energy penetrating the 1 mm thick glass.
Ultraviolet light was applied to SSP glass slides with the aim of identifying fluorescent TET adhesion to hair anatomical parts.

Fluorescent Tetracycline Crystals Selective Adhesion to Follicles
Three experiments consistently showed evaporated liquid TET, crystals detected by its fluorescent property selectively adhering to the hair follicles. In all samples, hair shafts also showed adhered TET crystals This evidence is unseen when the hair proper is in place. (Figures 1,1A).

Human Hair Immersed in Saturated Liquid Tetracycline Adhesion to Keratin Skeleton
When a human hair on a glass slide is in contact with a saturated solution of liquid TET, only the keratin skeleton remains on the slide. This effect is governed by the degree of estimated TET % saturation. The greater the amount of solute (TET mgs) in 3 medicine dropper water drops, the greater the soft tissue damage (Figures 3,4)

DISCUSSION
In this manuscript, in vitro experiments, the effect of the synthetic antibiotic Tetracycline (Doxycycline) was evaluated by using human hair follicles as sentinels. The experiments show: 1) A strong affinity of the antibiotic towards keratin.

Figures 3,4,5. 2)
A strong time dependent cellular changes and adhesive preference to the metabolic engine of the follicle a.k.a Dermal Papilla (DP). As note of interest, the antibiotic has been shown to inhibit prevalent cell-free protein synthesis (7,8). Figures 6,7,8,9 3) The antibiotic fluorescence under UV light was detected in all compartments of the human hair. Figure 1A  4) The adhesive property of the antibiotic allowed for time dependent documentation of cellular changes in the dermal papilla, as well as a disruption of the energy emissions (metabolism) of the hair follicle. Figure 10.

SUMMARY
Tetracycline causes structural physical damage as well disruption in metabolism demonstrated by changes in the orderly electromagnetic radiation emissions of the human hair follicle.
A demonstration of the usefulness of the human hair as sentinel for drugs evaluation is reintroduced. The first paper showing the deleterious effect of increased blood alcohol levels disrupting the follicle's energy emissions (9). This time the effect of a commonly used antibiotic (tetracycline) is shown as to cause structural damage and disruption on the intrinsic follicle's energy emissions. This finding is supported by another report where experimentally depleted Mitochondrial DNA (mtDNA) mouse resulted in increased number of dysfunctional hair follicles; and after a diet of Doxycycline which is a synthetic Tetracycline, fifty percent animals in the study died around 40 days and the remaining within 150 days. Conversely, in the same report, a month later after doxycycline induction was stopped, restoration of depleted mtDNA occurred. The authors of the study concluded, "In the present study, we demonstrate that mtDNA depletion-induced phenotypic changes can be reversed by restoration of mitochondrial function upon repletion of mtDNA", in other words, in mtDNA depleted mouse population, tetracycline infusion was documented to have a lethal effect; and this effect was reversed by a timely discontinuation of the infusion.
The experiments herein presented correlate and confirm previous findings of long-term exposure to tetracycline causing not only damage to pathogens; but also healthy human cells.

ADDENDUM
The photos and caption below support the reversal of a deleterious effect of Doxycycline (Tetracycline) induction on the hair follicles.
Based on the findings presented, it could be concluded that the adhesive property of the antibiotic is identified as a mechanism for its cellular effects.

SOURCES OF FUNDING
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

CONFLICT OF INTEREST
The author have declared that no competing interests exist.

ACKNOWLEDGMENT
The author acknowledges the invaluable help of Benjamin Befeler MD (University of Miami Professor) for he historical perspective on Tetracycline and its Fluorescence property on cancerous gastric cells, as well as for the supply of 500 mg Tetracycline capsules.